const settings = require('../data/settings.json');

const MovieDB = require('moviedb')(settings.tmdbApiKey);
const _ = require('lodash');

const GENRE_TRANSLATIONS = settings.genre.translations;
const GENRE_WEIGHTS = settings.genre.weights;
const GENRE_COMBINATIONS = settings.genre.combinations;

const searchQuery = name => {
  let parts = name.match(/(.+?)(\s\((\d{4})\))$/);
  let query = (parts && parts.length > 0) ? parts[1] : name;
  let year = (parts && parts.length > 2) ? parts[3] : false;
  return { query:query, year:year };
};

const searchFilter = (data, year = false) => {
  if (!year) return data;
  return data.filter(d => d.release_date.toString().includes(year.toString()));
};

const searchMovie = name => {
  const { query, year } = searchQuery(name);
  return new Promise((resolve, reject) => {
    MovieDB.searchMovie({ query: query }, (err, res) => {
      if (err) reject(err);
      resolve(searchFilter(res.results,year));
    });
  });
};

const searchTv = name => {
  const { query, year } = searchQuery(name);
  return new Promise((resolve, reject) => {
    MovieDB.searchMovie({ query: query }, (err, res) => {
      if (err) reject(err);
      resolve(searchFilter(res.results,year));
    });
  });
};

const infoMovie = id => {
  return new Promise((resolve, reject) => {
    MovieDB.movieInfo({ id: id }, (err, res) => {
      if (err) reject(err);
      resolve(res);
    });
  });
};

const infoTv = id => {
  return new Promise((resolve, reject) => {
    MovieDB.tvInfo({ id: id }, (err, res) => {
      if (err) reject(err);
      resolve(res);
    });
  });
};

const genreTranslate = (data = {}) => {
  let genres = Object.keys(data);
  let translations = Object.keys(GENRE_TRANSLATIONS);
  for (let i=0, l=translations.length; i<l; i++) {
    let to = translations[i];
    let froms = GENRE_TRANSLATIONS[to];
    for (let j=0, c=froms.length; j<c; j++) {
      let from = froms[j];
      if (data[from]) { // if we have the from ... translate
        if (!data[to]) data[to] = 0; // init the to value
        data[to] += data[from];  // translate value and add value
        delete data[from];  // delete the orig
      }
    }
  }
  let combinations = Object.keys(GENRE_COMBINATIONS);
  for (let i=0, l=combinations.length; i<l; i++) {
    let to = combinations[i]; // new to combination
    let froms = GENRE_COMBINATIONS[to]; // get the list of things to combine
    // check if we have all the genre intersections with the froms
    if (_.intersection(genres,froms).length === froms.length) {
      if (!data[to]) data[to] = 0; // init the to combination value
      for (let j=0, c=froms.length; j<c; j++) {
        let from = froms[j];
        if (data[from]) { // if we have the from ... translate
          data[to] += data[from];
          delete data[from];  // delete the orig
        }
      }
    }
  }
};

const genreTally = (data = {}, info = {}) => {
  let genres = info && info.genres ? info.genres.map(g => g.name) : [];
  for (let i = 0, l = genres.length; i < l; i++) {
    let genre = genres[i];
    if (!data) data = {};
    if (!data[genre]) data[genre] = 0;
    data[genre] = data[genre] + 1;
  }
  genreTranslate(data);
};

const genreSorted = data => {
  if (!data) return [];
  let keys = Object.keys(data);
  let values = Object.values(data);
  // get a distinctset of values
  let distinctValues = [...new Set(values)];
  // sort the keys based on current values
  let sorted = keys.sort((a, b) => data[b] - data[a]);
  // only one key ... return
  if (keys.length === 1) return sorted;
  // we have more than 1 distinct value
  if (distinctValues.length > 1) return sorted;
  // we have one entry and all genere are equally weighted ... apply boosting
  let genreWeightKeys = Object.keys(GENRE_WEIGHTS); // get the key list
  for (let i=0, l=genreWeightKeys.length; i<l; i++) { // loop the list
    let genreWeightKey = genreWeightKeys[i];  // pointer to the key name
    if (genreWeightKey && keys && keys.includes(genreWeightKey)) // we have a match
      data[genreWeightKey] += GENRE_WEIGHTS[genreWeightKey]; // boost
  }
  // re-sort boosted values
  return keys.sort((a, b) => data[b] - data[a]);
};

const genrePrimary = data => {
  if (!data) return 'Unknown';
  let sorted = genreSorted(data);
  return sorted[0];
};

const genreMovie = async (name, list = false) => {
  let results = await searchMovie(name);
  let genres = {};
  for (let i = 0, l = results.length; i < l; i++) {
    let result = results[i];
    let info = await infoMovie(result.id);
    genreTally(genres, info);
  }
  return (list) ? genreSorted(genres) : genrePrimary(genres);
};

const genreTv = async (name, list = false) => {
  let results = await searchTv(name);
  let genres = {};
  for (let i = 0, l = results.length; i < l; i++) {
    let result = results[i];
    let info = await infoTv(result.id);
    genreTally(genres, info);
  }
  return (list) ? genreSorted(genres) : genrePrimary(genres);
};

const search = async (name, type = 'movie') => {
  if (!name) return new Error('nothing to search');
  switch (type) {
    case 'tv':
      return await searchTv(name);
    case 'movie':
      return await searchMovie(name);
    default:
      return new Error('invalid type specified');
  }
};

const info = async (id, type = 'movie') => {
  if (!id) return new Error('no id specified');
  switch (type) {
    case 'tv':
      return await infoTv(id);
    case 'movie':
      return await infoMovie(id);
    default:
      return new Error('invalid type specified');
  }
};

const genre = async (name, type = 'movie') => {
  if (!name) return new Error('nothing to search');
  switch (type) {
    case 'tv':
      return await genreTv(name);
    case 'movie':
      return await genreMovie(name);
    default:
      return new Error('invalid type specified');
  }
};

const genres = async (name, type = 'movie') => {
  if (!name) return new Error('nothing to search');
  switch (type) {
    case 'tv':
      return await genreTv(name, true);
    case 'movie':
      return await genreMovie(name, true);
    default:
      return new Error('invalid type specified');
  }
};

module.exports = {
  search,
  info,
  genre,
  genres,
};