# frozen_string_literal: true

require "yaml"

module Backup
  class Database
    attr_reader :progress
    attr_reader :config, :db_file_name

    def initialize(progress)
      @progress = progress
      @config = YAML.load_file(File.join(Rails.root, "config", "database.yml"))[Rails.env]
      @db_file_name = File.join(Gitlab.config.backup.path, "db", "database.sql.gz")
    end

    def dump
      FileUtils.mkdir_p(File.dirname(db_file_name))
      FileUtils.rm_f(db_file_name)
      compress_rd, compress_wr = IO.pipe
      compress_pid = spawn("gzip", "-1", "-c", in: compress_rd, out: [db_file_name, "w", 0o600])
      compress_rd.close

      dump_pid =
        case config["adapter"]
        when /^mysql/ then
          progress.print "Dumping MySQL database #{config["database"]} ... "
          # Workaround warnings from MySQL 5.6 about passwords on cmd line
          ENV["MYSQL_PWD"] = config["password"].to_s if config["password"]
          spawn("mysqldump", *mysql_args, config["database"], out: compress_wr)
        when "postgresql" then
          progress.print "Dumping PostgreSQL database #{config["database"]} ... "
          pg_env
          pgsql_args = ["--clean"] # Pass '--clean' to include 'DROP TABLE' statements in the DB dump.
          if Gitlab.config.backup.pg_schema
            pgsql_args << "-n"
            pgsql_args << Gitlab.config.backup.pg_schema
          end

          spawn("pg_dump", *pgsql_args, config["database"], out: compress_wr)
        end
      compress_wr.close

      success = [compress_pid, dump_pid].all? { |pid|
        Process.waitpid(pid)
        $?.success?
      }

      report_success(success)
      raise Backup::Error, "Backup failed" unless success
    end

    def restore
      decompress_rd, decompress_wr = IO.pipe
      decompress_pid = spawn("gzip", "-cd", out: decompress_wr, in: db_file_name)
      decompress_wr.close

      restore_pid =
        case config["adapter"]
        when /^mysql/ then
          progress.print "Restoring MySQL database #{config["database"]} ... "
          # Workaround warnings from MySQL 5.6 about passwords on cmd line
          ENV["MYSQL_PWD"] = config["password"].to_s if config["password"]
          spawn("mysql", *mysql_args, config["database"], in: decompress_rd)
        when "postgresql" then
          progress.print "Restoring PostgreSQL database #{config["database"]} ... "
          pg_env
          spawn("psql", config["database"], in: decompress_rd)
        end
      decompress_rd.close

      success = [decompress_pid, restore_pid].all? { |pid|
        Process.waitpid(pid)
        $?.success?
      }

      report_success(success)
      abort Backup::Error, "Restore failed" unless success
    end

    protected

    def mysql_args
      args = {
        "host" => "--host",
        "port" => "--port",
        "socket" => "--socket",
        "username" => "--user",
        "encoding" => "--default-character-set",
        # SSL
        "sslkey" => "--ssl-key",
        "sslcert" => "--ssl-cert",
        "sslca" => "--ssl-ca",
        "sslcapath" => "--ssl-capath",
        "sslcipher" => "--ssl-cipher",
      }
      args.map { |opt, arg| "#{arg}=#{config[opt]}" if config[opt] }.compact
    end

    def pg_env
      args = {
        "username" => "PGUSER",
        "host" => "PGHOST",
        "port" => "PGPORT",
        "password" => "PGPASSWORD",
        # SSL
        "sslmode" => "PGSSLMODE",
        "sslkey" => "PGSSLKEY",
        "sslcert" => "PGSSLCERT",
        "sslrootcert" => "PGSSLROOTCERT",
        "sslcrl" => "PGSSLCRL",
        "sslcompression" => "PGSSLCOMPRESSION",
      }
      args.each { |opt, arg| ENV[arg] = config[opt].to_s if config[opt] }
    end

    def report_success(success)
      if success
        progress.puts "[DONE]".color(:green)
      else
        progress.puts "[FAILED]".color(:red)
      end
    end
  end
end