# VPC Module Example
# Full implementation available in repository

resource "aws_vpc" "main" {
  cidr_block           = var.vpc_cidr
  enable_dns_hostnames = true
  enable_dns_support   = true
  
  tags = merge(var.tags, {
    Name = var.vpc_name
  })
}

resource "aws_internet_gateway" "main" {
  vpc_id = aws_vpc.main.id
  tags   = merge(var.tags, { Name = "${var.vpc_name}-igw" })
}

resource "aws_subnet" "public" {
  count                   = length(var.public_subnet_cidrs)
  vpc_id                  = aws_vpc.main.id
  cidr_block              = var.public_subnet_cidrs[count.index]
  availability_zone       = var.azs[count.index]
  map_public_ip_on_launch = true
  
  tags = merge(var.tags, {
    Name = "${var.vpc_name}-public-${var.azs[count.index]}"
    Tier = "Public"
  })
}

resource "aws_subnet" "private" {
  count             = length(var.private_subnet_cidrs)
  vpc_id            = aws_vpc.main.id
  cidr_block        = var.private_subnet_cidrs[count.index]
  availability_zone = var.azs[count.index]
  
  tags = merge(var.tags, {
    Name = "${var.vpc_name}-private-${var.azs[count.index]}"
    Tier = "Private"
  })
}

resource "aws_eip" "nat" {
  count  = var.enable_nat_gateway ? (var.single_nat_gateway ? 1 : length(var.azs)) : 0
  domain = "vpc"
  tags   = merge(var.tags, { Name = "${var.vpc_name}-nat-eip" })
}

resource "aws_nat_gateway" "main" {
  count         = var.enable_nat_gateway ? (var.single_nat_gateway ? 1 : length(var.azs)) : 0
  allocation_id = aws_eip.nat[count.index].id
  subnet_id     = aws_subnet.public[count.index].id
  tags          = merge(var.tags, { Name = "${var.vpc_name}-nat" })
}

# Route tables, associations, and other resources...
# See full implementation in repository

output "vpc_id" {
  value = aws_vpc.main.id
}

output "public_subnet_ids" {
  value = aws_subnet.public[*].id
}

output "private_subnet_ids" {
  value = aws_subnet.private[*].id
}