require 'mysql2'
require 'flydata/compatibility_check'
require 'flydata-core/mysql/config'
require 'flydata-core/mysql/command_generator'
require 'flydata-core/mysql/compatibility_checker'
require 'flydata-core/errors'

module Flydata
module SourceMysql

  class MysqlCompatibilityCheck < CompatibilityCheck
    include InitialSyncChecks

    def initialize(dp_hash, de_hash, options={})
      super
      @db_opts = FlydataCore::Mysql::Config.build_mysql_db_opts(de_hash)
      @dump_dir = options[:dump_dir] || nil
      @backup_dir = options[:backup_dir] || nil
      @tables = de_hash['tables']
    end

    def print_errors
      return if @errors.empty?
      log_error_stderr "There may be some compatibility issues with your MySQL credentials: "
      @errors.each do |error|
        log_error_stderr "  * #{error.message}"
      end
      raise "Please correct these errors if you wish to run FlyData Sync"
    end

    def check_compatibility56_variable
      FlydataCore::Mysql::MySqlVersion57CompabilityChecker.new(@db_opts).do_check
    end

    def check_mysql_user_compat
      FlydataCore::Mysql::SyncPermissionChecker.new(@db_opts).do_check
    end

    def check_mysql_protocol_tcp_compat
      query = FlydataCore::Mysql::CommandGenerator.generate_mysql_show_grants_cmd(@db_opts)

      Open3.popen3(query) do |stdin, stdout, stderr|
        stdin.close
        while !stderr.eof?
          lines = []
          while line = stderr.gets do
            lines << line.strip unless line =~ /Warning: Using a password on the command line interface can be insecure/
          end
          unless lines.empty?
            err_reason = lines.join(" ")
            log_error("Error occured during access to mysql server.", err: err_reason)
            raise FlydataCore::MysqlCompatibilityError, "Cannot connect to MySQL database. Please make sure you can connect with this command:\n      $ mysql -u #{@db_opts[:username]} -h #{@db_opts[:host]} -P #{@db_opts[:port]} #{@db_opts[:database]} --protocol=tcp -p"
          end
        end
      end
    end

    def check_rds_master_status
      if is_rds?
        FlydataCore::Mysql::RdsMasterStatusChecker.new(@db_opts).do_check
      end
    end

    def check_mysql_parameters_compat
      begin
        FlydataCore::Mysql::OptionalBinlogParameterChecker.new(@db_opts).do_check
      rescue FlydataCore::MysqlCompatibilityError => e
        log_warn_stderr(e.to_s)
      end
      FlydataCore::Mysql::RequiredBinlogParameterChecker.new(@db_opts).do_check
    end

    def check_mysql_binlog_retention
      if is_rds?
        run_rds_retention_check
      else
        run_mysql_retention_check
      end
    end

    # If table_type='VIEW' or engine='MEMORY', raise error.
    def check_mysql_table_types
      return if @tables.empty?
      option = @db_opts.dup.merge(tables: @tables)
      FlydataCore::Mysql::TableTypeChecker.new(option).do_check
    end

    def run_mysql_retention_check
      FlydataCore::Mysql::NonRdsRetentionChecker.new(@db_opts).do_check
    end

    def run_rds_retention_check
      FlydataCore::Mysql::RdsRetentionChecker.new(@db_opts).do_check
    rescue Mysql2::Error => e
      if e.message =~ /command denied to user/
        retention_hours = FlydataCore::Mysql::RdsRetentionChecker::BINLOG_RETENTION_HOURS
        log_warn_stderr("[WARNING]Cannot verify RDS retention period on current MySQL user account.\n" +
                        "To see retention period, please run this on your RDS:\n" +
                        "  $> call mysql.rds_show_configuration;\n" +
                        "Please verify that the hours is not nil and is at least #{retention_hours} hours\n" +
                        "To set binlog retention hours, you can run this on your RDS:\n" +
                        "  $> call mysql.rds_set_configuration('binlog retention hours', #{retention_hours});\n"
                       )
      else
        raise e
      end
    end

    def is_rds?(hostname = @db_opts[:host])
      hostname.match(/rds.amazonaws.com$/) != nil
    end
  end

end
end