/* globals hljs, ClipboardJS, showdown */
/* TODO
- URL should match code. e.g. go to biden, change colors, go to ava. Biden's colors are in URL
*/
async function init() {
  const response = await fetch("dist/characterlist.json");
  const chars = await response.json();

  // Current values of character name and parent attributes. If these change, menu should be redrawn
  let current = {};

  // Return the menu dropdowns given a selection (q).
  // Result = {label: [option, option, ...], label: [...]}
  const options = function (q) {
    let result = { name: Object.keys(chars) };
    const char = chars[q.name] || Object.values(chars)[0];
    current = { name: char };
    // If the character is a template, i.e. uses other characters, index.json/lookup defines
    // dropdowns for each parameter. For example:
    //    "dee_emotion": { "select": "emotion", "from": "dee", "where": { "angle": "side" } }
    // ... means that ?dee_emotion= is picked up from the "emotion" dropdown from character "dee".
    // TODO: Not yet implemented
    _.each(char.lookups, (lookup, key) => {
      let filter = { name: lookup.from };
      _.each(lookup.where, (filter_val, filter_key) => {
        if (filter_val.expr) {
          // TODO: Don't hard-code side
          let expr = new Function("q", `return q["${filter_val.expr}"] || 'side'`);
          filter[filter_key] = expr(q);
        } else {
          filter[filter_key] = filter_val;
        }
      });
      result[key] = options(filter)[lookup.select];
    });
    // If the character is a basic character, i.e. its made of files under its own directory,
    // index.json/patterns defines dropdowns for each parameter.
    char.patterns.forEach((pattern) => {
      let node = char.files;
      let hierarchy = [];
      // Split each pattern by "/" like the directory structure
      for (const dir of pattern.split(/\s*\/\s*/)) {
        // (Recursively) loop through each directory
        if (dir.match(/\{\{/)) {
          // If dir is a variable (e.g. "{{face}}" or "{{face}}.svg"), get all matching keys, filter by current/first option
          let key = dir.slice(2, -2);
          result[key] = Object.keys(node);
          hierarchy.push(key);
          node = node[q[key]] || Object.values(node)[0];
        } else {
          // If dir is a value (e.g. "face"), filter all nodes
          node = node[dir];
        }
      }
      // When a parent in the dropdown hierarchy changes, redraw the menu.
      // e.g. in {{angle}}/pose/{{pose}}.svg, if angle changes, redraw for new poses.
      hierarchy.slice(0, -1).forEach((key) => (current[key] = ""));
    });
    return result;
  };

  const menu_template = _.template(document.querySelector("#menu-template").innerHTML);
  const code_template = _.template(document.querySelector("#codegen").innerHTML);
  const $codetemp = document.querySelector("#codetemp");
  const $menu = document.querySelector("#menu");
  const $character = document.querySelector("#character .target");
  // ID of the dropdown that last triggered a change. Useful to re-focus on it if menu is redrawn
  let trigger_id = "";
  // Current background color. When the menu is redrawn, preserve this color on the page
  let state = { bgcolor: "#ffffff" };
  const config = {
    typeclass: {
      color: "form-control-color",
      number: "form-control-number",
      range: "form-range d-inline-block my-2 border-0",
    },
  };

  function getParams() {
    let params = new URLSearchParams();
    for (let node of $menu.querySelectorAll("select, input")) params.append(node.name, node.value);
    return params;
  }

  function bg_color(e) {
    if (e.target.classList.contains("bg-color"))
      // The first rule in the first sheet defines the background color for the target-container
      state.bgcolor = document.styleSheets[0].cssRules[0].style.backgroundColor = e.target.value;
  }

  // Render the document based on query parameters
  async function render() {
    let q = g1.url.parse(location.hash.replace(/^#/, "?")).searchKey;
    // If the name or parent keys have changed, re-render the menu
    const menu_change = !current.name || _.some(current, (val, key) => current[key] != q[key]);
    // If the menu has changed, re-render the menu
    if (menu_change) {
      let opt = options(q);
      $menu.innerHTML = menu_template({ q, chars, config, options: opt });
      for (let key in current) current[key] = q[key];
    }
    let params = getParams();
    const response = await fetch("comic?" + params);
    $character.innerHTML = await response.text();
    $codetemp.innerHTML = code_template({
      url: location.origin + location.pathname + "comic?" + params || "",
      state,
      code_template,
    });
    if (trigger_id) document.querySelector(`#${trigger_id}`).focus();
  }

  // When location hash changes (or initially), re-render
  window.addEventListener("hashchange", render, false);
  render();

  // When inputs change, change location hash -- but no oftener than 200ms
  let delay = 200;
  let lastUpdated = 0;
  let event, timeout;
  $menu.addEventListener("input", (e) => {
    event = { hash: getParams(), id: e.target.id };
    let diff = +new Date() - lastUpdated;
    if (diff < delay) {
      if (timeout) clearTimeout(timeout);
      timeout = setTimeout(updateURL, diff);
      return;
    }
    updateURL();
  });

  function updateURL() {
    location.hash = event.hash;
    trigger_id = event.id;
    lastUpdated = +new Date();
  }

  document.body.addEventListener("input", bg_color, false);
  document.body.addEventListener("change", bg_color, false);

  new ClipboardJS(".copy");
}
init();

// Render part of README.md as Markdown. Sections delimited by <!-- var ... !>...<!-- end -->
$.get("README.md").done(function (text) {
  let converter = new showdown.Converter({ ghCodeBlocks: true, tables: true });
  text.match(/<!--\s*var\s+\S*\s*-->[\s\S]*?<!--\s*end\s*-->/gim).forEach(function (match) {
    let lines = match.split(/\n/);
    let name = lines[0].replace(/^<!--\s*var\s+/, "").replace(/\s*-->$/, "");
    $('md[data-target="' + name + '"]')
      .addClass("d-block my-4")
      .html(converter.makeHtml(lines.slice(1, -1).join("\n")))
      .find("pre")
      .each(function () {
        hljs.highlightBlock(this);
      });
  });
  $("md table")
    .addClass("table table-sm")
    .find("a")
    .each(function () {
      $(this).attr("target", "_blank");
    });
});