###########
# Defaults
##########

terraform {
  required_version = ">= 0.13"

}
# ---------------------------------------------------------------------------------------------------------------------
# Set the AWS REGION
# ---------------------------------------------------------------------------------------------------------------------

provider "aws" {
  region = var.region
}

######
# Collect data
######

data "aws_availability_zones" "available" {
  state = "available"
}


######
# VPC
######
resource "aws_vpc" "main" {
  cidr_block                       = var.cidr
  instance_tenancy                 = var.instance_tenancy
  enable_dns_hostnames             = var.enable_dns_hostnames
  enable_dns_support               = var.enable_dns_support

  tags = {
    Terraform = "true"
    Name      = "${var.name}_vpc"
  }
}

resource "aws_vpc_endpoint" "dynamodb" {
  vpc_id       = aws_vpc.main.id
  service_name = "com.amazonaws.${var.region}.dynamodb"
 
  tags = {
    Terraform = "true"
    Name      = "${var.name}_vpc_endpoint"
  }
}

resource "aws_vpc_endpoint_route_table_association" "private_A" {
  count = 2

  route_table_id  = aws_route_table.private_A[count.index].id
  vpc_endpoint_id = aws_vpc_endpoint.dynamodb.id
}

###################
# Internet Gateway
###################
resource "aws_internet_gateway" "gw" {
  vpc_id = aws_vpc.main.id

  tags = {
    Name = "${var.name}_iGW"
  }

}

################
# Publiс routes
################
resource "aws_route_table" "public" {
  vpc_id = aws_vpc.main.id

 tags = {
    Name = "${var.name}_public_routes"
  }

}

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.gw.id

  timeouts {
    create = "5m"
  }
}

#################
# Private routes A
# There are as many routing tables as the number of NAT gateways
#################
resource "aws_route_table" "private_A" {
  count = 2
  vpc_id = aws_vpc.main.id

 tags = {
    Name = "${var.name}_private_routes_A"
  }
}

################
# Public subnet
################
resource "aws_subnet" "public" {
  count = 2
  vpc_id                          = aws_vpc.main.id
  cidr_block                      = var.public_subnets[count.index]
  availability_zone               = data.aws_availability_zones.available.names[count.index]
  map_public_ip_on_launch         = true 

tags = {
    Name = "${var.name}_public_subnets"
  }
}

#################
# Private subnet A
#################
resource "aws_subnet" "private_A" {
  count = 2
  vpc_id                          = aws_vpc.main.id
  cidr_block                      = var.private_subnets_A[count.index]    
  availability_zone               = data.aws_availability_zones.available.names[count.index]

 tags = {
    Name = "${var.name}_private_subnets_A"
  }
}


########################
# Shared Default Network ACLs
########################
resource "aws_network_acl" "public" {
  vpc_id     = aws_vpc.main.id
  subnet_ids = concat(aws_subnet.private_A.*.id, aws_subnet.public.*.id)

  tags = {
    Name = "${var.name}_shared_default_nework_acl"
  }
}

resource "aws_network_acl_rule" "public_inbound" {
  network_acl_id = aws_network_acl.public.id

  egress          = false
  rule_number     = var.public_inbound_acl_rules[0]["rule_number"]
  rule_action     = var.public_inbound_acl_rules[0]["rule_action"]
  from_port       = lookup(var.public_inbound_acl_rules[0], "from_port", null)
  to_port         = lookup(var.public_inbound_acl_rules[0], "to_port", null)
  icmp_code       = lookup(var.public_inbound_acl_rules[0], "icmp_code", null)
  icmp_type       = lookup(var.public_inbound_acl_rules[0], "icmp_type", null)
  protocol        = var.public_inbound_acl_rules[0]["protocol"]
  cidr_block      = lookup(var.public_inbound_acl_rules[0], "cidr_block", null)
}

resource "aws_network_acl_rule" "public_outbound" {
  network_acl_id = aws_network_acl.public.id

  egress          = true
  rule_number     = var.public_outbound_acl_rules[0]["rule_number"]
  rule_action     = var.public_outbound_acl_rules[0]["rule_action"]
  from_port       = lookup(var.public_outbound_acl_rules[0], "from_port", null)
  to_port         = lookup(var.public_outbound_acl_rules[0], "to_port", null)
  icmp_code       = lookup(var.public_outbound_acl_rules[0], "icmp_code", null)
  icmp_type       = lookup(var.public_outbound_acl_rules[0], "icmp_type", null)
  protocol        = var.public_outbound_acl_rules[0]["protocol"]
  cidr_block      = lookup(var.public_outbound_acl_rules[0], "cidr_block", null)
}

##############
# NAT Gateway
##############

resource "aws_eip" "nat" {
  count = 2
  vpc = true

tags = {
    Name = "${var.name}_EIP_nat"
  }
}

resource "aws_nat_gateway" "nat_gw" {
  count = 2
  allocation_id = aws_eip.nat[count.index].id
  subnet_id = aws_subnet.public[count.index].id

tags = {
    Name = "${var.name}_EIP_nat_gateway"
  }
  depends_on = [aws_internet_gateway.gw]
}

resource "aws_route" "private_A_nat_gateway" {
  count = 2
  route_table_id         = aws_route_table.private_A[count.index].id
  destination_cidr_block = "0.0.0.0/0"
  nat_gateway_id         = aws_nat_gateway.nat_gw[count.index].id

  timeouts {
    create = "5m"
  }
}

##########################
# Route table association
##########################
resource "aws_route_table_association" "private_A" {
  count = 2
  subnet_id = aws_subnet.private_A[count.index].id
  route_table_id = aws_route_table.private_A[count.index].id
}

resource "aws_route_table_association" "public" {
 count = 2
 subnet_id = aws_subnet.public[count.index].id
 route_table_id = aws_route_table.public.id
}