/* global CodeMirror semverCompare closeCurrentTab */
/* global messageBox download chromeLocal */
'use strict';

(() => {
  // TODO: remove .replace(/^\?/, '') when minimum_chrome_version >= 52 (https://crbug.com/601425)
  const params = new URLSearchParams(location.search.replace(/^\?/, ''));
  let liveReload = false;
  let installed = false;

  const tabId = Number(params.get('tabId'));
  let port;

  if (params.has('direct')) {
    $('.live-reload').remove();
    getCodeDirectly();
  } else {
    port = chrome.tabs.connect(tabId);
    port.postMessage({method: 'getSourceCode'});
    port.onMessage.addListener(msg => {
      switch (msg.method) {
        case 'getSourceCodeResponse':
          if (msg.error) {
            messageBox.alert(msg.error);
          } else {
            initSourceCode(msg.sourceCode);
          }
          break;
        case 'sourceCodeChanged':
          if (msg.error) {
            messageBox.alert(msg.error);
          } else {
            liveReloadUpdate(msg.sourceCode);
          }
          break;
      }
    });
    port.onDisconnect.addListener(closeCurrentTab);
  }

  const cm = CodeMirror($('.main'), {readOnly: true});
  let liveReloadPending = Promise.resolve();
  window.addEventListener('resize', adjustCodeHeight);

  setTimeout(() => {
    if (!installed) {
      $('.header').appendChild($create('.lds-spinner',
        new Array(12).fill($create('div')).map(e => e.cloneNode())));
    }
  }, 200);

  function liveReloadUpdate(sourceCode) {
    liveReloadPending = liveReloadPending.then(() => {
      const scrollInfo = cm.getScrollInfo();
      const cursor = cm.getCursor();
      cm.setValue(sourceCode);
      cm.setCursor(cursor);
      cm.scrollTo(scrollInfo.left, scrollInfo.top);

      return sendMessage({
        id: installed.id,
        method: 'saveUsercss',
        reason: 'update',
        sourceCode
      }).then(updateMeta)
        .catch(showError);
    });
  }

  function updateMeta(style, dup) {
    const data = style.usercssData;
    const dupData = dup && dup.usercssData;
    const versionTest = dup && semverCompare(data.version, dupData.version);

    // update editor
    cm.setPreprocessor(data.preprocessor);

    // update metas
    document.title = `${installButtonLabel()} ${data.name}`;

    $('.install').textContent = installButtonLabel();
    $('.install').classList.add(installButtonClass());
    $('.set-update-url').title = dup && dup.updateUrl && t('installUpdateFrom', dup.updateUrl) || '';
    $('.meta-name').textContent = data.name;
    $('.meta-version').textContent = data.version;
    $('.meta-description').textContent = data.description;

    if (data.author) {
      $('.meta-author').parentNode.style.display = '';
      $('.meta-author').textContent = '';
      $('.meta-author').appendChild(makeAuthor(data.author));
    } else {
      $('.meta-author').parentNode.style.display = 'none';
    }

    $('.meta-license').parentNode.style.display = data.license ? '' : 'none';
    $('.meta-license').textContent = data.license;

    $('.applies-to').textContent = '';
    getAppliesTo(style).forEach(pattern =>
      $('.applies-to').appendChild($create('li', pattern)));

    $('.external-link').textContent = '';
    const externalLink = makeExternalLink();
    if (externalLink) {
      $('.external-link').appendChild(externalLink);
    }

    $('.header').classList.add('meta-init');
    $('.header').classList.remove('meta-init-error');
    setTimeout(() => $.remove('.lds-spinner'), 1000);

    showError('');
    requestAnimationFrame(adjustCodeHeight);

    function makeAuthor(text) {
      const match = text.match(/^(.+?)(?:\s+<(.+?)>)?(?:\s+\((.+?)\))$/);
      if (!match) {
        return document.createTextNode(text);
      }
      const [, name, email, url] = match;
      const frag = document.createDocumentFragment();
      if (email) {
        frag.appendChild($createLink(`mailto:${email}`, name));
      } else {
        frag.appendChild($create('span', name));
      }
      if (url) {
        frag.appendChild($createLink(url,
          $create('SVG:svg.svg-icon', {viewBox: '0 0 20 20'},
            $create('SVG:path', {
              d: 'M4,4h5v2H6v8h8v-3h2v5H4V4z M11,3h6v6l-2-2l-4,4L9,9l4-4L11,3z'
            }))
        ));
      }
      return frag;
    }

    function makeExternalLink() {
      const urls = [
        data.homepageURL && [data.homepageURL, t('externalHomepage')],
        data.supportURL && [data.supportURL, t('externalSupport')],
      ];
      return (data.homepageURL || data.supportURL) && (
        $create('div', [
          $create('h3', t('externalLink')),
          $create('ul', urls.map(args => args &&
            $create('li',
              $createLink(...args)
            )
          ))
        ]));
    }

    function installButtonClass() {
      return installed ? 'installed' :
        !dup ? 'install' :
        versionTest > 0 ? 'update' : 'reinstall';
    }

    function installButtonLabel() {
      return t(
        installed ? 'installButtonInstalled' :
        !dup ? 'installButton' :
        versionTest > 0 ? 'installButtonUpdate' : 'installButtonReinstall'
      );
    }
  }

  function showError(err) {
    $('.warnings').textContent = '';
    if (err) {
      $('.warnings').appendChild(buildWarning(err));
    }
    $('.warnings').classList.toggle('visible', Boolean(err));
    $('.container').classList.toggle('has-warnings', Boolean(err));
    adjustCodeHeight();
  }

  function install(style) {
    installed = style;

    $$.remove('.warning');
    $('button.install').disabled = true;
    $('button.install').classList.add('installed');
    $('h2.installed').classList.add('active');
    $('.set-update-url input[type=checkbox]').disabled = true;
    $('.set-update-url').title = style.updateUrl ?
      t('installUpdateFrom', style.updateUrl) : '';

    updateMeta(style);

    if (!liveReload && !prefs.get('openEditInWindow')) {
      chrome.tabs.update({url: '/edit.html?id=' + style.id});
    } else {
      BG.openEditor(style.id);
      if (!liveReload) {
        closeCurrentTab();
      }
    }

    window.dispatchEvent(new CustomEvent('installed'));
  }

  function initSourceCode(sourceCode) {
    cm.setValue(sourceCode);
    cm.refresh();
    BG.usercssHelper.build(BG.deepCopy({sourceCode, checkDup: true}))
      .then(r => init(deepCopy(r)))
      .catch(err => {
        $('.header').classList.add('meta-init-error');
        showError(err);
      });
  }

  function buildWarning(err) {
    const contents = Array.isArray(err) ?
      $create('pre', err.join('\n')) :
      [err && err.message || err || 'Unknown error'];
    if (Number.isInteger(err.index)) {
      const pos = cm.posFromIndex(err.index);
      contents[0] = `${pos.line + 1}:${pos.ch + 1} ` + contents[0];
      contents.push($create('pre', drawLinePointer(pos)));
      setTimeout(() => {
        cm.scrollIntoView({line: pos.line + 1, ch: pos.ch}, window.innerHeight / 4);
        cm.setCursor(pos.line, pos.ch + 1);
        cm.focus();
      });
    }
    return $create('.warning', [
      t('parseUsercssError'),
      '\n',
      ...contents,
    ]);
  }

  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 init({style, dup}) {
    const data = style.usercssData;
    const dupData = dup && dup.usercssData;
    const versionTest = dup && semverCompare(data.version, dupData.version);

    updateMeta(style, dup);

    // update UI
    if (versionTest < 0) {
      $('.actions').parentNode.insertBefore(
        $create('.warning', t('versionInvalidOlder')),
        $('.actions')
      );
    }
    $('button.install').onclick = () => {
      (!dup ?
        Promise.resolve(true) :
        messageBox.confirm(t('styleInstallOverwrite', [
          data.name,
          dupData.version,
          data.version,
        ]))
      ).then(ok => ok &&
        BG.usercssHelper.save(BG.deepCopy(Object.assign(style, dup && {reason: 'update'})))
          .then(r => install(deepCopy(r)))
          .catch(err => messageBox.alert(t('styleInstallFailed', err)))
      );
    };

    // set updateUrl
    const setUpdate = $('.set-update-url input[type=checkbox]');
    const updateUrl = new URL(params.get('updateUrl'));
    $('.set-update-url > span').textContent = t('installUpdateFromLabel');
    if (dup && dup.updateUrl === updateUrl.href) {
      setUpdate.checked = true;
      // there is no way to "unset" updateUrl, you can only overwrite it.
      setUpdate.disabled = true;
    } else if (updateUrl.protocol !== 'file:') {
      setUpdate.checked = true;
      style.updateUrl = updateUrl.href;
    }
    setUpdate.onchange = e => {
      if (e.target.checked) {
        style.updateUrl = updateUrl.href;
      } else {
        delete style.updateUrl;
      }
    };

    if (!port) {
      return;
    }

    // live reload
    const setLiveReload = $('.live-reload input[type=checkbox]');
    if (updateUrl.protocol !== 'file:') {
      setLiveReload.parentNode.remove();
    } else {
      setLiveReload.addEventListener('change', () => {
        liveReload = setLiveReload.checked;
        if (installed) {
          const method = 'liveReload' + (liveReload ? 'Start' : 'Stop');
          port.postMessage({method});
        }
      });
      window.addEventListener('installed', () => {
        if (liveReload) {
          port.postMessage({method: 'liveReloadStart'});
        }
      });
    }
  }

  function getAppliesTo(style) {
    function *_gen() {
      for (const section of style.sections) {
        for (const type of ['urls', 'urlPrefixes', 'domains', 'regexps']) {
          if (section[type]) {
            yield *section[type];
          }
        }
      }
    }
    const result = [..._gen()];
    if (!result.length) {
      result.push(chrome.i18n.getMessage('appliesToEverything'));
    }
    return result;
  }

  function adjustCodeHeight() {
    // Chrome-only bug (apparently): it doesn't limit the scroller element height
    const scroller = cm.display.scroller;
    const prevWindowHeight = adjustCodeHeight.prevWindowHeight;
    if (scroller.scrollHeight === scroller.clientHeight ||
        prevWindowHeight && window.innerHeight !== prevWindowHeight) {
      adjustCodeHeight.prevWindowHeight = window.innerHeight;
      cm.setSize(null, $('.main').offsetHeight - $('.warnings').offsetHeight);
    }
  }

  function getCodeDirectly() {
    // FF applies page CSP even to content scripts, https://bugzil.la/1267027
    // To circumvent that, the bg process downloads the code directly
    const key = 'tempUsercssCode' + tabId;
    chrome.storage.local.get(key, data => {
      const code = data && data[key];

      // bg already downloaded the code
      if (typeof code === 'string') {
        initSourceCode(code);
        chrome.storage.local.remove(key);
        return;
      }

      // bg still downloads the code
      if (code && code.loading) {
        const waitForCodeInStorage = (changes, area) => {
          if (area === 'local' && key in changes) {
            initSourceCode(changes[key].newValue);
            chrome.storage.onChanged.removeListener(waitForCodeInStorage);
            chrome.storage.local.remove(key);
          }
        };
        chrome.storage.onChanged.addListener(waitForCodeInStorage);
        return;
      }

      // on the off-chance dbExecChromeStorage.getAll ran right after bg download was saved
      download(params.get('updateUrl'))
        .then(initSourceCode)
        .catch(err => messageBox.alert(t('styleInstallFailed', String(err))));
    });
  }
})();