import 'package:codebrowser_dart/project.dart';
import 'package:codebrowser_dart/tag.dart';
import 'package:analyzer/dart/ast/token.dart';
import 'dart:io';
import 'package:path/path.dart' as path;
import 'package:codebrowser_dart/html_header.dart';

class Generator {
  List<Tag> tags = [];

  static bool _isLiteral(Token tok) {
    return tok.lexeme == 'true' ||
        tok.lexeme == 'false' ||
        tok.lexeme == 'null';
  }

  void addTag(int start, int end, String name, {String attributes = ""}) {
    tags.add(Tag(start, end, name, attributes));
  }

  void syntaxHighlight(Token begin, Token end) {
    Token? tok = begin;
    while (tok != end) {
      switch (tok!.type) {
        case TokenType.INT:
        case TokenType.DOUBLE:
        case TokenType.HEXADECIMAL:
          addTag(tok.charOffset, tok.charEnd, 'var');
          break;
        default:
          if (tok.isKeyword || tok.isModifier) {
            if (_isLiteral(tok)) {
              addTag(tok.charOffset, tok.charEnd, 'var');
              break;
            }
            addTag(tok.charOffset, tok.charEnd, 'b');
            break;
          }
          break;
      }

      tok = tok.next;
      if (tok == null) {
        break;
      }
    }
  }

  void generateHtml(
    Project project,
    String sourceCode,
    String fileName,
    String dataPath,
    String outputDir,
  ) {
    String relativeDataPath =
        path.relative(dataPath, from: path.dirname(fileName));
    String relativeFilePath = path.relative(fileName, from: outputDir);
    String relativeOutputPath =
        path.relative(outputDir, from: path.dirname(fileName));

    StringBuffer out = StringBuffer(
        createHeader(relativeFilePath, relativeOutputPath, relativeDataPath, project));

    out.write("<div id='content'>\n");
    out.write("<table class='code'>\n");
    out.write("<tbody>\n");

    tags.sort((a, b) => a.start - b.start);
    out.write('<tr>\n');
    int linenum = 1;
    out.write('<th>$linenum</th>');
    out.write('<td>');

    bool inComment = false;

    List<Tag> stack = [];
    int? currentTagEnd;
    int lastFoundTagIdx = 0;

    for (int i = 0; i < sourceCode.length; ++i) {
      // skip until we find a newline or `/`. `/` because it can be comment end
      if (inComment && sourceCode[i] != '\n' && sourceCode[i] != '/') {
        out.write(sourceCode[i]);
        continue;
      }

      if (currentTagEnd != null && i == currentTagEnd) {
        // remove from stack till we currentTagEnd == stack.top.end
        while (stack.isNotEmpty) {
          out.write(stack.last.close());
          stack.removeLast();

          if (stack.lastOrNull?.end != currentTagEnd) {
            break;
          }
        }
        currentTagEnd = stack.lastOrNull?.end;
      }

      for (int idx = lastFoundTagIdx; idx < tags.length; ++idx) {
        if (tags[idx].start == i) {
          final tag = tags[idx];
          out.write(tag.open());
          stack.add(tag);
          lastFoundTagIdx = idx + 1;
          currentTagEnd = stack.lastOrNull?.end;
        } else {
          break;
        }
      }

      switch (sourceCode[i]) {
        case '\n':
          if (inComment) {
            out.write('</i>');
          }

          var stackCopy = [...stack];
          while (stack.isNotEmpty) {
            out.write(stack.last.close());
            stack.removeLast();
          }

          out.write('</td></tr>\n');
          linenum++;
          out.write('<tr><th id="$linenum">$linenum</th><td>');

          if (inComment) {
            out.write("<i>");
          }

          for (final tag in stackCopy) {
            out.write(tag.open());
          }
          stack = stackCopy;

          break;
        case ' ':
          out.write(' ');
          break;
        case '<':
          out.write('&lt;');
          break;
        case '>':
          out.write('&gt;');
          break;
        case '&':
          out.write('&amp;');
          break;
        case '/':
          if (i + 1 < sourceCode.length && sourceCode[i + 1] == '/') {
            // skip if doc comment
            if (i + 2 < sourceCode.length && sourceCode[i + 2] == '/') {
              out.write(sourceCode[i]);
              out.write(sourceCode[i + 1]);
              i += 1;
              break;
            } else {
              out.write("<i>");
              int end = sourceCode.indexOf('\n', i);
              out.write(sourceCode.substring(i, end));
              out.write("</i>");
              i = end - 1;
              break;
            }
          } else if (i + 1 < sourceCode.length && sourceCode[i + 1] == '*') {
            out.write("<i>");
            inComment = true;
          } else if (inComment && i > 0 && sourceCode[i - 1] == '*') {
            inComment = false;
            out.write(sourceCode[i]);
            out.write("</i>");
            break;
          }
          out.write(sourceCode[i]);
          break;
        default:
          out.write(sourceCode[i]);
          break;
      }
    }
    out.write("</tbody>\n</table>\n");
    out.write(createFooter(project));
    out.write("</div>\n</body>\n</html>\n");

    File file = File("$fileName.html");
    file.writeAsString(out.toString());
  }
}