/* global
  createAppliesToLineWidget messageBox
  sectionsToMozFormat
  createMetaCompiler linter createLivePreview cmFactory $ $create API prefs t
  chromeSync */
/* exported createSourceEditor */
'use strict';

function createSourceEditor(editorBase) {
  const {style, dirty} = editorBase;

  $('#mozilla-format-container').remove();
  $('#header').addEventListener('wheel', headerOnScroll);
  $('#sections').textContent = '';
  $('#sections').appendChild($create('.single-editor'));

  // normalize style
  if (!style.id) setupNewStyle(style);

  const cm = cmFactory.create($('.single-editor'), {
    value: style.sourceCode,
  });
  let savedGeneration = cm.changeGeneration();

  const livePreview = createLivePreview(preprocess);
  livePreview.show(Boolean(style.id));

  cm.on('changes', () => {
    dirty.modify('sourceGeneration', savedGeneration, cm.changeGeneration());
    updateLivePreview();
  });

  cm.operation(initAppliesToLineWidget);

  const metaCompiler = createMetaCompiler(cm);
  metaCompiler.onUpdated(meta => {
    style.usercssData = meta;
    style.name = meta.name;
    style.url = meta.homepageURL || style.installationUrl;
    updateMeta();
  });

  updateMeta().then(() => {

    linter.enableForEditor(cm);

    let prevMode = NaN;
    cm.on('optionChange', (cm, option) => {
      if (option !== 'mode') return;
      const mode = getModeName();
      if (mode === prevMode) return;
      prevMode = mode;
      linter.run();
      updateLinterSwitch();
    });

    $('#editor.linter').addEventListener('change', updateLinterSwitch);
    updateLinterSwitch();

    setTimeout(() => {
      if ((document.activeElement || {}).localName !== 'input') {
        cm.focus();
      }
    });
  });

  function preprocess(style) {
    return API.buildUsercss({
      styleId: style.id,
      sourceCode: style.sourceCode,
      assignVars: true
    })
      .then(({style: newStyle}) => {
        delete newStyle.enabled;
        return Object.assign(style, newStyle);
      });
  }

  function updateLivePreview() {
    if (!style.id) {
      return;
    }
    livePreview.update(Object.assign({}, style, {sourceCode: cm.getValue()}));
  }

  function initAppliesToLineWidget() {
    const PREF_NAME = 'editor.appliesToLineWidget';
    const widget = createAppliesToLineWidget(cm);
    widget.toggle(prefs.get(PREF_NAME));
    prefs.subscribe([PREF_NAME], (key, value) => widget.toggle(value));
  }

  function updateLinterSwitch() {
    const el = $('#editor.linter');
    el.value = getCurrentLinter();
    const cssLintOption = $('[value="csslint"]', el);
    const mode = getModeName();
    if (mode !== 'css') {
      cssLintOption.disabled = true;
      cssLintOption.title = t('linterCSSLintIncompatible', mode);
    } else {
      cssLintOption.disabled = false;
      cssLintOption.title = '';
    }
  }

  function getCurrentLinter() {
    const name = prefs.get('editor.linter');
    if (cm.getOption('mode') !== 'css' && name === 'csslint') {
      return 'stylelint';
    }
    return name;
  }

  function setupNewStyle(style) {
    style.sections[0].code = ' '.repeat(prefs.get('editor.tabSize')) +
      `/* ${t('usercssReplaceTemplateSectionBody')} */`;
    let section = sectionsToMozFormat(style);
    if (!section.includes('@-moz-document')) {
      style.sections[0].domains = ['example.com'];
      section = sectionsToMozFormat(style);
    }
    const DEFAULT_CODE = `
      /* ==UserStyle==
      @name           ${''/* a trick to preserve the trailing spaces */}
      @namespace      github.com/openstyles/stylus
      @version        1.0.0
      @description    A new userstyle
      @author         Me
      ==/UserStyle== */
    `.replace(/^\s+/gm, '');

    dirty.clear('sourceGeneration');
    style.sourceCode = '';

    chromeSync.getLZValue('usercssTemplate').then(code => {
      const name = style.name || t('usercssReplaceTemplateName');
      const date = new Date().toLocaleString();
      code = code || DEFAULT_CODE;
      code = code.replace(/@name(\s*)(?=[\r\n])/, (str, space) =>
        `${str}${space ? '' : ' '}${name} - ${date}`);
      // strip the last dummy section if any, add an empty line followed by the section
      style.sourceCode = code.replace(/\s*@-moz-document[^{]*\{[^}]*\}\s*$|\s+$/g, '') + '\n\n' + section;
      cm.startOperation();
      cm.setValue(style.sourceCode);
      cm.clearHistory();
      cm.markClean();
      cm.endOperation();
      dirty.clear('sourceGeneration');
      savedGeneration = cm.changeGeneration();
    });
  }

  function updateMeta() {
    $('#name').value = style.customName || style.name;
    $('#enabled').checked = style.enabled;
    $('#url').href = style.url;
    editorBase.updateName();
    return cm.setPreprocessor((style.usercssData || {}).preprocessor);
  }

  function replaceStyle(newStyle, codeIsUpdated) {
    dirty.clear('name');
    const sameCode = newStyle.sourceCode === cm.getValue();
    if (sameCode) {
      savedGeneration = cm.changeGeneration();
      dirty.clear('sourceGeneration');
    }
    if (codeIsUpdated === false || sameCode) {
      updateEnvironment();
      dirty.clear('enabled');
      updateLivePreview();
      return;
    }

    Promise.resolve(messageBox.confirm(t('styleUpdateDiscardChanges'))).then(ok => {
      if (!ok) return;
      updateEnvironment();
      if (!sameCode) {
        const cursor = cm.getCursor();
        cm.setValue(style.sourceCode);
        cm.setCursor(cursor);
        savedGeneration = cm.changeGeneration();
      }
      if (sameCode) {
        // the code is same but the environment is changed
        updateLivePreview();
      }
      dirty.clear();
    });

    function updateEnvironment() {
      if (style.id !== newStyle.id) {
        history.replaceState({}, '', `?id=${newStyle.id}`);
      }
      sessionStorage.justEditedStyleId = newStyle.id;
      Object.assign(style, newStyle);
      $('#preview-label').classList.remove('hidden');
      updateMeta();
      livePreview.show(Boolean(style.id));
    }
  }

  function save() {
    if (!dirty.isDirty()) return;
    const code = cm.getValue();
    return ensureUniqueStyle(code)
      .then(() => API.editSaveUsercss({
        id: style.id,
        enabled: style.enabled,
        sourceCode: code,
        customName: style.customName,
      }))
      .then(replaceStyle)
      .catch(err => {
        if (err.handled) return;
        const contents = Array.isArray(err) ?
          $create('pre', err.join('\n')) :
          [err.message || String(err)];
        if (Number.isInteger(err.index)) {
          const pos = cm.posFromIndex(err.index);
          const meta = drawLinePointer(pos);

          // save template
          if (err.code === 'missingValue' && meta.includes('@name')) {
            messageBox.confirm(t('usercssReplaceTemplateConfirmation')).then(ok => ok &&
              chromeSync.setLZValue('usercssTemplate', code)
                .then(() => chromeSync.getLZValue('usercssTemplate'))
                .then(saved => saved !== code && messageBox.alert(t('syncStorageErrorSaving'))));
            return;
          }
          contents[0] += ` (line ${pos.line + 1} col ${pos.ch + 1})`;
          contents.push($create('pre', meta));
        }
        messageBox.alert(contents, 'pre');
      });
  }

  function ensureUniqueStyle(code) {
    return style.id ? Promise.resolve() :
      API.buildUsercss({
        sourceCode: code,
        checkDup: true,
        metaOnly: true,
      }).then(({dup}) => {
        if (dup) {
          messageBox.alert(t('usercssAvoidOverwriting'), 'danger', t('genericError'));
          return Promise.reject({handled: true});
        }
      });
  }

  function drawLinePointer(pos) {
    const SIZE = 60;
    const line = cm.getLine(pos.line);
    const numTabs = pos.ch + 1 - line.slice(0, pos.ch + 1).replace(/\t/g, '').length;
    const pointer = ' '.repeat(pos.ch) + '^';
    const start = Math.max(Math.min(pos.ch - SIZE / 2, line.length - SIZE), 0);
    const end = Math.min(Math.max(pos.ch + SIZE / 2, SIZE), line.length);
    const leftPad = start !== 0 ? '...' : '';
    const rightPad = end !== line.length ? '...' : '';
    return (
      leftPad +
      line.slice(start, end).replace(/\t/g, ' '.repeat(cm.options.tabSize)) +
      rightPad +
      '\n' +
      ' '.repeat(leftPad.length + numTabs * cm.options.tabSize) +
      pointer.slice(start, end)
    );
  }

  function nextPrevMozDocument(cm, dir) {
    const MOZ_DOC = '@-moz-document';
    const cursor = cm.getCursor();
    const usePrevLine = dir < 0 && cursor.ch <= MOZ_DOC.length;
    let line = cursor.line + (usePrevLine ? -1 : 0);
    let start = usePrevLine ? 1e9 : cursor.ch + (dir > 0 ? 1 : -MOZ_DOC.length);
    let found;
    if (dir > 0) {
      cm.doc.iter(cursor.line, cm.doc.size, goFind);
      if (!found && cursor.line > 0) {
        line = 0;
        cm.doc.iter(0, cursor.line + 1, goFind);
      }
    } else {
      let handle, parentLines;
      let passesRemain = line < cm.doc.size - 1 ? 2 : 1;
      let stopAtLine = 0;
      while (passesRemain--) {
        let indexInParent = 0;
        while (line >= stopAtLine) {
          if (!indexInParent--) {
            handle = cm.getLineHandle(line);
            parentLines = handle.parent.lines;
            indexInParent = parentLines.indexOf(handle);
          } else {
            handle = parentLines[indexInParent];
          }
          if (goFind(handle)) {
            return true;
          }
        }
        line = cm.doc.size - 1;
        stopAtLine = cursor.line;
      }
    }
    function goFind({text}) {
      // use the initial 'start' on cursor row...
      let ch = start;
      // ...and reset it for the rest
      start = dir > 0 ? 0 : 1e9;
      while (true) {
        // indexOf is 1000x faster than toLowerCase().indexOf() so we're trying it first
        ch = dir > 0 ? text.indexOf('@-', ch) : text.lastIndexOf('@-', ch);
        if (ch < 0) {
          line += dir;
          return;
        }
        if (text.substr(ch, MOZ_DOC.length).toLowerCase() === MOZ_DOC &&
            cm.getTokenTypeAt({line, ch: ch + 1}) === 'def') {
          break;
        }
        ch += dir * 3;
      }
      cm.setCursor(line, ch);
      if (cm.cursorCoords().bottom > cm.display.scroller.clientHeight - 100) {
        const margin = Math.min(100, cm.display.scroller.clientHeight / 4);
        line += prefs.get('editor.appliesToLineWidget') ? 1 : 0;
        cm.scrollIntoView({line, ch}, margin);
      }
      found = true;
      return true;
    }
  }

  function headerOnScroll({target, deltaY, deltaMode, shiftKey}) {
    while ((target = target.parentElement)) {
      if (deltaY < 0 && target.scrollTop ||
          deltaY > 0 && target.scrollTop + target.clientHeight < target.scrollHeight) {
        return;
      }
    }
    cm.display.scroller.scrollTop +=
      // WheelEvent.DOM_DELTA_LINE
      deltaMode === 1 ? deltaY * cm.defaultTextHeight() :
      // WheelEvent.DOM_DELTA_PAGE
      deltaMode === 2 || shiftKey ? Math.sign(deltaY) * cm.display.scroller.clientHeight :
      // WheelEvent.DOM_DELTA_PIXEL
      deltaY;
  }

  function getModeName() {
    const mode = cm.doc.mode;
    if (!mode) return '';
    return (mode.name || mode || '') +
           (mode.helperType || '');
  }

  return Object.assign({}, editorBase, {
    ready: Promise.resolve(),
    replaceStyle,
    getEditors: () => [cm],
    scrollToEditor: () => {},
    getEditorTitle: () => '',
    save,
    prevEditor: cm => nextPrevMozDocument(cm, -1),
    nextEditor: cm => nextPrevMozDocument(cm, 1),
    closestVisible: () => cm,
    getSearchableInputs: () => [],
    updateLivePreview,
  });
}