private static void BuildRegions()

in Nodejs/Product/Nodejs/Jade/Outlining/IndentBasedRegionBuilder.cs [43:156]
88 lines of code
19 McCabe index (conditional complexity)

        private static void BuildRegions(OutlineRegionCollection newRegions, ITextSnapshot snapshot)
        {
            // Figure out regions based on line indent
            if (snapshot.LineCount == 0)
            {
                return;
            }

            var regionStack = new Stack<CodeBlock>();
            var lineLengths = new int[snapshot.LineCount];

            var lastBlockIndent = 0;

            for (var i = 0; i < snapshot.LineCount; i++)
            {
                var line = snapshot.GetLineFromLineNumber(i);

                var lineText = line.GetText();
                if (string.IsNullOrWhiteSpace(lineText))
                {
                    lineLengths[i] = 0;
                    continue;
                }

                lineLengths[i] = line.Length;
                var indent = GetLineIndent(line);

                if (regionStack.Count > 0)
                {
                    lastBlockIndent = regionStack.Peek().Indent;
                }
                else
                {
                    lastBlockIndent = 0;
                }

                if (indent <= lastBlockIndent)
                {
                    // We add regions optimistically since any line can
                    // start a new region if lines below it are indented
                    // deeper that this line.
                    while (regionStack.Count > 0)
                    {
                        // If we have line with the same indent, remove previously added region
                        // and replace it with a new one potentially starting with the current line.
                        var prevCodeBlock = regionStack.Pop();
                        var startLine = snapshot.GetLineNumberFromPosition(prevCodeBlock.Start);

                        // Trim empty lines
                        var j = i - 1;
                        for (; j >= 0; j--)
                        {
                            if (lineLengths[j] > 0)
                            {
                                break;
                            }
                        }

                        j++;

                        if (j > 0 && j - startLine >= _minLinesToOutline)
                        {
                            var prevLine = snapshot.GetLineFromLineNumber(j - 1);

                            if (prevCodeBlock.Start < prevLine.End)
                            {
                                newRegions.Add(OutlineRegion.FromBounds(snapshot.TextBuffer, prevCodeBlock.Start, prevLine.End));
                            }
                        }

                        if (regionStack.Count > 0)
                        {
                            prevCodeBlock = regionStack.Peek();
                            if (prevCodeBlock.Indent < indent)
                            {
                                break;
                            }
                        }
                    }
                }

                lastBlockIndent = indent;
                regionStack.Push(new CodeBlock(line.Start, indent));
            }

            // Note that last region may be bogus since we add regions optimistically.
            // Remove last region if its indent is the same as the line before it
            if (regionStack.Count > 0)
            {
                var codeBlock = regionStack.Peek();
                var lineNumber = snapshot.GetLineNumberFromPosition(codeBlock.Start);
                if (lineNumber > 0)
                {
                    var prevLine = snapshot.GetLineFromLineNumber(lineNumber - 1);
                    var indent = GetLineIndent(prevLine);

                    if (indent == codeBlock.Indent)
                    {
                        regionStack.Pop();
                    }
                }
            }

            while (regionStack.Count > 0)
            {
                var codeBlock = regionStack.Pop();

                var startLine = snapshot.GetLineNumberFromPosition(codeBlock.Start);
                if (snapshot.LineCount - startLine >= _minLinesToOutline)
                {
                    newRegions.Add(OutlineRegion.FromBounds(snapshot.TextBuffer, codeBlock.Start, snapshot.Length));
                }
            }
        }