export const languageConfiguration = {
  wordPattern: /(-?\d*\.\d\w*)|([^\`\~\!\@\#\%\^\&\*\(\)\-\=\+\[\{\]\}\\\|\;\:\'\"\,\.\<\>\/\?\s]+)/g,
  comments: {
    lineComment: '#',
  },
  brackets: [
    ['{', '}'],
    ['[', ']'],
  ],
  autoClosingPairs: [
    { open: '{', close: '}' },
    { open: '[', close: ']' },
    { open: '"', close: '"' },
    { open: "'", close: "'" },
  ],
  surroundingPairs: [
    { open: '{', close: '}' },
    { open: '[', close: ']' },
    { open: '"', close: '"' },
    { open: "'", close: "'" },
  ],
  folding: {
    offSide: true,
  },
};

// YAML keywords
const keywords = ['true', 'false', 'null', 'True', 'False', 'Null', 'TRUE', 'FALSE', 'NULL', 'yes', 'no', 'Yes', 'No', 'YES', 'NO', 'on', 'off', 'On', 'Off', 'ON', 'OFF'];

// YAML operators and special characters (for future use)
// const operators = [':', '-', '|', '>', '&', '*', '!', '%', '@'];

export const language = {
  tokenPostfix: '.yaml',
  brackets: [
    { token: 'delimiter.bracket', open: '{', close: '}' },
    { token: 'delimiter.square', open: '[', close: ']' },
  ],
  keywords: keywords,
  numberInteger: /(?:0|[+-]?[0-9]+)/,
  numberFloat: /(?:0|[+-]?[0-9]+)(?:\.[0-9]+)?(?:e[-+][1-9][0-9]*)?/,
  numberOctal: /0o[0-7]+/,
  numberHex: /0x[0-9a-fA-F]+/,
  numberInfinity: /[+-]?\.(?:inf|Inf|INF)/,
  numberNaN: /\.(?:nan|Nan|NAN)/,
  numberDate: /\d{4}-\d{2}-\d{2}(?:[Tt ]\d{1,2}:\d{2}:\d{2}(?:\.\d*)?(?:[ \t]*(?:Z|[-+]\d{1,2}(?::\d{2})?))?)?/,
  escapes: /\\(?:[btnfr\\"']|[0-7][0-7]?|[0-3][0-7]{2})/,

  tokenizer: {
    root: [
      { include: '@whitespace' },
      { include: '@comment' },

      // Document markers
      [/^---/, 'meta.document'],
      [/^\.{3}/, 'meta.document'],

      // Keys (property names)
      [/^(\s*)([^:\s]+)(\s*)(:)/, ['white', 'key', 'white', 'delimiter']],
      [/(\s*)([^:\s]+)(\s*)(:)/, ['white', 'key', 'white', 'delimiter']],

      // Flow collections
      [/\{/, '@brackets', '@flowMap'],
      [/\[/, '@brackets', '@flowSequence'],

      // Block scalars
      [/[|>][-+]?(\d+)?/, 'string.block', '@blockScalar'],

      // Numbers
      [/@numberInfinity/, 'number.infinity'],
      [/@numberNaN/, 'number.nan'],
      [/@numberDate/, 'number.date'],
      [/@numberHex/, 'number.hex'],
      [/@numberOctal/, 'number.octal'],
      [/@numberFloat/, 'number.float'],
      [/@numberInteger/, 'number'],

      // Strings
      [/"([^"\\]|\\.)*$/, 'string.invalid'],
      [/'([^'\\]|\\.)*$/, 'string.invalid'],
      [/"/, 'string', '@doubleQuotedString'],
      [/'/, 'string', '@singleQuotedString'],

      // Anchors and aliases
      [/&\w+/, 'tag.anchor'],
      [/\*\w+/, 'tag.alias'],

      // Tags
      [/![\w\-\/]+/, 'tag'],

      // Keywords
      [
        /[^\s\[\{\,]+/,
        {
          cases: {
            '@keywords': 'keyword',
            '@default': 'string.unquoted',
          },
        },
      ],

      // List items
      [/^(\s*)(-\s)/, ['white', 'delimiter']],
      [/(\s*)(-\s)/, ['white', 'delimiter']],
    ],

    whitespace: [[/[ \t\r\n]+/, 'white']],

    comment: [[/#.*$/, 'comment']],

    doubleQuotedString: [
      [/[^\\"]+/, 'string'],
      [/@escapes/, 'string.escape'],
      [/\\./, 'string.escape.invalid'],
      [/"/, 'string', '@pop'],
    ],

    singleQuotedString: [
      [/[^\\']+/, 'string'],
      [/''/, 'string.escape'],
      [/'/, 'string', '@pop'],
    ],

    blockScalar: [
      [/^(\s*).+$/, 'string.block'],
      [/^(?!\s)/, '', '@pop'],
    ],

    flowMap: [
      { include: '@whitespace' },
      { include: '@comment' },
      [/\}/, '@brackets', '@pop'],
      [/,/, 'delimiter'],
      [/:/, 'delimiter'],
      [/"/, 'string', '@doubleQuotedString'],
      [/'/, 'string', '@singleQuotedString'],
      [/[^\s\,\}\:]+/, 'string.unquoted'],
    ],

    flowSequence: [
      { include: '@whitespace' },
      { include: '@comment' },
      [/\]/, '@brackets', '@pop'],
      [/,/, 'delimiter'],
      [/"/, 'string', '@doubleQuotedString'],
      [/'/, 'string', '@singleQuotedString'],
      [/[^\s\,\]]+/, 'string.unquoted'],
    ],
  },
};