terraform {
  required_version = ">= 1.5"
  required_providers {
    aws     = { source = "hashicorp/aws", version = "~> 5.0" }
    archive = { source = "hashicorp/archive", version = "~> 2.0" }
  }
}

provider "aws" {
  region = var.region

  # Every taggable resource created by this stack carries this tag, on top of any
  # per-resource tags (e.g. the on-prem/cloud Zone tags).
  default_tags {
    tags = {
      Owner = "conan hncb demo"
    }
  }
}

locals {
  name = var.project
  # Logical trust zones are represented by tags for the demo (everything is one account).
  onprem_tag = { Zone = "on-prem-VPC-A" }
  cloud_tag  = { Zone = "cloud-VPC-B" }
}

########################################
# Token vault + seeded customer data (both live in the "on-prem" zone)
########################################
resource "aws_dynamodb_table" "vault" {
  name         = "${local.name}-vault"
  billing_mode = "PAY_PER_REQUEST"
  hash_key     = "token"
  attribute {
    name = "token"
    type = "S"
  }
  ttl {
    attribute_name = "expires_at"
    enabled        = true
  }
  tags = local.onprem_tag
}

resource "aws_dynamodb_table" "customers" {
  name         = "${local.name}-customers"
  billing_mode = "PAY_PER_REQUEST"
  hash_key     = "customer_id"
  attribute {
    name = "customer_id"
    type = "S"
  }
  tags = local.onprem_tag
}

########################################
# RAG tool Lambda (step 4-6): resolves the token, reads customer data,
# returns a de-identified evidence package. Never returns raw PII.
########################################
data "archive_file" "rag" {
  type        = "zip"
  source_dir  = "${path.module}/../lambda_rag"
  output_path = "${path.module}/rag_lambda.zip"
}

resource "aws_iam_role" "rag" {
  name = "${local.name}-rag-role"
  assume_role_policy = jsonencode({
    Version = "2012-10-17"
    Statement = [{
      Effect    = "Allow"
      Principal = { Service = "lambda.amazonaws.com" }
      Action    = "sts:AssumeRole"
    }]
  })
}

resource "aws_iam_role_policy" "rag" {
  name = "${local.name}-rag-policy"
  role = aws_iam_role.rag.id
  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Effect   = "Allow"
        Action   = ["dynamodb:GetItem", "dynamodb:Query"]
        Resource = [aws_dynamodb_table.vault.arn, aws_dynamodb_table.customers.arn]
      },
      {
        Effect   = "Allow"
        Action   = ["logs:CreateLogGroup", "logs:CreateLogStream", "logs:PutLogEvents"]
        Resource = "arn:aws:logs:*:*:*"
      }
    ]
  })
}

resource "aws_lambda_function" "rag" {
  function_name    = "${local.name}-rag-tool"
  role             = aws_iam_role.rag.arn
  runtime          = "python3.12"
  handler          = "handler.lambda_handler"
  filename         = data.archive_file.rag.output_path
  source_code_hash = data.archive_file.rag.output_base64sha256
  timeout          = 15
  environment {
    variables = {
      VAULT_TABLE     = aws_dynamodb_table.vault.name
      CUSTOMERS_TABLE = aws_dynamodb_table.customers.name
    }
  }
  tags = local.onprem_tag
}

########################################
# Outputs
########################################
output "region" { value = var.region }
output "vault_table" { value = aws_dynamodb_table.vault.name }
output "customers_table" { value = aws_dynamodb_table.customers.name }
output "rag_lambda_name" { value = aws_lambda_function.rag.function_name }
output "rag_lambda_arn" { value = aws_lambda_function.rag.arn }
output "bedrock_model_id" { value = var.bedrock_model_id }