package checker

import (
	"cmp"
	"slices"
	"strings"
	"sync"
	"unicode/utf8"

	"github.com/microsoft/typescript-go/internal/ast"
	"github.com/microsoft/typescript-go/internal/binder"
	"github.com/microsoft/typescript-go/internal/core"
	"github.com/microsoft/typescript-go/internal/diagnostics"
	"github.com/microsoft/typescript-go/internal/jsnum"
	"github.com/microsoft/typescript-go/internal/module"
	"github.com/microsoft/typescript-go/internal/printer"
	"github.com/microsoft/typescript-go/internal/scanner"
	"github.com/microsoft/typescript-go/internal/tspath"
)

func NewDiagnosticForNode(node *ast.Node, message *diagnostics.Message, args ...any) *ast.Diagnostic {
	var file *ast.SourceFile
	var loc core.TextRange
	if node != nil {
		file = ast.GetSourceFileOfNode(node)
		loc = scanner.GetErrorRangeForNode(file, node)
	}
	return ast.NewDiagnostic(file, loc, message, args...)
}

func NewDiagnosticChainForNode(chain *ast.Diagnostic, node *ast.Node, message *diagnostics.Message, args ...any) *ast.Diagnostic {
	if chain != nil {
		return ast.NewDiagnosticChain(chain, message, args...)
	}
	return NewDiagnosticForNode(node, message, args...)
}

func findInMap[K comparable, V any](m map[K]V, predicate func(V) bool) V {
	for _, value := range m {
		if predicate(value) {
			return value
		}
	}
	return *new(V)
}

func isCompoundAssignment(token ast.Kind) bool {
	return token >= ast.KindFirstCompoundAssignment && token <= ast.KindLastCompoundAssignment
}

func tokenIsIdentifierOrKeyword(token ast.Kind) bool {
	return token >= ast.KindIdentifier
}

func tokenIsIdentifierOrKeywordOrGreaterThan(token ast.Kind) bool {
	return token == ast.KindGreaterThanToken || tokenIsIdentifierOrKeyword(token)
}

func hasOverrideModifier(node *ast.Node) bool {
	return ast.HasSyntacticModifier(node, ast.ModifierFlagsOverride)
}

func hasAbstractModifier(node *ast.Node) bool {
	return ast.HasSyntacticModifier(node, ast.ModifierFlagsAbstract)
}

func hasAmbientModifier(node *ast.Node) bool {
	return ast.HasSyntacticModifier(node, ast.ModifierFlagsAmbient)
}

func hasAsyncModifier(node *ast.Node) bool {
	return ast.HasSyntacticModifier(node, ast.ModifierFlagsAsync)
}

func getSelectedModifierFlags(node *ast.Node, flags ast.ModifierFlags) ast.ModifierFlags {
	return node.ModifierFlags() & flags
}

func hasReadonlyModifier(node *ast.Node) bool {
	return ast.HasModifier(node, ast.ModifierFlagsReadonly)
}

func isStaticPrivateIdentifierProperty(s *ast.Symbol) bool {
	return s.ValueDeclaration != nil && ast.IsPrivateIdentifierClassElementDeclaration(s.ValueDeclaration) && ast.IsStatic(s.ValueDeclaration)
}

func isEmptyObjectLiteral(expression *ast.Node) bool {
	return ast.IsObjectLiteralExpression(expression) && len(expression.Properties()) == 0
}

type AssignmentKind int32

const (
	AssignmentKindNone AssignmentKind = iota
	AssignmentKindDefinite
	AssignmentKindCompound
)

type AssignmentTarget = ast.Node // BinaryExpression | PrefixUnaryExpression | PostfixUnaryExpression | ForInOrOfStatement

func getAssignmentTargetKind(node *ast.Node) AssignmentKind {
	target := ast.GetAssignmentTarget(node)
	if target == nil {
		return AssignmentKindNone
	}
	switch target.Kind {
	case ast.KindBinaryExpression:
		binaryOperator := target.AsBinaryExpression().OperatorToken.Kind
		if binaryOperator == ast.KindEqualsToken || ast.IsLogicalOrCoalescingAssignmentOperator(binaryOperator) {
			return AssignmentKindDefinite
		}
		return AssignmentKindCompound
	case ast.KindPrefixUnaryExpression, ast.KindPostfixUnaryExpression:
		return AssignmentKindCompound
	case ast.KindForInStatement, ast.KindForOfStatement:
		return AssignmentKindDefinite
	}
	panic("Unhandled case in getAssignmentTargetKind")
}

func isDeleteTarget(node *ast.Node) bool {
	if !ast.IsAccessExpression(node) {
		return false
	}
	node = ast.WalkUpParenthesizedExpressions(node.Parent)
	return node != nil && node.Kind == ast.KindDeleteExpression
}

func isInCompoundLikeAssignment(node *ast.Node) bool {
	target := ast.GetAssignmentTarget(node)
	return target != nil && ast.IsAssignmentExpression(target /*excludeCompoundAssignment*/, true) && isCompoundLikeAssignment(target)
}

func isCompoundLikeAssignment(assignment *ast.Node) bool {
	right := ast.SkipParentheses(assignment.AsBinaryExpression().Right)
	return right.Kind == ast.KindBinaryExpression && isShiftOperatorOrHigher(right.AsBinaryExpression().OperatorToken.Kind)
}

func isConstTypeReference(node *ast.Node) bool {
	return ast.IsTypeReferenceNode(node) && len(node.TypeArguments()) == 0 && ast.IsIdentifier(node.AsTypeReferenceNode().TypeName) && node.AsTypeReferenceNode().TypeName.Text() == "const"
}

func GetSingleVariableOfVariableStatement(node *ast.Node) *ast.Node {
	if !ast.IsVariableStatement(node) {
		return nil
	}
	return core.FirstOrNil(node.AsVariableStatement().DeclarationList.AsVariableDeclarationList().Declarations.Nodes)
}

func isTypeReferenceIdentifier(node *ast.Node) bool {
	for node.Parent.Kind == ast.KindQualifiedName {
		node = node.Parent
	}
	return ast.IsTypeReferenceNode(node.Parent)
}

func IsInTypeQuery(node *ast.Node) bool {
	// TypeScript 1.0 spec (April 2014): 3.6.3
	// A type query consists of the keyword typeof followed by an expression.
	// The expression is restricted to a single identifier or a sequence of identifiers separated by periods
	return ast.FindAncestorOrQuit(node, func(n *ast.Node) ast.FindAncestorResult {
		switch n.Kind {
		case ast.KindTypeQuery:
			return ast.FindAncestorTrue
		case ast.KindIdentifier, ast.KindQualifiedName:
			return ast.FindAncestorFalse
		}
		return ast.FindAncestorQuit
	}) != nil
}

func nodeCanBeDecorated(useLegacyDecorators bool, node *ast.Node, parent *ast.Node, grandparent *ast.Node) bool {
	// private names cannot be used with decorators yet
	if useLegacyDecorators && node.Name() != nil && ast.IsPrivateIdentifier(node.Name()) {
		return false
	}
	switch node.Kind {
	case ast.KindClassDeclaration:
		// class declarations are valid targets
		return true
	case ast.KindClassExpression:
		// class expressions are valid targets for native decorators
		return !useLegacyDecorators
	case ast.KindPropertyDeclaration:
		// property declarations are valid if their parent is a class declaration.
		return parent != nil && (useLegacyDecorators && ast.IsClassDeclaration(parent) ||
			!useLegacyDecorators && ast.IsClassLike(parent) && !hasAbstractModifier(node) && !hasAmbientModifier(node))
	case ast.KindGetAccessor, ast.KindSetAccessor, ast.KindMethodDeclaration:
		// if this method has a body and its parent is a class declaration, this is a valid target.
		return parent != nil && node.Body() != nil && (useLegacyDecorators && ast.IsClassDeclaration(parent) ||
			!useLegacyDecorators && ast.IsClassLike(parent))
	case ast.KindParameter:
		// TODO(rbuckton): Parameter decorator support for ES decorators must wait until it is standardized
		if !useLegacyDecorators {
			return false
		}
		// if the parameter's parent has a body and its grandparent is a class declaration, this is a valid target.
		return parent != nil && parent.Body() != nil &&
			(parent.Kind == ast.KindConstructor || parent.Kind == ast.KindMethodDeclaration || parent.Kind == ast.KindSetAccessor) &&
			ast.GetThisParameter(parent) != node && grandparent != nil && grandparent.Kind == ast.KindClassDeclaration
	}

	return false
}

func canHaveLocals(node *ast.Node) bool {
	switch node.Kind {
	case ast.KindArrowFunction, ast.KindBlock, ast.KindCallSignature, ast.KindCaseBlock, ast.KindCatchClause,
		ast.KindClassStaticBlockDeclaration, ast.KindConditionalType, ast.KindConstructor, ast.KindConstructorType,
		ast.KindConstructSignature, ast.KindForStatement, ast.KindForInStatement, ast.KindForOfStatement, ast.KindFunctionDeclaration,
		ast.KindFunctionExpression, ast.KindFunctionType, ast.KindGetAccessor, ast.KindIndexSignature,
		ast.KindJSDocSignature, ast.KindMappedType,
		ast.KindMethodDeclaration, ast.KindMethodSignature, ast.KindModuleDeclaration, ast.KindSetAccessor, ast.KindSourceFile,
		ast.KindTypeAliasDeclaration, ast.KindJSTypeAliasDeclaration:
		return true
	}
	return false
}

func isShorthandAmbientModuleSymbol(moduleSymbol *ast.Symbol) bool {
	return isShorthandAmbientModule(moduleSymbol.ValueDeclaration)
}

func isShorthandAmbientModule(node *ast.Node) bool {
	// The only kind of module that can be missing a body is a shorthand ambient module.
	return node != nil && node.Kind == ast.KindModuleDeclaration && node.Body() == nil
}

func getAliasDeclarationFromName(node *ast.Node) *ast.Node {
	switch node.Parent.Kind {
	case ast.KindImportClause, ast.KindImportSpecifier, ast.KindNamespaceImport, ast.KindExportSpecifier, ast.KindExportAssignment, ast.KindJSExportAssignment,
		ast.KindImportEqualsDeclaration, ast.KindNamespaceExport:
		return node.Parent
	case ast.KindQualifiedName:
		return getAliasDeclarationFromName(node.Parent)
	}
	return nil
}

func entityNameToString(name *ast.Node) string {
	switch name.Kind {
	case ast.KindThisKeyword:
		return "this"
	case ast.KindIdentifier, ast.KindPrivateIdentifier:
		if ast.NodeIsSynthesized(name) {
			return name.Text()
		}
		return scanner.GetTextOfNode(name)
	case ast.KindQualifiedName:
		return entityNameToString(name.AsQualifiedName().Left) + "." + entityNameToString(name.AsQualifiedName().Right)
	case ast.KindPropertyAccessExpression:
		return entityNameToString(name.Expression()) + "." + entityNameToString(name.AsPropertyAccessExpression().Name())
	case ast.KindJsxNamespacedName:
		return entityNameToString(name.AsJsxNamespacedName().Namespace) + ":" + entityNameToString(name.AsJsxNamespacedName().Name())
	}
	panic("Unhandled case in entityNameToString")
}

func getContainingQualifiedNameNode(node *ast.Node) *ast.Node {
	for ast.IsQualifiedName(node.Parent) {
		node = node.Parent
	}
	return node
}

func isSideEffectImport(node *ast.Node) bool {
	ancestor := ast.FindAncestor(node, ast.IsImportDeclaration)
	return ancestor != nil && ancestor.ImportClause() == nil
}

func getExternalModuleRequireArgument(node *ast.Node) *ast.Node {
	if ast.IsVariableDeclarationInitializedToRequire(node) {
		return node.Initializer().Arguments()[0]
	}
	return nil
}

func isRightSideOfAccessExpression(node *ast.Node) bool {
	return node.Parent != nil && (ast.IsPropertyAccessExpression(node.Parent) && node.Parent.Name() == node ||
		ast.IsElementAccessExpression(node.Parent) && node.Parent.AsElementAccessExpression().ArgumentExpression == node)
}

func isTopLevelInExternalModuleAugmentation(node *ast.Node) bool {
	return node != nil && node.Parent != nil && ast.IsModuleBlock(node.Parent) && ast.IsExternalModuleAugmentation(node.Parent.Parent)
}

func isSyntacticDefault(node *ast.Node) bool {
	return (ast.IsExportAssignment(node) && !node.AsExportAssignment().IsExportEquals) ||
		ast.HasSyntacticModifier(node, ast.ModifierFlagsDefault) ||
		ast.IsExportSpecifier(node) ||
		ast.IsNamespaceExport(node)
}

func hasExportAssignmentSymbol(moduleSymbol *ast.Symbol) bool {
	return moduleSymbol.Exports[ast.InternalSymbolNameExportEquals] != nil
}

func isTypeAlias(node *ast.Node) bool {
	return ast.IsTypeOrJSTypeAliasDeclaration(node)
}

func hasOnlyExpressionInitializer(node *ast.Node) bool {
	switch node.Kind {
	case ast.KindVariableDeclaration, ast.KindParameter, ast.KindBindingElement, ast.KindPropertyDeclaration, ast.KindPropertyAssignment, ast.KindEnumMember:
		return true
	}
	return false
}

func hasDotDotDotToken(node *ast.Node) bool {
	switch node.Kind {
	case ast.KindParameter:
		return node.AsParameterDeclaration().DotDotDotToken != nil
	case ast.KindBindingElement:
		return node.AsBindingElement().DotDotDotToken != nil
	case ast.KindNamedTupleMember:
		return node.AsNamedTupleMember().DotDotDotToken != nil
	case ast.KindJsxExpression:
		return node.AsJsxExpression().DotDotDotToken != nil
	}
	return false
}

func IsTypeAny(t *Type) bool {
	return t != nil && t.flags&TypeFlagsAny != 0
}

func isJSDocOptionalParameter(node *ast.ParameterDeclaration) bool {
	return false // !!!
}

func isExclamationToken(node *ast.Node) bool {
	return node != nil && node.Kind == ast.KindExclamationToken
}

func isOptionalDeclaration(declaration *ast.Node) bool {
	return ast.HasQuestionToken(declaration)
}

func isEmptyArrayLiteral(expression *ast.Node) bool {
	return ast.IsArrayLiteralExpression(expression) && len(expression.Elements()) == 0
}

func declarationBelongsToPrivateAmbientMember(declaration *ast.Node) bool {
	root := ast.GetRootDeclaration(declaration)
	memberDeclaration := root
	if root.Kind == ast.KindParameter {
		memberDeclaration = root.Parent
	}
	return isPrivateWithinAmbient(memberDeclaration)
}

func isPrivateWithinAmbient(node *ast.Node) bool {
	return (ast.HasModifier(node, ast.ModifierFlagsPrivate) || ast.IsPrivateIdentifierClassElementDeclaration(node)) && node.Flags&ast.NodeFlagsAmbient != 0
}

func isTypeAssertion(node *ast.Node) bool {
	return ast.IsAssertionExpression(ast.SkipParentheses(node))
}

func createSymbolTable(symbols []*ast.Symbol) ast.SymbolTable {
	if len(symbols) == 0 {
		return nil
	}
	result := make(ast.SymbolTable)
	for _, symbol := range symbols {
		result[symbol.Name] = symbol
	}
	return result
}

func (c *Checker) sortSymbols(symbols []*ast.Symbol) {
	slices.SortFunc(symbols, c.compareSymbols)
}

func (c *Checker) compareSymbolsWorker(s1, s2 *ast.Symbol) int {
	if s1 == s2 {
		return 0
	}
	if s1 == nil {
		return 1
	}
	if s2 == nil {
		return -1
	}
	if len(s1.Declarations) != 0 && len(s2.Declarations) != 0 {
		if r := c.compareNodes(s1.Declarations[0], s2.Declarations[0]); r != 0 {
			return r
		}
	} else if len(s1.Declarations) != 0 {
		return -1
	} else if len(s2.Declarations) != 0 {
		return 1
	}
	if r := strings.Compare(s1.Name, s2.Name); r != 0 {
		return r
	}
	// Fall back to symbol IDs. This is a last resort that should happen only when symbols have
	// no declaration and duplicate names.
	return int(ast.GetSymbolId(s1)) - int(ast.GetSymbolId(s2))
}

func (c *Checker) compareNodes(n1, n2 *ast.Node) int {
	if n1 == n2 {
		return 0
	}
	if n1 == nil {
		return 1
	}
	if n2 == nil {
		return -1
	}
	s1 := ast.GetSourceFileOfNode(n1)
	s2 := ast.GetSourceFileOfNode(n2)
	if s1 != s2 {
		f1 := c.fileIndexMap[s1]
		f2 := c.fileIndexMap[s2]
		// Order by index of file in the containing program
		return f1 - f2
	}
	// In the same file, order by source position
	return n1.Pos() - n2.Pos()
}

func CompareTypes(t1, t2 *Type) int {
	if t1 == t2 {
		return 0
	}
	if t1 == nil {
		return -1
	}
	if t2 == nil {
		return 1
	}
	if t1.checker != t2.checker {
		panic("Cannot compare types from different checkers")
	}
	// First sort in order of increasing type flags values.
	if c := getSortOrderFlags(t1) - getSortOrderFlags(t2); c != 0 {
		return c
	}
	// Order named types by name and, in the case of aliased types, by alias type arguments.
	if c := compareTypeNames(t1, t2); c != 0 {
		return c
	}
	// We have unnamed types or types with identical names. Now sort by data specific to the type.
	switch {
	case t1.flags&(TypeFlagsAny|TypeFlagsUnknown|TypeFlagsString|TypeFlagsNumber|TypeFlagsBoolean|TypeFlagsBigInt|TypeFlagsESSymbol|TypeFlagsVoid|TypeFlagsUndefined|TypeFlagsNull|TypeFlagsNever|TypeFlagsNonPrimitive) != 0:
		// Only distinguished by type IDs, handled below.
	case t1.flags&TypeFlagsObject != 0:
		// Order unnamed or identically named object types by symbol.
		if c := t1.checker.compareSymbols(t1.symbol, t2.symbol); c != 0 {
			return c
		}
		// When object types have the same or no symbol, order by kind. We order type references before other kinds.
		if t1.objectFlags&ObjectFlagsReference != 0 && t2.objectFlags&ObjectFlagsReference != 0 {
			r1 := t1.AsTypeReference()
			r2 := t2.AsTypeReference()
			if r1.target.objectFlags&ObjectFlagsTuple != 0 && r2.target.objectFlags&ObjectFlagsTuple != 0 {
				// Tuple types have no associated symbol, instead we order by tuple element information.
				if c := compareTupleTypes(r1.target.AsTupleType(), r2.target.AsTupleType()); c != 0 {
					return c
				}
			}
			// Here we know we have references to instantiations of the same type because we have matching targets.
			if r1.node == nil && r2.node == nil {
				// Non-deferred type references with the same target are sorted by their type argument lists.
				if c := compareTypeLists(t1.AsTypeReference().resolvedTypeArguments, t2.AsTypeReference().resolvedTypeArguments); c != 0 {
					return c
				}
			} else {
				// Deferred type references with the same target are ordered by the source location of the reference.
				if c := t1.checker.compareNodes(r1.node, r2.node); c != 0 {
					return c
				}
				// Instantiations of the same deferred type reference are ordered by their associated type mappers
				// (which reflect the mapping of in-scope type parameters to type arguments).
				if c := compareTypeMappers(t1.AsObjectType().mapper, t2.AsObjectType().mapper); c != 0 {
					return c
				}
			}
		} else if t1.objectFlags&ObjectFlagsReference != 0 {
			return -1
		} else if t2.objectFlags&ObjectFlagsReference != 0 {
			return 1
		} else {
			// Order unnamed non-reference object types by kind associated type mappers. Reverse mapped types have
			// neither symbols nor mappers so they're ultimately ordered by unstable type IDs, but given their rarity
			// this should be fine.
			if c := int(t1.objectFlags&ObjectFlagsObjectTypeKindMask) - int(t2.objectFlags&ObjectFlagsObjectTypeKindMask); c != 0 {
				return c
			}
			if c := compareTypeMappers(t1.AsObjectType().mapper, t2.AsObjectType().mapper); c != 0 {
				return c
			}
		}
	case t1.flags&TypeFlagsUnion != 0:
		// Unions are ordered by origin and then constituent type lists.
		o1 := t1.AsUnionType().origin
		o2 := t2.AsUnionType().origin
		if o1 == nil && o2 == nil {
			if c := compareTypeLists(t1.Types(), t2.Types()); c != 0 {
				return c
			}
		} else if o1 == nil {
			return 1
		} else if o2 == nil {
			return -1
		} else {
			if c := CompareTypes(o1, o2); c != 0 {
				return c
			}
		}
	case t1.flags&TypeFlagsIntersection != 0:
		// Intersections are ordered by their constituent type lists.
		if c := compareTypeLists(t1.Types(), t2.Types()); c != 0 {
			return c
		}
	case t1.flags&(TypeFlagsEnum|TypeFlagsEnumLiteral|TypeFlagsUniqueESSymbol) != 0:
		// Enum members are ordered by their symbol (and thus their declaration order).
		if c := t1.checker.compareSymbols(t1.symbol, t2.symbol); c != 0 {
			return c
		}
	case t1.flags&TypeFlagsStringLiteral != 0:
		// String literal types are ordered by their values.
		if c := strings.Compare(t1.AsLiteralType().value.(string), t2.AsLiteralType().value.(string)); c != 0 {
			return c
		}
	case t1.flags&TypeFlagsNumberLiteral != 0:
		// Numeric literal types are ordered by their values.
		if c := cmp.Compare(t1.AsLiteralType().value.(jsnum.Number), t2.AsLiteralType().value.(jsnum.Number)); c != 0 {
			return c
		}
	case t1.flags&TypeFlagsBooleanLiteral != 0:
		b1 := t1.AsLiteralType().value.(bool)
		b2 := t2.AsLiteralType().value.(bool)
		if b1 != b2 {
			if b1 {
				return 1
			}
			return -1
		}
	case t1.flags&TypeFlagsTypeParameter != 0:
		if c := t1.checker.compareSymbols(t1.symbol, t2.symbol); c != 0 {
			return c
		}
	case t1.flags&TypeFlagsIndex != 0:
		if c := CompareTypes(t1.AsIndexType().target, t2.AsIndexType().target); c != 0 {
			return c
		}
		if c := int(t1.AsIndexType().flags) - int(t2.AsIndexType().flags); c != 0 {
			return c
		}
	case t1.flags&TypeFlagsIndexedAccess != 0:
		if c := CompareTypes(t1.AsIndexedAccessType().objectType, t2.AsIndexedAccessType().objectType); c != 0 {
			return c
		}
		if c := CompareTypes(t1.AsIndexedAccessType().indexType, t2.AsIndexedAccessType().indexType); c != 0 {
			return c
		}
	case t1.flags&TypeFlagsConditional != 0:
		if c := t1.checker.compareNodes(t1.AsConditionalType().root.node.AsNode(), t2.AsConditionalType().root.node.AsNode()); c != 0 {
			return c
		}
		if c := compareTypeMappers(t1.AsConditionalType().mapper, t2.AsConditionalType().mapper); c != 0 {
			return c
		}
	case t1.flags&TypeFlagsSubstitution != 0:
		if c := CompareTypes(t1.AsSubstitutionType().baseType, t2.AsSubstitutionType().baseType); c != 0 {
			return c
		}
		if c := CompareTypes(t1.AsSubstitutionType().constraint, t2.AsSubstitutionType().constraint); c != 0 {
			return c
		}
	case t1.flags&TypeFlagsTemplateLiteral != 0:
		if c := slices.Compare(t1.AsTemplateLiteralType().texts, t2.AsTemplateLiteralType().texts); c != 0 {
			return c
		}
		if c := compareTypeLists(t1.AsTemplateLiteralType().types, t2.AsTemplateLiteralType().types); c != 0 {
			return c
		}
	case t1.flags&TypeFlagsStringMapping != 0:
		if c := CompareTypes(t1.AsStringMappingType().target, t2.AsStringMappingType().target); c != 0 {
			return c
		}
	}
	// Fall back to type IDs. This results in type creation order for built-in types.
	return int(t1.id) - int(t2.id)
}

func getSortOrderFlags(t *Type) int {
	// Return TypeFlagsEnum for all enum-like unit types (they'll be sorted by their symbols)
	if t.flags&(TypeFlagsEnumLiteral|TypeFlagsEnum) != 0 && t.flags&TypeFlagsUnion == 0 {
		return int(TypeFlagsEnum)
	}
	return int(t.flags)
}

func compareTypeNames(t1, t2 *Type) int {
	s1 := getTypeNameSymbol(t1)
	s2 := getTypeNameSymbol(t2)
	if s1 == s2 {
		if t1.alias != nil {
			return compareTypeLists(t1.alias.typeArguments, t2.alias.typeArguments)
		}
		return 0
	}
	if s1 == nil {
		return 1
	}
	if s2 == nil {
		return -1
	}
	return strings.Compare(s1.Name, s2.Name)
}

func getTypeNameSymbol(t *Type) *ast.Symbol {
	if t.alias != nil {
		return t.alias.symbol
	}
	if t.flags&(TypeFlagsTypeParameter|TypeFlagsStringMapping) != 0 || t.objectFlags&(ObjectFlagsClassOrInterface|ObjectFlagsReference) != 0 {
		return t.symbol
	}
	return nil
}

func getObjectTypeName(t *Type) *ast.Symbol {
	if t.objectFlags&(ObjectFlagsClassOrInterface|ObjectFlagsReference) != 0 {
		return t.symbol
	}
	return nil
}

func compareTupleTypes(t1, t2 *TupleType) int {
	if t1 == t2 {
		return 0
	}
	if t1.readonly != t2.readonly {
		return core.IfElse(t1.readonly, 1, -1)
	}
	if len(t1.elementInfos) != len(t2.elementInfos) {
		return len(t1.elementInfos) - len(t2.elementInfos)
	}
	for i := range t1.elementInfos {
		if c := int(t1.elementInfos[i].flags) - int(t2.elementInfos[i].flags); c != 0 {
			return c
		}
	}
	for i := range t1.elementInfos {
		if c := compareElementLabels(t1.elementInfos[i].labeledDeclaration, t2.elementInfos[i].labeledDeclaration); c != 0 {
			return c
		}
	}
	return 0
}

func compareElementLabels(n1, n2 *ast.Node) int {
	if n1 == n2 {
		return 0
	}
	if n1 == nil {
		return -1
	}
	if n2 == nil {
		return 1
	}
	return strings.Compare(n1.Name().Text(), n2.Name().Text())
}

func compareTypeLists(s1, s2 []*Type) int {
	if len(s1) != len(s2) {
		return len(s1) - len(s2)
	}
	for i, t1 := range s1 {
		if c := CompareTypes(t1, s2[i]); c != 0 {
			return c
		}
	}
	return 0
}

func compareTypeMappers(m1, m2 *TypeMapper) int {
	if m1 == m2 {
		return 0
	}
	if m1 == nil {
		return 1
	}
	if m2 == nil {
		return -1
	}
	kind1 := m1.Kind()
	kind2 := m2.Kind()
	if kind1 != kind2 {
		return int(kind1) - int(kind2)
	}
	switch kind1 {
	case TypeMapperKindSimple:
		m1 := m1.data.(*SimpleTypeMapper)
		m2 := m2.data.(*SimpleTypeMapper)
		if c := CompareTypes(m1.source, m2.source); c != 0 {
			return c
		}
		return CompareTypes(m1.target, m2.target)
	case TypeMapperKindArray:
		m1 := m1.data.(*ArrayTypeMapper)
		m2 := m2.data.(*ArrayTypeMapper)
		if c := compareTypeLists(m1.sources, m2.sources); c != 0 {
			return c
		}
		return compareTypeLists(m1.targets, m2.targets)
	case TypeMapperKindMerged:
		m1 := m1.data.(*MergedTypeMapper)
		m2 := m2.data.(*MergedTypeMapper)
		if c := compareTypeMappers(m1.m1, m2.m1); c != 0 {
			return c
		}
		return compareTypeMappers(m1.m2, m2.m2)
	}
	return 0
}

func getDeclarationModifierFlagsFromSymbol(s *ast.Symbol) ast.ModifierFlags {
	return getDeclarationModifierFlagsFromSymbolEx(s, false /*isWrite*/)
}

func getDeclarationModifierFlagsFromSymbolEx(s *ast.Symbol, isWrite bool) ast.ModifierFlags {
	if s.ValueDeclaration != nil {
		var declaration *ast.Node
		if isWrite {
			declaration = core.Find(s.Declarations, ast.IsSetAccessorDeclaration)
		}
		if declaration == nil && s.Flags&ast.SymbolFlagsGetAccessor != 0 {
			declaration = core.Find(s.Declarations, ast.IsGetAccessorDeclaration)
		}
		if declaration == nil {
			declaration = s.ValueDeclaration
		}
		flags := ast.GetCombinedModifierFlags(declaration)
		if s.Parent != nil && s.Parent.Flags&ast.SymbolFlagsClass != 0 {
			return flags
		}
		return flags & ^ast.ModifierFlagsAccessibilityModifier
	}
	if s.CheckFlags&ast.CheckFlagsSynthetic != 0 {
		var accessModifier ast.ModifierFlags
		switch {
		case s.CheckFlags&ast.CheckFlagsContainsPrivate != 0:
			accessModifier = ast.ModifierFlagsPrivate
		case s.CheckFlags&ast.CheckFlagsContainsPublic != 0:
			accessModifier = ast.ModifierFlagsPublic
		default:
			accessModifier = ast.ModifierFlagsProtected
		}
		var staticModifier ast.ModifierFlags
		if s.CheckFlags&ast.CheckFlagsContainsStatic != 0 {
			staticModifier = ast.ModifierFlagsStatic
		}
		return accessModifier | staticModifier
	}
	if s.Flags&ast.SymbolFlagsPrototype != 0 {
		return ast.ModifierFlagsPublic | ast.ModifierFlagsStatic
	}
	return ast.ModifierFlagsNone
}

func isExponentiationOperator(kind ast.Kind) bool {
	return kind == ast.KindAsteriskAsteriskToken
}

func isMultiplicativeOperator(kind ast.Kind) bool {
	return kind == ast.KindAsteriskToken || kind == ast.KindSlashToken || kind == ast.KindPercentToken
}

func isMultiplicativeOperatorOrHigher(kind ast.Kind) bool {
	return isExponentiationOperator(kind) || isMultiplicativeOperator(kind)
}

func isAdditiveOperator(kind ast.Kind) bool {
	return kind == ast.KindPlusToken || kind == ast.KindMinusToken
}

func isAdditiveOperatorOrHigher(kind ast.Kind) bool {
	return isAdditiveOperator(kind) || isMultiplicativeOperatorOrHigher(kind)
}

func isShiftOperator(kind ast.Kind) bool {
	return kind == ast.KindLessThanLessThanToken || kind == ast.KindGreaterThanGreaterThanToken ||
		kind == ast.KindGreaterThanGreaterThanGreaterThanToken
}

func isShiftOperatorOrHigher(kind ast.Kind) bool {
	return isShiftOperator(kind) || isAdditiveOperatorOrHigher(kind)
}

func isRelationalOperator(kind ast.Kind) bool {
	return kind == ast.KindLessThanToken || kind == ast.KindLessThanEqualsToken || kind == ast.KindGreaterThanToken ||
		kind == ast.KindGreaterThanEqualsToken || kind == ast.KindInstanceOfKeyword || kind == ast.KindInKeyword
}

func isRelationalOperatorOrHigher(kind ast.Kind) bool {
	return isRelationalOperator(kind) || isShiftOperatorOrHigher(kind)
}

func isEqualityOperator(kind ast.Kind) bool {
	return kind == ast.KindEqualsEqualsToken || kind == ast.KindEqualsEqualsEqualsToken ||
		kind == ast.KindExclamationEqualsToken || kind == ast.KindExclamationEqualsEqualsToken
}

func isEqualityOperatorOrHigher(kind ast.Kind) bool {
	return isEqualityOperator(kind) || isRelationalOperatorOrHigher(kind)
}

func isBitwiseOperator(kind ast.Kind) bool {
	return kind == ast.KindAmpersandToken || kind == ast.KindBarToken || kind == ast.KindCaretToken
}

func isBitwiseOperatorOrHigher(kind ast.Kind) bool {
	return isBitwiseOperator(kind) || isEqualityOperatorOrHigher(kind)
}

func isLogicalOperatorOrHigher(kind ast.Kind) bool {
	return ast.IsLogicalBinaryOperator(kind) || isBitwiseOperatorOrHigher(kind)
}

func isAssignmentOperatorOrHigher(kind ast.Kind) bool {
	return kind == ast.KindQuestionQuestionToken || isLogicalOperatorOrHigher(kind) || ast.IsAssignmentOperator(kind)
}

func isBinaryOperator(kind ast.Kind) bool {
	return isAssignmentOperatorOrHigher(kind) || kind == ast.KindCommaToken
}

func isObjectLiteralType(t *Type) bool {
	return t.objectFlags&ObjectFlagsObjectLiteral != 0
}

func isDeclarationReadonly(declaration *ast.Node) bool {
	return ast.GetCombinedModifierFlags(declaration)&ast.ModifierFlagsReadonly != 0 && !ast.IsParameterPropertyDeclaration(declaration, declaration.Parent)
}

type orderedSet[T comparable] struct {
	valuesByKey map[T]struct{}
	values      []T
}

func (s *orderedSet[T]) contains(value T) bool {
	_, ok := s.valuesByKey[value]
	return ok
}

func (s *orderedSet[T]) add(value T) {
	if s.valuesByKey == nil {
		s.valuesByKey = make(map[T]struct{})
	}
	s.valuesByKey[value] = struct{}{}
	s.values = append(s.values, value)
}

func getContainingFunctionOrClassStaticBlock(node *ast.Node) *ast.Node {
	return ast.FindAncestor(node.Parent, ast.IsFunctionLikeOrClassStaticBlockDeclaration)
}

func isNodeDescendantOf(node *ast.Node, ancestor *ast.Node) bool {
	for node != nil {
		if node == ancestor {
			return true
		}
		node = node.Parent
	}
	return false
}

func isTypeUsableAsPropertyName(t *Type) bool {
	return t.flags&TypeFlagsStringOrNumberLiteralOrUnique != 0
}

/**
 * Gets the symbolic name for a member from its type.
 */
func getPropertyNameFromType(t *Type) string {
	switch {
	case t.flags&TypeFlagsStringLiteral != 0:
		return t.AsLiteralType().value.(string)
	case t.flags&TypeFlagsNumberLiteral != 0:
		return t.AsLiteralType().value.(jsnum.Number).String()
	case t.flags&TypeFlagsUniqueESSymbol != 0:
		return t.AsUniqueESSymbolType().name
	}
	panic("Unhandled case in getPropertyNameFromType")
}

func isNumericLiteralName(name string) bool {
	// The intent of numeric names is that
	//     - they are names with text in a numeric form, and that
	//     - setting properties/indexing with them is always equivalent to doing so with the numeric literal 'numLit',
	//         acquired by applying the abstract 'ToNumber' operation on the name's text.
	//
	// The subtlety is in the latter portion, as we cannot reliably say that anything that looks like a numeric literal is a numeric name.
	// In fact, it is the case that the text of the name must be equal to 'ToString(numLit)' for this to hold.
	//
	// Consider the property name '"0xF00D"'. When one indexes with '0xF00D', they are actually indexing with the value of 'ToString(0xF00D)'
	// according to the ECMAScript specification, so it is actually as if the user indexed with the string '"61453"'.
	// Thus, the text of all numeric literals equivalent to '61543' such as '0xF00D', '0xf00D', '0170015', etc. are not valid numeric names
	// because their 'ToString' representation is not equal to their original text.
	// This is motivated by ECMA-262 sections 9.3.1, 9.8.1, 11.1.5, and 11.2.1.
	//
	// Here, we test whether 'ToString(ToNumber(name))' is exactly equal to 'name'.
	// The '+' prefix operator is equivalent here to applying the abstract ToNumber operation.
	// Applying the 'toString()' method on a number gives us the abstract ToString operation on a number.
	//
	// Note that this accepts the values 'Infinity', '-Infinity', and 'NaN', and that this is intentional.
	// This is desired behavior, because when indexing with them as numeric entities, you are indexing
	// with the strings '"Infinity"', '"-Infinity"', and '"NaN"' respectively.
	return jsnum.FromString(name).String() == name
}

func isThisProperty(node *ast.Node) bool {
	return (ast.IsPropertyAccessExpression(node) || ast.IsElementAccessExpression(node)) && node.Expression().Kind == ast.KindThisKeyword
}

func isValidNumberString(s string, roundTripOnly bool) bool {
	if s == "" {
		return false
	}
	n := jsnum.FromString(s)
	return !n.IsNaN() && !n.IsInf() && (!roundTripOnly || n.String() == s)
}

func isValidBigIntString(s string, roundTripOnly bool) bool {
	if s == "" {
		return false
	}
	scanner := scanner.NewScanner()
	scanner.SetSkipTrivia(false)
	success := true
	scanner.SetOnError(func(diagnostic *diagnostics.Message, start, length int, args ...any) {
		success = false
	})
	scanner.SetText(s + "n")
	result := scanner.Scan()
	negative := result == ast.KindMinusToken
	if negative {
		result = scanner.Scan()
	}
	flags := scanner.TokenFlags()
	// validate that
	// * scanning proceeded without error
	// * a bigint can be scanned, and that when it is scanned, it is
	// * the full length of the input string (so the scanner is one character beyond the augmented input length)
	// * it does not contain a numeric separator (the `BigInt` constructor does not accept a numeric separator in its input)
	return success && result == ast.KindBigIntLiteral && scanner.TokenEnd() == len(s)+1 && flags&ast.TokenFlagsContainsSeparator == 0 &&
		(!roundTripOnly || s == pseudoBigIntToString(jsnum.NewPseudoBigInt(jsnum.ParsePseudoBigInt(scanner.TokenValue()), negative)))
}

func isValidESSymbolDeclaration(node *ast.Node) bool {
	if ast.IsVariableDeclaration(node) {
		return ast.IsVarConst(node) && ast.IsIdentifier(node.AsVariableDeclaration().Name()) && isVariableDeclarationInVariableStatement(node)
	}
	if ast.IsPropertyDeclaration(node) {
		return hasReadonlyModifier(node) && ast.HasStaticModifier(node)
	}
	return ast.IsPropertySignatureDeclaration(node) && hasReadonlyModifier(node)
}

func isVariableDeclarationInVariableStatement(node *ast.Node) bool {
	return ast.IsVariableDeclarationList(node.Parent) && ast.IsVariableStatement(node.Parent.Parent)
}

func IsKnownSymbol(symbol *ast.Symbol) bool {
	return isLateBoundName(symbol.Name)
}

func IsPrivateIdentifierSymbol(symbol *ast.Symbol) bool {
	if symbol == nil {
		return false
	}
	return strings.HasPrefix(symbol.Name, ast.InternalSymbolNamePrefix+"#")
}

func isLateBoundName(name string) bool {
	return len(name) >= 2 && name[0] == '\xfe' && name[1] == '@'
}

func isObjectOrArrayLiteralType(t *Type) bool {
	return t.objectFlags&(ObjectFlagsObjectLiteral|ObjectFlagsArrayLiteral) != 0
}

func getContainingClassExcludingClassDecorators(node *ast.Node) *ast.ClassLikeDeclaration {
	decorator := ast.FindAncestorOrQuit(node.Parent, func(n *ast.Node) ast.FindAncestorResult {
		if ast.IsClassLike(n) {
			return ast.FindAncestorQuit
		}
		if ast.IsDecorator(n) {
			return ast.FindAncestorTrue
		}
		return ast.FindAncestorFalse
	})
	if decorator != nil && ast.IsClassLike(decorator.Parent) {
		return ast.GetContainingClass(decorator.Parent)
	}
	if decorator != nil {
		return ast.GetContainingClass(decorator)
	}
	return ast.GetContainingClass(node)
}

func isThisTypeParameter(t *Type) bool {
	return t.flags&TypeFlagsTypeParameter != 0 && t.AsTypeParameter().isThisType
}

func isClassInstanceProperty(node *ast.Node) bool {
	return node.Parent != nil && ast.IsClassLike(node.Parent) && ast.IsPropertyDeclaration(node) && !ast.HasAccessorModifier(node)
}

func isThisInitializedObjectBindingExpression(node *ast.Node) bool {
	return node != nil && (ast.IsShorthandPropertyAssignment(node) || ast.IsPropertyAssignment(node)) && ast.IsBinaryExpression(node.Parent.Parent) &&
		node.Parent.Parent.AsBinaryExpression().OperatorToken.Kind == ast.KindEqualsToken &&
		node.Parent.Parent.AsBinaryExpression().Right.Kind == ast.KindThisKeyword
}

func isThisInitializedDeclaration(node *ast.Node) bool {
	return node != nil && ast.IsVariableDeclaration(node) && node.Initializer() != nil && node.Initializer().Kind == ast.KindThisKeyword
}

func isInfinityOrNaNString(name string) bool {
	return name == "Infinity" || name == "-Infinity" || name == "NaN"
}

func (c *Checker) isConstantVariable(symbol *ast.Symbol) bool {
	return symbol.Flags&ast.SymbolFlagsVariable != 0 && (c.getDeclarationNodeFlagsFromSymbol(symbol)&ast.NodeFlagsConstant) != 0
}

func (c *Checker) isParameterOrMutableLocalVariable(symbol *ast.Symbol) bool {
	// Return true if symbol is a parameter, a catch clause variable, or a mutable local variable
	if symbol.ValueDeclaration != nil {
		declaration := ast.GetRootDeclaration(symbol.ValueDeclaration)
		return declaration != nil && (ast.IsParameter(declaration) || ast.IsVariableDeclaration(declaration) && (ast.IsCatchClause(declaration.Parent) || c.isMutableLocalVariableDeclaration(declaration)))
	}
	return false
}

func (c *Checker) isMutableLocalVariableDeclaration(declaration *ast.Node) bool {
	// Return true if symbol is a non-exported and non-global `let` variable
	return declaration.Parent.Flags&ast.NodeFlagsLet != 0 && !(ast.GetCombinedModifierFlags(declaration)&ast.ModifierFlagsExport != 0 || declaration.Parent.Parent.Kind == ast.KindVariableStatement && ast.IsGlobalSourceFile(declaration.Parent.Parent.Parent))
}

func isInAmbientOrTypeNode(node *ast.Node) bool {
	return node.Flags&ast.NodeFlagsAmbient != 0 || ast.FindAncestor(node, func(n *ast.Node) bool {
		return ast.IsInterfaceDeclaration(n) || ast.IsTypeOrJSTypeAliasDeclaration(n) || ast.IsTypeLiteralNode(n)
	}) != nil
}

func isLiteralExpressionOfObject(node *ast.Node) bool {
	switch node.Kind {
	case ast.KindObjectLiteralExpression, ast.KindArrayLiteralExpression, ast.KindRegularExpressionLiteral,
		ast.KindFunctionExpression, ast.KindClassExpression:
		return true
	}
	return false
}

func canHaveFlowNode(node *ast.Node) bool {
	return node.FlowNodeData() != nil
}

func isNonNullAccess(node *ast.Node) bool {
	return ast.IsAccessExpression(node) && ast.IsNonNullExpression(node.Expression())
}

func getBindingElementPropertyName(node *ast.Node) *ast.Node {
	return node.PropertyNameOrName()
}

func isCallChain(node *ast.Node) bool {
	return ast.IsCallExpression(node) && node.Flags&ast.NodeFlagsOptionalChain != 0
}

func (c *Checker) callLikeExpressionMayHaveTypeArguments(node *ast.Node) bool {
	return ast.IsCallOrNewExpression(node) || ast.IsTaggedTemplateExpression(node) || ast.IsJsxOpeningLikeElement(node)
}

func isSuperCall(n *ast.Node) bool {
	return ast.IsCallExpression(n) && n.Expression().Kind == ast.KindSuperKeyword
}

/**
 * Determines whether a node is a property or element access expression for `super`.
 *
 * @internal
 */
func isSuperProperty(node *ast.Node) bool {
	return ast.IsAccessExpression(node) && node.Expression().Kind == ast.KindSuperKeyword
}

func getMembersOfDeclaration(node *ast.Node) []*ast.Node {
	switch node.Kind {
	case ast.KindInterfaceDeclaration, ast.KindClassDeclaration, ast.KindClassExpression, ast.KindTypeLiteral:
		return node.Members()
	case ast.KindObjectLiteralExpression:
		return node.Properties()
	}
	return nil
}

type FunctionFlags uint32

const (
	FunctionFlagsNormal         FunctionFlags = 0
	FunctionFlagsGenerator      FunctionFlags = 1 << 0
	FunctionFlagsAsync          FunctionFlags = 1 << 1
	FunctionFlagsInvalid        FunctionFlags = 1 << 2
	FunctionFlagsAsyncGenerator FunctionFlags = FunctionFlagsAsync | FunctionFlagsGenerator
)

func getFunctionFlags(node *ast.Node) FunctionFlags {
	if node == nil {
		return FunctionFlagsInvalid
	}
	data := node.BodyData()
	if data == nil {
		return FunctionFlagsInvalid
	}
	flags := FunctionFlagsNormal
	switch node.Kind {
	case ast.KindFunctionDeclaration, ast.KindFunctionExpression, ast.KindMethodDeclaration:
		if data.AsteriskToken != nil {
			flags |= FunctionFlagsGenerator
		}
		fallthrough
	case ast.KindArrowFunction:
		if ast.HasSyntacticModifier(node, ast.ModifierFlagsAsync) {
			flags |= FunctionFlagsAsync
		}
	}
	if data.Body == nil {
		flags |= FunctionFlagsInvalid
	}
	return flags
}

func isInRightSideOfImportOrExportAssignment(node *ast.EntityName) bool {
	for node.Parent.Kind == ast.KindQualifiedName {
		node = node.Parent
	}

	return node.Parent.Kind == ast.KindImportEqualsDeclaration && node.Parent.AsImportEqualsDeclaration().ModuleReference == node ||
		(node.Parent.Kind == ast.KindExportAssignment || node.Parent.Kind == ast.KindJSExportAssignment) && node.Parent.Expression() == node
}

func isJsxIntrinsicTagName(tagName *ast.Node) bool {
	return ast.IsIdentifier(tagName) && scanner.IsIntrinsicJsxName(tagName.Text()) || ast.IsJsxNamespacedName(tagName)
}

func getContainingObjectLiteral(f *ast.SignatureDeclaration) *ast.Node {
	if (f.Kind == ast.KindMethodDeclaration ||
		f.Kind == ast.KindGetAccessor ||
		f.Kind == ast.KindSetAccessor) && f.Parent.Kind == ast.KindObjectLiteralExpression {
		return f.Parent
	} else if f.Kind == ast.KindFunctionExpression && f.Parent.Kind == ast.KindPropertyAssignment {
		return f.Parent.Parent
	}
	return nil
}

func isImportTypeQualifierPart(node *ast.Node) *ast.Node {
	parent := node.Parent
	for ast.IsQualifiedName(parent) {
		node = parent
		parent = parent.Parent
	}

	if parent != nil && parent.Kind == ast.KindImportType && parent.AsImportTypeNode().Qualifier == node {
		return parent
	}

	return nil
}

func isInNameOfExpressionWithTypeArguments(node *ast.Node) bool {
	for node.Parent.Kind == ast.KindPropertyAccessExpression {
		node = node.Parent
	}

	return node.Parent.Kind == ast.KindExpressionWithTypeArguments
}

func getIndexSymbolFromSymbolTable(symbolTable ast.SymbolTable) *ast.Symbol {
	return symbolTable[ast.InternalSymbolNameIndex]
}

// Indicates whether the result of an `Expression` will be unused.
// NOTE: This requires a node with a valid `parent` pointer.
func expressionResultIsUnused(node *ast.Node) bool {
	for {
		parent := node.Parent
		// walk up parenthesized expressions, but keep a pointer to the top-most parenthesized expression
		if ast.IsParenthesizedExpression(parent) {
			node = parent
			continue
		}
		// result is unused in an expression statement, `void` expression, or the initializer or incrementer of a `for` loop
		if ast.IsExpressionStatement(parent) || ast.IsVoidExpression(parent) || ast.IsForStatement(parent) && (parent.Initializer() == node || parent.AsForStatement().Incrementor == node) {
			return true
		}
		if ast.IsBinaryExpression(parent) && parent.AsBinaryExpression().OperatorToken.Kind == ast.KindCommaToken {
			// left side of comma is always unused
			if node == parent.AsBinaryExpression().Left {
				return true
			}
			// right side of comma is unused if parent is unused
			node = parent
			continue
		}
		return false
	}
}

func pseudoBigIntToString(value jsnum.PseudoBigInt) string {
	return value.String()
}

func getSuperContainer(node *ast.Node, stopOnFunctions bool) *ast.Node {
	for {
		node = node.Parent
		if node == nil {
			return nil
		}
		switch node.Kind {
		case ast.KindComputedPropertyName:
			node = node.Parent
		case ast.KindFunctionDeclaration, ast.KindFunctionExpression, ast.KindArrowFunction:
			if !stopOnFunctions {
				continue
			}
			fallthrough
		case ast.KindPropertyDeclaration, ast.KindPropertySignature, ast.KindMethodDeclaration, ast.KindMethodSignature, ast.KindConstructor,
			ast.KindGetAccessor, ast.KindSetAccessor, ast.KindClassStaticBlockDeclaration:
			return node
		case ast.KindDecorator:
			// Decorators are always applied outside of the body of a class or method.
			if ast.IsParameter(node.Parent) && ast.IsClassElement(node.Parent.Parent) {
				// If the decorator's parent is a Parameter, we resolve the this container from
				// the grandparent class declaration.
				node = node.Parent.Parent
			} else if ast.IsClassElement(node.Parent) {
				// If the decorator's parent is a class element, we resolve the 'this' container
				// from the parent class declaration.
				node = node.Parent
			}
		}
	}
}

func forEachYieldExpression(body *ast.Node, visitor func(expr *ast.Node)) {
	var traverse func(*ast.Node) bool
	traverse = func(node *ast.Node) bool {
		switch node.Kind {
		case ast.KindYieldExpression:
			visitor(node)
			operand := node.Expression()
			if operand != nil {
				traverse(operand)
			}
		case ast.KindEnumDeclaration, ast.KindInterfaceDeclaration, ast.KindModuleDeclaration, ast.KindTypeAliasDeclaration:
			// These are not allowed inside a generator now, but eventually they may be allowed
			// as local types. Regardless, skip them to avoid the work.
		default:
			if ast.IsFunctionLike(node) {
				if node.Name() != nil && ast.IsComputedPropertyName(node.Name()) {
					// Note that we will not include methods/accessors of a class because they would require
					// first descending into the class. This is by design.
					traverse(node.Name().Expression())
				}
			} else if !ast.IsPartOfTypeNode(node) {
				// This is the general case, which should include mostly expressions and statements.
				// Also includes NodeArrays.
				node.ForEachChild(traverse)
			}
		}
		return false
	}
	traverse(body)
}

func SkipTypeChecking(sourceFile *ast.SourceFile, options *core.CompilerOptions, host Program, ignoreNoCheck bool) bool {
	return (!ignoreNoCheck && options.NoCheck.IsTrue()) ||
		options.SkipLibCheck.IsTrue() && sourceFile.IsDeclarationFile ||
		options.SkipDefaultLibCheck.IsTrue() && host.IsSourceFileDefaultLibrary(sourceFile.Path()) ||
		host.IsSourceFromProjectReference(sourceFile.Path()) ||
		!canIncludeBindAndCheckDiagnostics(sourceFile, options)
}

func canIncludeBindAndCheckDiagnostics(sourceFile *ast.SourceFile, options *core.CompilerOptions) bool {
	if sourceFile.CheckJsDirective != nil && !sourceFile.CheckJsDirective.Enabled {
		return false
	}

	if sourceFile.ScriptKind == core.ScriptKindTS || sourceFile.ScriptKind == core.ScriptKindTSX || sourceFile.ScriptKind == core.ScriptKindExternal {
		return true
	}

	isJS := sourceFile.ScriptKind == core.ScriptKindJS || sourceFile.ScriptKind == core.ScriptKindJSX
	isCheckJS := isJS && ast.IsCheckJSEnabledForFile(sourceFile, options)
	isPlainJS := ast.IsPlainJSFile(sourceFile, options.CheckJs)

	// By default, only type-check .ts, .tsx, Deferred, plain JS, checked JS and External
	// - plain JS: .js files with no // ts-check and checkJs: undefined
	// - check JS: .js files with either // ts-check or checkJs: true
	// - external: files that are added by plugins
	return isPlainJS || isCheckJS || sourceFile.ScriptKind == core.ScriptKindDeferred
}

func getEnclosingContainer(node *ast.Node) *ast.Node {
	return ast.FindAncestor(node.Parent, func(n *ast.Node) bool {
		return binder.GetContainerFlags(n)&binder.ContainerFlagsIsContainer != 0
	})
}

func getDeclarationsOfKind(symbol *ast.Symbol, kind ast.Kind) []*ast.Node {
	return core.Filter(symbol.Declarations, func(d *ast.Node) bool { return d.Kind == kind })
}

func hasType(node *ast.Node) bool {
	return node.Type() != nil
}

func getNonRestParameterCount(sig *Signature) int {
	return len(sig.parameters) - core.IfElse(signatureHasRestParameter(sig), 1, 0)
}

func minAndMax[T any](slice []T, getValue func(value T) int) (int, int) {
	var minValue, maxValue int
	for i, element := range slice {
		value := getValue(element)
		if i == 0 {
			minValue = value
			maxValue = value
		} else {
			minValue = min(minValue, value)
			maxValue = max(maxValue, value)
		}
	}
	return minValue, maxValue
}

func getNonModifierTokenRangeOfNode(node *ast.Node) core.TextRange {
	pos := node.Pos()
	if last := ast.FindLastVisibleNode(node.ModifierNodes()); last != nil {
		pos = last.Pos()
	}
	return scanner.GetRangeOfTokenAtPosition(ast.GetSourceFileOfNode(node), pos)
}

type FeatureMapEntry struct {
	lib   string
	props []string
}

var getFeatureMap = sync.OnceValue(func() map[string][]FeatureMapEntry {
	return map[string][]FeatureMapEntry{
		"Array": {
			{lib: "es2015", props: []string{"find", "findIndex", "fill", "copyWithin", "entries", "keys", "values"}},
			{lib: "es2016", props: []string{"includes"}},
			{lib: "es2019", props: []string{"flat", "flatMap"}},
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Iterator": {
			{lib: "es2015", props: []string{}},
		},
		"AsyncIterator": {
			{lib: "es2015", props: []string{}},
		},
		"ArrayBuffer": {
			{lib: "es2024", props: []string{
				"maxByteLength",
				"resizable",
				"resize",
				"detached",
				"transfer",
				"transferToFixedLength",
			}},
		},
		"Atomics": {
			{lib: "es2017", props: []string{
				"add",
				"and",
				"compareExchange",
				"exchange",
				"isLockFree",
				"load",
				"or",
				"store",
				"sub",
				"wait",
				"notify",
				"xor",
			}},
			{lib: "es2024", props: []string{
				"waitAsync",
			}},
		},
		"SharedArrayBuffer": {
			{lib: "es2017", props: []string{
				"byteLength",
				"slice",
			}},
			{lib: "es2024", props: []string{
				"growable",
				"maxByteLength",
				"grow",
			}},
		},
		"AsyncIterable": {
			{lib: "es2018", props: []string{}},
		},
		"AsyncIterableIterator": {
			{lib: "es2018", props: []string{}},
		},
		"AsyncGenerator": {
			{lib: "es2018", props: []string{}},
		},
		"AsyncGeneratorFunction": {
			{lib: "es2018", props: []string{}},
		},
		"RegExp": {
			{lib: "es2015", props: []string{"flags", "sticky", "unicode"}},
			{lib: "es2018", props: []string{"dotAll"}},
			{lib: "es2024", props: []string{"unicodeSets"}},
		},
		"Reflect": {
			{lib: "es2015", props: []string{"apply", "construct", "defineProperty", "deleteProperty", "get", "getOwnPropertyDescriptor", "getPrototypeOf", "has", "isExtensible", "ownKeys", "preventExtensions", "set", "setPrototypeOf"}},
		},
		"ArrayConstructor": {
			{lib: "es2015", props: []string{"from", "of"}},
			{lib: "esnext", props: []string{"fromAsync"}},
		},
		"ObjectConstructor": {
			{lib: "es2015", props: []string{"assign", "getOwnPropertySymbols", "keys", "is", "setPrototypeOf"}},
			{lib: "es2017", props: []string{"values", "entries", "getOwnPropertyDescriptors"}},
			{lib: "es2019", props: []string{"fromEntries"}},
			{lib: "es2022", props: []string{"hasOwn"}},
			{lib: "es2024", props: []string{"groupBy"}},
		},
		"NumberConstructor": {
			{lib: "es2015", props: []string{"isFinite", "isInteger", "isNaN", "isSafeInteger", "parseFloat", "parseInt"}},
		},
		"Math": {
			{lib: "es2015", props: []string{"clz32", "imul", "sign", "log10", "log2", "log1p", "expm1", "cosh", "sinh", "tanh", "acosh", "asinh", "atanh", "hypot", "trunc", "fround", "cbrt"}},
		},
		"Map": {
			{lib: "es2015", props: []string{"entries", "keys", "values"}},
		},
		"MapConstructor": {
			{lib: "es2024", props: []string{"groupBy"}},
		},
		"Set": {
			{lib: "es2015", props: []string{"entries", "keys", "values"}},
			{lib: "esnext", props: []string{
				"union",
				"intersection",
				"difference",
				"symmetricDifference",
				"isSubsetOf",
				"isSupersetOf",
				"isDisjointFrom",
			}},
		},
		"PromiseConstructor": {
			{lib: "es2015", props: []string{"all", "race", "reject", "resolve"}},
			{lib: "es2020", props: []string{"allSettled"}},
			{lib: "es2021", props: []string{"any"}},
			{lib: "es2024", props: []string{"withResolvers"}},
		},
		"Symbol": {
			{lib: "es2015", props: []string{"for", "keyFor"}},
			{lib: "es2019", props: []string{"description"}},
		},
		"WeakMap": {
			{lib: "es2015", props: []string{"entries", "keys", "values"}},
		},
		"WeakSet": {
			{lib: "es2015", props: []string{"entries", "keys", "values"}},
		},
		"String": {
			{lib: "es2015", props: []string{"codePointAt", "includes", "endsWith", "normalize", "repeat", "startsWith", "anchor", "big", "blink", "bold", "fixed", "fontcolor", "fontsize", "italics", "link", "small", "strike", "sub", "sup"}},
			{lib: "es2017", props: []string{"padStart", "padEnd"}},
			{lib: "es2019", props: []string{"trimStart", "trimEnd", "trimLeft", "trimRight"}},
			{lib: "es2020", props: []string{"matchAll"}},
			{lib: "es2021", props: []string{"replaceAll"}},
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2024", props: []string{"isWellFormed", "toWellFormed"}},
		},
		"StringConstructor": {
			{lib: "es2015", props: []string{"fromCodePoint", "raw"}},
		},
		"DateTimeFormat": {
			{lib: "es2017", props: []string{"formatToParts"}},
		},
		"Promise": {
			{lib: "es2015", props: []string{}},
			{lib: "es2018", props: []string{"finally"}},
		},
		"RegExpMatchArray": {
			{lib: "es2018", props: []string{"groups"}},
		},
		"RegExpExecArray": {
			{lib: "es2018", props: []string{"groups"}},
		},
		"Intl": {
			{lib: "es2018", props: []string{"PluralRules"}},
		},
		"NumberFormat": {
			{lib: "es2018", props: []string{"formatToParts"}},
		},
		"SymbolConstructor": {
			{lib: "es2020", props: []string{"matchAll"}},
			{lib: "esnext", props: []string{
				"metadata",
				"dispose",
				"asyncDispose",
			}},
		},
		"DataView": {
			{lib: "es2020", props: []string{"setBigInt64", "setBigUint64", "getBigInt64", "getBigUint64"}},
		},
		"BigInt": {
			{lib: "es2020", props: []string{}},
		},
		"RelativeTimeFormat": {
			{lib: "es2020", props: []string{"format", "formatToParts", "resolvedOptions"}},
		},
		"Int8Array": {
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Uint8Array": {
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Uint8ClampedArray": {
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Int16Array": {
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Uint16Array": {
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Int32Array": {
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Uint32Array": {
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Float32Array": {
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Float64Array": {
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"BigInt64Array": {
			{lib: "es2020", props: []string{}},
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"BigUint64Array": {
			{lib: "es2020", props: []string{}},
			{lib: "es2022", props: []string{"at"}},
			{lib: "es2023", props: []string{"findLastIndex", "findLast", "toReversed", "toSorted", "toSpliced", "with"}},
		},
		"Error": {
			{lib: "es2022", props: []string{"cause"}},
		},
	}
})

func rangeOfTypeParameters(sourceFile *ast.SourceFile, typeParameters *ast.NodeList) core.TextRange {
	return core.NewTextRange(typeParameters.Pos()-1, min(len(sourceFile.Text()), scanner.SkipTrivia(sourceFile.Text(), typeParameters.End())+1))
}

func tryGetPropertyAccessOrIdentifierToString(expr *ast.Node) string {
	switch {
	case ast.IsPropertyAccessExpression(expr):
		baseStr := tryGetPropertyAccessOrIdentifierToString(expr.Expression())
		if baseStr != "" {
			return baseStr + "." + entityNameToString(expr.Name())
		}
	case ast.IsElementAccessExpression(expr):
		baseStr := tryGetPropertyAccessOrIdentifierToString(expr.Expression())
		if baseStr != "" && ast.IsPropertyName(expr.AsElementAccessExpression().ArgumentExpression) {
			return baseStr + "." + ast.GetPropertyNameForPropertyNameNode(expr.AsElementAccessExpression().ArgumentExpression)
		}
	case ast.IsIdentifier(expr):
		return expr.Text()
	case ast.IsJsxNamespacedName(expr):
		return entityNameToString(expr)
	}
	return ""
}

func getFirstJSDocTag(node *ast.Node, f func(*ast.Node) bool) *ast.Node {
	for _, jsdoc := range node.JSDoc(nil) {
		tags := jsdoc.AsJSDoc().Tags
		if tags != nil {
			for _, tag := range tags.Nodes {
				if f(tag) {
					return tag
				}
			}
		}
	}
	return nil
}

func getJSDocDeprecatedTag(node *ast.Node) *ast.Node {
	return getFirstJSDocTag(node, ast.IsJSDocDeprecatedTag)
}

func allDeclarationsInSameSourceFile(symbol *ast.Symbol) bool {
	if len(symbol.Declarations) > 1 {
		var sourceFile *ast.SourceFile
		for i, d := range symbol.Declarations {
			if i == 0 {
				sourceFile = ast.GetSourceFileOfNode(d)
			} else if ast.GetSourceFileOfNode(d) != sourceFile {
				return false
			}
		}
	}
	return true
}

func containsNonMissingUndefinedType(c *Checker, t *Type) bool {
	var candidate *Type
	if t.flags&TypeFlagsUnion != 0 {
		candidate = t.AsUnionType().types[0]
	} else {
		candidate = t
	}
	return candidate.flags&TypeFlagsUndefined != 0 && candidate != c.missingType
}

func getAnyImportSyntax(node *ast.Node) *ast.Node {
	var importNode *ast.Node
	switch node.Kind {
	case ast.KindImportEqualsDeclaration:
		importNode = node
	case ast.KindImportClause:
		importNode = node.Parent
	case ast.KindNamespaceImport:
		importNode = node.Parent.Parent
	case ast.KindImportSpecifier:
		importNode = node.Parent.Parent.Parent
	default:
		return nil
	}
	return importNode
}

// A reserved member name consists of the byte 0xFE (which is an invalid UTF-8 encoding) followed by one or more
// characters where the first character is not '@' or '#'. The '@' character indicates that the name is denoted by
// a well known ES Symbol instance and the '#' character indicates that the name is a PrivateIdentifier.
func isReservedMemberName(name string) bool {
	return len(name) >= 2 && name[0] == '\xFE' && name[1] != '@' && name[1] != '#'
}

func introducesArgumentsExoticObject(node *ast.Node) bool {
	switch node.Kind {
	case ast.KindMethodDeclaration, ast.KindMethodSignature, ast.KindConstructor, ast.KindGetAccessor,
		ast.KindSetAccessor, ast.KindFunctionDeclaration, ast.KindFunctionExpression:
		return true
	}
	return false
}

func symbolsToArray(symbols ast.SymbolTable) []*ast.Symbol {
	var result []*ast.Symbol
	for id, symbol := range symbols {
		if !isReservedMemberName(id) {
			result = append(result, symbol)
		}
	}
	return result
}

// See comment on `declareModuleMember` in `binder.go`.
func GetCombinedLocalAndExportSymbolFlags(symbol *ast.Symbol) ast.SymbolFlags {
	if symbol.ExportSymbol != nil {
		return symbol.Flags | symbol.ExportSymbol.Flags
	}
	return symbol.Flags
}

func SkipAlias(symbol *ast.Symbol, checker *Checker) *ast.Symbol {
	if symbol.Flags&ast.SymbolFlagsAlias != 0 {
		return checker.GetAliasedSymbol(symbol)
	}
	return symbol
}

// True if the symbol is for an external module, as opposed to a namespace.
func IsExternalModuleSymbol(moduleSymbol *ast.Symbol) bool {
	firstRune, _ := utf8.DecodeRuneInString(moduleSymbol.Name)
	return moduleSymbol.Flags&ast.SymbolFlagsModule != 0 && firstRune == '"'
}

func (c *Checker) isCanceled() bool {
	return c.ctx != nil && c.ctx.Err() != nil
}

func (c *Checker) checkNotCanceled() {
	if c.wasCanceled {
		panic("Checker was previously cancelled")
	}
}

func (c *Checker) getPackagesMap() map[string]bool {
	if c.packagesMap == nil {
		c.packagesMap = make(map[string]bool)
		resolvedModules := c.program.GetResolvedModules()
		for _, resolvedModulesInFile := range resolvedModules {
			for _, module := range resolvedModulesInFile {
				if module.PackageId.Name != "" {
					c.packagesMap[module.PackageId.Name] = c.packagesMap[module.PackageId.Name] || module.Extension == tspath.ExtensionDts
				}
			}
		}
	}
	return c.packagesMap
}

func (c *Checker) typesPackageExists(packageName string) bool {
	packagesMap := c.getPackagesMap()
	_, ok := packagesMap[module.GetTypesPackageName(packageName)]
	return ok
}

func (c *Checker) packageBundlesTypes(packageName string) bool {
	packagesMap := c.getPackagesMap()
	hasTypes, _ := packagesMap[packageName]
	return hasTypes
}

func ValueToString(value any) string {
	switch value := value.(type) {
	case string:
		return "\"" + printer.EscapeString(value, '"') + "\""
	case jsnum.Number:
		return value.String()
	case bool:
		return core.IfElse(value, "true", "false")
	case jsnum.PseudoBigInt:
		return value.String() + "n"
	}
	panic("unhandled value type in valueToString")
}

func nodeStartsNewLexicalEnvironment(node *ast.Node) bool {
	switch node.Kind {
	case ast.KindConstructor, ast.KindFunctionExpression, ast.KindFunctionDeclaration, ast.KindArrowFunction,
		ast.KindMethodDeclaration, ast.KindGetAccessor, ast.KindSetAccessor, ast.KindModuleDeclaration, ast.KindSourceFile:
		return true
	}
	return false
}

// Determines whether a did-you-mean error should be a suggestion in an unchecked JS file.
// Only applies to unchecked JS files without checkJS, // @ts-check or // @ts-nocheck
// It does not suggest when the suggestion:
// - Is from a global file that is different from the reference file, or
// - (optionally) Is a class, or is a this.x property access expression
func (c *Checker) isUncheckedJSSuggestion(node *ast.Node, suggestion *ast.Symbol, excludeClasses bool) bool {
	file := ast.GetSourceFileOfNode(node)
	if file != nil {
		if c.compilerOptions.CheckJs.IsUnknown() && file.CheckJsDirective == nil && (file.ScriptKind == core.ScriptKindJS || file.ScriptKind == core.ScriptKindJSX) {
			var declarationFile *ast.SourceFile
			if suggestion != nil {
				if firstDeclaration := core.FirstOrNil(suggestion.Declarations); firstDeclaration != nil {
					declarationFile = ast.GetSourceFileOfNode(firstDeclaration)
				}
			}
			suggestionHasNoExtendsOrDecorators := suggestion == nil ||
				suggestion.ValueDeclaration == nil ||
				!ast.IsClassLike(suggestion.ValueDeclaration) ||
				len(ast.GetExtendsHeritageClauseElements(suggestion.ValueDeclaration)) != 0 ||
				classOrConstructorParameterIsDecorated(suggestion.ValueDeclaration)
			return !(file != declarationFile && declarationFile != nil && ast.IsGlobalSourceFile(declarationFile.AsNode())) &&
				!(excludeClasses && suggestion != nil && suggestion.Flags&ast.SymbolFlagsClass != 0 && suggestionHasNoExtendsOrDecorators) &&
				!(node != nil && excludeClasses && ast.IsPropertyAccessExpression(node) && node.Expression().Kind == ast.KindThisKeyword && suggestionHasNoExtendsOrDecorators)
		}
	}
	return false
}

func classOrConstructorParameterIsDecorated(node *ast.Node) bool {
	if nodeIsDecorated(node, nil, nil) {
		return true
	}
	constructor := ast.GetFirstConstructorWithBody(node)
	return constructor != nil && childIsDecorated(constructor, node)
}

func nodeIsDecorated(node *ast.Node, parent *ast.Node, grandparent *ast.Node) bool {
	return ast.HasDecorators(node) && nodeCanBeDecorated(false, node, parent, grandparent)
}

func nodeOrChildIsDecorated(node *ast.Node, parent *ast.Node, grandparent *ast.Node) bool {
	return nodeIsDecorated(node, parent, grandparent) || childIsDecorated(node, parent)
}

func childIsDecorated(node *ast.Node, parent *ast.Node) bool {
	switch node.Kind {
	case ast.KindClassDeclaration, ast.KindClassExpression:
		return core.Some(node.Members(), func(m *ast.Node) bool {
			return nodeOrChildIsDecorated(m, node, parent)
		})
	case ast.KindMethodDeclaration,
		ast.KindSetAccessor,
		ast.KindConstructor:
		return core.Some(node.Parameters(), func(p *ast.Node) bool {
			return nodeIsDecorated(p, node, parent)
		})
	default:
		return false
	}
}

// Returns if a type is or consists of a JSLiteral object type
// In addition to objects which are directly literals,
// * unions where every element is a jsliteral
// * intersections where at least one element is a jsliteral
// * and instantiable types constrained to a jsliteral
// Should all count as literals and not print errors on access or assignment of possibly existing properties.
// This mirrors the behavior of the index signature propagation, to which this behaves similarly (but doesn't affect assignability or inference).
func (c *Checker) isJSLiteralType(t *Type) bool {
	if c.noImplicitAny {
		return false
		// Flag is meaningless under `noImplicitAny` mode
	}
	if t.objectFlags&ObjectFlagsJSLiteral != 0 {
		return true
	}
	if t.flags&TypeFlagsUnion != 0 {
		return core.Every(t.AsUnionType().types, c.isJSLiteralType)
	}
	if t.flags&TypeFlagsIntersection != 0 {
		return core.Some(t.AsIntersectionType().types, c.isJSLiteralType)
	}
	if t.flags&TypeFlagsInstantiable != 0 {
		constraint := c.getResolvedBaseConstraint(t, nil)
		return constraint != t && c.isJSLiteralType(constraint)
	}
	return false
}