defmodule Mv.Membership.MemberPoliciesTest do
  @moduledoc """
  Tests for Member resource authorization policies.

  Tests all 4 permission sets (own_data, read_only, normal_user, admin)
  and verifies that policies correctly enforce access control based on
  user roles and permission sets.
  """
  # async: false because we need database commits to be visible across queries
  # in the same test (especially for unlinked members)
  use Mv.DataCase, async: false

  alias Mv.Membership
  alias Mv.Accounts
  alias Mv.Authorization

  require Ash.Query

  # Helper to create a role with a specific permission set
  defp create_role_with_permission_set(permission_set_name) do
    role_name = "Test Role #{permission_set_name} #{System.unique_integer([:positive])}"

    case Authorization.create_role(%{
           name: role_name,
           description: "Test role for #{permission_set_name}",
           permission_set_name: permission_set_name
         }) do
      {:ok, role} -> role
      {:error, error} -> raise "Failed to create role: #{inspect(error)}"
    end
  end

  # Helper to create a user with a specific permission set
  # Returns user with role preloaded (required for authorization)
  defp create_user_with_permission_set(permission_set_name) do
    # Create role with permission set
    role = create_role_with_permission_set(permission_set_name)

    # Create user
    {:ok, user} =
      Accounts.User
      |> Ash.Changeset.for_create(:register_with_password, %{
        email: "user#{System.unique_integer([:positive])}@example.com",
        password: "testpassword123"
      })
      |> Ash.create()

    # Assign role to user
    {:ok, user} =
      user
      |> Ash.Changeset.for_update(:update, %{})
      |> Ash.Changeset.manage_relationship(:role, role, type: :append_and_remove)
      |> Ash.update()

    # Reload user with role preloaded (critical for authorization!)
    {:ok, user_with_role} = Ash.load(user, :role, domain: Mv.Accounts)
    user_with_role
  end

  # Helper to create an admin user (for creating test fixtures)
  defp create_admin_user do
    create_user_with_permission_set("admin")
  end

  # Helper to create a member linked to a user
  defp create_linked_member_for_user(user) do
    admin = create_admin_user()

    # Create member
    # NOTE: We need to ensure the member is actually persisted to the database
    # before we try to link it. Ash may delay writes, so we explicitly return the struct.
    {:ok, member} =
      Membership.Member
      |> Ash.Changeset.for_create(:create_member, %{
        first_name: "Linked",
        last_name: "Member",
        email: "linked#{System.unique_integer([:positive])}@example.com"
      })
      |> Ash.create(actor: admin, return_notifications?: false)

    # Link member to user (User.member_id = member.id)
    # We use force_change_attribute because the member already exists and we just
    # need to set the foreign key. This avoids the issue where manage_relationship
    # tries to query the member without the actor context.
    result =
      user
      |> Ash.Changeset.for_update(:update, %{})
      |> Ash.Changeset.force_change_attribute(:member_id, member.id)
      |> Ash.update(actor: admin, domain: Mv.Accounts, return_notifications?: false)

    {:ok, _user} = result

    # Return the member struct directly - no need to reload since we just created it
    # and we're in the same transaction/sandbox
    member
  end

  # Helper to create an unlinked member (no user relationship)
  defp create_unlinked_member do
    admin = create_admin_user()

    {:ok, member} =
      Membership.Member
      |> Ash.Changeset.for_create(:create_member, %{
        first_name: "Unlinked",
        last_name: "Member",
        email: "unlinked#{System.unique_integer([:positive])}@example.com"
      })
      |> Ash.create(actor: admin)

    member
  end

  describe "own_data permission set (Mitglied)" do
    setup do
      user = create_user_with_permission_set("own_data")
      linked_member = create_linked_member_for_user(user)
      unlinked_member = create_unlinked_member()

      # Reload user to get updated member_id
      {:ok, user} = Ash.get(Accounts.User, user.id, domain: Mv.Accounts, load: [:role])
      {:ok, user} = Ash.load(user, :member, domain: Mv.Accounts)

      %{user: user, linked_member: linked_member, unlinked_member: unlinked_member}
    end

    test "can read linked member", %{user: user, linked_member: linked_member} do
      {:ok, member} =
        Ash.get(Membership.Member, linked_member.id, actor: user, domain: Mv.Membership)

      assert member.id == linked_member.id
    end

    test "can update linked member", %{user: user, linked_member: linked_member} do
      {:ok, updated_member} =
        linked_member
        |> Ash.Changeset.for_update(:update_member, %{first_name: "Updated"})
        |> Ash.update(actor: user)

      assert updated_member.first_name == "Updated"
    end

    test "cannot read unlinked member (returns forbidden)", %{
      user: user,
      unlinked_member: unlinked_member
    } do
      # Note: With auto_filter policies, when a user tries to read a member that doesn't
      # match the filter (id == actor.member_id), Ash returns NotFound, not Forbidden.
      # This is the expected behavior - the filter makes the record "invisible" to the user.
      assert_raise Ash.Error.Invalid, fn ->
        Ash.get!(Membership.Member, unlinked_member.id, actor: user, domain: Mv.Membership)
      end
    end

    test "cannot update unlinked member (returns forbidden)", %{
      user: user,
      unlinked_member: unlinked_member
    } do
      assert_raise Ash.Error.Forbidden, fn ->
        unlinked_member
        |> Ash.Changeset.for_update(:update_member, %{first_name: "Updated"})
        |> Ash.update!(actor: user)
      end
    end

    test "list members returns only linked member", %{user: user, linked_member: linked_member} do
      {:ok, members} = Ash.read(Membership.Member, actor: user, domain: Mv.Membership)

      # Should only return the linked member (scope :linked filters)
      assert length(members) == 1
      assert hd(members).id == linked_member.id
    end

    test "cannot create member (returns forbidden)", %{user: user} do
      assert_raise Ash.Error.Forbidden, fn ->
        Membership.Member
        |> Ash.Changeset.for_create(:create_member, %{
          first_name: "New",
          last_name: "Member",
          email: "new#{System.unique_integer([:positive])}@example.com"
        })
        |> Ash.create!(actor: user)
      end
    end

    test "cannot destroy member (returns forbidden)", %{user: user, linked_member: linked_member} do
      assert_raise Ash.Error.Forbidden, fn ->
        Ash.destroy!(linked_member, actor: user)
      end
    end
  end

  describe "read_only permission set (Vorstand/Buchhaltung)" do
    setup do
      user = create_user_with_permission_set("read_only")
      linked_member = create_linked_member_for_user(user)
      unlinked_member = create_unlinked_member()

      # Reload user to get updated member_id
      {:ok, user} = Ash.get(Accounts.User, user.id, domain: Mv.Accounts, load: [:role])

      %{user: user, linked_member: linked_member, unlinked_member: unlinked_member}
    end

    test "can read all members", %{
      user: user,
      linked_member: linked_member,
      unlinked_member: unlinked_member
    } do
      {:ok, members} = Ash.read(Membership.Member, actor: user, domain: Mv.Membership)

      # Should return all members (scope :all)
      member_ids = Enum.map(members, & &1.id)
      assert linked_member.id in member_ids
      assert unlinked_member.id in member_ids
    end

    test "can read individual member", %{user: user, unlinked_member: unlinked_member} do
      {:ok, member} =
        Ash.get(Membership.Member, unlinked_member.id, actor: user, domain: Mv.Membership)

      assert member.id == unlinked_member.id
    end

    test "cannot create member (returns forbidden)", %{user: user} do
      assert_raise Ash.Error.Forbidden, fn ->
        Membership.Member
        |> Ash.Changeset.for_create(:create_member, %{
          first_name: "New",
          last_name: "Member",
          email: "new#{System.unique_integer([:positive])}@example.com"
        })
        |> Ash.create!(actor: user)
      end
    end

    test "cannot update any member (returns forbidden)", %{
      user: user,
      linked_member: linked_member
    } do
      assert_raise Ash.Error.Forbidden, fn ->
        linked_member
        |> Ash.Changeset.for_update(:update_member, %{first_name: "Updated"})
        |> Ash.update!(actor: user)
      end
    end

    test "cannot destroy any member (returns forbidden)", %{
      user: user,
      unlinked_member: unlinked_member
    } do
      assert_raise Ash.Error.Forbidden, fn ->
        Ash.destroy!(unlinked_member, actor: user)
      end
    end
  end

  describe "normal_user permission set (Kassenwart)" do
    setup do
      user = create_user_with_permission_set("normal_user")
      linked_member = create_linked_member_for_user(user)
      unlinked_member = create_unlinked_member()

      # Reload user to get updated member_id
      {:ok, user} = Ash.get(Accounts.User, user.id, domain: Mv.Accounts, load: [:role])

      %{user: user, linked_member: linked_member, unlinked_member: unlinked_member}
    end

    test "can read all members", %{
      user: user,
      linked_member: linked_member,
      unlinked_member: unlinked_member
    } do
      {:ok, members} = Ash.read(Membership.Member, actor: user, domain: Mv.Membership)

      # Should return all members (scope :all)
      member_ids = Enum.map(members, & &1.id)
      assert linked_member.id in member_ids
      assert unlinked_member.id in member_ids
    end

    test "can create member", %{user: user} do
      {:ok, member} =
        Membership.Member
        |> Ash.Changeset.for_create(:create_member, %{
          first_name: "New",
          last_name: "Member",
          email: "new#{System.unique_integer([:positive])}@example.com"
        })
        |> Ash.create(actor: user)

      assert member.first_name == "New"
    end

    test "can update any member", %{user: user, unlinked_member: unlinked_member} do
      {:ok, updated_member} =
        unlinked_member
        |> Ash.Changeset.for_update(:update_member, %{first_name: "Updated"})
        |> Ash.update(actor: user)

      assert updated_member.first_name == "Updated"
    end

    test "cannot destroy member (safety - not in permission set)", %{
      user: user,
      unlinked_member: unlinked_member
    } do
      assert_raise Ash.Error.Forbidden, fn ->
        Ash.destroy!(unlinked_member, actor: user)
      end
    end
  end

  describe "admin permission set" do
    setup do
      user = create_user_with_permission_set("admin")
      linked_member = create_linked_member_for_user(user)
      unlinked_member = create_unlinked_member()

      # Reload user to get updated member_id
      {:ok, user} = Ash.get(Accounts.User, user.id, domain: Mv.Accounts, load: [:role])

      %{user: user, linked_member: linked_member, unlinked_member: unlinked_member}
    end

    test "can read all members", %{
      user: user,
      linked_member: linked_member,
      unlinked_member: unlinked_member
    } do
      {:ok, members} = Ash.read(Membership.Member, actor: user, domain: Mv.Membership)

      # Should return all members (scope :all)
      member_ids = Enum.map(members, & &1.id)
      assert linked_member.id in member_ids
      assert unlinked_member.id in member_ids
    end

    test "can create member", %{user: user} do
      {:ok, member} =
        Membership.Member
        |> Ash.Changeset.for_create(:create_member, %{
          first_name: "New",
          last_name: "Member",
          email: "new#{System.unique_integer([:positive])}@example.com"
        })
        |> Ash.create(actor: user)

      assert member.first_name == "New"
    end

    test "can update any member", %{user: user, unlinked_member: unlinked_member} do
      {:ok, updated_member} =
        unlinked_member
        |> Ash.Changeset.for_update(:update_member, %{first_name: "Updated"})
        |> Ash.update(actor: user)

      assert updated_member.first_name == "Updated"
    end

    test "can destroy any member", %{user: user, unlinked_member: unlinked_member} do
      :ok = Ash.destroy(unlinked_member, actor: user)

      # Verify member is deleted
      assert {:error, _} = Ash.get(Membership.Member, unlinked_member.id, domain: Mv.Membership)
    end
  end

  describe "special case: user can always access linked member" do
    test "own_data user can read linked member even without explicit permission" do
      user = create_user_with_permission_set("own_data")
      linked_member = create_linked_member_for_user(user)

      # Reload user to get updated member_id
      {:ok, user} = Ash.get(Accounts.User, user.id, domain: Mv.Accounts, load: [:role])
      {:ok, user} = Ash.load(user, :member, domain: Mv.Accounts)

      # Should succeed (special case policy takes precedence)
      {:ok, member} =
        Ash.get(Membership.Member, linked_member.id, actor: user, domain: Mv.Membership)

      assert member.id == linked_member.id
    end

    test "read_only user can read linked member (via special case)" do
      user = create_user_with_permission_set("read_only")
      linked_member = create_linked_member_for_user(user)

      # Reload user to get updated member_id
      {:ok, user} = Ash.get(Accounts.User, user.id, domain: Mv.Accounts, load: [:role])
      {:ok, user} = Ash.load(user, :member, domain: Mv.Accounts)

      # Should succeed (special case policy takes precedence)
      {:ok, member} =
        Ash.get(Membership.Member, linked_member.id, actor: user, domain: Mv.Membership)

      assert member.id == linked_member.id
    end

    test "own_data user can update linked member even without explicit permission" do
      user = create_user_with_permission_set("own_data")
      linked_member = create_linked_member_for_user(user)

      # Reload user to get updated member_id
      {:ok, user} = Ash.get(Accounts.User, user.id, domain: Mv.Accounts, load: [:role])
      {:ok, user} = Ash.load(user, :member, domain: Mv.Accounts)

      # Should succeed (special case policy takes precedence)
      {:ok, updated_member} =
        linked_member
        |> Ash.Changeset.for_update(:update_member, %{first_name: "Updated"})
        |> Ash.update(actor: user)

      assert updated_member.first_name == "Updated"
    end
  end
end