public async provideCompletionItems()

in src/completion/completionProvider.ts [33:126]
89 lines of code
22 McCabe index (conditional complexity)

    public async provideCompletionItems(document: vscode.TextDocument, position: vscode.Position, _token: vscode.CancellationToken, _context: vscode.CompletionContext): Promise<vscode.CompletionItem[] | vscode.CompletionList | undefined> {
        const documentText: string = document.getText();
        const cursorOffset: number = document.offsetAt(position);
        const currentNode: ElementNode | undefined = getCurrentNode(documentText, cursorOffset);
        if (currentNode === undefined || currentNode.contentStart === undefined) {
            return undefined;
        }

        const targetRange: vscode.Range = new vscode.Range(document.positionAt(currentNode.contentStart), position);
        switch (currentNode.tag) {
            case XmlTagName.GroupId: {
                const siblingNodes: ElementNode[] = _.get(currentNode, "parent.children", []);
                const artifactIdNode: ElementNode | undefined = siblingNodes.find(elem => elem.tag === XmlTagName.ArtifactId);
                const groupIdHint: string = currentNode.text ? currentNode.text : "";
                const artifactIdHint: string = artifactIdNode && artifactIdNode.text ? artifactIdNode.text : "";
                const centralItems: vscode.CompletionItem[] = await centralProvider.getGroupIdCandidates(groupIdHint, artifactIdHint);
                const indexItems: vscode.CompletionItem[] = await indexProvider.getGroupIdCandidates(groupIdHint, artifactIdHint);
                const localItems: vscode.CompletionItem[] = await localProvider.getGroupIdCandidates(groupIdHint, artifactIdHint);
                const mergedItems: vscode.CompletionItem[] = this.deDuplicate(centralItems, indexItems, localItems, (item) => item.insertText);
                mergedItems.forEach(item => item.range = targetRange);

                return new vscode.CompletionList(mergedItems, _.isEmpty(centralItems));
            }
            case XmlTagName.ArtifactId: {
                const siblingNodes: ElementNode[] = _.get(currentNode, "parent.children", []);
                const groupIdNode: ElementNode | undefined = siblingNodes.find(elem => elem.tag === XmlTagName.GroupId);
                const groupIdHint: string = groupIdNode && groupIdNode.text ? groupIdNode.text : "";
                const artifactIdHint: string = currentNode.text ? currentNode.text : "";

                const centralItems: vscode.CompletionItem[] = await centralProvider.getArtifactIdCandidates(groupIdHint, artifactIdHint);
                const indexItems: vscode.CompletionItem[] = await indexProvider.getArtifactIdCandidates(groupIdHint, artifactIdHint);
                const localItems: vscode.CompletionItem[] = await localProvider.getArtifactIdCandidates(groupIdHint, artifactIdHint);
                let mergedItems: vscode.CompletionItem[] = [];
                const ID_SEPARATOR: string = ":";
                // tslint:disable-next-line: restrict-plus-operands
                mergedItems = this.deDuplicate(centralItems, indexItems, localItems, (item) => _.get(item, "data.groupId") + ID_SEPARATOR + item.insertText);
                mergedItems = this.reserveGidMatch(mergedItems, groupIdHint);
                if (groupIdNode && groupIdNode.contentStart !== undefined && groupIdNode.contentEnd !== undefined) {
                    for (const item of mergedItems) {
                        const matchedGroupId: string = _.get(item, "data.groupId");
                        if (matchedGroupId) {
                            const groupIdRange: vscode.Range = new vscode.Range(document.positionAt(groupIdNode.contentStart), document.positionAt(groupIdNode.contentEnd));
                            item.additionalTextEdits = [new vscode.TextEdit(groupIdRange, matchedGroupId)];
                        }
                    }
                }
                mergedItems.forEach(item => item.range = targetRange);
                return new vscode.CompletionList(mergedItems, _.isEmpty(centralItems));
            }
            case XmlTagName.Version: {
                const siblingNodes: ElementNode[] = _.get(currentNode, "parent.children", []);
                const groupIdNode: ElementNode | undefined = siblingNodes.find(elem => elem.tag === XmlTagName.GroupId);
                const artifactIdNode: ElementNode | undefined = siblingNodes.find(elem => elem.tag === XmlTagName.ArtifactId);
                const groupIdHint: string | undefined = groupIdNode?.text || DEFAULT_GROUP_ID;
                const artifactIdHint: string | undefined = artifactIdNode?.text;
                if (!groupIdHint || !artifactIdHint) {
                    return [];
                }

                const centralItems: vscode.CompletionItem[] = await centralProvider.getVersionCandidates(groupIdHint, artifactIdHint);
                const indexItems: vscode.CompletionItem[] = await indexProvider.getVersionCandidates(groupIdHint, artifactIdHint);
                const localItems: vscode.CompletionItem[] = await localProvider.getVersionCandidates(groupIdHint, artifactIdHint);
                const mergedItems: vscode.CompletionItem[] = this.deDuplicate(centralItems, indexItems, localItems, (item) => item.insertText);
                mergedItems.forEach(item => item.range = targetRange);
                return new vscode.CompletionList(mergedItems, false);
            }
            case XmlTagName.Dependencies: {
                const snippetItem: vscode.CompletionItem = new vscode.CompletionItem("dependency", vscode.CompletionItemKind.Snippet);
                const snippetContent: string = trimBrackets(dependencySnippetString, documentText, cursorOffset);
                const dependencySnippet: vscode.SnippetString = new vscode.SnippetString(snippetContent);
                snippetItem.insertText = dependencySnippet;
                snippetItem.detail = "Maven Snippet";
                snippetItem.command = {
                    title: "selected", command: COMMAND_COMPLETION_ITEM_SELECTED,
                    arguments: [{ completeFor: "dependency", source: "snippet" }]
                };
                return new vscode.CompletionList([snippetItem], false);
            }
            case XmlTagName.Plugins: {
                const snippetItem: vscode.CompletionItem = new vscode.CompletionItem("plugin", vscode.CompletionItemKind.Snippet);
                const snippetContent: string = trimBrackets(pluginSnippetString, documentText, cursorOffset);
                const pluginSnippet: vscode.SnippetString = new vscode.SnippetString(snippetContent);
                snippetItem.insertText = pluginSnippet;
                snippetItem.detail = "Maven Snippet";
                snippetItem.command = {
                    title: "selected", command: COMMAND_COMPLETION_ITEM_SELECTED,
                    arguments: [{ completeFor: "plugin", source: "snippet" }]
                };
                return new vscode.CompletionList([snippetItem], false);
            }
            default:
                return undefined;
        }
    }