const redis = require("../redis")

const { ObjectId } = require('mongodb');
const connector = require("./CONNECTOR");
var dbo;
connector.connect().then((ret) => {
  dbo = ret;
  dbo.collection("albums").createIndex({ artist_name: 1, year: 1, title: 1 });
  // TEMPORARY
  dbo.collection("albums").updateMany({}, { $unset: { cover32: 1, cover64: 1, cover128: 1, cover256: 1, cover512: 1 } });
  updateArtistName();
});

function updateArtistName() {
  dbo.collection("albums")
    .find({ artist_name: undefined })
    .toArray((err, result) => {
      result.forEach(item => {
        dbo.collection("artists")
          .findOne({ _id: item.artist_id })
          .then(artist => {
            if (artist) {
              dbo.collection("albums")
                .updateOne(
                  { _id: item._id },
                  { $set: { artist_id: artist._id, artist_name: artist.name } },
                  { upsert: false });
            }
          });
      })
    });
}

exports.collection = function (page, filter, callback) {
  process.stdout.write("services/db_manager ALBUMS Collection: " + page + "\n");
  let redis_key = "albumsCollection_" + (filter || '') + '_' + page;

  redis.get(redis_key, (value) => {
    if (value) {
      process.stdout.write("services/db_manager ALBUMS Collection REDIS: " + page + "\n");
      callback(value);
    } else {
      let aggregate = [
        { $project: { "covers.cover256": false, "covers.cover64": false, "covers.cover32": false } },
        { $match: { visibility: { $not: { $eq: 'hidden' } } } },
        { $sort: { artist_name: 1, year: 1, title: 1 } },
      ];

      if (filter) {
        aggregate.push({
          $match: { visibility: { $in: filter } }
        });
      }

      if (page > -1) {
        let pageSize = 12;
        let skip = (page - 1) * pageSize;
        aggregate.push(
          { $skip: skip },
          { $limit: pageSize });
      }
      dbo
        .collection("albums")
        .aggregate(aggregate, { allowDiskUse: true })
        .toArray((err, result) => {
          if (err) throw err;
          if (result) {
            result.forEach(album => {
              album.type = "album";
              album.tracks = [];
              album.share = {};
            });
          }
          process.stdout.write("services/db_manager ALBUMS Collection MONGO: " + page + "\n");
          callback(result);
          redis.set(redis_key, result);
        });
    }
  });
};

exports.favourites = function (id, callback) {
  dbo.collection("favourites")
    .find({ userId: id, type: "album" })
    .toArray((err, favourites) => {
      if (err) throw err;
      let aggregate = [
        { $match: { _id: { $in: favourites.map(m => m.itemId) } } },
        { $project: { "covers.cover256": false, "covers.cover64": false, "covers.cover32": false } },
      ]
      dbo.collection("albums")
        .aggregate(aggregate)
        .toArray((err, result) => {
          result.forEach(album => {
            album.type = "album";
            album.tracks = [];
          });
          callback(result);
        });
    })
};

exports.newest = function (count, filter, callback) {
  let aggregate = [
    { $project: { "covers.cover256": false, "covers.cover128": false, "covers.cover32": false } },
    { $match: { visibility: { $not: { $eq: 'hidden' } } } },
    { $sort: { _id: -1 } },
  ];

  if (filter) {
    aggregate.push({
      $match: { visibility: { $in: filter } }
    });
  }
  aggregate.push({ $limit: count })

  dbo
    .collection("albums")
    .aggregate(aggregate, {
      allowDiskUse: true
    })
    .toArray((err, result) => {
      if (err) throw err;
      if (result) {
        result.forEach(album => {
          album.type = "album";
          album.tracks = [];
        });
      }
      callback(result);
    });
};

exports.byId = function (id, filter, callback) {
  process.stdout.write("services/db_manager ALBUM by id: " + id + "\n");
  let redis_key = "albumId_" + (filter || '') + '_' + id;

  redis.get(redis_key, (value) => {
    if (value) {
      process.stdout.write("services/db_manager ALBUM by id REDIS: " + id + "\n");
      callback(value);
    } else {
      let aggregate = [
        {
          $lookup: {
            from: "tracks",
            localField: "_id",
            foreignField: "album_id",
            as: "tracks"
          }
        }, {
          $lookup: {
            from: "shares",
            localField: "_id",
            foreignField: "object_id",
            as: "share"
          }
        },
        { $match: { _id: ObjectId(id) } }
      ]

      if (filter) {
        aggregate.push({
          $match: { visibility: { $in: filter } }
        });
      }

      dbo
        .collection("albums")
        .aggregate(aggregate)
        .toArray((err, result) => {
          if (err) throw err;
          if (result) {
            result.forEach(album => {
              album.type = "album";
              if (album.share.length > 0) {
                album.share = album.share[0];
              } else {
                album.share = {};
              }
            });
          }
          process.stdout.write("services/db_manager ALBUM by id MONGO: " + id + "\n");
          callback(result[0]);
          redis.set(redis_key, result[0]);
        });
    }
  });
};

exports.filter = function (term, callback) {
  let aggregate = [
    { $project: { 'parent.covers': false, 'covers.cover32': false, 'covers.cover256': false } },
    { $match: { title: { $regex: term, $options: "i" } }, },
    { $limit: 6 }
  ]
  dbo
    .collection("albums")
    .aggregate(aggregate)
    .toArray((err, result) => {
      if (err) throw err;
      callback(result);
    });
};

exports.tracks = function (id, callback) {
  process.stdout.write("services/db_manager TRACKS by id: " + id + "\n");

  let request = [
    {
      $lookup: {
        from: "tracks",
        localField: "_id",
        foreignField: "album_id",
        as: "tracks"
      }
    },
    { $match: { _id: ObjectId(id) } }
  ];

  dbo
    .collection("albums")
    .aggregate(request)
    .toArray((err, result) => {
      if (result) {
        callback(result[0]);
      } else {
        if (err) {
          process.stderr("services/db_manager ALBUM by id ERROR: " + err.message);
        }
        callback(null);
      }
    });
};

exports.delete = function (album, callback) {
  dbo.collection("albums")
    .deleteOne({ _id: ObjectId(album._id) }, err => {
      if (err) throw err;
      if (callback) {
        callback();
      }
    });
};

exports.update = function (album, callback) {
  dbo.collection("albums")
    .updateOne(
      { _id: ObjectId(album._id) },
      {
        $set: {
          visibility: album.visibility
        }
      },
      { upsert: false },
      err => {
        if (err) throw err;
        if (callback) {
          callback();
        }
      }
    );
}

exports.updateCovers = function (album, covers, callback) {
  dbo.collection("albums")
    .updateOne(
      { _id: ObjectId(album._id) },
      { $set: { covers: covers } },
      { upsert: false },
      err => {
        if (err) throw err;
        if (callback) {
          callback();
        }
      }
    );
};

exports.moveTo = function (album, callback) {
  process.stdout.write("services/db_manager ALBUM '" + album._id + "' move to '" + album.artist_id + "'\n");

  dbo
    .collection("albums")
    .updateOne(
      { _id: ObjectId(album._id) },
      { $set: { artist_id: ObjectId(album.artist_id), artist_name: album.artist_name } },
      { upsert: false },
      err => {
        if (err) throw err;
        if (callback) {
          callback();
        }
      });
};

exports.empty = function (callback) {
  dbo
    .collection("albums")
    .aggregate([
      {
        $lookup: {
          from: "tracks",
          localField: "_id",
          foreignField: "album_id",
          as: "tracks"
        }
      }
    ])
    .toArray((err, result) => {
      callback(result.filter(f => !f.tracks || f.tracks.length == 0));
    });
};

exports.randomCovers = function (count, size, callback) {
  dbo
    .collection("albums")
    .find({ "covers.cover64": { $exists: true } })
    .project({ "covers.cover64": true })
    .toArray((err, result) => {
      let res = [];
      if (result.length > count) {
        let i = 0;
        while (i < count) {
          let rnd = randomNumber(0, result.length);
          res.push(result[rnd]);
          i++;
        }
        callback(res);
      } else {
        callback(result);
      }
    })
}

function randomNumber(min, max) {
  return Math.floor(Math.random() * (max - min) + min);
}