/* global Diff2HtmlUI */

/*
 * Example URLs:
 *
 * https://github.com/rtfpessoa/diff2html/commit/7d02e67f3b3386ac5d804f974d025cd7a1165839
 * https://github.com/rtfpessoa/diff2html/pull/106
 *
 * https://gitlab.com/gitlab-org/gitlab-ce/commit/4e963fed42ad518caa7353d361a38a1250c99c41
 * https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6763
 *
 * https://bitbucket.org/atlassian/amps/commits/52c38116f12475f75af4a147b7a7685478b83eca
 * https://bitbucket.org/atlassian/amps/pull-requests/236
 */

$(document).ready(function() {
  // Improves browser compatibility
  require("whatwg-fetch");

  const searchParam = "diff";

  const $container = $(".container");
  const $url = $("#url");
  const $outputFormat = $("#diff-url-options-output-format");
  const $showFiles = $("#diff-url-options-show-files");
  const $matching = $("#diff-url-options-matching");
  const $wordsThreshold = $("#diff-url-options-match-words-threshold");
  const $matchingMaxComparisons = $("#diff-url-options-matching-max-comparisons");

  if (window.location.search) {
    const url = getUrlFromSearch(window.location.search);
    $url.val(url);
    smartDraw(url);
  }

  bind();

  $outputFormat
    .add($showFiles)
    .add($matching)
    .add($wordsThreshold)
    .add($matchingMaxComparisons)
    .change(function(e) {
      console.log("");
      console.log(e);
      console.log("");
      smartDraw(null, true);
    });

  function getUrlFromSearch(search) {
    try {
      return search
        .split("?")[1]
        .split(searchParam + "=")[1]
        .split("&")[0];
    } catch (_ignore) {}

    return null;
  }

  function getParamsFromSearch(search) {
    const map = {};
    try {
      search
        .split("?")[1]
        .split("&")
        .map(function(e) {
          const values = e.split("=");
          map[values[0]] = values[1];
        });
    } catch (_ignore) {}

    return map;
  }

  function bind() {
    $("#url-btn").click(function(e) {
      e.preventDefault();
      const url = $url.val();
      smartDraw(url);
    });

    $url.on("paste", function(e) {
      const url = e.originalEvent.clipboardData.getData("Text");
      smartDraw(url);
    });
  }

  function prepareUrl(url) {
    let fetchUrl;
    const headers = new Headers();

    const githubCommitUrl = /^https?:\/\/(?:www\.)?github\.com\/(.*?)\/(.*?)\/commit\/(.*?)(?:\.diff)?(?:\.patch)?(?:\/.*)?$/;
    const githubPrUrl = /^https?:\/\/(?:www\.)?github\.com\/(.*?)\/(.*?)\/pull\/(.*?)(?:\.diff)?(?:\.patch)?(?:\/.*)?$/;

    const gitlabCommitUrl = /^https?:\/\/(?:www\.)?gitlab\.com\/(.*?)\/(.*?)\/commit\/(.*?)(?:\.diff)?(?:\.patch)?(?:\/.*)?$/;
    const gitlabPrUrl = /^https?:\/\/(?:www\.)?gitlab\.com\/(.*?)\/(.*?)\/merge_requests\/(.*?)(?:\.diff)?(?:\.patch)?(?:\/.*)?$/;

    const bitbucketCommitUrl = /^https?:\/\/(?:www\.)?bitbucket\.org\/(.*?)\/(.*?)\/commits\/(.*?)(?:\/raw)?(?:\/.*)?$/;
    const bitbucketPrUrl = /^https?:\/\/(?:www\.)?bitbucket\.org\/(.*?)\/(.*?)\/pull-requests\/(.*?)(?:\/.*)?$/;

    function gitLabUrlGen(userName, projectName, type, value) {
      return (
        "https://crossorigin.me/https://gitlab.com/" + userName + "/" + projectName + "/" + type + "/" + value + ".diff"
      );
    }

    function gitHubUrlGen(userName, projectName, type, value) {
      headers.append("Accept", "application/vnd.github.v3.diff");
      return "https://api.github.com/repos/" + userName + "/" + projectName + "/" + type + "/" + value;
    }

    function bitbucketUrlGen(userName, projectName, type, value) {
      const baseUrl = "https://bitbucket.org/api/2.0/repositories/";
      if (type === "pullrequests") {
        return baseUrl + userName + "/" + projectName + "/pullrequests/" + value + "/diff";
      }
      return baseUrl + userName + "/" + projectName + "/diff/" + value;
    }

    let values;
    if ((values = githubCommitUrl.exec(url))) {
      fetchUrl = gitHubUrlGen(values[1], values[2], "commits", values[3]);
    } else if ((values = githubPrUrl.exec(url))) {
      fetchUrl = gitHubUrlGen(values[1], values[2], "pulls", values[3]);
    } else if ((values = gitlabCommitUrl.exec(url))) {
      fetchUrl = gitLabUrlGen(values[1], values[2], "commit", values[3]);
    } else if ((values = gitlabPrUrl.exec(url))) {
      fetchUrl = gitLabUrlGen(values[1], values[2], "merge_requests", values[3]);
    } else if ((values = bitbucketCommitUrl.exec(url))) {
      fetchUrl = bitbucketUrlGen(values[1], values[2], "commit", values[3]);
    } else if ((values = bitbucketPrUrl.exec(url))) {
      fetchUrl = bitbucketUrlGen(values[1], values[2], "pullrequests", values[3]);
    } else {
      console.info("Could not parse url, using the provided url.");
      fetchUrl = "https://crossorigin.me/" + url;
    }

    return {
      originalUrl: url,
      url: fetchUrl,
      headers: headers
    };
  }

  function smartDraw(urlOpt, forced) {
    const url = urlOpt || $url.val();
    const req = prepareUrl(url);
    draw(req, forced);
  }

  function draw(req, forced) {
    if (!validateUrl(req.url)) {
      console.error("Invalid url provided!");
      return;
    }

    if (validateUrl(req.originalUrl)) updateUrl(req.originalUrl);

    const outputFormat = $outputFormat.val();
    const showFiles = $showFiles.is(":checked");
    const matching = $matching.val();
    const wordsThreshold = $wordsThreshold.val();
    const matchingMaxComparisons = $matchingMaxComparisons.val();

    fetch(req.url, {
      method: "GET",
      headers: req.headers,
      mode: "cors",
      cache: "default"
    })
      .then(function(res) {
        return res.text();
      })
      .then(function(data) {
        const container = "#url-diff-container";
        const diff2htmlUi = new Diff2HtmlUI({ diff: data });

        if (outputFormat === "side-by-side") {
          $container.css({ width: "100%" });
        } else {
          $container.css({ width: "" });
        }

        const params = getParamsFromSearch(window.location.search);
        delete params[searchParam];

        if (forced) {
          params.outputFormat = outputFormat;
          params.showFiles = showFiles;
          params.matching = matching;
          params.wordsThreshold = wordsThreshold;
          params.matchingMaxComparisons = matchingMaxComparisons;
        } else {
          params.outputFormat = params.outputFormat || outputFormat;
          params.showFiles = String(params.showFiles) !== "false" || (params.showFiles === null && showFiles);
          params.matching = params.matching || matching;
          params.wordsThreshold = params.wordsThreshold || wordsThreshold;
          params.matchingMaxComparisons = params.matchingMaxComparisons || matchingMaxComparisons;

          $outputFormat.val(params.outputFormat);
          $showFiles.prop("checked", params.showFiles);
          $matching.val(params.matching);
          $wordsThreshold.val(params.wordsThreshold);
          $matchingMaxComparisons.val(params.matchingMaxComparisons);
        }

        params.synchronisedScroll = params.synchronisedScroll || true;

        diff2htmlUi.draw(container, params);
        diff2htmlUi.fileListCloseable(container, params.fileListCloseable || false);
        if (params.highlight === undefined || params.highlight) {
          diff2htmlUi.highlightCode(container);
        }
      });
  }

  function validateUrl(url) {
    return /^(?:(?:(?:https?|ftp):)?\/\/)(?:\S+(?::\S*)?@)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,})).?)(?::\d{2,5})?(?:[/?#]\S*)?$/i.test(
      url
    );
  }

  function updateUrl(url) {
    const params = getParamsFromSearch(window.location.search);

    if (params[searchParam] === url) return;

    params[searchParam] = url;

    const paramString = Object.keys(params)
      .map(function(k) {
        return k + "=" + params[k];
      })
      .join("&");

    window.location = "demo.html?" + paramString;
  }
});