/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

import { SAX } from "resource:///modules/sax.sys.mjs";

var NS = {
  xml: "http://www.w3.org/XML/1998/namespace",
  xhtml: "http://www.w3.org/1999/xhtml",
  xhtml_im: "http://jabber.org/protocol/xhtml-im",

  // auth
  client: "jabber:client",
  streams: "http://etherx.jabber.org/streams",
  stream: "urn:ietf:params:xml:ns:xmpp-streams",
  sasl: "urn:ietf:params:xml:ns:xmpp-sasl",
  tls: "urn:ietf:params:xml:ns:xmpp-tls",
  bind: "urn:ietf:params:xml:ns:xmpp-bind",
  session: "urn:ietf:params:xml:ns:xmpp-session",
  auth: "jabber:iq:auth",
  auth_feature: "http://jabber.org/features/iq-auth",
  http_bind: "http://jabber.org/protocol/httpbind",
  http_auth: "http://jabber.org/protocol/http-auth",
  xbosh: "urn:xmpp:xbosh",

  private: "jabber:iq:private",
  xdata: "jabber:x:data",

  // roster
  roster: "jabber:iq:roster",
  roster_versioning: "urn:xmpp:features:rosterver",
  roster_delimiter: "roster:delimiter",

  // privacy lists
  privacy: "jabber:iq:privacy",

  // discovering
  disco_info: "http://jabber.org/protocol/disco#info",
  disco_items: "http://jabber.org/protocol/disco#items",
  caps: "http://jabber.org/protocol/caps",

  // addressing
  address: "http://jabber.org/protocol/address",

  muc_user: "http://jabber.org/protocol/muc#user",
  muc_owner: "http://jabber.org/protocol/muc#owner",
  muc_admin: "http://jabber.org/protocol/muc#admin",
  muc_rooms: "http://jabber.org/protocol/muc#rooms",
  conference: "jabber:x:conference",
  muc: "http://jabber.org/protocol/muc",
  register: "jabber:iq:register",
  delay: "urn:xmpp:delay",
  delay_legacy: "jabber:x:delay",
  bookmarks: "storage:bookmarks",
  chatstates: "http://jabber.org/protocol/chatstates",
  event: "jabber:x:event",
  stanzas: "urn:ietf:params:xml:ns:xmpp-stanzas",
  vcard: "vcard-temp",
  vcard_update: "vcard-temp:x:update",
  ping: "urn:xmpp:ping",
  carbons: "urn:xmpp:carbons:2",

  geoloc: "http://jabber.org/protocol/geoloc",
  geoloc_notify: "http://jabber.org/protocol/geoloc+notify",
  mood: "http://jabber.org/protocol/mood",
  tune: "http://jabber.org/protocol/tune",
  nick: "http://jabber.org/protocol/nick",
  nick_notify: "http://jabber.org/protocol/nick+notify",
  activity: "http://jabber.org/protocol/activity",
  rsm: "http://jabber.org/protocol/rsm",
  last: "jabber:iq:last",
  version: "jabber:iq:version",
  avatar_data: "urn:xmpp:avatar:data",
  avatar_data_notify: "urn:xmpp:avatar:data+notify",
  avatar_metadata: "urn:xmpp:avatar:metadata",
  avatar_metadata_notify: "urn:xmpp:avatar:metadata+notify",
  pubsub: "http://jabber.org/protocol/pubsub",
  pubsub_event: "http://jabber.org/protocol/pubsub#event",
};

var TOP_LEVEL_ELEMENTS = {
  message: "jabber:client",
  presence: "jabber:client",
  iq: "jabber:client",
  "stream:features": "http://etherx.jabber.org/streams",
  proceed: "urn:ietf:params:xml:ns:xmpp-tls",
  failure: [
    "urn:ietf:params:xml:ns:xmpp-tls",
    "urn:ietf:params:xml:ns:xmpp-sasl",
  ],
  success: "urn:ietf:params:xml:ns:xmpp-sasl",
  challenge: "urn:ietf:params:xml:ns:xmpp-sasl",
  error: "urn:ietf:params:xml:ns:xmpp-streams",
};

// Features that we support in XMPP.
// Don't forget to add your new features here.
export var SupportedFeatures = [
  NS.chatstates,
  NS.conference,
  NS.disco_info,
  NS.last,
  NS.muc,
  NS.ping,
  NS.vcard,
  NS.version,
];

/* Stanza Builder */
export var Stanza = {
  NS,

  /* Create a presence stanza */
  presence: (aAttr, aData) => Stanza.node("presence", null, aAttr, aData),

  /* Create a message stanza */
  message(aTo, aMsg, aState, aAttr = {}, aData = []) {
    aAttr.to = aTo;
    if (!("type" in aAttr)) {
      aAttr.type = "chat";
    }

    if (aMsg) {
      aData.push(Stanza.node("body", null, null, aMsg));
    }

    if (aState) {
      aData.push(Stanza.node(aState, Stanza.NS.chatstates));
    }

    return Stanza.node("message", null, aAttr, aData);
  },

  /* Create a iq stanza */
  iq(aType, aId, aTo, aData) {
    let attrs = { type: aType };
    if (aId) {
      attrs.id = aId;
    }
    if (aTo) {
      attrs.to = aTo;
    }
    return this.node("iq", null, attrs, aData);
  },

  /* Create a XML node */
  node(aName, aNs, aAttr, aData) {
    let node = new XMLNode(null, aNs, aName, aName, aAttr);
    if (aData) {
      if (!Array.isArray(aData)) {
        aData = [aData];
      }
      for (let child of aData) {
        node[typeof child == "string" ? "addText" : "addChild"](child);
      }
    }

    return node;
  },
};

/* Text node
 * Contains a text */
function TextNode(aText) {
  this.text = aText;
}
TextNode.prototype = {
  get type() {
    return "text";
  },

  append(aText) {
    this.text += aText;
  },

  /* For debug purposes, returns an indented (unencoded) string */
  convertToString(aIndent) {
    return aIndent + this.text + "\n";
  },

  /* Returns the encoded XML */
  getXML() {
    return Cc["@mozilla.org/txttohtmlconv;1"]
      .getService(Ci.mozITXTToHTMLConv)
      .scanTXT(this.text, Ci.mozITXTToHTMLConv.kEntities);
  },

  /* To read the unencoded data. */
  get innerText() {
    return this.text;
  },
};

/* XML node */
/* https://www.w3.org/TR/2008/REC-xml-20081126 */
/* aUri is the namespace. */
/* aLocalName must have value, otherwise throws. */
/* aAttr is an object */
/* Example: <f:a xmlns:f='g' d='1'> is parsed to
   uri/namespace='g', localName='a', qName='f:a', attributes={d='1'} */
function XMLNode(
  aParentNode,
  aUri,
  aLocalName,
  aQName = aLocalName,
  aAttr = {}
) {
  if (!aLocalName) {
    throw new Error("aLocalName must have value");
  }

  this._parentNode = aParentNode; // Used only for parsing
  this.uri = aUri;
  this.localName = aLocalName;
  this.qName = aQName;
  this.attributes = {};
  this.children = [];

  for (let attributeName in aAttr) {
    // Each attribute specification has a name and a value.
    if (aAttr[attributeName]) {
      this.attributes[attributeName] = aAttr[attributeName];
    }
  }
}
XMLNode.prototype = {
  get type() {
    return "node";
  },

  /* Add a new child node */
  addChild(aNode) {
    this.children.push(aNode);
  },

  /* Add text node */
  addText(aText) {
    let lastIndex = this.children.length - 1;
    if (lastIndex >= 0 && this.children[lastIndex] instanceof TextNode) {
      this.children[lastIndex].append(aText);
    } else {
      this.children.push(new TextNode(aText));
    }
  },

  /* Get child elements by namespace */
  getChildrenByNS(aNS) {
    return this.children.filter(c => c.uri == aNS);
  },

  /* Get the first element anywhere inside the node (including child nodes)
     that matches the query.
     A query consists of an array of localNames. */
  getElement(aQuery) {
    if (aQuery.length == 0) {
      return this;
    }

    let nq = aQuery.slice(1);
    for (let child of this.children) {
      if (child.type == "text" || child.localName != aQuery[0]) {
        continue;
      }
      let n = child.getElement(nq);
      if (n) {
        return n;
      }
    }

    return null;
  },

  /* Get all elements of the node (including child nodes) that match the query.
     A query consists of an array of localNames. */
  getElements(aQuery) {
    if (aQuery.length == 0) {
      return [this];
    }

    let c = this.getChildren(aQuery[0]);
    let nq = aQuery.slice(1);
    let res = [];
    for (let child of c) {
      let n = child.getElements(nq);
      res = res.concat(n);
    }

    return res;
  },

  /* Get immediate children by the node name */
  getChildren(aName) {
    return this.children.filter(c => c.type != "text" && c.localName == aName);
  },

  // Test if the node is a stanza and its namespace is valid.
  isXmppStanza() {
    if (!TOP_LEVEL_ELEMENTS.hasOwnProperty(this.qName)) {
      return false;
    }
    let ns = TOP_LEVEL_ELEMENTS[this.qName];
    return ns == this.uri || (Array.isArray(ns) && ns.includes(this.uri));
  },

  /* Returns indented XML */
  convertToString(aIndent = "") {
    let s =
      aIndent + "<" + this.qName + this._getXmlns() + this._getAttributeText();
    let content = "";
    for (let child of this.children) {
      content += child.convertToString(aIndent + " ");
    }
    return (
      s +
      (content ? ">\n" + content + aIndent + "</" + this.qName : "/") +
      ">\n"
    );
  },

  /* Returns the XML */
  getXML() {
    let s = "<" + this.qName + this._getXmlns() + this._getAttributeText();
    let innerXML = this.innerXML;
    return s + (innerXML ? ">" + innerXML + "</" + this.qName : "/") + ">";
  },

  get innerXML() {
    return this.children.map(c => c.getXML()).join("");
  },
  get innerText() {
    return this.children.map(c => c.innerText).join("");
  },

  /* Private methods */
  _getXmlns() {
    return this.uri ? ' xmlns="' + this.uri + '"' : "";
  },
  _getAttributeText() {
    let s = "";
    for (let name in this.attributes) {
      s += " " + name + '="' + this.attributes[name] + '"';
    }
    return s;
  },
};

export function XMPPParser(aListener) {
  this._listener = aListener;

  // We only get tagName from onclosetag callback, but we need more, so save the
  // opening tags.
  let tagStack = [];
  this._parser = SAX.parser(true, { xmlns: true, lowercase: true });
  this._parser.onopentag = node => {
    if (this._parser.error) {
      // sax-js doesn't stop on error, but we want to.
      return;
    }
    let attrs = {};
    for (let [name, attr] of Object.entries(node.attributes)) {
      if (name == "xmlns") {
        continue;
      }
      attrs[name] = attr.value;
    }
    this.startElement(node.uri, node.local, node.name, attrs);
    tagStack.push(node);
  };
  this._parser.onclosetag = tagName => {
    if (this._parser.error) {
      return;
    }
    let node = tagStack.pop();
    if (tagName == node.name) {
      this.endElement(node.uri, node.local, node.name);
    } else {
      this.error(`Unexpected </${tagName}>, expecting </${node.name}>`);
    }
  };
  this._parser.ontext = t => {
    if (this._parser.error) {
      return;
    }
    this.characters(t);
  };
  this._parser.onerror = this.error;
}

XMPPParser.prototype = {
  _decoder: new TextDecoder(),
  _destroyPending: false,
  destroy() {
    delete this._listener;

    try {
      this._parser.close();
    } catch (e) {}
    delete this._parser;
  },

  _logReceivedData(aData) {
    this._listener.LOG("received:\n" + aData);
  },
  /**
   * Decodes the byte string to UTF-8 (via byte array) before feeding it to the
   * SAXML parser.
   *
   * @param {string} data - Raw XML byte string.
   */
  onDataAvailable(data) {
    let bytes = new Uint8Array(data.length);
    for (let i = 0; i < data.length; i++) {
      bytes[i] = data.charCodeAt(i);
    }
    let utf8Data = this._decoder.decode(bytes);
    this._parser.write(utf8Data);
  },

  startElement(aUri, aLocalName, aQName, aAttributes) {
    if (aQName == "stream:stream") {
      let node = new XMLNode(null, aUri, aLocalName, aQName, aAttributes);
      // The node we created doesn't have children, but
      // <stream:stream> isn't closed, so avoid displaying /> at the end.
      this._logReceivedData(node.convertToString().slice(0, -3) + ">\n");

      if ("_node" in this) {
        this._listener.onXMLError(
          "unexpected-stream-start",
          "stream:stream inside an already started stream"
        );
        return;
      }

      this._listener._streamId = node.attributes.id;
      if (!("version" in node.attributes)) {
        this._listener.startLegacyAuth();
      }

      this._node = null;
      return;
    }

    let node = new XMLNode(this._node, aUri, aLocalName, aQName, aAttributes);
    if (this._node) {
      this._node.addChild(node);
    }

    this._node = node;
  },

  characters(aCharacters) {
    if (!this._node) {
      // Ignore whitespace received on the stream to keep the connection alive.
      if (aCharacters.trim()) {
        this._listener.onXMLError(
          "parsing-characters",
          "No parent for characters: " + aCharacters
        );
      }
      return;
    }

    this._node.addText(aCharacters);
  },

  endElement(aUri, aLocalName, aQName) {
    if (aQName == "stream:stream") {
      this._logReceivedData("</stream:stream>");
      delete this._node;
      return;
    }

    if (!this._node) {
      this._listener.onXMLError(
        "parsing-node",
        "No parent for node : " + aLocalName
      );
      return;
    }

    // RFC 6120 (8): XML Stanzas.
    // Checks if the node is the root and it's valid.
    if (!this._node._parentNode) {
      if (this._node.isXmppStanza()) {
        this._logReceivedData(this._node.convertToString());
        try {
          this._listener.onXmppStanza(this._node);
        } catch (e) {
          console.error(e);
          dump(e + "\n");
        }
      } else {
        this._listener.onXMLError(
          "parsing-node",
          "Root node " + aLocalName + " is not valid."
        );
      }
    }

    this._node = this._node._parentNode;
  },

  error(aError) {
    if (this._listener) {
      this._listener.onXMLError("parse-error", aError);
    }
  },
};