terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = ">= 4.0"
    }
  }
}

# Define the provider
provider "aws" {
  region = "us-east-1"
}

# Define VPC
resource "aws_vpc" "prod-vpc" {
  cidr_block = "192.168.0.0/16"
  enable_dns_hostnames = true
  tags = {
    Name = "main-vpc"
  }
}

# Creating Public subnet!
resource "aws_subnet" "subnet1" {
  vpc_id            = aws_vpc.prod-vpc.id
  cidr_block        = "192.168.0.0/24"
  availability_zone = "us-east-1a"
  map_public_ip_on_launch = true
  tags = {
    Name = "Public Subnet1"
  }
}

# Creating Private subnet!
resource "aws_subnet" "subnet2" {
  vpc_id            = aws_vpc.prod-vpc.id
  cidr_block        = "192.168.1.0/24"
  availability_zone = "us-east-1b"
  tags = {
    Name = "Private Subnet1"
  }
}

# Creating 2nd Private subnet!
resource "aws_subnet" "subnet3" {
  vpc_id            = aws_vpc.prod-vpc.id
  cidr_block        = "192.168.2.0/24"
  availability_zone = "us-east-1c"
  tags = {
    Name = "Private Subnet2"
  }
}

resource "aws_db_subnet_group" "private" {
  name       = "main"
  subnet_ids = [aws_subnet.subnet2.id, aws_subnet.subnet3.id]

  tags = {
    Name = "My DB subnet group"
  }
}

# Creating an Internet Gateway for the VPC
resource "aws_internet_gateway" "Internet_Gateway" {
  vpc_id = aws_vpc.prod-vpc.id

  tags = {
    Name = "IG-Public-&-Private-VPC"
  }
}

# Creating an Route Table for the public subnet!
resource "aws_route_table" "Public-Subnet-RT" {
  vpc_id = aws_vpc.prod-vpc.id

  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.Internet_Gateway.id
  }

  tags = {
    Name = "Route Table for Internet Gateway"
  }
}

# Creating a resource for the Route Table Association!
resource "aws_route_table_association" "RT-IG-Association" {
  subnet_id       = aws_subnet.subnet1.id
  route_table_id  = aws_route_table.Public-Subnet-RT.id
}

# Define the security group for the WordPress EC2 instance
resource "aws_security_group" "wordpress_sg" {
  name_prefix = "wordpress-sg-"

  vpc_id = aws_vpc.prod-vpc.id

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

  ingress {
    from_port   = 3306
    to_port     = 3306
    protocol    = "tcp"
    security_groups = [aws_security_group.mariadb_sg.id]
  }

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

# Define the security group for the MariaDB RDS instance
resource "aws_security_group" "mariadb_sg" {
  name_prefix = "mariadb-sg-"

  vpc_id = aws_vpc.prod-vpc.id

  # Inbound traffic
  ingress {
    from_port   = 3306
    to_port     = 3306
    protocol    = "tcp"
    security_groups = [aws_security_group.wordpress_sg.id]
  }

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

# Define the EC2 instance for WordPress
resource "aws_instance" "wordpress" {
  ami           = "ami-xxxxxxxxxxxxxxx" # Replace with the desired AMI ID with AWS Linux 2 for LAMP stack
  instance_type = "t2.micro"            # The instance type to use, e.g., t2.micro

  subnet_id     = aws_subnet.subnet1.id  # Place the EC2 instance in the public subnet

  # Associate the security group with the EC2 instance
  vpc_security_group_ids = [aws_security_group.wordpress_sg.id]

  user_data = data.template_cloudinit_config.user_data.rendered

  tags = {
    Name = "WordPress-Instance"
  }
}
# Define the RDS instance
resource "aws_db_instance" "wordpressdb" {
  allocated_storage      = 20
  engine                 = "mysql"
  engine_version         = "5.7"
  instance_class         = "db.t2.micro"
  db_name                = "mydb"
  username               = "myuser"
  password               = "mypassword"
  db_subnet_group_name   = aws_db_subnet_group.private.id
  vpc_security_group_ids = [aws_security_group.mariadb_sg.id]

  tags = {
    Name = "MySQL"
  }
}
# Define the Application Load Balancer
resource "aws_lb" "wordpress_alb" {
  name               = "wordpress-alb"
  internal           = false
  load_balancer_type = "application"

  subnets         = [aws_subnet.subnet1.id, aws_subnet.subnet2.id, aws_subnet.subnet3.id]
  security_groups = [aws_security_group.wordpress_sg.id]

  tags = {
    Name = "wordpress-alb"
  }
}

# Define the ALB Target Group for the EC2 instances
resource "aws_lb_target_group" "wordpress_target_group" {
  name     = "wordpress-target-group"
  port     = 80
  protocol = "HTTP"
  vpc_id   = aws_vpc.prod-vpc.id

  health_check {
    path                = "/"
    protocol            = "HTTP"
    interval            = 30
    timeout             = 5
    healthy_threshold   = 2
    unhealthy_threshold = 2
  }
}

# Associate the EC2 instances with the ALB Target Group
resource "aws_lb_target_group_attachment" "wordpress_target_attachment" {
  target_group_arn = aws_lb_target_group.wordpress_target_group.arn
  target_id        = aws_instance.wordpress.id
  port             = 80
}

# Define the ALB Listener to forward traffic to the Target Group
resource "aws_lb_listener" "wordpress_listener" {
  load_balancer_arn = aws_lb.wordpress_alb.arn
  port              = "80"
  protocol          = "HTTP"

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

# Variables section
variable "database_user" {
  description = "Username for the WordPress database"
  default     = "myuser"
}

variable "database_password" {
  description = "Password for the WordPress database"
  default     = "mypassword"
}

variable "database_name" {
  description = "Name of the WordPress database"
  default     = "mydb"
}

# Combine Terraform template and userdata script
data "template_cloudinit_config" "user_data" {
  gzip          = true
  base64_encode = true

  part {
    content_type = "text/x-shellscript"
    content      = <<-EOF
      #!/bin/bash
      db_username=${var.database_user}
      db_user_password=${var.database_password}
      db_name=${var.database_name}
      db_RDS=${aws_db_instance.wordpressdb.endpoint}

      # Install LAMP Server
      yum update -y
      yum install -y httpd
      yum install -y mysql

      # Enable PHP 7.xx from Amazon Linux Extra and install it
      amazon-linux-extras enable php7.4
      yum clean metadata
      yum install -y php php-{pear,cgi,common,curl,mbstring,gd,mysqlnd,gettext,bcmath,json,xml,fpm,intl,zip,imap,devel}

      # Install Imagick extension
      yum -y install gcc ImageMagick ImageMagick-devel ImageMagick-perl
      pecl install imagick
      chmod 755 /usr/lib64/php/modules/imagick.so
      cat <>/etc/php.d/20-imagick.ini

      extension=imagick

      EOI

      systemctl restart php-fpm.service
      systemctl start  httpd

      # Change OWNER and permission of directory /var/www
      usermod -a -G apache ec2-user
      chown -R ec2-user:apache /var/www
      find /var/www -type d -exec chmod 2775 {} \;
      find /var/www -type f -exec chmod 0664 {} \;

      yum -y install mariadb-server
      service mariadb start

      # Install WordPress using WP CLI
      curl -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar
      chmod +x wp-cli.phar
      mv wp-cli.phar /usr/local/bin/wp
      wp core download --path=/var/www/html --allow-root
      wp config create --dbname=$db_name --dbuser=$db_username --dbpass=$db_user_password --dbhost=$db_RDS --path=/var/www/html --allow-root --extra-php </,/<\/Directory>/ s/AllowOverride None/AllowOverride all/' /etc/httpd/conf/httpd.conf

      # Make Apache autostart and restart Apache
      systemctl enable httpd.service
      systemctl restart httpd.service

      echo "WordPress Installed"
    EOF
  }
}