resource "aws_rds_cluster" "main" {
  cluster_identifier                  = local.aurora_cluster_identifier
  database_name                       = local.aurora_database_name
  master_username                     = local.aurora_master_username
  master_password                     = local.aurora_master_password
  db_cluster_parameter_group_name     = aws_rds_cluster_parameter_group.main.name
  db_subnet_group_name                = data.aws_db_subnet_group.main.name
  deletion_protection                 = true
  skip_final_snapshot                 = false
  engine                              = "aurora-mysql"
  engine_version                      = "5.7.mysql_aurora.2.07.1"
  engine_mode                         = "serverless"
  backup_retention_period             = 7
  storage_encrypted                   = true
  iam_database_authentication_enabled = false
  enable_http_endpoint                = true

  scaling_configuration {
    min_capacity = 2
    max_capacity = 256
    auto_pause   = true
  }

  lifecycle {
    ignore_changes = [
      availability_zones,
      engine_version,
      master_username,
      master_password,
    ]
  }
}

resource "aws_rds_cluster_parameter_group" "main" {
  name        = "cluster-pg"
  family      = "aurora-mysql5.7"
  description = "RDS cluster parameter group"
  parameter {
    name  = "character_set_server"
    value = "utf8"
  }
  parameter {
    name  = "character_set_client"
    value = "utf8"
  }
  parameter {
    apply_method = "immediate"
    name         = "server_audit_events"
    value        = "QUERY"
  }
  parameter {
    apply_method = "immediate"
    name         = "server_audit_logging"
    value        = "1"
  }
  parameter {
    apply_method = "immediate"
    name         = "time_zone"
    value        = "Asia/Tokyo"
  }
}

resource "random_password" "main" {
  length           = 16
  special          = true
  override_special = "_!%^"
}

resource "aws_rds_cluster" "main" {
  cluster_identifier                  = local.aurora_cluster_identifier
  engine                              = "aurora-postgresql"
  engine_version                      = "13.6"
  engine_mode                         = "provisioned"
  master_username                     = local.aurora_master_username
  master_password                     = local.aurora_master_password
  port                                = 5432
  database_name                       = local.aurora_database_name
  vpc_security_group_ids              = [aws_security_group.aurora.id]
  db_subnet_group_name                = aws_db_subnet_group.main.name
  db_cluster_parameter_group_name     = aws_rds_cluster_parameter_group.main.name
  iam_database_authentication_enabled = true

  serverlessv2_scaling_configuration {
    min_capacity = 0.5
    max_capacity = 1.0
  }

  skip_final_snapshot = true
  apply_immediately   = true
}

resource "aws_rds_cluster_instance" "main" {
  cluster_identifier = aws_rds_cluster.main.id
  identifier         = "${local.aurora_cluster_identifier}-serverless-instance"
  engine                  = aws_rds_cluster.main.engine
  engine_version          = aws_rds_cluster.main.engine_version
  instance_class          = "db.serverless"
  db_subnet_group_name    = aws_db_subnet_group.main.name
  db_parameter_group_name = aws_db_parameter_group.main.name

  monitoring_role_arn = aws_iam_role.aurora_monitoring.arn
  monitoring_interval = 60

  publicly_accessible = true
}

resource "aws_db_subnet_group" "main" {
  name       = local.db_subnet_group_name
  subnet_ids = data.aws_subnet_ids.main.ids
}

resource "aws_rds_cluster_parameter_group" "main" {
  name   = local.cluster_parameter_group_name
  family = "aurora-postgresql13"
}

resource "aws_db_parameter_group" "main" {
  name   = local.db_parameter_group_name
  family = "aurora-postgresql13"

  parameter {
    apply_method = "pending-reboot"
    name         = "shared_preload_libraries"
    value        = "pg_stat_statements,pg_hint_plan"
  }
}