class Baza::Driver::ActiveRecord < Baza::BaseSqlDriver
  AutoAutoloader.autoload_sub_classes(self, __FILE__)

  attr_reader :db, :conn, :sep_table, :sep_col, :sep_val, :symbolize, :driver_type
  attr_accessor :tables, :cols, :indexes

  def self.from_object(args)
    if args[:object].class.name.include?("ActiveRecord::ConnectionAdapters")
      if args[:object].class.name.include?("ConnectionPool")
        object_to_use = args[:object].connection
      else
        object_to_use = args[:object]
      end

      return {
        type: :success,
        args: {
          type: :active_record,
          conn: object_to_use
        }
      }
    end

    nil
  end

  def initialize(db)
    @db = db
    @conn = @db.opts.fetch(:conn)

    raise "No conn given" unless @conn

    conn_name = @conn.class.name.to_s.downcase

    if conn_name.include?("mysql2")
      require_relative "mysql2"
      require_relative "mysql2/result"

      @sep_database = "`"
      @sep_table = "`"
      @sep_col = "`"
      @sep_val = "'"
      @sep_index = "`"
      @driver_type = :mysql2
      @result_constant = Baza::Driver::Mysql2::Result
    elsif conn_name.include?("mysql")
      unless RUBY_PLATFORM == "java"
        require_relative "mysql"
        require_relative "mysql/result"
        @result_constant = Baza::Driver::Mysql::Result
      end

      @sep_database = "`"
      @sep_table = "`"
      @sep_col = "`"
      @sep_val = "'"
      @sep_index = "`"
      @driver_type = :mysql
    elsif conn_name.include?("sqlite")
      @sep_database = "`"
      @sep_table = "`"
      @sep_col = "`"
      @sep_val = "'"
      @sep_index = "`"
      @driver_type = :sqlite3
    elsif conn_name.include?("postgresqladapter")
      @sep_database = '"'
      @sep_table = '"'
      @sep_col = '"'
      @sep_index = '"'
      @sep_val = "'"
      @driver_type = :pg
      @result_constant = Baza::Driver::Pg::Result
    else
      raise "Unknown type: '#{conn_name}'"
    end

    @result_constant ||= Baza::Driver::ActiveRecord::Result

    if conn_name.include?("mysql")
      @db.opts[:db] ||= query("SELECT DATABASE()").fetch.fetch(:"DATABASE()")
    elsif @driver_type == :pg
      @conn.reconnect! unless postgres_connection_active?
      @db.opts[:db] ||= query("SELECT current_database()").fetch.values.first
    end
  end

  def postgres_connection_active?
    @conn.active?
  rescue PG::ConnectionBad
    true
  end

  def query(sql)
    @result_constant.new(self, @conn.execute(sql))
  end

  alias query_ubuf query

  def escape(str)
    @conn.quote_string(str.to_s)
  end

  def escape_column(string)
    string = string.to_s
    raise "Invalid column-string: #{string}" if string.include?(@sep_col)
    string
  end

  def escape_table(string)
    string = string.to_s
    raise "Invalid column-string: #{string}" if string.include?(@sep_col)
    string
  end

  def close
    @conn.close
  end

  def transaction
    if @driver_type == :mysql || @driver_type == :mysql2 || @driver_type == :pg
      query("START TRANSACTION")
    elsif @driver_type == :sqlite3
      query("BEGIN TRANSACTION")
    else
      raise "Don't know how to start transaction"
    end

    begin
      yield @db
      query("COMMIT")
    rescue
      query("ROLLBACK")
      raise
    end
  end

  def supports_multiple_databases?
    conn_name.include?("mysql") || @driver_type == :pg
  end

  def save_model!(model, args = {})
    raise ActiveRecord::InvalidRecord, model if (!args.key?(:validate) || args[:validate]) && !model.valid?

    attributes = {}
    model.changes.each do |column_name, value_array|
      attributes[column_name.to_s] = value_array.last
    end

    attributes = attributes.delete_if { |_key, value| value.nil? } if model.new_record?

    table_name = model.class.table_name

    if model.new_record?
      if args[:update_on_duplicate_key]
        id = @db.upsert_duplicate_key(table_name, attributes, {}, return_id: true)
      else
        id = @db.insert(table_name, attributes, return_id: true)
      end

      if id && id.to_i > 0
        model.id = id
      else
        raise "Invalid ID: #{id}" unless id.to_i > 0
      end
    else
      @db.update(table_name, attributes, id: model.id)
    end

    model.reload
  end
end