resource "authentik_group" "this" {
  for_each = var.groups

  name         = each.value.name
  is_superuser = each.value.is_superuser
  parents      = each.value.parents
  attributes   = jsonencode(each.value.attributes)
}

# Permission groups (akP-*): atomic, leaf groups. Mapped to app roles via the
# groups claim and bound to applications for access.
resource "authentik_group" "permission" {
  for_each = var.permission_groups

  name       = each.key
  attributes = jsonencode(each.value.attributes)
}

# Role groups (akR-*): what users are assigned to. Each nests permission groups
# as parents, so a role member is an effective member of every permission it
# grants. Separate resource from permissions so this reference is not a
# self-reference (authentik_group cannot refer to itself).
resource "authentik_group" "role" {
  for_each = var.role_groups

  name         = each.key
  is_superuser = each.value.is_superuser
  parents      = [for p in each.value.permissions : authentik_group.permission[p].id]
  attributes   = jsonencode(each.value.attributes)
}

# Emit an `ak_groups` claim containing the user's groups AND all inherited
# (ancestor) groups, so role -> permission nesting reaches apps. The default
# profile mapping only emits *direct* groups under `groups`
# (goauthentik/authentik#15579); we use a distinct claim key so there is no
# collision with that (Authentik dict-overrides same-key claims in an
# unpredictable order). Apps request the `ak_groups` scope and read the
# `ak_groups` claim. Walks each direct group up through `.parents`.
resource "authentik_property_mapping_provider_scope" "groups_hierarchical" {
  name       = "unkin: ak_groups (hierarchical)"
  scope_name = "ak_groups"
  expression = <<-EOT
    groups = {}
    pending = list(user.ak_groups.all())
    while pending:
        grp = pending.pop()
        if grp.pk in groups:
            continue
        groups[grp.pk] = grp.name
        pending += list(grp.parents.all())
    return {"ak_groups": sorted(groups.values())}
  EOT
}

# Resolve SAML flows by slug and the signing keypair by name, so configs use
# human-readable names instead of Authentik UUIDs (mirrors the oauth2 handling).
data "authentik_flow" "saml_authorization" {
  for_each = var.providers_saml
  slug     = each.value.authorization_flow
}

data "authentik_flow" "saml_invalidation" {
  for_each = var.providers_saml
  slug     = each.value.invalidation_flow
}

data "authentik_certificate_key_pair" "saml_signing" {
  for_each = { for k, v in var.providers_saml : k => v if v.signing_kp != null }
  name     = each.value.signing_kp
}

resource "authentik_provider_saml" "this" {
  for_each = var.providers_saml

  name               = each.value.name
  authorization_flow = data.authentik_flow.saml_authorization[each.key].id
  invalidation_flow  = data.authentik_flow.saml_invalidation[each.key].id
  acs_url            = each.value.acs_url
  sp_binding         = each.value.sp_binding
  audience           = each.value.audience
  name_id_mapping    = each.value.name_id_mapping
  signing_kp         = each.value.signing_kp != null ? data.authentik_certificate_key_pair.saml_signing[each.key].id : null
}

# Build a Python expression per app that emits a role claim from the user's
# effective (hierarchical) group membership. Assembled from the config rules so
# the generated code has predictable indentation (no template-directive quirks).
locals {
  role_mapping_expr = {
    for k, v in var.providers_oauth2 : k => join("\n", concat(
      [
        "groups = {}",
        "pending = list(user.ak_groups.all())",
        "while pending:",
        "    grp = pending.pop()",
        "    if grp.pk in groups:",
        "        continue",
        "    groups[grp.pk] = grp.name",
        "    pending += list(grp.parents.all())",
        "names = set(groups.values())",
      ],
      flatten([
        for rule in coalesce(try(v.role_mappings.rules, null), []) : [
          "if ${jsonencode(rule.group)} in names:",
          "    return {${jsonencode(try(v.role_mappings.claim, ""))}: ${jsonencode(rule.role)}}",
        ]
      ]),
      ["return {${jsonencode(try(v.role_mappings.claim, ""))}: ${jsonencode(try(v.role_mappings.default, ""))}}"],
    ))
    if v.role_mappings != null
  }
}

resource "authentik_property_mapping_provider_scope" "role" {
  for_each = { for k, v in var.providers_oauth2 : k => v if v.role_mappings != null }

  name       = "unkin: ${each.key} role"
  scope_name = each.value.role_mappings.claim
  expression = local.role_mapping_expr[each.key]
}

# Resolve oauth2 flows by slug and scope mappings by managed identifier, and
# read client secrets from Vault so nothing sensitive is committed.
data "authentik_flow" "oauth2_authorization" {
  for_each = var.providers_oauth2
  slug     = each.value.authorization_flow
}

data "authentik_flow" "oauth2_invalidation" {
  for_each = var.providers_oauth2
  slug     = each.value.invalidation_flow
}

data "authentik_property_mapping_provider_scope" "oauth2" {
  for_each     = { for k, v in var.providers_oauth2 : k => v if length(v.scope_mappings) > 0 }
  managed_list = each.value.scope_mappings
}

data "vault_kv_secret_v2" "oauth2" {
  for_each = { for k, v in var.providers_oauth2 : k => v if v.client_secret_vault != null }
  mount    = each.value.client_secret_vault.mount
  name     = each.value.client_secret_vault.path
}

# Default JWT signing key for OAuth2 providers. Without a signing_key Authentik
# signs ID tokens with HS256, which RS256-only RP clients (argocd, grafana, ...)
# reject. Look up the estate's RSA keypair by name so providers default to RS256.
data "authentik_certificate_key_pair" "signing" {
  name = var.oauth2_signing_key_name
}

resource "authentik_provider_oauth2" "this" {
  for_each = var.providers_oauth2

  name               = each.value.name
  authorization_flow = data.authentik_flow.oauth2_authorization[each.key].id
  invalidation_flow  = data.authentik_flow.oauth2_invalidation[each.key].id
  client_type        = each.value.client_type
  client_id          = each.value.client_id
  client_secret      = each.value.client_secret_vault != null ? data.vault_kv_secret_v2.oauth2[each.key].data["client_secret"] : null
  property_mappings = concat(
    try(data.authentik_property_mapping_provider_scope.oauth2[each.key].ids, []),
    [authentik_property_mapping_provider_scope.groups_hierarchical.id],
    try([authentik_property_mapping_provider_scope.role[each.key].id], []),
  )
  signing_key           = coalesce(each.value.signing_key, data.authentik_certificate_key_pair.signing.id)
  access_token_validity = each.value.access_token_validity
  allowed_redirect_uris = each.value.redirect_uris
  grant_types           = each.value.grant_types
}

resource "authentik_provider_ldap" "this" {
  for_each = var.providers_ldap

  name             = each.value.name
  bind_flow        = each.value.bind_flow
  unbind_flow      = each.value.unbind_flow
  base_dn          = each.value.base_dn
  certificate      = each.value.certificate
  tls_server_name  = each.value.tls_server_name
  uid_start_number = each.value.uid_start_number
  gid_start_number = each.value.gid_start_number
  search_mode      = each.value.search_mode
  bind_mode        = each.value.bind_mode
  mfa_support      = each.value.mfa_support
}

resource "authentik_application" "saml" {
  for_each = var.providers_saml

  name              = each.value.name
  slug              = each.key
  protocol_provider = authentik_provider_saml.this[each.key].id
}

resource "authentik_application" "oauth2" {
  for_each = var.providers_oauth2

  name              = each.value.name
  slug              = each.key
  protocol_provider = authentik_provider_oauth2.this[each.key].id
  # Null keeps Authentik's derived launch URL (from the first redirect_uri).
  meta_launch_url = each.value.launch_url
}

resource "authentik_application" "ldap" {
  for_each = var.providers_ldap

  name              = each.value.name
  slug              = each.key
  protocol_provider = authentik_provider_ldap.this[each.key].id
}

resource "authentik_outpost" "ldap" {
  for_each = var.providers_ldap

  name               = "${each.key}-outpost"
  type               = "ldap"
  protocol_providers = [authentik_provider_ldap.this[each.key].id]
}

# Gate application access: bind each permission group that names an `application`
# to that app. Authentik ORs bindings, and membership propagates from child
# groups, so a member of any role that nests the permission is also covered.
# With any binding present, only these groups (and their children) can authorize.
resource "authentik_policy_binding" "app_access" {
  for_each = { for k, v in var.permission_groups : k => v if v.application != null }

  target = authentik_application.oauth2[each.value.application].uuid
  group  = authentik_group.permission[each.key].id
  order  = 0
}