resource "aws_security_group" "instance" {
  name        = "forgejo"
  description = "Forgejo git server"
  vpc_id      = var.existing_vpc_id
}

resource "aws_vpc_security_group_ingress_rule" "instance_http_alb" {
  security_group_id            = aws_security_group.instance.id
  referenced_security_group_id = aws_security_group.alb.id
  from_port                    = 3000
  to_port                      = 3000
  ip_protocol                  = "tcp"
  description                  = "HTTP from the Forgejo ALB"
}

resource "aws_vpc_security_group_ingress_rule" "instance_http_vpc" {
  security_group_id = aws_security_group.instance.id
  cidr_ipv4         = local.vpc_cidr
  from_port         = 3000
  to_port           = 3000
  ip_protocol       = "tcp"
  description       = "HTTP from the prod VPC"
}

resource "aws_vpc_security_group_ingress_rule" "instance_http_office" {
  security_group_id = aws_security_group.instance.id
  cidr_ipv4         = local.office_vpn_cidr
  from_port         = 3000
  to_port           = 3000
  ip_protocol       = "tcp"
  description       = "HTTP from the office VPN. 10.10 is not routed to 10.70 yet."
}

resource "aws_vpc_security_group_ingress_rule" "instance_ssh_vpc" {
  security_group_id = aws_security_group.instance.id
  cidr_ipv4         = local.vpc_cidr
  from_port         = 2222
  to_port           = 2222
  ip_protocol       = "tcp"
  description       = "Git SSH from the prod VPC"
}

resource "aws_vpc_security_group_ingress_rule" "instance_ssh_office" {
  security_group_id = aws_security_group.instance.id
  cidr_ipv4         = local.office_vpn_cidr
  from_port         = 2222
  to_port           = 2222
  ip_protocol       = "tcp"
  description       = "Git SSH from the office VPN. 10.10 is not routed to 10.70 yet."
}

resource "aws_vpc_security_group_egress_rule" "instance_all" {
  security_group_id = aws_security_group.instance.id
  cidr_ipv4         = "0.0.0.0/0"
  ip_protocol       = "-1"
  description       = "Outbound for GitHub, Codeberg, S3, and SSM"
}

resource "aws_instance" "forgejo" {
  ami                         = var.ami_id
  instance_type               = "t4g.small"
  subnet_id                   = local.instance_subnet_id
  vpc_security_group_ids      = [aws_security_group.instance.id]
  iam_instance_profile        = aws_iam_instance_profile.forgejo.name
  associate_public_ip_address = true
  user_data                   = local.user_data
  user_data_replace_on_change = true

  metadata_options {
    http_endpoint = "enabled"
    http_tokens   = "required"
  }

  root_block_device {
    volume_size           = 20
    volume_type           = "gp3"
    encrypted             = true
    delete_on_termination = true
  }

  tags = {
    Name           = "forgejo"
    forgejo-backup = "true"
  }
}

resource "aws_ebs_volume" "data" {
  availability_zone = data.aws_subnet.instance.availability_zone
  size              = 50
  type              = "gp3"
  encrypted         = true

  tags = {
    Name           = "forgejo-data"
    forgejo-backup = "true"
  }

  lifecycle {
    prevent_destroy = true
  }
}

resource "aws_volume_attachment" "data" {
  device_name                    = "/dev/xvdf"
  volume_id                      = aws_ebs_volume.data.id
  instance_id                    = aws_instance.forgejo.id
  stop_instance_before_detaching = true
}

resource "aws_ssm_parameter" "backup_prefix" {
  name        = "/forgejo/backup-s3-prefix"
  description = "S3 key prefix for Forgejo backup dumps"
  type        = "String"
  value       = local.backup_s3_prefix
}

resource "aws_dlm_lifecycle_policy" "snapshots" {
  description        = "Nightly EBS snapshots for Forgejo"
  execution_role_arn = aws_iam_role.dlm.arn
  state              = "ENABLED"

  policy_details {
    resource_types = ["INSTANCE"]
    target_tags = {
      forgejo-backup = "true"
    }

    schedule {
      name = "forgejo-nightly"

      create_rule {
        interval      = 24
        interval_unit = "HOURS"
        times         = ["06:00"]
      }

      retain_rule {
        count = 30
      }

      copy_tags = true

      tags_to_add = {
        forgejo-backup = "true"
      }
    }
  }
}