ash_dispatch

defmodule Mix.Tasks.AshDispatch.Install.Docs do
  @moduledoc false

  def short_doc do
    "Installs AshDispatch into a project"
  end

  def example do
    "mix igniter.install ash_dispatch"
  end

  def long_doc do
    """
    #{short_doc()}

    This installer will:
    - Add AshDispatch configuration to config files
    - Create Notification and DeliveryReceipt resources
    - Create Notifications and Deliveries domains
    - Add domains to your :ash_domains configuration
    - Create a RecipientResolver module for declarative audience resolution
    - Set up email layout templates
    - Optionally set up Phoenix channel for real-time updates

    ## Example

    ```bash
    #{example()}
    ```

    ## Options

    * `--no-phoenix` - Skip Phoenix channel setup
    * `--no-email` - Skip email backend configuration
    * `--no-typescript` - Skip TypeScript SDK generation (runs automatically if any domain uses AshTypescript.Rpc)
    """
  end
end

if Code.ensure_loaded?(Igniter) do
  defmodule Mix.Tasks.AshDispatch.Install do
    @shortdoc "#{__MODULE__.Docs.short_doc()}"

    @moduledoc __MODULE__.Docs.long_doc()

    use Igniter.Mix.Task

    @impl Igniter.Mix.Task
    def info(_argv, _composing_task) do
      %Igniter.Mix.Task.Info{
        group: :ash,
        installs: [{:ash, "~> 3.0"}, {:oban, "~> 2.0"}],
        example: __MODULE__.Docs.example(),
        schema: [
          phoenix: :boolean,
          email: :boolean,
          typescript: :boolean
        ],
        defaults: [
          phoenix: true,
          email: true,
          typescript: true
        ],
        aliases: []
      }
    end

    @impl Igniter.Mix.Task
    def igniter(igniter) do
      opts = igniter.args.options
      otp_app = Igniter.Project.Application.app_name(igniter)
      app_module = Igniter.Project.Module.module_name(igniter, "")

      # Detect user resource (common patterns)
      user_resource = detect_user_resource(igniter, app_module)

      igniter
      |> Igniter.Project.Formatter.import_dep(:ash_dispatch)
      |> configure_ash_dispatch(otp_app)
      |> configure_test(otp_app)
      |> create_notification_resource(otp_app, app_module, user_resource)
      |> create_delivery_receipt_resource(otp_app, app_module)
      |> create_notifications_domain(app_module)
      |> create_deliveries_domain(app_module)
      |> add_domains_to_config(otp_app, app_module)
      |> create_recipient_resolver(app_module, user_resource)
      |> setup_email_layouts()
      |> maybe_setup_phoenix(opts[:phoenix], otp_app, app_module)
      |> maybe_configure_email(opts[:email], otp_app, app_module)
      |> maybe_run_typescript(opts[:typescript])
      |> add_final_notice(otp_app, app_module, user_resource)
    end

    # ============================================
    # Configuration
    # ============================================

    defp configure_ash_dispatch(igniter, otp_app) do
      igniter
      |> Igniter.Project.Config.configure_new(
        "config.exs",
        :ash_dispatch,
        [:otp_app],
        otp_app
      )
    end

    defp configure_test(igniter, otp_app) do
      # Configure Oban for inline testing if Oban config exists
      igniter
      |> Igniter.Project.Config.configure_new(
        "test.exs",
        otp_app,
        [Oban, :testing],
        :inline
      )
    end

    # ============================================
    # Resource Generation
    # ============================================

    defp create_notification_resource(igniter, otp_app, app_module, user_resource) do
      module_name = Module.concat([app_module, Notifications, Notification])

      user_resource_str =
        if user_resource do
          "user_resource: #{inspect(user_resource)},"
        else
          "# user_resource: #{inspect(app_module)}.Accounts.User,  # Uncomment and update"
        end

      content = """
      defmodule #{inspect(module_name)} do
        @moduledoc \"\"\"
        In-app notification resource for storing user notifications.

        Generated by `mix ash_dispatch.install`.
        \"\"\"

        use AshDispatch.Notification,
          domain: #{inspect(Module.concat(app_module, Notifications))},
          #{user_resource_str}
          otp_app: :#{otp_app}
      end
      """

      Igniter.Project.Module.create_module(igniter, module_name, content)
    end

    defp create_delivery_receipt_resource(igniter, otp_app, app_module) do
      module_name = Module.concat([app_module, Deliveries, DeliveryReceipt])

      content = """
      defmodule #{inspect(module_name)} do
        @moduledoc \"\"\"
        Delivery receipt resource for tracking all notification deliveries.

        Generated by `mix ash_dispatch.install`.
        \"\"\"

        use AshDispatch.DeliveryReceipt,
          domain: #{inspect(Module.concat(app_module, Deliveries))},
          otp_app: :#{otp_app}
      end
      """

      Igniter.Project.Module.create_module(igniter, module_name, content)
    end

    # ============================================
    # Domain Generation
    # ============================================

    defp create_notifications_domain(igniter, app_module) do
      module_name = Module.concat(app_module, Notifications)
      resource_name = Module.concat([app_module, Notifications, Notification])

      content = """
      defmodule #{inspect(module_name)} do
        @moduledoc \"\"\"
        Domain for in-app notifications.

        Generated by `mix ash_dispatch.install`.
        \"\"\"

        use Ash.Domain

        resources do
          resource #{inspect(resource_name)}
        end
      end
      """

      Igniter.Project.Module.create_module(igniter, module_name, content)
    end

    defp create_deliveries_domain(igniter, app_module) do
      module_name = Module.concat(app_module, Deliveries)
      resource_name = Module.concat([app_module, Deliveries, DeliveryReceipt])

      content = """
      defmodule #{inspect(module_name)} do
        @moduledoc \"\"\"
        Domain for delivery receipts and tracking.

        Generated by `mix ash_dispatch.install`.
        \"\"\"

        use Ash.Domain

        resources do
          resource #{inspect(resource_name)}
        end
      end
      """

      Igniter.Project.Module.create_module(igniter, module_name, content)
    end

    defp add_domains_to_config(igniter, otp_app, app_module) do
      notifications_domain = Module.concat(app_module, Notifications)
      deliveries_domain = Module.concat(app_module, Deliveries)

      igniter
      |> Igniter.Project.Config.configure(
        "config.exs",
        otp_app,
        [:ash_domains],
        [notifications_domain, deliveries_domain],
        updater: fn zipper ->
          zipper
          |> Igniter.Code.List.append_new_to_list(notifications_domain)
          |> case do
            {:ok, zipper} -> Igniter.Code.List.append_new_to_list(zipper, deliveries_domain)
            other -> other
          end
        end
      )
    end

    # ============================================
    # Recipient Resolver
    # ============================================

    defp create_recipient_resolver(igniter, app_module, user_resource) do
      resolver_module = Module.concat(app_module, RecipientResolver)
      user_resource_str = inspect(user_resource || Module.concat(app_module, Accounts.User))

      content = """
      @moduledoc \"\"\"
      Recipient resolver for notification audiences.

      Define how to resolve recipients for each audience type using
      the AshDispatch.RecipientResolver DSL.

      ## Audience Strategies

      | Strategy | Example | Description |
      |----------|---------|-------------|
      | `from_context` | `from_context: :user` | Extract from context.data |
      | `query` | `query: [role: :admin]` | Query user_resource with Ash filter |
      | `path` | `path: [:team, :users]` | Follow relationship path on resource |
      | `combine` | `combine: [:owner, :team]` | Union of other audiences |
      | `resolve` | `resolve: :resolve_owner` | Custom resolver function |

      ## Usage

      Reference audiences in your dispatch DSL:

          dispatch do
            event :order_created do
              channel :in_app, audience: :owner
              channel :email, audience: :team
            end
          end
      \"\"\"

      use AshDispatch.RecipientResolver,
        user_resource: #{user_resource_str}

      audiences do
        # Context-based - extract user from event context
        audience :user, from_context: :user

        # Fallback chain - tries :user first, then :assignee
        audience :assignee, from_context: [:user, :assignee]

        # Query-based - find users matching filter
        # audience :admins, query: [role: :admin, is_active: true]

        # Relationship path - follow relationships on the resource
        # audience :team, path: [:team_members, :user]

        # Composite - union of other audiences (deduped by id)
        # audience :stakeholders, combine: [:owner, :team]

        # Custom resolver - for complex business logic
        # audience :owner, resolve: :resolve_owner

        # Custom resolver returning raw maps (not user structs)
        # audience :lead_contact, resolve: :resolve_lead_contact, raw: true
      end

      @impl true
      def to_recipient(%#{user_resource_str}{} = user) do
        %{
          id: user.id,
          email: to_string(user.email),
          display_name: extract_display_name(user)
        }
      end

      defp extract_display_name(user) do
        cond do
          Map.has_key?(user, :full_name) && user.full_name ->
            to_string(user.full_name)

          Map.has_key?(user, :first_name) && user.first_name ->
            to_string(user.first_name)

          true ->
            to_string(user.email)
        end
      end

      # Example custom resolver:
      #
      # def resolve_owner(resource, context) do
      #   case Map.get(context.data, :owner) do
      #     nil -> []
      #     owner -> [owner]
      #   end
      # end
      """

      igniter
      |> Igniter.Project.Module.create_module(resolver_module, content)
      |> Igniter.Project.Config.configure_new(
        "config.exs",
        :ash_dispatch,
        [:recipient_resolver],
        resolver_module
      )
    end

    # ============================================
    # Email Layouts
    # ============================================

    defp setup_email_layouts(igniter) do
      html_layout = email_html_layout_content()
      text_layout = email_text_layout_content()

      igniter
      |> Igniter.create_new_file(
        "priv/ash_dispatch/layouts/email.html.heex",
        html_layout,
        on_exists: :skip
      )
      |> Igniter.create_new_file(
        "priv/ash_dispatch/layouts/email.text.eex",
        text_layout,
        on_exists: :skip
      )
    end

    defp email_html_layout_content do
      ~S"""
      <!DOCTYPE html>
      <html lang="en">
      <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <title><%= @subject %></title>
        <!--[if mso]>
        <noscript>
          <xml>
            <o:OfficeDocumentSettings>
              <o:PixelsPerInch>96</o:PixelsPerInch>
            </o:OfficeDocumentSettings>
          </xml>
        </noscript>
        <![endif]-->
        <style type="text/css">
          /* Reset styles */
          body, table, td, p, a, li, blockquote {
            -webkit-text-size-adjust: 100%;
            -ms-text-size-adjust: 100%;
          }
          table, td {
            mso-table-lspace: 0pt;
            mso-table-rspace: 0pt;
          }
          img {
            -ms-interpolation-mode: bicubic;
            border: 0;
            height: auto;
            line-height: 100%;
            outline: none;
            text-decoration: none;
          }
          body {
            margin: 0 !important;
            padding: 0 !important;
            width: 100% !important;
            background-color: #f4f4f5;
          }
          /* Link styles */
          a {
            color: #2563eb;
            text-decoration: none;
          }
          a:hover {
            text-decoration: underline;
          }
        </style>
      </head>
      <body style="margin: 0; padding: 0; background-color: #f4f4f5; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;">
        <!-- Wrapper table -->
        <table role="presentation" width="100%" cellpadding="0" cellspacing="0" style="background-color: #f4f4f5;">
          <tr>
            <td align="center" style="padding: 40px 20px;">
              <!-- Main content container -->
              <table role="presentation" width="100%" cellpadding="0" cellspacing="0" style="max-width: 600px; background-color: #ffffff; border-radius: 8px; box-shadow: 0 1px 3px rgba(0,0,0,0.1);">
                <!-- Header -->
                <tr>
                  <td style="padding: 32px 40px 24px 40px; border-bottom: 1px solid #e5e7eb;">
                    <!-- Replace with your logo -->
                    <img src="https://via.placeholder.com/150x40?text=Your+Logo" alt="Logo" style="max-height: 40px; width: auto;">
                  </td>
                </tr>

                <!-- Body content -->
                <tr>
                  <td style="padding: 32px 40px;">
                    <%= @inner_content %>
                  </td>
                </tr>

                <!-- Footer -->
                <tr>
                  <td style="padding: 24px 40px 32px 40px; border-top: 1px solid #e5e7eb; background-color: #f9fafb; border-radius: 0 0 8px 8px;">
                    <p style="margin: 0 0 8px 0; font-size: 12px; color: #6b7280; text-align: center;">
                      This email was sent by Your Company Name
                    </p>
                    <p style="margin: 0; font-size: 12px; color: #6b7280; text-align: center;">
                      <a href="#" style="color: #6b7280; text-decoration: underline;">Unsubscribe</a> &middot;
                      <a href="#" style="color: #6b7280; text-decoration: underline;">Privacy Policy</a>
                    </p>
                  </td>
                </tr>
              </table>
            </td>
          </tr>
        </table>
      </body>
      </html>
      """
    end

    defp email_text_layout_content do
      """
      <%= @inner_content %>

      ---
      This email was sent by Your Company Name
      To unsubscribe, visit: [unsubscribe link]
      """
    end

    # ============================================
    # Phoenix Integration
    # ============================================

    defp maybe_setup_phoenix(igniter, false, _otp_app, _app_module), do: igniter

    defp maybe_setup_phoenix(igniter, true, otp_app, app_module) do
      web_module = detect_web_module(igniter, app_module)

      if web_module do
        igniter
        |> create_user_channel(web_module)
        |> create_inbox_controller(web_module, otp_app)
        |> add_inbox_routes(web_module)
        |> configure_counter_broadcast(otp_app, web_module)
      else
        Igniter.add_notice(
          igniter,
          """
          ⚠️  Phoenix web module not detected. Skipping channel setup.

          You can manually create a UserChannel for real-time notifications.
          See: https://ash-dispatch-docs.pages.dev/phoenix-integration
          """
        )
      end
    end

    defp create_user_channel(igniter, web_module) do
      channel_module = Module.concat(web_module, UserChannel)
      web_module_str = inspect(web_module) |> String.replace_prefix("Elixir.", "")

      content = """
      defmodule #{inspect(channel_module)} do
        @moduledoc \"\"\"
        Phoenix channel for real-time user notifications and counter updates.

        Generated by `mix ash_dispatch.install`.
        \"\"\"

        use Phoenix.Channel
        alias AshDispatch.Helpers.ChannelState

        @doc \"\"\"
        Join the user's personal channel.
        \"\"\"
        def join("user:" <> user_id, _params, socket) do
          if authorized?(socket, user_id) do
            send(self(), :after_join)
            {:ok, socket}
          else
            {:error, %{reason: "unauthorized"}}
          end
        end

        @doc \"\"\"
        Send initial state after joining.
        \"\"\"
        def handle_info(:after_join, socket) do
          user_id = socket.assigns.user_id

          # Load all counters and recent notifications
          initial_state = ChannelState.build(user_id)

          push(socket, "initial_state", initial_state)
          {:noreply, socket}
        end

        @doc \"\"\"
        Broadcast a counter update to the user's channel.

        Called by AshDispatch when counters change.
        \"\"\"
        def broadcast_counter(user_id, counter_name, value) do
          #{web_module_str}.Endpoint.broadcast(
            "user:\#{user_id}",
            "counter_update",
            %{counter: counter_name, value: value}
          )
        end

        defp authorized?(socket, user_id) do
          # Verify the user can access this channel
          socket.assigns[:user_id] == user_id
        end
      end
      """

      Igniter.Project.Module.create_module(igniter, channel_module, content)
    end

    defp create_inbox_controller(igniter, web_module, _otp_app) do
      controller_module = Module.concat(web_module, InboxApiController)
      web_module_str = inspect(web_module) |> String.replace_prefix("Elixir.", "")

      content = """
      defmodule #{inspect(controller_module)} do
        @moduledoc \"\"\"
        API controller for inbox-related endpoints.

        Generated by `mix ash_dispatch.install`.
        \"\"\"

        use #{web_module_str}, :controller

        @doc \"\"\"
        Generate a socket token for the current user.

        Used by the frontend to authenticate Phoenix channel connections.
        \"\"\"
        def socket_token(conn, _params) do
          user = conn.assigns[:current_user]

          if user do
            token = Phoenix.Token.sign(#{web_module_str}.Endpoint, "user socket", user.id)
            json(conn, %{success: true, data: %{token: token}})
          else
            conn
            |> put_status(:unauthorized)
            |> json(%{success: false, error: "Not authenticated"})
          end
        end
      end
      """

      Igniter.Project.Module.create_module(igniter, controller_module, content)
    end

    defp add_inbox_routes(igniter, web_module) do
      route_code = """
        # AshDispatch inbox API
        get "/api/inbox/socket-token", InboxApiController, :socket_token
      """

      Igniter.Libs.Phoenix.append_to_scope(igniter, "/", route_code,
        arg2: web_module,
        placement: :after
      )
    rescue
      _ ->
        Igniter.add_notice(
          igniter,
          """
          ⚠️  Could not automatically add inbox routes.

          Please add manually to your router:

              get "/api/inbox/socket-token", InboxApiController, :socket_token
          """
        )
    end

    defp configure_counter_broadcast(igniter, _otp_app, web_module) do
      channel_module = Module.concat(web_module, UserChannel)

      Igniter.Project.Config.configure_new(
        igniter,
        "config.exs",
        :ash_dispatch,
        [:counter_broadcast_fn],
        {channel_module, :broadcast_counter}
      )
    end

    # ============================================
    # Email Configuration
    # ============================================

    defp maybe_configure_email(igniter, false, _otp_app, _app_module), do: igniter

    defp maybe_configure_email(igniter, true, _otp_app, app_module) do
      mailer_module = Module.concat(app_module, Mailer)

      # Check if mailer exists
      {mailer_exists?, igniter} = Igniter.Project.Module.module_exists(igniter, mailer_module)

      if mailer_exists? do
        igniter
        |> Igniter.Project.Config.configure_new(
          "config.exs",
          :ash_dispatch,
          [:email_backend],
          AshDispatch.EmailBackend.Swoosh
        )
        |> Igniter.Project.Config.configure_new(
          "config.exs",
          :ash_dispatch,
          [:swoosh_mailer],
          mailer_module
        )
      else
        Igniter.add_notice(
          igniter,
          """
          ⚠️  Mailer module #{inspect(mailer_module)} not found.

          To enable email notifications, configure Swoosh:

              config :ash_dispatch,
                email_backend: AshDispatch.EmailBackend.Swoosh,
                swoosh_mailer: #{inspect(mailer_module)}
          """
        )
      end
    end

    # ============================================
    # TypeScript SDK
    # ============================================

    defp maybe_run_typescript(igniter, false), do: igniter

    defp maybe_run_typescript(igniter, true) do
      # Check if ash_typescript is actually being used in the project
      # by checking if any domain has the AshTypescript.Rpc extension
      if ash_typescript_in_use?() do
        Igniter.add_task(igniter, "ash_dispatch.gen")
      else
        # ash_typescript not in use - just skip silently (it's optional)
        # User can run `mix ash_dispatch.gen` later if they set it up
        igniter
      end
    end

    defp ash_typescript_in_use? do
      # Check if AshTypescript.Rpc module exists
      if Code.ensure_loaded?(AshTypescript.Rpc) do
        # Check if any domain uses the AshTypescript.Rpc extension
        otp_app = Mix.Project.config()[:app]
        domains = Application.get_env(otp_app, :ash_domains, [])

        Enum.any?(domains, fn domain ->
          Code.ensure_loaded?(domain) and
            function_exported?(domain, :spark_dsl_config, 0) and
            has_ash_typescript_extension?(domain)
        end)
      else
        false
      end
    end

    defp has_ash_typescript_extension?(domain) do
      try do
        extensions = Spark.extensions(domain)
        AshTypescript.Rpc in extensions
      rescue
        _ -> false
      end
    end

    # ============================================
    # Helpers
    # ============================================

    defp detect_user_resource(igniter, app_module) do
      # Common user resource locations
      candidates = [
        Module.concat([app_module, Accounts, User]),
        Module.concat([app_module, Users, User]),
        Module.concat([app_module, User])
      ]

      Enum.find(candidates, fn module ->
        {exists?, _} = Igniter.Project.Module.module_exists(igniter, module)
        exists?
      end)
    end

    defp detect_web_module(igniter, app_module) do
      # Common web module patterns
      candidates = [
        Module.concat(app_module, Web),
        Module.concat([app_module |> to_string() |> Kernel.<>("Web") |> String.to_atom()])
      ]

      Enum.find(candidates, fn module ->
        {exists?, _} = Igniter.Project.Module.module_exists(igniter, module)
        exists?
      end)
    end

    # ============================================
    # Final Notice
    # ============================================

    defp add_final_notice(igniter, _otp_app, app_module, user_resource) do
      user_notice =
        if user_resource do
          ""
        else
          """

          ⚠️  User resource not detected. Update your Notification resource:

              use AshDispatch.Notification,
                user_resource: YourApp.Accounts.User,
                ...
          """
        end

      notice = """
      🎉 AshDispatch has been installed!

      Created:
        - #{inspect(Module.concat([app_module, Notifications, Notification]))}
        - #{inspect(Module.concat(app_module, Notifications))} (domain)
        - #{inspect(Module.concat([app_module, Deliveries, DeliveryReceipt]))}
        - #{inspect(Module.concat(app_module, Deliveries))} (domain)
        - priv/ash_dispatch/layouts/email.html.heex
        - priv/ash_dispatch/layouts/email.text.eex
      #{user_notice}
      Next Steps:

      1. Run migrations:
         mix ash.codegen add_ash_dispatch
         mix ash.migrate

      2. Add events to your resources:

         defmodule #{inspect(app_module)}.Orders.Order do
           use Ash.Resource,
             extensions: [AshDispatch.Resource]

           dispatch do
             event :created,
               trigger_on: :create,
               channels: [
                 [transport: :in_app, audience: :user]
               ],
               content: [
                 notification_title: "Order Created",
                 notification_message: "Your order #\{\{id\}\} was created"
               ]
           end
         end

      3. Generate email templates (if using email channel):
         mix ash.codegen

      4. (Optional) Generate TypeScript SDK:
         mix ash_dispatch.gen

      📚 Documentation: https://ash-dispatch-docs.pages.dev
      """

      Igniter.add_notice(igniter, notice)
    end
  end
else
  defmodule Mix.Tasks.AshDispatch.Install do
    @shortdoc "#{__MODULE__.Docs.short_doc()} | Install `igniter` to use"

    @moduledoc __MODULE__.Docs.long_doc()

    use Mix.Task

    def run(_argv) do
      Mix.shell().error("""
      The task 'ash_dispatch.install' requires igniter. Please install igniter and try again.

      For more information, see: https://hexdocs.pm/igniter/readme.html#installation
      """)

      exit({:shutdown, 1})
    end
  end
end