# VPC for meteor application (only if using Fargate)
resource "aws_vpc" "main" {
  count                = var.enable_fargate ? 1 : 0
  cidr_block           = "10.0.0.0/16"
  enable_dns_hostnames = true
  enable_dns_support   = true

  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-vpc"
  })
}

# Internet Gateway
resource "aws_internet_gateway" "main" {
  count  = var.enable_fargate ? 1 : 0
  vpc_id = aws_vpc.main[0].id

  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-igw"
  })
}

# Data source for availability zones
data "aws_availability_zones" "available" {
  state = "available"
}

# Public Subnets
resource "aws_subnet" "public" {
  count = var.enable_fargate ? 2 : 0

  vpc_id                  = aws_vpc.main[0].id
  cidr_block              = "10.0.${count.index + 1}.0/24"
  availability_zone       = data.aws_availability_zones.available.names[count.index]
  map_public_ip_on_launch = true

  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-public-subnet-${count.index + 1}"
    Type = "Public"
  })
}

# Private Subnets
resource "aws_subnet" "private" {
  count = var.enable_fargate ? 2 : 0

  vpc_id            = aws_vpc.main[0].id
  cidr_block        = "10.0.${count.index + 10}.0/24"
  availability_zone = data.aws_availability_zones.available.names[count.index]

  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-private-subnet-${count.index + 1}"
    Type = "Private"
  })
}

# Elastic IPs for NAT Gateways
resource "aws_eip" "nat" {
  count  = var.enable_fargate ? 2 : 0
  domain = "vpc"

  depends_on = [aws_internet_gateway.main]

  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-nat-eip-${count.index + 1}"
  })
}

# NAT Gateways
resource "aws_nat_gateway" "main" {
  count = var.enable_fargate ? 2 : 0

  allocation_id = aws_eip.nat[count.index].id
  subnet_id     = aws_subnet.public[count.index].id

  depends_on = [aws_internet_gateway.main]

  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-nat-${count.index + 1}"
  })
}

# Route Table for Public Subnets
resource "aws_route_table" "public" {
  count  = var.enable_fargate ? 1 : 0
  vpc_id = aws_vpc.main[0].id

  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.main[0].id
  }

  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-public-rt"
  })
}

# Route Table Associations for Public Subnets
resource "aws_route_table_association" "public" {
  count = var.enable_fargate ? 2 : 0

  subnet_id      = aws_subnet.public[count.index].id
  route_table_id = aws_route_table.public[0].id
}

# Route Tables for Private Subnets
resource "aws_route_table" "private" {
  count = var.enable_fargate ? 2 : 0

  vpc_id = aws_vpc.main[0].id

  route {
    cidr_block     = "0.0.0.0/0"
    nat_gateway_id = aws_nat_gateway.main[count.index].id
  }

  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-private-rt-${count.index + 1}"
  })
}

# Route Table Associations for Private Subnets
resource "aws_route_table_association" "private" {
  count = var.enable_fargate ? 2 : 0

  subnet_id      = aws_subnet.private[count.index].id
  route_table_id = aws_route_table.private[count.index].id
}

# Security Group for ECS Tasks
resource "aws_security_group" "ecs_tasks" {
  count       = var.enable_fargate ? 1 : 0
  name        = "${local.name_prefix}-ecs-tasks"
  description = "Security group for ECS tasks"
  vpc_id      = aws_vpc.main[0].id

  ingress {
    from_port   = 3000
    to_port     = 3000
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
    description = "HTTP from Load Balancer"
  }

  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
    description = "All outbound traffic"
  }

  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-ecs-tasks"
  })
}

# VPC Endpoints for AWS services (to reduce NAT Gateway costs)
resource "aws_vpc_endpoint" "s3" {
  count        = var.enable_fargate ? 1 : 0
  vpc_id       = aws_vpc.main[0].id
  service_name = "com.amazonaws.${data.aws_region.current.name}.s3"
  
  tags = merge(local.common_tags, {
    Name = "${local.name_prefix}-s3-endpoint"
  })
}

resource "aws_vpc_endpoint_route_table_association" "s3_private" {
  count = var.enable_fargate ? 2 : 0

  vpc_endpoint_id = aws_vpc_endpoint.s3[0].id
  route_table_id  = aws_route_table.private[count.index].id
}