# create vpc

resource "aws_vpc" "main" {
  cidr_block       = var.cidr
  instance_tenancy = "default"

  tags = {
    Name = var.vpc_name
  }
}

resource "aws_subnet" "subnet1" {
  vpc_id            = aws_vpc.main.id
  cidr_block        = var.subnet1_cidr
  availability_zone = "us-east-1a"

  tags = {
    Name = "pub-subnet1"
  }
}


resource "aws_subnet" "subnet2" {
  vpc_id            = aws_vpc.main.id
  cidr_block        = var.subnet2_cidr
  availability_zone = "us-east-1b"

  tags = {
    Name = "pub-subnet2"
  }
}

resource "aws_subnet" "subnet3" {
  vpc_id            = aws_vpc.main.id
  cidr_block        = var.subnet3_cidr
  availability_zone = "us-east-1a"

  tags = {
    Name = "pvt-subnet1"
  }
}


resource "aws_subnet" "subnet4" {
  vpc_id            = aws_vpc.main.id
  cidr_block        = var.subnet4_cidr
  availability_zone = "us-east-1b"

  tags = {
    Name = "pvt-subnet2"
  }
}


resource "aws_internet_gateway" "web-gw" {
  vpc_id = aws_vpc.main.id

  tags = {
    Name = "web-internetgateway"
  }
}

resource "aws_route_table" "pubroute" {
  vpc_id = aws_vpc.main.id

  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.web-gw.id
  }


  tags = {
    Name = "pubroute"
  }
}

resource "aws_route_table" "pvtroute" {
  vpc_id = aws_vpc.main.id

 
  tags = {
    Name = "pvtroute"
  }
}

resource "aws_route_table_association" "pubsub1" {
  subnet_id      = aws_subnet.subnet1.id
  route_table_id = aws_route_table.pubroute.id
}

resource "aws_route_table_association" "pvtsub2" {
  subnet_id      = aws_subnet.subnet2.id
  route_table_id = aws_route_table.pubroute.id
}


resource "aws_route_table_association" "pvtsub1" {
  subnet_id      = aws_subnet.subnet3.id
  route_table_id = aws_route_table.pvtroute.id
}

resource "aws_route_table_association" "pvtsub2" {
  subnet_id      = aws_subnet.subnet4.id
  route_table_id = aws_route_table.pvtroute.id
}


############  EC2 Creation with ALB & Auto scaling Group ##########

resource "aws_security_group" "web_sg" {
  name_prefix = "web-sg-"

  # Inbound rule for SSH traffic
  ingress {
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"] 
  }

  # Inbound rule for HTTP traffic
  ingress {
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"] 
  }

  # Inbound rule for HTTPS traffic
  ingress {
    from_port   = 443
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"] 
  }

 # Outbound rule allowing all traffic
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}


resource "aws_launch_configuration" "web_lc" {
  name_prefix   = "web-lc"
  image_id      = var.ami
  instance_type = var.instance_type

  security_groups = [aws_security_group.web_sg.id]
  key_name = var.keyname
  user_data = <<-EOF
              #!/bin/bash
              apt update
              apt upgrade -y
              EOF

  lifecycle {
    create_before_destroy = true
  }
}

resource "aws_autoscaling_group" "web_asg" {
  name_prefix = "web-asg"
  min_size     = 2
  max_size     = 5
  desired_capacity = 2
  launch_configuration = aws_launch_configuration.web_lc.name

  // Define your load balancer target group ARNs here
}

resource "aws_lb" "example_alb" {
  name               = "web-alb"
  internal           = false
  load_balancer_type = "application"
  subnets            = [aws_subnet.subnet1.id, aws_subnet.subnet2.id] 
}

resource "aws_lb_listener" "example_listener" {
  load_balancer_arn = aws_lb.example_alb.arn
  port              = 80
  protocol          = "HTTP"

  default_action {
    type             = "fixed-response"
    fixed_response {
      content_type = "/"
      status_code  = "200"
    }
  }
}

resource "aws_lb_target_group" "web_target_group" {
  name     = "web-target-group"
  port     = 80
  protocol = "HTTP"
  vpc_id   = aws_vpc.main.id  
}

resource "aws_autoscaling_attachment" "web_asg_attachment" {
  autoscaling_group_name = aws_autoscaling_group.web_asg.name
  alb_target_group_arn   = aws_lb_target_group.web_target_group.arn
}