# --- EKS cluster role -------------------------------------------------------

data "aws_iam_policy_document" "cluster_assume" {
  statement {
    actions = ["sts:AssumeRole"]
    principals {
      type        = "Service"
      identifiers = ["eks.amazonaws.com"]
    }
  }
}

resource "aws_iam_role" "cluster" {
  name               = "${local.name_prefix}-cluster"
  assume_role_policy = data.aws_iam_policy_document.cluster_assume.json
}

resource "aws_iam_role_policy_attachment" "cluster_AmazonEKSClusterPolicy" {
  role       = aws_iam_role.cluster.name
  policy_arn = "arn:aws:iam::aws:policy/AmazonEKSClusterPolicy"
}

resource "aws_iam_role_policy_attachment" "cluster_AmazonEKSVPCResourceController" {
  role       = aws_iam_role.cluster.name
  policy_arn = "arn:aws:iam::aws:policy/AmazonEKSVPCResourceController"
}

# --- Managed node group role ------------------------------------------------

data "aws_iam_policy_document" "node_assume" {
  statement {
    actions = ["sts:AssumeRole"]
    principals {
      type        = "Service"
      identifiers = ["ec2.amazonaws.com"]
    }
  }
}

resource "aws_iam_role" "node" {
  name               = "${local.name_prefix}-node"
  assume_role_policy = data.aws_iam_policy_document.node_assume.json
}

resource "aws_iam_role_policy_attachment" "node_AmazonEKSWorkerNodePolicy" {
  role       = aws_iam_role.node.name
  policy_arn = "arn:aws:iam::aws:policy/AmazonEKSWorkerNodePolicy"
}

resource "aws_iam_role_policy_attachment" "node_AmazonEKS_CNI_Policy" {
  role       = aws_iam_role.node.name
  policy_arn = "arn:aws:iam::aws:policy/AmazonEKS_CNI_Policy"
}

resource "aws_iam_role_policy_attachment" "node_AmazonEC2ContainerRegistryReadOnly" {
  role       = aws_iam_role.node.name
  policy_arn = "arn:aws:iam::aws:policy/AmazonEC2ContainerRegistryReadOnly"
}

resource "aws_iam_role_policy_attachment" "node_AmazonSSMManagedInstanceCore" {
  role       = aws_iam_role.node.name
  policy_arn = "arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore"
}

# --- IRSA (IAM Roles for Service Accounts) ----------------------------------
#
# EKS exposes an OIDC issuer URL; pairing it with an IAM OIDC provider lets
# pods assume IAM roles via a service-account annotation. The service plane
# (service-datalake) uses this to grant the data-plane pod S3 access on the
# archive-tier bucket without storing AWS credentials anywhere.

data "tls_certificate" "cluster_oidc" {
  url = aws_eks_cluster.main.identity[0].oidc[0].issuer
}

resource "aws_iam_openid_connect_provider" "cluster" {
  url             = aws_eks_cluster.main.identity[0].oidc[0].issuer
  client_id_list  = ["sts.amazonaws.com"]
  thumbprint_list = [data.tls_certificate.cluster_oidc.certificates[0].sha1_fingerprint]
  tags            = { Name = "${local.name_prefix}-oidc" }
}