resource "aws_lambda_layer_version" "aws_wrangler" {
    filename = "../lambda/awswrangler-layer-2.7.0-py3.8.zip"
    layer_name = "aws_wrangler_${var.account_number}_${var.student_initials}_${var.student_index_no}"
    source_code_hash = "${filebase64sha256("../lambda/awswrangler-layer-2.7.0-py3.8.zip")}"
    compatible_runtimes = ["python3.8"]
}

resource "aws_lambda_function" "etl_post_processing" {
    function_name = "etl-post-processing-${var.account_number}-${var.student_initials}-${var.student_index_no}"
    filename = "lambda_definition.zip"
    handler = "lambda_definition.etl_function"
    runtime = "python3.8"
    role = var.lab_role_arn
    timeout = 300
    memory_size = 512
    source_code_hash= filebase64sha256("lambda_definition.zip")
    layers = ["${aws_lambda_layer_version.aws_wrangler.arn}"]
}

resource "aws_lambda_permission" "allow_bucket" {
    statement_id = "AllowExecutionFromS3Bucket"
    action = "lambda:InvokeFunction"
    function_name = aws_lambda_function.etl_post_processing.arn
    principal = "s3.amazonaws.com"
    source_arn = aws_s3_bucket.raw_bucket.arn
}

resource "aws_s3_bucket_notification" "trigger_etl_lambda" {
    bucket = aws_s3_bucket.raw_bucket.id
    lambda_function {
        lambda_function_arn = aws_lambda_function.etl_post_processing.arn
        events = ["s3:ObjectCreated:*"]
        filter_prefix = "raw-zone/"
    }
    depends_on = [aws_lambda_permission.allow_bucket]
}