defmodule SimpleshopTheme.Sync.MockupEnricher do
  @moduledoc """
  Oban worker that enriches Printful products with extra mockup angle images.

  After product sync, Printful products only have front-view preview images.
  This worker uses the legacy mockup generator API to produce extra angles
  (back, left, right, etc.) and appends them as additional product images.

  Each product is processed as a separate job so failures don't block others.
  The temporary S3 URLs from the mockup generator are downloaded via the
  existing ImageDownloadWorker pipeline.
  """

  use Oban.Worker, queue: :images, max_attempts: 5

  alias SimpleshopTheme.Clients.Printful, as: Client
  alias SimpleshopTheme.Products
  alias SimpleshopTheme.Products.ProviderConnection
  alias SimpleshopTheme.Sync.ImageDownloadWorker

  require Logger

  @poll_interval_ms 3_000
  @max_poll_attempts 20

  # Mockup generator config per catalog product type:
  # {placement, area_width, area_height}
  # Apparel/accessories use "front", flat products use "default"
  @product_configs %{
    1 => {"default", 4500, 6750},
    3 => {"default", 4800, 7200},
    19 => {"default", 3150, 1350},
    71 => {"front", 4500, 5100},
    146 => {"front", 4500, 4500},
    181 => {"default", 1092, 2286},
    274 => {"default", 3300, 3300},
    394 => {"default", 3900, 2925},
    395 => {"default", 9000, 10800}
  }

  # Stagger jobs to avoid hammering Printful's rate limits
  @job_stagger_seconds 45

  @doc """
  Enqueue mockup enrichment for a product.

  Accepts an optional `delay_index` to stagger jobs (each index adds
  #{@job_stagger_seconds}s of delay).
  """
  def enqueue(conn_id, product_id, delay_index \\ 0) do
    delay = delay_index * @job_stagger_seconds
    scheduled_at = DateTime.add(DateTime.utc_now(), delay, :second)

    %{provider_connection_id: conn_id, product_id: product_id}
    |> new(scheduled_at: scheduled_at)
    |> Oban.insert()
  end

  @impl Oban.Worker
  def perform(%Oban.Job{
        args: %{"provider_connection_id" => conn_id, "product_id" => product_id}
      }) do
    with %ProviderConnection{} = conn <- Products.get_provider_connection(conn_id),
         product when not is_nil(product) <- Products.get_product(product_id),
         :ok <- set_credentials(conn) do
      enrich_product(product)
    else
      nil -> {:cancel, :not_found}
      {:error, _} = error -> error
    end
  end

  defp enrich_product(product) do
    provider_data = product.provider_data || %{}

    catalog_product_id =
      provider_data["catalog_product_id"] || provider_data[:catalog_product_id]

    artwork_url = provider_data["artwork_url"] || provider_data[:artwork_url]

    catalog_variant_ids =
      provider_data["catalog_variant_ids"] || provider_data[:catalog_variant_ids] || []

    cond do
      is_nil(catalog_product_id) ->
        Logger.info("[MockupEnricher] No catalog_product_id for #{product.title}, skipping")
        :ok

      is_nil(artwork_url) ->
        Logger.info("[MockupEnricher] No artwork_url for #{product.title}, skipping")
        :ok

      already_enriched?(product) ->
        Logger.info("[MockupEnricher] Already enriched #{product.title}, skipping")
        :ok

      true ->
        # Pick one representative variant for mockup generation
        variant_id = List.first(catalog_variant_ids)

        case generate_and_append(product, catalog_product_id, variant_id, artwork_url) do
          {:ok, count} ->
            Logger.info("[MockupEnricher] Added #{count} extra angle(s) for #{product.title}")

            :ok

          {:error, {429, _}} ->
            Logger.info("[MockupEnricher] Rate limited for #{product.title}, snoozing 60s")
            {:snooze, 60}

          {:error, {400, _} = reason} ->
            # Permanent API error (wrong placement, unsupported product, etc.)
            Logger.info("[MockupEnricher] #{product.title} not supported: #{inspect(reason)}")
            :ok

          {:error, reason} ->
            Logger.warning("[MockupEnricher] Failed for #{product.title}: #{inspect(reason)}")

            {:error, reason}
        end
    end
  end

  defp generate_and_append(product, catalog_product_id, variant_id, artwork_url) do
    {placement, area_width, area_height} =
      Map.get(@product_configs, catalog_product_id, {"front", 4500, 5100})

    body = %{
      variant_ids: if(variant_id, do: [variant_id], else: []),
      format: "jpg",
      files: [
        %{
          placement: placement,
          image_url: artwork_url,
          position: %{
            area_width: area_width,
            area_height: area_height,
            width: area_width,
            height: area_height,
            top: 0,
            left: 0
          }
        }
      ]
    }

    with {:ok, task_data} <- Client.create_mockup_generator_task(catalog_product_id, body),
         task_key <- task_data["task_key"],
         {:ok, result} <- poll_generator_task(task_key),
         extra_images <- extract_extra_images(result) do
      if extra_images == [] do
        {:ok, 0}
      else
        append_images_to_product(product, extra_images)
      end
    end
  end

  defp poll_generator_task(task_key), do: poll_generator_task(task_key, 0)

  defp poll_generator_task(_task_key, attempt) when attempt >= @max_poll_attempts do
    {:error, :timeout}
  end

  defp poll_generator_task(task_key, attempt) do
    Process.sleep(@poll_interval_ms)

    case Client.get_mockup_generator_task(task_key) do
      {:ok, %{"status" => "completed"} = result} ->
        {:ok, result}

      {:ok, %{"status" => "error", "error" => error}} ->
        {:error, {:mockup_error, error}}

      {:ok, %{"status" => _pending}} ->
        poll_generator_task(task_key, attempt + 1)

      {:error, {429, _}} ->
        # Rate limited — back off and retry
        Process.sleep(60_000)
        poll_generator_task(task_key, attempt + 1)

      {:error, reason} ->
        {:error, reason}
    end
  end

  # Collect all extra angle URLs from the mockup generator response.
  # The "extra" array contains alternate views (back, left, right, etc.)
  defp extract_extra_images(result) do
    (result["mockups"] || [])
    |> Enum.flat_map(fn mockup ->
      (mockup["extra"] || [])
      |> Enum.map(fn extra ->
        %{
          src: extra["url"],
          alt: extra["title"]
        }
      end)
    end)
    |> Enum.reject(&is_nil(&1.src))
    |> Enum.uniq_by(& &1.src)
  end

  defp append_images_to_product(product, extra_images) do
    # Find the current max position so we append after existing images
    existing_images = Products.list_product_images(product.id)
    max_position = existing_images |> Enum.map(& &1.position) |> Enum.max(fn -> -1 end)

    results =
      extra_images
      |> Enum.with_index(max_position + 1)
      |> Enum.map(fn {img, position} ->
        attrs = %{
          product_id: product.id,
          src: img.src,
          alt: img.alt,
          position: position
        }

        case Products.create_product_image(attrs) do
          {:ok, product_image} ->
            ImageDownloadWorker.enqueue(product_image.id)
            {:ok, product_image}

          {:error, reason} ->
            Logger.warning("[MockupEnricher] Failed to create image: #{inspect(reason)}")
            {:error, reason}
        end
      end)

    count = Enum.count(results, &match?({:ok, _}, &1))
    {:ok, count}
  end

  # Check if this product already has extra angle images from a prior enrichment
  defp already_enriched?(product) do
    images = Products.list_product_images(product.id)
    Enum.any?(images, fn img -> img.alt in ["Front", "Back", "Left", "Right"] end)
  end

  defp set_credentials(conn) do
    case ProviderConnection.get_api_key(conn) do
      api_key when is_binary(api_key) ->
        Process.put(:printful_api_key, api_key)
        store_id = get_in(conn.config, ["store_id"])
        if store_id, do: Process.put(:printful_store_id, store_id)
        :ok

      nil ->
        {:error, :no_api_key}
    end
  end
end