import sqlite3 from 'sqlite3'
import bcrypt from 'bcryptjs'
import ErrorType from '../error/types.error.js'
import serverConfig from '../configuration/server.config.js'

sqlite3.verbose()

const tableName = 'Users'

class User {
  constructor(options = {}) {
    if (!options.username || !options.password) {
      throw new Error('User has to have a username, a password')
    }
    this.username = options.username
    this.password_ = options.password
  }

  static findAll() {
    return new Promise((resolve, reject) => {
      const db = openDB()
      db.serialize(() => {
        db.all(`SELECT * FROM ${tableName}`, (err, users) => {
          if (err) reject(new Error(ErrorType.TECHNICAL_UNKNOWN))
          else {
            const array = [];
            for (const user of users) {
              array.push(createUserFromDB(user))
            }
            resolve(array);
          }
        })
        closeDB(db)
      })
    })
  }

  static findByName(username) {
    return new Promise((resolve, reject) => {
      const db = openDB();
      db.serialize(() => {
        db.get(`SELECT * FROM ${tableName} WHERE username = '${username}'`, (err, user) => {
          if (err) reject(new Error(ErrorType.TECHNICAL_UNKNOWN))
          else {
            if (user) resolve(createUserFromDB(user))
            else resolve(null)
          }
        })
      })
      closeDB(db)
    })
  }

  static delete(username) {
    return new Promise((resolve, reject) => {
      const db = openDB();
      db.serialize(() => {
        db.run(`DELETE FROM ${tableName} WHERE username = '${username}'`, (err, user) => {
          if (err) reject(new Error(ErrorType.TECHNICAL_UNKNOWN))
          else resolve(user)
        })
      })
      closeDB(db)
    })
  }

  async insert() {
    this.password_ = await hashPassword(this.password);
    await this.write_();
  }

  async update() {
    if (this.isModifiedPassword_) {
      this.password_ = await hashPassword(this.password);
    }
    await this.write_();
  }

  write_() {
    return new Promise((resolve, reject) => {
      const values = `'${this.username}', '${this.password}'`;
      const db = openDB();
      db.serialize(() => {
        db.run(`INSERT OR REPLACE INTO ${tableName} (username, password) VALUES (${values})`, err => {
          if (err) reject(new Error(ErrorType.TECHNICAL_UNKNOWN))
          else resolve()
        })
      })
      closeDB(db)
    })
  }

  comparePassword(candidatePassword) {
    return bcrypt.compare(candidatePassword, this.password);
  }

  toJson() {
    return {
      username: this.username
    }
  }

  get password() {
    return this.password_
  }

  set password(newPassword) {
    this.password_ = newPassword
    this.isModifiedPassword_ = true
    this.activated = true
  }
}

export default User

function openDB() {
  const env = process.env.NODE_ENV || 'development'
  return new sqlite3.Database(serverConfig.database[env].path, err => {
    if (err) throw new Error(err)
  })
}

function closeDB(db) {
  db.close(err => {
    if (err) throw new Error(err)
  })
}

function createUserFromDB(dbUser) {
  return new User({
    username: dbUser.username,
    password: dbUser.password
  })
}

async function hashPassword(password) {
  const salt = await bcrypt.genSalt(10)
  return bcrypt.hash(password, salt)
}