/* global CodeMirror prefs loadScript editor */

'use strict';

(function () {
  // CodeMirror miserably fails on keyMap='' so let's ensure it's not
  if (!prefs.get('editor.keyMap')) {
    prefs.reset('editor.keyMap');
  }

  const defaults = {
    mode: 'css',
    lineNumbers: true,
    lineWrapping: true,
    foldGutter: true,
    gutters: [
      'CodeMirror-linenumbers',
      'CodeMirror-foldgutter',
      ...(prefs.get('editor.linter') ? ['CodeMirror-lint-markers'] : []),
    ],
    matchBrackets: true,
    highlightSelectionMatches: {showToken: /[#.\-\w]/, annotateScrollbar: true},
    hintOptions: {},
    lintReportDelay: prefs.get('editor.lintReportDelay'),
    styleActiveLine: true,
    theme: 'default',
    keyMap: prefs.get('editor.keyMap'),
    extraKeys: {
      // independent of current keyMap
      'Alt-Enter': 'toggleStyle',
      'Alt-PageDown': 'nextEditor',
      'Alt-PageUp': 'prevEditor'
    }
  };

  Object.assign(CodeMirror.defaults, defaults, prefs.get('editor.options'));

  CodeMirror.commands.blockComment = cm => {
    cm.blockComment(cm.getCursor('from'), cm.getCursor('to'), {fullLines: false});
  };

  // 'basic' keymap only has basic keys by design, so we skip it

  const extraKeysCommands = {};
  Object.keys(CodeMirror.defaults.extraKeys).forEach(key => {
    extraKeysCommands[CodeMirror.defaults.extraKeys[key]] = true;
  });
  if (!extraKeysCommands.jumpToLine) {
    CodeMirror.keyMap.sublime['Ctrl-G'] = 'jumpToLine';
    CodeMirror.keyMap.emacsy['Ctrl-G'] = 'jumpToLine';
    CodeMirror.keyMap.pcDefault['Ctrl-J'] = 'jumpToLine';
    CodeMirror.keyMap.macDefault['Cmd-J'] = 'jumpToLine';
  }
  if (!extraKeysCommands.autocomplete) {
    // will be used by 'sublime' on PC via fallthrough
    CodeMirror.keyMap.pcDefault['Ctrl-Space'] = 'autocomplete';
    // OSX uses Ctrl-Space and Cmd-Space for something else
    CodeMirror.keyMap.macDefault['Alt-Space'] = 'autocomplete';
    // copied from 'emacs' keymap
    CodeMirror.keyMap.emacsy['Alt-/'] = 'autocomplete';
    // 'vim' and 'emacs' define their own autocomplete hotkeys
  }
  if (!extraKeysCommands.blockComment) {
    CodeMirror.keyMap.sublime['Shift-Ctrl-/'] = 'blockComment';
  }

  if (navigator.appVersion.includes('Windows')) {
    // 'pcDefault' keymap on Windows should have F3/Shift-F3
    if (!extraKeysCommands.findNext) {
      CodeMirror.keyMap.pcDefault['F3'] = 'findNext';
    }
    if (!extraKeysCommands.findPrev) {
      CodeMirror.keyMap.pcDefault['Shift-F3'] = 'findPrev';
    }

    // try to remap non-interceptable Ctrl-(Shift-)N/T/W hotkeys
    ['N', 'T', 'W'].forEach(char => {
      [
        {from: 'Ctrl-', to: ['Alt-', 'Ctrl-Alt-']},
        // Note: modifier order in CodeMirror is S-C-A
        {from: 'Shift-Ctrl-', to: ['Ctrl-Alt-', 'Shift-Ctrl-Alt-']}
      ].forEach(remap => {
        const oldKey = remap.from + char;
        Object.keys(CodeMirror.keyMap).forEach(keyMapName => {
          const keyMap = CodeMirror.keyMap[keyMapName];
          const command = keyMap[oldKey];
          if (!command) {
            return;
          }
          remap.to.some(newMod => {
            const newKey = newMod + char;
            if (!(newKey in keyMap)) {
              delete keyMap[oldKey];
              keyMap[newKey] = command;
              return true;
            }
          });
        });
      });
    });
  }

  Object.assign(CodeMirror.mimeModes['text/css'].propertyKeywords, {
    'mix-blend-mode': true,
    'isolation': true,
  });
  Object.assign(CodeMirror.mimeModes['text/css'].valueKeywords, {
    'isolate': true,
  });

  const MODE = {
    stylus: 'stylus',
    uso: 'css'
  };

  CodeMirror.defineExtension('setPreprocessor', function (preprocessor, force = false) {
    const mode = MODE[preprocessor] || 'css';
    if ((this.doc.mode || {}).name === mode && !force) {
      return Promise.resolve();
    }
    if (mode === 'css') {
      this.setOption('mode', mode);
      return Promise.resolve();
    }
    return loadScript(`/vendor/codemirror/mode/${mode}/${mode}.js`).then(() => {
      this.setOption('mode', mode);
    });
  });

  CodeMirror.defineExtension('isBlank', function () {
    // superfast checking as it runs only until the first non-blank line
    let isBlank = true;
    this.doc.eachLine(line => {
      if (line.text && line.text.trim()) {
        isBlank = false;
        return true;
      }
    });
    return isBlank;
  });
})();

// eslint-disable-next-line no-unused-expressions
CodeMirror.hint && (() => {
  const USO_VAR = 'uso-variable';
  const USO_VALID_VAR = 'variable-3 ' + USO_VAR;
  const USO_INVALID_VAR = 'error ' + USO_VAR;

  const originalHelper = CodeMirror.hint.css || (() => {});
  CodeMirror.registerHelper('hint', 'css', function (cm) {
    const {line, ch} = cm.getCursor();
    const {styles, text} = cm.getLineHandle(line);
    if (!styles || !editor) {
      return originalHelper(cm);
    }
    let prev = 0;
    for (let i = 1; i < styles.length; i += 2) {
      let end = styles[i];
      if (prev <= ch && ch <= end &&
          (styles[i + 1] || '').includes(USO_VAR)) {
        const adjust = text[prev] === '/' ? 4 : 0;
        prev += adjust;
        end -= adjust;
        const leftPart = text.slice(prev, ch);
        const list = Object.keys(editor.getStyle().usercssData.vars)
          .filter(name => name.startsWith(leftPart));
        return {
          list,
          from: {line, ch: prev},
          to: {line, ch: end},
        };
      }
      prev = end;
    }
    return originalHelper(cm);
  });

  const hooks = CodeMirror.mimeModes['text/css'].tokenHooks;
  const originalCommentHook = hooks['/'];
  hooks['/'] = tokenizeUsoVariables;

  function tokenizeUsoVariables(stream) {
    const token = originalCommentHook.apply(this, arguments);
    if (token[1] !== 'comment') {
      return token;
    }
    const {string, start, pos} = stream;
    // /*[[install-key]]*/
    // 01234          43210
    if (string[start + 2] === '[' &&
        string[start + 3] === '[' &&
        string[pos - 3] === ']' &&
        string[pos - 4] === ']') {
      if (typeof editor !== 'undefined' &&
          Object.hasOwnProperty.call(
            editor.getStyle().usercssData.vars,
            string.slice(start + 4, pos - 4))) {
        token[0] = USO_VALID_VAR;
      } else {
        token[0] = USO_INVALID_VAR;
      }
    }
    return token;
  }
})();