# libraries
bcrypt = (require 'bcrypt')
sqlite3 = (require 'sqlite3').verbose()

# bruteforce countermeasure
saltRounds = 13

FFTCGDB = (filename, truncate) ->
  that = @
  @filename = filename

  @db = new sqlite3.Database @filename, (err) ->
    if err
      console.error err.message

    else
      console.log "[FFTCGDB] Connected to '#{that.filename}'"

      that.db.run 'PRAGMA foreign_keys = ON;', (err) ->
        console.error err.message if err

        if truncate == true
          that.db.run 'DROP TABLE IF EXISTS users;', (err) ->
            console.error err.message if err
            that.db.run '''
              CREATE TABLE users (
                user integer PRIMARY KEY,
                login text NOT NULL COLLATE NOCASE,
                pwdhash text NOT NULL,
                UNIQUE(login)
              );
              ''', (err) ->
                console.error err.message if err

          that.db.run 'DROP TABLE IF EXISTS decks;', (err) ->
            console.error err.message if err
            that.db.run '''
              CREATE TABLE decks (
                deck integer PRIMARY KEY,
                user integer NOT NULL,
                FOREIGN KEY (user) REFERENCES users (user)
                  ON DELETE CASCADE
              );
              ''', (err) ->
                console.error err.message if err

          that.db.run 'DROP TABLE IF EXISTS decks_cards;', (err) ->
            console.error err.message if err
            that.db.run '''
              CREATE TABLE decks_cards (
                deck integer NOT NULL,
                card text NOT NULL,
                quant integer NOT NULL,
                UNIQUE(deck, card),
                FOREIGN KEY (deck) REFERENCES decks (deck)
                  ON DELETE CASCADE
              );
              ''', (err) ->
                console.error err.message if err

          console.log "[FFTCGDB] recreated DB"

  return

FFTCGDB::close = ->
  new Promise (resolve, reject) ->
    @db.close (err) ->
      if err
        resolve "[FFTCGDB] Error closing: '#{err.message}'"
      else
        reject "[FFTCGDB] Closed '#{@filename}'"

FFTCGDB::register = (login, password) ->
  that = @

  new Promise (resolve, reject) ->
    # validate user input
    if login == '' or password == ''
      # no user name or password given
      console.log "[FFTCGDB] reg: user name '#{login}' or password empty"
      reject 'invalid'

    # hash password
    bcrypt.hash password, saltRounds, (err, hash) ->
      if err
        console.log "[FFTCGDB] reg: hash fail for name '#{login}'"
        reject 'hash'

      # try creating row in users table
      stmt = that.db.prepare 'INSERT INTO users (login, pwdhash) VALUES (?, ?)'
      stmt.run [login, hash], (err) ->
        if err
          console.log "[FFTCGDB] reg: DB fail '#{err.code}' for name '#{login}'"
          stmt.finalize()
          # reduce attack surface, don't disclose user names
          reject 'db' # user already exists

        else
          console.log "[FFTCGDB] reg: OK '#{login}'"
          stmt.finalize()
          # registration successful
          resolve
            user: @lastID
            login: login

FFTCGDB::login = (login, password) ->
  that = @

  new Promise (resolve, reject) ->
    # get users table row
    stmt = that.db.prepare 'SELECT user, login, pwdhash FROM users WHERE login = ?'
    stmt.get [login], (err, row) ->
      if err
        console.log "[FFTCGDB] login: DB fail '#{err.code}' for name '#{login}'"
        stmt.finalize()
        reject 'db'

      else if not row
        # hash the password for timing attack reasons
        bcrypt.hash password, saltRounds, (err, hash) ->
          console.log "[FFTCGDB] login: nonexistent '#{login}'"
          stmt.finalize()
          # reduce attack surface, don't disclose user names
          reject 'login' # user doesnt exist

      else
        bcrypt.compare password, row.pwdhash, (err, res) ->
          if err
            console.log "[FFTCGDB] login: hash fail for name '#{login}'"
            reject 'hash'

          if res == true
            console.log "[FFTCGDB] login: OK '#{row.login}'"
            stmt.finalize()
            # login successful
            resolve
              user: row.user
              login: row.login

          else
            console.log "[FFTCGDB] login: wrong password for '#{login}'"
            stmt.finalize()
            # login failed
            reject 'login'

FFTCGDB::addDeck = (user, deckCards) ->
  that = @

  new Promise (resolve, reject) ->
    # try creating row in decks table
    stmt = that.db.prepare 'INSERT INTO decks (user) VALUES (?)'
    stmt.run [user], (err) ->
      if err
        console.log "[FFTCGDB] addDeck: DB fail '#{err.code}' for id '#{user}'"
        stmt.finalize()
        reject 'db'

      else
        stmt.finalize()
        # deck added successfully
        deckID = @lastID
        stmt = that.db.prepare 'INSERT INTO decks_cards (deck, card, quant) VALUES (?, ?, ?)'
        # add individual cards
        that.db.parallelize ->
          # needs to be done in several queries
          promiseCount = deckCards.length
          deckCards.forEach (card) ->
            stmt.run [deckID, card.id, card.quant], (err) ->
              if err
                console.log "[FFTCGDB] addDeck: DB fail '#{err.code}' for card '#{deckID}', '#{card.id}', '#{card.quant}'"
                stmt.finalize()
                reject 'db'
              else
                # check if all queries are done
                promiseCount -= 1
                if promiseCount == 0
                  console.log "[FFTCGDB] addDeck: OK '#{user}'"
                  stmt.finalize()
                  resolve deckID

FFTCGDB::delDeck = (deck) ->
  that = @

  new Promise (resolve, reject) ->
    # try creating row in decks table
    stmt = that.db.prepare 'DELETE FROM decks WHERE deck = ?'
    stmt.run [deck], (err)


module.exports = FFTCGDB