// This file originates from
// https://github.com/webxdc/hello/blob/master/webxdc.js
// It's a stub `webxdc.js` that adds a webxdc API stub for easy testing in
// browsers. In an actual webxdc environment (e.g. Delta Chat messenger) this
// file is not used and will automatically be replaced with a real one.
// See https://docs.webxdc.org/spec.html#webxdc-api
let ephemeralUpdateKey = "__xdcEphemeralUpdateKey__";

/**
 * @typedef {import('./webxdc.d.ts').RealtimeListener} RT
 * @type {RT}
 */
class RealtimeListener {
  constructor() {
    this.listener = null;
    this.trashed = false;
  }

  is_trashed() {
    return this.trashed;
  }

  receive(data) {
    if (this.trashed) {
      throw new Error("realtime listener is trashed and can no longer be used");
    }
    if (this.listener) {
      this.listener(data);
    }
  }

  setListener(listener) {
    this.listener = listener;
  }

  send(data) {
    if (!data instanceof Uint8Array) {
      throw new Error("realtime listener data must be a Uint8Array");
    }
    window.localStorage.setItem(
      ephemeralUpdateKey,
      JSON.stringify([window.webxdc.selfAddr, Array.from(data), Date.now()]) // Date.now() is needed to trigger the event
    );
  }

  leave() {
    this.trashed = true;
  }
}

// debug friend: document.writeln(JSON.stringify(value));
//@ts-check
/** @type {import('./webxdc').Webxdc<any>} */
window.webxdc = (() => {
  var updateListener = (_) => {};
  /**
   * @type {RT | null}
   */
  var realtimeListener = null;
  var updatesKey = "__xdcUpdatesKey__";
  window.addEventListener("storage", (event) => {
    if (event.key == null) {
      window.location.reload();
    } else if (event.key === updatesKey) {
      var updates = JSON.parse(event.newValue);
      var update = updates[updates.length - 1];
      update.max_serial = updates.length;
      console.log("[Webxdc] " + JSON.stringify(update));
      updateListener(update);
    } else if (event.key === ephemeralUpdateKey) {
      var [sender, update] = JSON.parse(event.newValue);
      if (window.webxdc.selfAddr !== sender && realtimeListener && !realtimeListener.is_trashed()) {
        realtimeListener.receive( Uint8Array.from(update));
      }
    }
  });

  function getUpdates() {
    var updatesJSON = window.localStorage.getItem(updatesKey);
    return updatesJSON ? JSON.parse(updatesJSON) : [];
  }

  var params = new URLSearchParams(window.location.hash.substr(1));
  return {
    selfAddr: params.get("addr") || "device0@local.host",
    selfName: params.get("name") || "device0",
    setUpdateListener: (cb, serial = 0) => {
      var updates = getUpdates();
      var maxSerial = updates.length;
      updates.forEach((update) => {
        if (update.serial > serial) {
          update.max_serial = maxSerial;
          cb(update);
        }
      });
      updateListener = cb;
      return Promise.resolve();
    },
    joinRealtimeChannel: (cb) => {
      if (realtimeListener && realtimeListener.is_trashed()) {
        return;
      }
      rt = new RealtimeListener();
      // mimic connection establishment time
      setTimeout(() => realtimeListener = rt, 500);
      return rt;
    },
    getAllUpdates: () => {
      console.log("[Webxdc] WARNING: getAllUpdates() is deprecated.");
      return Promise.resolve([]);
    },
    sendUpdate: (update, description) => {
      var updates = getUpdates();
      var serial = updates.length + 1;
      var _update = {
        payload: update.payload,
        summary: update.summary,
        info: update.info,
        document: update.document,
        serial: serial,
      };
      updates.push(_update);
      window.localStorage.setItem(updatesKey, JSON.stringify(updates));
      _update.max_serial = serial;
      console.log(
        '[Webxdc] description="' + description + '", ' + JSON.stringify(_update)
      );
      updateListener(_update);
    },
    sendToChat: async (content) => {
      if (!content.file && !content.text) {
        alert("🚨 Error: either file or text need to be set. (or both)");
        return Promise.reject(
          "Error from sendToChat: either file or text need to be set"
        );
      }

      /** @type {(file: Blob) => Promise<string>} */
      const blob_to_base64 = (file) => {
        const data_start = ";base64,";
        return new Promise((resolve, reject) => {
          const reader = new FileReader();
          reader.readAsDataURL(file);
          reader.onload = () => {
            /** @type {string} */
            //@ts-ignore
            let data = reader.result;
            resolve(data.slice(data.indexOf(data_start) + data_start.length));
          };
          reader.onerror = () => reject(reader.error);
        });
      };

      let base64Content;
      if (content.file) {
        if (!content.file.name) {
          return Promise.reject("file name is missing");
        }
        if (
          Object.keys(content.file).filter((key) =>
            ["blob", "base64", "plainText"].includes(key)
          ).length > 1
        ) {
          return Promise.reject(
            "you can only set one of `blob`, `base64` or `plainText`, not multiple ones"
          );
        }

        // @ts-ignore - needed because typescript imagines that blob would not exist
        if (content.file.blob instanceof Blob) {
          // @ts-ignore - needed because typescript imagines that blob would not exist
          base64Content = await blob_to_base64(content.file.blob);
          // @ts-ignore - needed because typescript imagines that base64 would not exist
        } else if (typeof content.file.base64 === "string") {
          // @ts-ignore - needed because typescript imagines that base64 would not exist
          base64Content = content.file.base64;
          // @ts-ignore - needed because typescript imagines that plainText would not exist
        } else if (typeof content.file.plainText === "string") {
          base64Content = await blob_to_base64(
            // @ts-ignore - needed because typescript imagines that plainText would not exist
            new Blob([content.file.plainText])
          );
        } else {
          return Promise.reject(
            "data is not set or wrong format, set one of `blob`, `base64` or `plainText`, see webxdc documentation for sendToChat"
          );
        }
      }
      const msg = `The app would now close and the user would select a chat to send this message:\nText: ${
        content.text ? `"${content.text}"` : "No Text"
      }\nFile: ${
        content.file
          ? `${content.file.name} - ${base64Content.length} bytes`
          : "No File"
      }`;
      if (content.file) {
        const confirmed = confirm(
          msg + "\n\nDownload the file in the browser instead?"
        );
        if (confirmed) {
          var element = document.createElement("a");
          element.setAttribute(
            "href",
            "data:application/octet-stream;base64," + base64Content
          );
          element.setAttribute("download", content.file.name);
          document.body.appendChild(element);
          element.click();
          document.body.removeChild(element);
        }
      } else {
        alert(msg);
      }
    },
    importFiles: (filters) => {
      var element = document.createElement("input");
      element.type = "file";
      element.accept = [
        ...(filters.extensions || []),
        ...(filters.mimeTypes || []),
      ].join(",");
      element.multiple = filters.multiple || false;
      const promise = new Promise((resolve, _reject) => {
        element.onchange = (_ev) => {
          console.log("element.files", element.files);
          const files = Array.from(element.files || []);
          document.body.removeChild(element);
          resolve(files);
        };
      });
      element.style.display = "none";
      document.body.appendChild(element);
      element.click();
      console.log(element);
      return promise;
    },
  };
})();

window.addXdcPeer = () => {
  var loc = window.location;
  // get next peer ID
  var params = new URLSearchParams(loc.hash.substr(1));
  var peerId = Number(params.get("next_peer")) || 1;

  // open a new window
  var peerName = "device" + peerId;
  var url =
    loc.protocol +
    "//" +
    loc.host +
    loc.pathname +
    "#name=" +
    peerName +
    "&addr=" +
    peerName +
    "@local.host";
  window.open(url);

  // update next peer ID
  params.set("next_peer", String(peerId + 1));
  window.location.hash = "#" + params.toString();
};

window.clearXdcStorage = () => {
  window.localStorage.clear();
  window.location.reload();
};

window.alterXdcApp = () => {
  var styleControlPanel =
    "position: fixed; bottom:1em; left:1em; background-color: #000; opacity:0.8; padding:.5em; font-size:16px; font-family: sans-serif; color:#fff; z-index: 9999";
  var styleMenuLink =
    "color:#fff; text-decoration: none; vertical-align: middle";
  var styleAppIcon =
    "height: 1.5em; width: 1.5em; margin-right: 0.5em; border-radius:10%; vertical-align: middle";
  var title = document.getElementsByTagName("title")[0];
  if (typeof title == "undefined") {
    title = document.createElement("title");
    document.getElementsByTagName("head")[0].append(title);
  }
  title.innerText = window.webxdc.selfAddr;

  if (window.webxdc.selfName === "device0") {
    var root = document.createElement("section");
    root.innerHTML =
      '<div id="webxdc-panel" style="' +
      styleControlPanel +
      '">' +
      '<header style="margin-bottom: 0.5em; font-size:12px;">webxdc dev tools</header>' +
      '<a href="javascript:window.addXdcPeer();" style="' +
      styleMenuLink +
      '">Add Peer</a>' +
      '<span style="' +
      styleMenuLink +
      '"> | </span>' +
      '<a id="webxdc-panel-clear" href="javascript:window.clearXdcStorage();" style="' +
      styleMenuLink +
      '">Reset</a>' +
      "<div>";
    var controlPanel = root.firstChild;

    function loadIcon(name) {
      var tester = new Image();
      tester.onload = () => {
        root.innerHTML =
          '<img src="' + name + '" style="' + styleAppIcon + '">';
        controlPanel.insertBefore(root.firstChild, controlPanel.childNodes[1]);

        var pageIcon = document.createElement("link");
        pageIcon.rel = "icon";
        pageIcon.href = name;
        document.head.append(pageIcon);
      };
      tester.src = name;
    }
    loadIcon("icon.png");
    loadIcon("icon.jpg");

    document.getElementsByTagName("body")[0].append(controlPanel);
  }
};

window.addEventListener("load", window.alterXdcApp);