# In-cluster PostgreSQL implementation of the `databases` entity contract.
# Same `databases` list + same output maps as modules/yc-database, so the shared
# k8s-secret module resolves credentials identically. `cluster_id` is a logical
# key only (all databases are created on the single server the root provider
# points at); host/port in outputs come from the database's own host or default_*.

locals {
  databases_map = { for db in var.databases : "${db.cluster_id}:${db.database.name}:${db.user.name}" => db }

  db_extensions = merge([
    for key, db in local.databases_map : {
      for ext in try(db.database.extensions, []) : "${key}:${ext}" => { key = key, ext = ext }
    }
  ]...)

  db_grants = merge([
    for key, db in local.databases_map : {
      for perm in distinct(compact(try(db.user.permissions, []))) : "${key}:${perm}" => { key = key, db = perm }
    }
  ]...)
}

resource "random_password" "user_password" {
  for_each = local.databases_map

  length  = try(each.value.user.password_length, 32)
  special = try(each.value.user.password_special, false)
  upper   = true
  lower   = true
  numeric = true

  lifecycle {
    ignore_changes = all
  }
}

resource "postgresql_role" "this" {
  for_each = local.databases_map

  name             = each.value.user.name
  login            = true
  password         = random_password.user_password[each.key].result
  connection_limit = try(each.value.user.conn_limit, 10)

  lifecycle {
    ignore_changes = [password]
  }
}

resource "postgresql_database" "this" {
  for_each = local.databases_map

  name       = each.value.database.name
  owner      = postgresql_role.this[each.key].name
  lc_collate = try(each.value.database.lc_collate, "en_US.UTF-8")
  lc_ctype   = try(each.value.database.lc_type, "en_US.UTF-8")
  # template0 is required when the collation/ctype differ from the server default.
  template = "template0"

  depends_on = [postgresql_role.this]
}

resource "postgresql_extension" "this" {
  for_each = local.db_extensions

  name     = each.value.ext
  database = postgresql_database.this[each.value.key].name
}

# CONNECT grants to OTHER existing databases (declared in user.permissions);
# the owner already has full access to its own database.
resource "postgresql_grant" "connect" {
  for_each = local.db_grants

  role        = postgresql_role.this[each.value.key].name
  database    = each.value.db
  object_type = "database"
  privileges  = ["CONNECT"]
}