/* global $ $$remove $create $isTextInput messageBoxProxy */// dom.js
/* global API */// msg.js
/* global CodeMirror */
/* global MozDocMapper */// util.js
/* global MozSectionFinder */
/* global MozSectionWidget */
/* global URLS debounce sessionStore */// toolbox.js
/* global chromeSync */// storage-util.js
/* global cmFactory */
/* global editor */
/* global linterMan */
/* global prefs */
/* global t */// localization.js
'use strict';

/* exported SourceEditor */
function SourceEditor() {
  const {style, /** @type DirtyReporter */dirty} = editor;
  let savedGeneration;
  let placeholderName = '';
  let prevMode = NaN;

  $$remove('.sectioned-only');
  $('#header').on('wheel', headerOnScroll);
  $('#sections').textContent = '';
  $('#sections').appendChild($create('.single-editor'));

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

  const cm = cmFactory.create($('.single-editor'));
  const sectionFinder = MozSectionFinder(cm);
  const sectionWidget = MozSectionWidget(cm, sectionFinder);
  editor.livePreview.init(preprocess, style.id);
  createMetaCompiler(meta => {
    style.usercssData = meta;
    style.name = meta.name;
    style.url = meta.homepageURL || style.installationUrl;
    updateMeta();
  });
  updateMeta();
  cm.setValue(style.sourceCode);

  /** @namespace Editor */
  Object.assign(editor, {
    sections: sectionFinder.sections,
    replaceStyle,
    updateLivePreview,
    closestVisible: () => cm,
    getEditors: () => [cm],
    getEditorTitle: () => '',
    getSearchableInputs: () => [],
    prevEditor: nextPrevSection.bind(null, -1),
    nextEditor: nextPrevSection.bind(null, 1),
    jumpToEditor(i) {
      const sec = sectionFinder.sections[i];
      if (sec) {
        sectionFinder.updatePositions(sec);
        cm.jumpToPos(sec.start);
      }
    },
    async save() {
      if (!dirty.isDirty()) return;
      const sourceCode = cm.getValue();
      try {
        const {customName, enabled, id} = style;
        if (!id &&
          (await API.usercss.build({sourceCode, checkDup: true, metaOnly: true})).dup) {
          messageBoxProxy.alert(t('usercssAvoidOverwriting'), 'danger', t('genericError'));
        } else {
          await replaceStyle(
            await API.usercss.editSave({customName, enabled, id, sourceCode}));
        }
      } catch (err) {
        const i = err.index;
        const isNameEmpty = i > 0 &&
          err.code === 'missingValue' &&
          sourceCode.slice(sourceCode.lastIndexOf('\n', i - 1), i).trim().endsWith('@name');
        return isNameEmpty
          ? saveTemplate(sourceCode)
          : showSaveError(err);
      }
    },
    scrollToEditor: () => {},
  });

  prefs.subscribeMany({
    'editor.linter': updateLinterSwitch,
    'editor.appliesToLineWidget': (k, val) => sectionWidget.toggle(val),
    'editor.toc.expanded': (k, val) => sectionFinder.onOff(editor.updateToc, val),
  }, {runNow: true});

  editor.applyScrollInfo(cm);
  cm.clearHistory();
  cm.markClean();
  savedGeneration = cm.changeGeneration();
  cm.on('changes', () => {
    dirty.modify('sourceGeneration', savedGeneration, cm.changeGeneration());
    debounce(updateLivePreview, editor.previewDelay);
  });
  cm.on('optionChange', (cm, option) => {
    if (option !== 'mode') return;
    const mode = getModeName();
    if (mode === prevMode) return;
    prevMode = mode;
    linterMan.run();
    updateLinterSwitch();
  });
  setTimeout(linterMan.enableForEditor, 0, cm);
  if (!$isTextInput(document.activeElement)) {
    cm.focus();
  }

  async function preprocess(style) {
    const {style: newStyle} = await API.usercss.build({
      styleId: style.id,
      sourceCode: style.sourceCode,
      assignVars: true,
    });
    delete newStyle.enabled;
    return Object.assign(style, newStyle);
  }

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

  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;
  }

  async function setupNewStyle(style) {
    style.sections[0].code = ' '.repeat(prefs.get('editor.tabSize')) +
      `/* ${t('usercssReplaceTemplateSectionBody')} */`;
    let section = MozDocMapper.styleToCss(style);
    if (!section.includes('@-moz-document')) {
      style.sections[0].domains = ['example.com'];
      section = MozDocMapper.styleToCss(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 = '';

    placeholderName = `${style.name || t('usercssReplaceTemplateName')} - ${new Date().toLocaleString()}`;
    let code = await chromeSync.getLZValue(chromeSync.LZ_KEY.usercssTemplate);
    code = code || DEFAULT_CODE;
    code = code.replace(/@name(\s*)(?=[\r\n])/, (str, space) =>
      `${str}${space ? '' : ' '}${placeholderName}`);
    // 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() {
    const name = style.customName || style.name;
    if (name !== placeholderName) {
      $('#name').value = name;
    }
    $('#enabled').checked = style.enabled;
    $('#url').href = style.url;
    editor.updateName();
    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(messageBoxProxy.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}`);
      }
      sessionStore.justEditedStyleId = newStyle.id;
      Object.assign(style, newStyle);
      $('#preview-label').classList.remove('hidden');
      updateMeta();
      editor.livePreview.toggle(Boolean(style.id));
    }
  }

  async function saveTemplate(code) {
    if (await messageBoxProxy.confirm(t('usercssReplaceTemplateConfirmation'))) {
      const key = chromeSync.LZ_KEY.usercssTemplate;
      await chromeSync.setLZValue(key, code);
      if (await chromeSync.getLZValue(key) !== code) {
        messageBoxProxy.alert(t('syncStorageErrorSaving'));
      }
    }
  }

  function showSaveError(err) {
    err = Array.isArray(err) ? err : [err];
    const text = err.map(e => e.message || e).join('\n');
    const points = err.map(e =>
      e.index >= 0 && cm.posFromIndex(e.index) || // usercss meta parser
      e.offset >= 0 && {line: e.line - 1, ch: e.col - 1} // csslint code parser
    ).filter(Boolean);
    cm.setSelections(points.map(p => ({anchor: p, head: p})));
    messageBoxProxy.alert($create('pre', text), 'pre');
  }

  function nextPrevSection(dir) {
    // ensure the data is ready in case the user wants to jump around a lot in a large style
    sectionFinder.keepAliveFor(nextPrevSection, 10e3);
    sectionFinder.updatePositions();
    const {sections} = sectionFinder;
    const num = sections.length;
    if (!num) return;
    dir = dir < 0 ? -1 : 0;
    const pos = cm.getCursor();
    let i = sections.findIndex(sec => CodeMirror.cmpPos(sec.start, pos) > Math.min(dir, 0));
    if (i < 0 && (!dir || CodeMirror.cmpPos(sections[num - 1].start, pos) < 0)) {
      i = 0;
    }
    cm.jumpToPos(sections[(i + dir + num) % num].start);
  }

  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 || '');
  }

  function createMetaCompiler(onUpdated) {
    let meta = null;
    let metaIndex = null;
    let cache = [];
    linterMan.register(async (text, options, _cm) => {
      if (_cm !== cm) {
        return;
      }
      const match = text.match(URLS.rxMETA);
      if (!match) {
        return [];
      }
      if (match[0] === meta && match.index === metaIndex) {
        return cache;
      }
      const {metadata, errors} = await linterMan.worker.metalint(match[0]);
      if (errors.every(err => err.code === 'unknownMeta')) {
        onUpdated(metadata);
      }
      cache = errors.map(err => ({
        from: cm.posFromIndex((err.index || 0) + match.index),
        to: cm.posFromIndex((err.index || 0) + match.index),
        message: err.code && t(`meta_${err.code}`, err.args, false) || err.message,
        severity: err.code === 'unknownMeta' ? 'warning' : 'error',
        rule: err.code,
      }));
      meta = match[0];
      metaIndex = match.index;
      return cache;
    });
  }
}