/**
 * The AuthorManager controlls all information about the Pad authors
 */

/*
 * 2011 Peter 'Pita' Martischka (Primary Technology Ltd)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS-IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

var db = require("./DB");
var customError = require("../utils/customError");
var randomString = require('ep_etherpad-lite/static/js/pad_utils').randomString;

exports.getColorPalette = function() {
  return [
    "#ffc7c7", "#fff1c7", "#e3ffc7", "#c7ffd5", "#c7ffff", "#c7d5ff", "#e3c7ff", "#ffc7f1",
    "#ffa8a8", "#ffe699", "#cfff9e", "#99ffb3", "#a3ffff", "#99b3ff", "#cc99ff", "#ff99e5",
    "#e7b1b1", "#e9dcAf", "#cde9af", "#bfedcc", "#b1e7e7", "#c3cdee", "#d2b8ea", "#eec3e6",
    "#e9cece", "#e7e0ca", "#d3e5c7", "#bce1c5", "#c1e2e2", "#c1c9e2", "#cfc1e2", "#e0bdd9",
    "#baded3", "#a0f8eb", "#b1e7e0", "#c3c8e4", "#cec5e2", "#b1d5e7", "#cda8f0", "#f0f0a8",
    "#f2f2a6", "#f5a8eb", "#c5f9a9", "#ececbb", "#e7c4bc", "#daf0b2", "#b0a0fd", "#bce2e7",
    "#cce2bb", "#ec9afe", "#edabbd", "#aeaeea", "#c4e7b1", "#d722bb", "#f3a5e7", "#ffa8a8",
    "#d8c0c5", "#eaaedd", "#adc6eb", "#bedad1", "#dee9af", "#e9afc2", "#f8d2a0", "#b3b3e6"
  ];
};

/**
 * Checks if the author exists
 */
exports.doesAuthorExist = async function(authorID) {
  let author = await db.get("globalAuthor:" + authorID);

  return author !== null;
}

/* exported for backwards compatibility */
exports.doesAuthorExists = exports.doesAuthorExist;

/**
 * Returns the AuthorID for a token.
 * @param {String} token The token
 */
exports.getAuthor4Token = async function(token) {
  let author = await mapAuthorWithDBKey("token2author", token);

  // return only the sub value authorID
  return author ? author.authorID : author;
}

/**
 * Returns the AuthorID for a mapper.
 * @param {String} token The mapper
 * @param {String} name The name of the author (optional)
 */
exports.createAuthorIfNotExistsFor = async function(authorMapper, name) {
  let author = await mapAuthorWithDBKey("mapper2author", authorMapper);

  if (name) {
    // set the name of this author
    await exports.setAuthorName(author.authorID, name);
  }

  return author;
};

/**
 * Returns the AuthorID for a mapper. We can map using a mapperkey,
 * so far this is token2author and mapper2author
 * @param {String} mapperkey The database key name for this mapper
 * @param {String} mapper The mapper
 */
async function mapAuthorWithDBKey (mapperkey, mapper) {
  // try to map to an author
  let author = await db.get(mapperkey + ":" + mapper);

  if (author === null) {
    // there is no author with this mapper, so create one
    let author = await exports.createAuthor(null);

    // create the token2author relation
    await db.set(mapperkey + ":" + mapper, author.authorID);

    // return the author
    return author;
  }

  // there is an author with this mapper
  // update the timestamp of this author
  await db.setSub("globalAuthor:" + author, ["timestamp"], Date.now());

  // return the author
  return { authorID: author};
}

/**
 * Internal function that creates the database entry for an author
 * @param {String} name The name of the author
 */
exports.createAuthor = function(name) {
  // create the new author name
  let author = "a." + randomString(16);

  // create the globalAuthors db entry
  let authorObj = {
    "colorId": Math.floor(Math.random() * (exports.getColorPalette().length)),
    "name": name,
    "timestamp": Date.now()
  };

  // set the global author db entry
  // NB: no await, since we're not waiting for the DB set to finish
  db.set("globalAuthor:" + author, authorObj);

  return { authorID: author };
}

/**
 * Returns the Author Obj of the author
 * @param {String} author The id of the author
 */
exports.getAuthor = function(author) {
  // NB: result is already a Promise
  return db.get("globalAuthor:" + author);
}

/**
 * Returns the color Id of the author
 * @param {String} author The id of the author
 */
exports.getAuthorColorId = function(author) {
  return db.getSub("globalAuthor:" + author, ["colorId"]);
}

/**
 * Sets the color Id of the author
 * @param {String} author The id of the author
 * @param {String} colorId The color id of the author
 */
exports.setAuthorColorId = function(author, colorId) {
  return db.setSub("globalAuthor:" + author, ["colorId"], colorId);
}

/**
 * Returns the name of the author
 * @param {String} author The id of the author
 */
exports.getAuthorName = function(author) {
  return db.getSub("globalAuthor:" + author, ["name"]);
}

/**
 * Sets the name of the author
 * @param {String} author The id of the author
 * @param {String} name The name of the author
 */
exports.setAuthorName = function(author, name) {
  return db.setSub("globalAuthor:" + author, ["name"], name);
}

/**
 * Returns an array of all pads this author contributed to
 * @param {String} author The id of the author
 */
exports.listPadsOfAuthor = async function(authorID) {
  /* There are two other places where this array is manipulated:
   * (1) When the author is added to a pad, the author object is also updated
   * (2) When a pad is deleted, each author of that pad is also updated
   */

  // get the globalAuthor
  let author = await db.get("globalAuthor:" + authorID);

  if (author === null) {
    // author does not exist
    throw new customError("authorID does not exist", "apierror");
  }

  // everything is fine, return the pad IDs
  let padIDs = Object.keys(author.padIDs || {});

  return { padIDs };
}

/**
 * Adds a new pad to the list of contributions
 * @param {String} author The id of the author
 * @param {String} padID The id of the pad the author contributes to
 */
exports.addPad = async function(authorID, padID) {
  // get the entry
  let author = await db.get("globalAuthor:" + authorID);

  if (author === null) return;

  /*
   * ACHTUNG: padIDs can also be undefined, not just null, so it is not possible
   * to perform a strict check here
   */
  if (!author.padIDs) {
    // the entry doesn't exist so far, let's create it
    author.padIDs = {};
  }

  // add the entry for this pad
  author.padIDs[padID] = 1; // anything, because value is not used

  // save the new element back
  db.set("globalAuthor:" + authorID, author);
}

/**
 * Removes a pad from the list of contributions
 * @param {String} author The id of the author
 * @param {String} padID The id of the pad the author contributes to
 */
exports.removePad = async function(authorID, padID) {
  let author = await db.get("globalAuthor:" + authorID);

  if (author === null) return;

  if (author.padIDs !== null) {
    // remove pad from author
    delete author.padIDs[padID];
    await db.set('globalAuthor:' + authorID, author);
  }
}