defmodule Mv.Accounts.EmailUniquenessTest do
  use Mv.DataCase, async: false

  alias Mv.Accounts
  alias Mv.Membership

  describe "Email uniqueness validation - Creation" do
    test "CAN create member with existing unlinked user email" do
      # Create a user with email
      {:ok, _user} =
        Accounts.create_user(%{
          email: "existing@example.com"
        })

      # Create member with same email - should succeed
      {:ok, member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "existing@example.com"
        })

      assert to_string(member.email) == "existing@example.com"
    end

    test "CAN create user with existing unlinked member email" do
      # Create a member with email
      {:ok, _member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "existing@example.com"
        })

      # Create user with same email - should succeed
      {:ok, user} =
        Accounts.create_user(%{
          email: "existing@example.com"
        })

      assert to_string(user.email) == "existing@example.com"
    end
  end

  describe "Email uniqueness validation - Updating unlinked entities" do
    test "unlinked member email CAN be changed to an existing unlinked user email" do
      # Create a user with email
      {:ok, _user} =
        Accounts.create_user(%{
          email: "existing_user@example.com"
        })

      # Create an unlinked member with different email
      {:ok, member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "member@example.com"
        })

      # Change member email to existing user email - should succeed (member is unlinked)
      {:ok, updated_member} =
        Membership.update_member(member, %{
          email: "existing_user@example.com"
        })

      assert to_string(updated_member.email) == "existing_user@example.com"
    end

    test "unlinked user email CAN be changed to an existing unlinked member email" do
      # Create a member with email
      {:ok, _member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "existing_member@example.com"
        })

      # Create an unlinked user with different email
      {:ok, user} =
        Accounts.create_user(%{
          email: "user@example.com"
        })

      # Change user email to existing member email - should succeed (user is unlinked)
      {:ok, updated_user} =
        Accounts.update_user(user, %{
          email: "existing_member@example.com"
        })

      assert to_string(updated_user.email) == "existing_member@example.com"
    end

    test "unlinked member email CANNOT be changed to an existing linked user email" do
      # Create a user and link it to a member - this makes the user "linked"
      {:ok, user} =
        Accounts.create_user(%{
          email: "linked_user@example.com"
        })

      {:ok, _member_a} =
        Membership.create_member(%{
          first_name: "Member",
          last_name: "A",
          email: "temp@example.com",
          user: %{id: user.id}
        })

      # Create an unlinked member with different email
      {:ok, member_b} =
        Membership.create_member(%{
          first_name: "Member",
          last_name: "B",
          email: "member_b@example.com"
        })

      # Try to change unlinked member's email to linked user's email - should fail
      result =
        Membership.update_member(member_b, %{
          email: "linked_user@example.com"
        })

      assert {:error, %Ash.Error.Invalid{} = error} = result

      assert error.errors
             |> Enum.any?(fn e ->
               e.field == :email and
                 (String.contains?(e.message, "already") or String.contains?(e.message, "used"))
             end)
    end

    test "unlinked user email CANNOT be changed to an existing linked member email" do
      # Create a user and link it to a member - this makes the member "linked"
      {:ok, user_a} =
        Accounts.create_user(%{
          email: "user_a@example.com"
        })

      {:ok, _member_a} =
        Membership.create_member(%{
          first_name: "Member",
          last_name: "A",
          email: "temp@example.com",
          user: %{id: user_a.id}
        })

      # Reload user to get updated member_id and linked member email
      {:ok, user_a_reloaded} = Ash.get(Mv.Accounts.User, user_a.id)
      {:ok, user_a_with_member} = Ash.load(user_a_reloaded, :member)
      linked_member_email = to_string(user_a_with_member.member.email)

      # Create an unlinked user with different email
      {:ok, user_b} =
        Accounts.create_user(%{
          email: "user_b@example.com"
        })

      # Try to change unlinked user's email to linked member's email - should fail
      result =
        Accounts.update_user(user_b, %{
          email: linked_member_email
        })

      assert {:error, %Ash.Error.Invalid{} = error} = result

      assert error.errors
             |> Enum.any?(fn e ->
               e.field == :email and
                 (String.contains?(e.message, "already") or String.contains?(e.message, "used"))
             end)
    end
  end

  describe "Email uniqueness validation - Creating with linked emails" do
    test "CANNOT create member with existing linked user email" do
      # Create a user and link it to a member
      {:ok, user} =
        Accounts.create_user(%{
          email: "linked@example.com"
        })

      {:ok, _member} =
        Membership.create_member(%{
          first_name: "First",
          last_name: "Member",
          email: "temp@example.com",
          user: %{id: user.id}
        })

      # Try to create a new member with the linked user's email - should fail
      result =
        Membership.create_member(%{
          first_name: "Second",
          last_name: "Member",
          email: "linked@example.com"
        })

      assert {:error, %Ash.Error.Invalid{} = error} = result

      assert error.errors
             |> Enum.any?(fn e ->
               e.field == :email and
                 (String.contains?(e.message, "already") or String.contains?(e.message, "used"))
             end)
    end

    test "CANNOT create user with existing linked member email" do
      # Create a user and link it to a member
      {:ok, user} =
        Accounts.create_user(%{
          email: "user@example.com"
        })

      {:ok, _member} =
        Membership.create_member(%{
          first_name: "Member",
          last_name: "One",
          email: "temp@example.com",
          user: %{id: user.id}
        })

      # Reload user to get the linked member's email
      {:ok, user_reloaded} = Ash.get(Mv.Accounts.User, user.id)
      {:ok, user_with_member} = Ash.load(user_reloaded, :member)
      linked_member_email = to_string(user_with_member.member.email)

      # Try to create a new user with the linked member's email - should fail
      result =
        Accounts.create_user(%{
          email: linked_member_email
        })

      assert {:error, %Ash.Error.Invalid{} = error} = result

      assert error.errors
             |> Enum.any?(fn e ->
               e.field == :email and
                 (String.contains?(e.message, "already") or String.contains?(e.message, "used"))
             end)
    end
  end

  describe "Email uniqueness validation - Updating linked entities" do
    test "linked member email CANNOT be changed to an existing user email" do
      # Create a user with email
      {:ok, _other_user} =
        Accounts.create_user(%{
          email: "other_user@example.com"
        })

      # Create a user and link it to a member
      {:ok, user} =
        Accounts.create_user(%{
          email: "user@example.com"
        })

      {:ok, member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "temp@example.com",
          user: %{id: user.id}
        })

      # Try to change linked member's email to other user's email - should fail
      result =
        Membership.update_member(member, %{
          email: "other_user@example.com"
        })

      assert {:error, %Ash.Error.Invalid{} = error} = result

      assert error.errors
             |> Enum.any?(fn e ->
               e.field == :email and
                 (String.contains?(e.message, "already") or String.contains?(e.message, "used"))
             end)
    end

    test "linked user email CANNOT be changed to an existing member email" do
      # Create a member with email
      {:ok, _other_member} =
        Membership.create_member(%{
          first_name: "Jane",
          last_name: "Doe",
          email: "other_member@example.com"
        })

      # Create a user and link it to a member
      {:ok, user} =
        Accounts.create_user(%{
          email: "user@example.com"
        })

      {:ok, _member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "temp@example.com",
          user: %{id: user.id}
        })

      # Reload user to get updated member_id
      {:ok, user_reloaded} = Ash.get(Mv.Accounts.User, user.id)

      # Try to change linked user's email to other member's email - should fail
      result =
        Accounts.update_user(user_reloaded, %{
          email: "other_member@example.com"
        })

      assert {:error, %Ash.Error.Invalid{} = error} = result

      assert error.errors
             |> Enum.any?(fn e ->
               e.field == :email and
                 (String.contains?(e.message, "already") or String.contains?(e.message, "used"))
             end)
    end
  end

  describe "Email uniqueness validation - Linking" do
    test "CANNOT link user to member if user email is already used by another unlinked member" do
      # Create a member with email
      {:ok, _other_member} =
        Membership.create_member(%{
          first_name: "Jane",
          last_name: "Doe",
          email: "duplicate@example.com"
        })

      # Create a user with same email
      {:ok, user} =
        Accounts.create_user(%{
          email: "duplicate@example.com"
        })

      # Create a member to link with the user
      {:ok, member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Smith",
          email: "john@example.com"
        })

      # Try to link user to member - should fail because user.email is already used by other_member
      result =
        Accounts.update_user(user, %{
          member: %{id: member.id}
        })

      assert {:error, %Ash.Error.Invalid{} = error} = result

      assert error.errors
             |> Enum.any?(fn e ->
               e.field == :email and
                 (String.contains?(e.message, "already") or String.contains?(e.message, "used"))
             end)
    end

    test "CAN link member to user even if member email is used by another user (member email gets overridden)" do
      # Create a user with email
      {:ok, _other_user} =
        Accounts.create_user(%{
          email: "duplicate@example.com"
        })

      # Create a member with same email
      {:ok, member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "duplicate@example.com"
        })

      # Create a user to link with the member
      {:ok, user} =
        Accounts.create_user(%{
          email: "user@example.com"
        })

      # Link member to user - should succeed because member.email will be overridden
      {:ok, updated_member} =
        Membership.update_member(member, %{
          user: %{id: user.id}
        })

      # Member email should now be the same as user email
      {:ok, member_reloaded} = Ash.get(Mv.Membership.Member, updated_member.id)
      assert to_string(member_reloaded.email) == "user@example.com"
    end
  end

  describe "Email syncing" do
    test "member email syncs to linked user email without validation error" do
      # Create a user
      {:ok, user} =
        Accounts.create_user(%{
          email: "user@example.com"
        })

      # Create a member linked to this user
      # The override change will set member.email = user.email automatically
      {:ok, member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "member@example.com",
          user: %{id: user.id}
        })

      # Member email should have been overridden to user email
      # This happens through our sync mechanism, which should NOT trigger
      # the "email already used" validation because it's the same user
      {:ok, member_after_link} = Ash.get(Mv.Membership.Member, member.id)
      assert member_after_link.email == "user@example.com"
    end

    test "user email syncs to linked member without validation error" do
      # Create a member
      {:ok, member} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "member@example.com"
        })

      # Create a user linked to this member
      # The override change will set member.email = user.email automatically
      {:ok, _user} =
        Accounts.create_user(%{
          email: "user@example.com",
          member: %{id: member.id}
        })

      # Member email should have been overridden to user email
      # This happens through our sync mechanism, which should NOT trigger
      # the "email already used" validation because it's the same member
      {:ok, member_after_link} = Ash.get(Mv.Membership.Member, member.id)
      assert member_after_link.email == "user@example.com"
    end

    test "two unlinked users cannot have the same email" do
      # Create first user
      {:ok, _user1} =
        Accounts.create_user(%{
          email: "duplicate@example.com"
        })

      # Try to create second user with same email
      result =
        Accounts.create_user(%{
          email: "duplicate@example.com"
        })

      assert {:error, %Ash.Error.Invalid{}} = result
    end

    test "two unlinked members cannot have the same email (members have unique constraint)" do
      # Create first member
      {:ok, _member1} =
        Membership.create_member(%{
          first_name: "John",
          last_name: "Doe",
          email: "duplicate@example.com"
        })

      # Try to create second member with same email - should fail
      result =
        Membership.create_member(%{
          first_name: "Jane",
          last_name: "Smith",
          email: "duplicate@example.com"
        })

      assert {:error, %Ash.Error.Invalid{}} = result
      # Members DO have a unique email constraint at database level
    end
  end
end