provider "aws" {
  region = "eu-central-1"
}

resource "aws_vpc" "main" {
  cidr_block = "10.0.0.0/16"

  tags = {
    Name = "gitea-vpc"
  }
}

resource "aws_subnet" "public_subnet" {
  vpc_id                  = aws_vpc.main.id
  cidr_block              = "10.0.0.0/24"
  availability_zone       = "eu-central-1a"
  map_public_ip_on_launch = true
  tags = {
    Name = "gitea-public-subnet"
  }
}

resource "aws_subnet" "private_subnet_server" {
  vpc_id                  = aws_vpc.main.id
  cidr_block              = "10.0.1.0/24"
  availability_zone       = "eu-central-1a"
  map_public_ip_on_launch = false
  tags = {
    Name = "gitea-server-private-subnet"
  }
}

resource "aws_subnet" "private_subnet_db" {
  vpc_id                  = aws_vpc.main.id
  cidr_block              = "10.0.2.0/24"
  availability_zone       = "eu-central-1a"
  map_public_ip_on_launch = false
  tags = {
    Name = "gitea-db-private-subnet"
  }
}

resource "aws_internet_gateway" "ig" {
  vpc_id = aws_vpc.main.id
  tags = {
    Name = "gitea-igw"
  }
}

resource "aws_eip" "nat_eip" {
  vpc = true
}

resource "aws_nat_gateway" "nat" {
  allocation_id = aws_eip.nat_eip.id
  subnet_id     = element(aws_subnet.public_subnet.*.id, 0)
  tags = {
    Name = "gitea-nat"
  }
}

resource "aws_route_table" "private" {
  vpc_id = aws_vpc.main.id
  tags = {
    Name = "gitea-private-route-table"
  }
}

resource "aws_route_table" "public" {
  vpc_id = aws_vpc.main.id
  tags = {
    Name = "gitea-public-route-table"
  }
}

resource "aws_route" "public_internet_gateway" {
  route_table_id         = aws_route_table.public.id
  destination_cidr_block = "0.0.0.0/0"
  gateway_id             = aws_internet_gateway.ig.id
}
resource "aws_route" "private_nat_gateway" {
  route_table_id         = aws_route_table.private.id
  destination_cidr_block = "0.0.0.0/0"
  nat_gateway_id         = aws_nat_gateway.nat.id
}

resource "aws_route_table_association" "public" {
  subnet_id      = aws_subnet.public_subnet.id
  route_table_id = aws_route_table.public.id
}
resource "aws_route_table_association" "private_server" {
  subnet_id      = aws_subnet.private_subnet_server.id
  route_table_id = aws_route_table.private.id
}
resource "aws_route_table_association" "private_db" {
  subnet_id      = aws_subnet.private_subnet_db.id
  route_table_id = aws_route_table.private.id
}

resource "aws_security_group" "default" {
  name        = "gitea-default-sg"
  description = "Default security group to allow inbound/outbound from the VPC"
  vpc_id      = aws_vpc.main.id
  ingress {
    description      = "SSH from VPC"
    from_port        = 22
    to_port          = 22
    protocol         = "tcp"
    cidr_blocks      = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }
  ingress {
    description      = "SSH from VPC"
    from_port        = 2222
    to_port          = 2222
    protocol         = "tcp"
    cidr_blocks      = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }

  ingress {
    description      = "HTTP from VPC"
    from_port        = 80
    to_port          = 80
    protocol         = "tcp"
    cidr_blocks      = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }
 ingress {
    description      = "HTTP from VPC"
    from_port        = 443
    to_port          = 443
    protocol         = "tcp"
    cidr_blocks      = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }

  ingress {
    description      = "HTTP from VPC"
    from_port        = 3000
    to_port          = 3000
    protocol         = "tcp"
    cidr_blocks      = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }

  ingress {
    description      = "HTTP from VPC"
    from_port        = 5432
    to_port          = 5432
    protocol         = "tcp"
    cidr_blocks      = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }

  egress {
    from_port        = 0
    to_port          = 0
    protocol         = "-1"
    cidr_blocks      = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }
}

data "aws_ami" "ubuntu" {
  most_recent = true

  filter {
    name   = "name"
    values = ["ubuntu/images/hvm-ssd/ubuntu-*20*-amd64-server-*"]
  }

  filter {
    name   = "virtualization-type"
    values = ["hvm"]
  }

  owners = ["099720109477"] # Canonical
}

data "template_file" "user_data_server" {
  template = file("server.yaml")

  vars = {
    private_ip = "${aws_instance.db.private_ip}:5432"
  }
}
data "template_file" "user_data_db" {
  template = file("db.yaml")
  vars = {
    fes_address = aws_efs_mount_target.alpha.dns_name
  }
}

resource "aws_instance" "server" {
  ami                    = data.aws_ami.ubuntu.id
  instance_type          = "t2.micro"
  subnet_id              = aws_subnet.private_subnet_server.id
  vpc_security_group_ids = [aws_security_group.default.id]
  user_data              = data.template_file.user_data_server.rendered

  tags = {
    Name = "ec2-gitea-server"
  }
}

resource "aws_instance" "db" {
  ami                    = data.aws_ami.ubuntu.id
  instance_type          = "t2.micro"
  subnet_id              = aws_subnet.private_subnet_db.id
  vpc_security_group_ids = [aws_security_group.default.id]
  user_data              = data.template_file.user_data_db.rendered

  tags = {
    Name = "ec2-gitea-db"
  }
}


resource "aws_lb" "lb" {
  name               = "gitea-lb"
  internal           = false
  load_balancer_type = "network"
  subnet_mapping {
      subnet_id = aws_subnet.public_subnet.id
  }
}

resource "aws_lb_listener" "main_80" {
  load_balancer_arn = aws_lb.lb.arn
  port              = "80"
  protocol          = "TCP"

  default_action {
    type             = "forward"
    target_group_arn = aws_lb_target_group.main.arn
  }
}

resource "aws_lb_listener" "main_443" {
  load_balancer_arn = aws_lb.lb.arn
  port              = "443"
  protocol          = "TCP"

  default_action {
    type             = "forward"
    target_group_arn = aws_lb_target_group.main.arn
  }
}

resource "aws_lb_listener" "main_22" {
  load_balancer_arn = aws_lb.lb.arn
  port              = "22"
  protocol          = "TCP"

  default_action {
    type             = "forward"
    target_group_arn = aws_lb_target_group.main_ssh.arn
  }
}

resource "aws_lb_target_group" "main" {
  name     = "tg"
  port     = 80
  protocol = "TCP"
  vpc_id   = aws_vpc.main.id
}


resource "aws_lb_target_group" "main_ssh" {
  name     = "tg-ssh"
  port     = 22
  protocol = "TCP"
  vpc_id   = aws_vpc.main.id
}

resource "aws_lb_target_group_attachment" "tg_attch_ssh" {
  target_group_arn = aws_lb_target_group.main_ssh.arn
  target_id        = aws_instance.server.id
  port             = 2222
}


resource "aws_lb_target_group_attachment" "tg_attch" {
  target_group_arn = aws_lb_target_group.main.arn
  target_id        = aws_instance.server.id
  port             = 3000
}


resource "aws_efs_file_system" "file_system" {
  availability_zone_name = "eu-central-1a"
  tags = {
    Name = "gitea-efs"
  }
}

resource "aws_efs_mount_target" "alpha" {
  file_system_id = aws_efs_file_system.file_system.id
  subnet_id      = aws_subnet.private_subnet_db.id
  security_groups = [aws_security_group.default.id]
}


output "lb_ip" {
  value = "http://${aws_lb.lb.dns_name}"
}