defmodule SimpleshopTheme.Theme.PreviewData do
  @moduledoc """
  Provides preview data for theme customization.

  Uses real product data when available, falls back to mock data otherwise.
  This allows users to preview themes before adding products to their shop.
  """

  alias SimpleshopTheme.Products

  @doc """
  Returns products for preview.

  Uses real products if available, otherwise returns mock product data.
  """
  def products do
    if has_real_products?() do
      get_real_products()
    else
      mock_products()
    end
  end

  @doc """
  Returns cart items for preview.

  Always returns mock data as cart is session-specific.
  """
  def cart_items do
    mock_cart_items()
  end

  @doc """
  Returns cart drawer items formatted for the cart drawer component.

  Format matches Cart.hydrate/1 output for consistency between preview and live modes.
  """
  def cart_drawer_items do
    [
      %{
        variant_id: "preview-1",
        product_id: "preview-product-1",
        name: "Mountain Sunrise Art Print",
        variant: "12″ x 18″ / Matte",
        price: 2400,
        quantity: 1,
        image: "/mockups/mountain-sunrise-print-1-400.webp"
      },
      %{
        variant_id: "preview-2",
        product_id: "preview-product-2",
        name: "Fern Leaf Mug",
        variant: "11oz / White",
        price: 1499,
        quantity: 2,
        image: "/mockups/fern-leaf-mug-1-400.webp"
      }
    ]
  end

  @doc """
  Returns testimonials for preview.

  Always returns mock data.
  """
  def testimonials do
    mock_testimonials()
  end

  @doc """
  Returns product reviews for preview.

  Always returns mock data formatted for the reviews_section component.
  """
  def reviews do
    [
      %{
        rating: 5,
        title: "Sample review – five stars",
        body:
          "This is an example review for the demo store. Real reviews from your customers will appear here once you start getting orders.",
        author: "Demo Customer",
        date: "2 weeks ago",
        verified: true
      },
      %{
        rating: 4,
        title: "Sample review – four stars",
        body:
          "Another example review to show how the layout handles multiple entries. You can customise the review section in the theme settings.",
        author: "Demo Shopper",
        date: "1 month ago",
        verified: true
      }
    ]
  end

  @doc """
  Returns about page content for preview.

  Returns structured content blocks for the rich_text component.
  """
  def about_content do
    [
      %{
        type: :lead,
        text:
          "This is a sample about page for your SimpleShop store. You're reading it as Robin, a fictional nature photographer – but this is where your own story goes."
      },
      %{
        type: :paragraph,
        text:
          "Tell your customers who you are and what inspires your work. Maybe it started as a hobby that grew into something bigger, or maybe you've been creating for years. Either way, this is the place to share it."
      },
      %{
        type: :paragraph,
        text:
          "In Robin's version, every design comes from their own photography – early morning mist over the hills, autumn leaves in the local woods, the quiet beauty of wildflower meadows. Your story will be different, and that's the point."
      },
      %{type: :heading, text: "Quality you can trust"},
      %{
        type: :paragraph,
        text:
          "This section is a good place to talk about your products and what makes them worth buying. Print on demand means every item is made to order using quality materials and printing techniques – tell your customers about that."
      },
      %{type: :heading, text: "Printed sustainably"},
      %{
        type: :paragraph,
        text:
          "And here's where you can mention anything else that matters to you – sustainability, packaging, your creative process, whatever sets your shop apart. No unsold stock means no waste, and your customers will appreciate knowing that."
      },
      %{type: :closing, text: "Thanks for checking out the demo. Make this page your own."}
    ]
  end

  @doc """
  Returns categories for preview.

  Uses real categories if available, otherwise returns mock data.
  """
  def categories do
    if has_real_categories?() do
      get_real_categories()
    else
      mock_categories()
    end
  end

  @doc """
  Returns a category by its slug.

  Returns nil if not found.
  """
  def category_by_slug(slug) do
    Enum.find(categories(), fn cat -> cat.slug == slug end)
  end

  @doc """
  Returns products filtered by category slug.

  If slug is nil or "all", returns all products.
  """
  def products_by_category(nil), do: products()
  def products_by_category("all"), do: products()

  def products_by_category(slug) do
    case category_by_slug(slug) do
      nil ->
        []

      category ->
        products()
        |> Enum.filter(fn product -> product.category == category.name end)
    end
  end

  @doc """
  Checks if the shop has real products.

  Returns true if at least one visible, active product exists in the database.
  Returns false if the database is unavailable (e.g., in tests without sandbox).
  """
  def has_real_products? do
    try do
      Products.list_products(visible: true, status: "active") |> Enum.any?()
    rescue
      DBConnection.OwnershipError -> false
    end
  end

  defp has_real_categories? do
    has_real_products?()
  end

  defp get_real_products do
    Products.list_products(
      visible: true,
      status: "active",
      preload: [images: :image, variants: []]
    )
    |> Enum.map(&product_to_map/1)
  end

  defp get_real_categories do
    Products.list_products(visible: true, status: "active")
    |> Enum.map(& &1.category)
    |> Enum.reject(&is_nil/1)
    |> Enum.frequencies()
    |> Enum.map(fn {name, count} ->
      %{
        id: Slug.slugify(name),
        name: name,
        slug: Slug.slugify(name),
        product_count: count,
        image_url: nil
      }
    end)
    |> Enum.sort_by(& &1.name)
  end

  # Transform a Product struct to the map format expected by shop components
  defp product_to_map(product) do
    # Get images sorted by position
    images = Enum.sort_by(product.images, & &1.position)
    first_image = List.first(images)
    second_image = Enum.at(images, 1)

    # Get available variants for pricing
    available_variants =
      product.variants
      |> Enum.filter(& &1.is_enabled)
      |> Enum.filter(& &1.is_available)

    # Get the cheapest available variant for display price
    cheapest_variant =
      available_variants
      |> Enum.min_by(& &1.price, fn -> nil end)

    # Determine stock and sale status
    in_stock = Enum.any?(available_variants)
    on_sale = Enum.any?(product.variants, &SimpleshopTheme.Products.ProductVariant.on_sale?/1)

    # Use local image if available, fall back to CDN URL
    {image_url, image_id, source_width} = image_attrs(first_image)
    {hover_image_url, hover_image_id, hover_source_width} = image_attrs(second_image)

    # Map variants to frontend format (only enabled/published ones)
    variants =
      product.variants
      |> Enum.filter(& &1.is_enabled)
      |> Enum.map(fn v ->
        %{
          id: v.id,
          provider_variant_id: v.provider_variant_id,
          title: v.title,
          price: v.price,
          compare_at_price: v.compare_at_price,
          options: v.options,
          is_available: v.is_available
        }
      end)

    # Extract option types, filtered to only values present in enabled variants
    option_types =
      SimpleshopTheme.Providers.Printify.extract_option_types(product.provider_data)
      |> filter_option_types_by_variants(variants)

    %{
      id: product.slug,
      name: product.title,
      description: product.description,
      price: if(cheapest_variant, do: cheapest_variant.price, else: 0),
      compare_at_price: if(cheapest_variant, do: cheapest_variant.compare_at_price, else: nil),
      image_url: image_url,
      image_id: image_id,
      hover_image_url: hover_image_url,
      hover_image_id: hover_image_id,
      source_width: source_width,
      hover_source_width: hover_source_width,
      category: product.category,
      slug: product.slug,
      in_stock: in_stock,
      on_sale: on_sale,
      inserted_at: product.inserted_at,
      option_types: option_types,
      variants: variants
    }
  end

  # Extract image attributes, preferring local Media.Image when available
  defp image_attrs(nil), do: {nil, nil, nil}

  defp image_attrs(%{image_id: image_id, image: %{source_width: source_width}})
       when not is_nil(image_id) do
    # Local image available - use image_id for responsive <picture> element
    {nil, image_id, source_width}
  end

  defp image_attrs(%{src: src}) do
    # Fall back to CDN URL
    {src, nil, nil}
  end

  # Filter option types to only include values present in enabled variants
  # This ensures we don't show unpublished options from the Printify catalog
  defp filter_option_types_by_variants(option_types, variants) do
    # Collect all option values present in the enabled variants
    values_in_use =
      Enum.reduce(variants, %{}, fn variant, acc ->
        Enum.reduce(variant.options, acc, fn {opt_name, opt_value}, inner_acc ->
          Map.update(inner_acc, opt_name, MapSet.new([opt_value]), &MapSet.put(&1, opt_value))
        end)
      end)

    # Filter each option type's values to only those in use
    option_types
    |> Enum.map(fn opt_type ->
      used_values = Map.get(values_in_use, opt_type.name, MapSet.new())

      filtered_values =
        opt_type.values
        |> Enum.filter(fn v -> MapSet.member?(used_values, v.title) end)

      %{opt_type | values: filtered_values}
    end)
    |> Enum.reject(fn opt_type -> opt_type.values == [] end)
  end

  # Default source width for mockup variants (max generated size)
  @mockup_source_width 1200

  defp mock_products do
    [
      # Art Prints
      %{
        id: "1",
        name: "Mountain Sunrise Art Print",
        description: "Capture the magic of dawn with this stunning mountain landscape print",
        price: 1999,
        compare_at_price: nil,
        image_url: "/mockups/mountain-sunrise-print-1",
        hover_image_url: "/mockups/mountain-sunrise-print-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Art Prints",
        in_stock: true,
        on_sale: false,
        option_types: [
          %{
            name: "Size",
            type: :size,
            values: [
              %{id: 1, title: "8×10"},
              %{id: 2, title: "12×18"},
              %{id: 3, title: "18×24"}
            ]
          }
        ],
        variants: [
          %{
            id: "p1",
            title: "8×10",
            price: 1999,
            options: %{"Size" => "8×10"},
            is_available: true
          },
          %{
            id: "p2",
            title: "12×18",
            price: 2400,
            options: %{"Size" => "12×18"},
            is_available: true
          },
          %{
            id: "p3",
            title: "18×24",
            price: 3200,
            options: %{"Size" => "18×24"},
            is_available: true
          }
        ]
      },
      %{
        id: "2",
        name: "Ocean Waves Art Print",
        description: "A calming sunset over ocean waves to bring peace to any room",
        price: 2400,
        compare_at_price: nil,
        image_url: "/mockups/ocean-waves-print-1",
        hover_image_url: "/mockups/ocean-waves-print-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Art Prints",
        in_stock: true,
        on_sale: false
      },
      %{
        id: "3",
        name: "Wildflower Meadow Art Print",
        description: "Beautiful wildflower meadow captured in the summer sunshine",
        price: 2400,
        compare_at_price: nil,
        image_url: "/mockups/wildflower-meadow-print-1",
        hover_image_url: "/mockups/wildflower-meadow-print-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Art Prints",
        in_stock: true,
        on_sale: false
      },
      %{
        id: "4",
        name: "Geometric Abstract Art Print",
        description: "Modern minimalist design with bold geometric shapes",
        price: 2800,
        compare_at_price: 3200,
        image_url: "/mockups/geometric-abstract-print-1",
        hover_image_url: "/mockups/geometric-abstract-print-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Art Prints",
        in_stock: true,
        on_sale: true
      },
      %{
        id: "5",
        name: "Botanical Illustration Print",
        description: "Vintage-inspired botanical drawing with intricate detail",
        price: 2400,
        compare_at_price: nil,
        image_url: "/mockups/botanical-illustration-print-1",
        hover_image_url: "/mockups/botanical-illustration-print-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Art Prints",
        in_stock: true,
        on_sale: false
      },
      # Apparel
      %{
        id: "6",
        name: "Forest Silhouette T-Shirt",
        description: "Soft cotton tee featuring a peaceful forest silhouette design",
        price: 2999,
        compare_at_price: nil,
        image_url: "/mockups/forest-silhouette-tshirt-1",
        hover_image_url: "/mockups/forest-silhouette-tshirt-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Apparel",
        in_stock: true,
        on_sale: false,
        option_types: [
          %{
            name: "Color",
            type: :color,
            values: [
              %{id: 1, title: "Black", hex: "#000000"},
              %{id: 2, title: "Navy", hex: "#1A2237"},
              %{id: 3, title: "White", hex: "#FFFFFF"},
              %{id: 4, title: "Sport Grey", hex: "#9CA3AF"}
            ]
          },
          %{
            name: "Size",
            type: :size,
            values: [
              %{id: 10, title: "S"},
              %{id: 11, title: "M"},
              %{id: 12, title: "L"},
              %{id: 13, title: "XL"},
              %{id: 14, title: "2XL"}
            ]
          }
        ],
        variants: [
          # Black variants
          %{
            id: "t1",
            title: "Black / S",
            price: 2999,
            options: %{"Color" => "Black", "Size" => "S"},
            is_available: true
          },
          %{
            id: "t2",
            title: "Black / M",
            price: 2999,
            options: %{"Color" => "Black", "Size" => "M"},
            is_available: true
          },
          %{
            id: "t3",
            title: "Black / L",
            price: 2999,
            options: %{"Color" => "Black", "Size" => "L"},
            is_available: true
          },
          %{
            id: "t4",
            title: "Black / XL",
            price: 2999,
            options: %{"Color" => "Black", "Size" => "XL"},
            is_available: true
          },
          %{
            id: "t5",
            title: "Black / 2XL",
            price: 3299,
            options: %{"Color" => "Black", "Size" => "2XL"},
            is_available: true
          },
          # Navy variants
          %{
            id: "t6",
            title: "Navy / S",
            price: 2999,
            options: %{"Color" => "Navy", "Size" => "S"},
            is_available: true
          },
          %{
            id: "t7",
            title: "Navy / M",
            price: 2999,
            options: %{"Color" => "Navy", "Size" => "M"},
            is_available: true
          },
          %{
            id: "t8",
            title: "Navy / L",
            price: 2999,
            options: %{"Color" => "Navy", "Size" => "L"},
            is_available: true
          },
          %{
            id: "t9",
            title: "Navy / XL",
            price: 2999,
            options: %{"Color" => "Navy", "Size" => "XL"},
            is_available: true
          },
          %{
            id: "t10",
            title: "Navy / 2XL",
            price: 3299,
            options: %{"Color" => "Navy", "Size" => "2XL"},
            is_available: false
          },
          # White variants
          %{
            id: "t11",
            title: "White / S",
            price: 2999,
            options: %{"Color" => "White", "Size" => "S"},
            is_available: true
          },
          %{
            id: "t12",
            title: "White / M",
            price: 2999,
            options: %{"Color" => "White", "Size" => "M"},
            is_available: true
          },
          %{
            id: "t13",
            title: "White / L",
            price: 2999,
            options: %{"Color" => "White", "Size" => "L"},
            is_available: true
          },
          %{
            id: "t14",
            title: "White / XL",
            price: 2999,
            options: %{"Color" => "White", "Size" => "XL"},
            is_available: false
          },
          %{
            id: "t15",
            title: "White / 2XL",
            price: 3299,
            options: %{"Color" => "White", "Size" => "2XL"},
            is_available: false
          },
          # Sport Grey variants
          %{
            id: "t16",
            title: "Sport Grey / S",
            price: 2999,
            options: %{"Color" => "Sport Grey", "Size" => "S"},
            is_available: true
          },
          %{
            id: "t17",
            title: "Sport Grey / M",
            price: 2999,
            options: %{"Color" => "Sport Grey", "Size" => "M"},
            is_available: true
          },
          %{
            id: "t18",
            title: "Sport Grey / L",
            price: 2999,
            options: %{"Color" => "Sport Grey", "Size" => "L"},
            is_available: true
          },
          %{
            id: "t19",
            title: "Sport Grey / XL",
            price: 2999,
            options: %{"Color" => "Sport Grey", "Size" => "XL"},
            is_available: true
          },
          %{
            id: "t20",
            title: "Sport Grey / 2XL",
            price: 3299,
            options: %{"Color" => "Sport Grey", "Size" => "2XL"},
            is_available: true
          }
        ]
      },
      %{
        id: "7",
        name: "Forest Light Hoodie",
        description: "Cosy fleece hoodie with stunning forest light photography",
        price: 4499,
        compare_at_price: 4999,
        image_url: "/mockups/forest-light-hoodie-1",
        hover_image_url: "/mockups/forest-light-hoodie-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Apparel",
        in_stock: true,
        on_sale: true
      },
      %{
        id: "8",
        name: "Wildflower Meadow Tote Bag",
        description: "Sturdy cotton tote bag with vibrant wildflower design",
        price: 1999,
        compare_at_price: nil,
        image_url: "/mockups/wildflower-meadow-tote-1",
        hover_image_url: "/mockups/wildflower-meadow-tote-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Apparel",
        in_stock: true,
        on_sale: false
      },
      %{
        id: "9",
        name: "Sunset Gradient Tote Bag",
        description: "Beautiful ocean sunset printed on durable canvas tote",
        price: 1999,
        compare_at_price: nil,
        image_url: "/mockups/sunset-gradient-tote-1",
        hover_image_url: "/mockups/sunset-gradient-tote-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Apparel",
        in_stock: true,
        on_sale: false
      },
      # Homewares
      %{
        id: "10",
        name: "Fern Leaf Mug",
        description: "Start your morning right with this nature-inspired ceramic mug",
        price: 1499,
        compare_at_price: nil,
        image_url: "/mockups/fern-leaf-mug-1",
        hover_image_url: "/mockups/fern-leaf-mug-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Homewares",
        in_stock: true,
        on_sale: false
      },
      %{
        id: "11",
        name: "Ocean Waves Cushion",
        description: "Soft polyester cushion featuring a stunning ocean sunset",
        price: 2999,
        compare_at_price: nil,
        image_url: "/mockups/ocean-waves-cushion-1",
        hover_image_url: "/mockups/ocean-waves-cushion-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Homewares",
        in_stock: true,
        on_sale: false
      },
      %{
        id: "12",
        name: "Night Sky Blanket",
        description: "Cosy sherpa fleece blanket with mesmerising milky way print",
        price: 5999,
        compare_at_price: 6999,
        image_url: "/mockups/night-sky-blanket-1",
        hover_image_url: "/mockups/night-sky-blanket-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Homewares",
        in_stock: true,
        on_sale: true
      },
      # Stationery
      %{
        id: "13",
        name: "Autumn Leaves Notebook",
        description: "Hardcover journal with beautiful autumn foliage design",
        price: 1999,
        compare_at_price: nil,
        image_url: "/mockups/autumn-leaves-notebook-1",
        hover_image_url: "/mockups/autumn-leaves-notebook-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Stationery",
        in_stock: true,
        on_sale: false
      },
      %{
        id: "14",
        name: "Monstera Leaf Notebook",
        description: "Tropical-inspired hardcover journal for your thoughts",
        price: 1999,
        compare_at_price: nil,
        image_url: "/mockups/monstera-leaf-notebook-1",
        hover_image_url: "/mockups/monstera-leaf-notebook-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Stationery",
        in_stock: true,
        on_sale: false
      },
      # Accessories
      %{
        id: "15",
        name: "Monstera Leaf Phone Case",
        description: "Tough phone case with stunning monstera leaf photography",
        price: 2499,
        compare_at_price: nil,
        image_url: "/mockups/monstera-leaf-phone-case-1",
        hover_image_url: "/mockups/monstera-leaf-phone-case-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Accessories",
        in_stock: true,
        on_sale: false
      },
      %{
        id: "16",
        name: "Blue Waves Laptop Sleeve",
        description: "Protective laptop sleeve with abstract blue gradient design",
        price: 3499,
        compare_at_price: nil,
        image_url: "/mockups/blue-waves-laptop-sleeve-1",
        hover_image_url: "/mockups/blue-waves-laptop-sleeve-2",
        source_width: @mockup_source_width,
        hover_source_width: @mockup_source_width,
        category: "Accessories",
        in_stock: true,
        on_sale: false
      }
    ]
  end

  defp mock_cart_items do
    products = mock_products()

    [
      %{
        product: Enum.at(products, 0),
        quantity: 1,
        variant: "12″ x 18″ / Matte"
      },
      %{
        product: Enum.at(products, 9),
        quantity: 2,
        variant: "11oz / White"
      },
      %{
        product: Enum.at(products, 5),
        quantity: 1,
        variant: "Large / Black"
      }
    ]
  end

  defp mock_testimonials do
    [
      %{
        id: "1",
        author: "Sample Customer A",
        content:
          "This is sample testimonial text for the demo store. Your real customer quotes will appear here – try to include specific details about what they loved.",
        rating: 5,
        date: "2025-01-15"
      },
      %{
        id: "2",
        author: "Sample Customer B",
        content:
          "Another example testimonial. A mix of short and longer quotes works well for the layout. This one's a bit longer to show how the card handles more text.",
        rating: 5,
        date: "2025-01-10"
      },
      %{
        id: "3",
        author: "Sample Customer C",
        content:
          "Short and sweet works too. Customers love seeing real feedback from other buyers.",
        rating: 5,
        date: "2025-01-05"
      },
      %{
        id: "4",
        author: "Sample Customer D",
        content:
          "Sample feedback showing how the grid handles four or more testimonials. Replace these with real quotes once you have them.",
        rating: 5,
        date: "2024-12-28"
      },
      %{
        id: "5",
        author: "Sample Customer E",
        content:
          "One more example to fill out the testimonials section. You can add as many as you like – the layout adapts to fit.",
        rating: 5,
        date: "2024-12-20"
      },
      %{
        id: "6",
        author: "Sample Customer F",
        content:
          "Final sample testimonial. When you connect your store, real reviews and feedback from customers will replace these placeholder entries.",
        rating: 5,
        date: "2024-12-15"
      }
    ]
  end

  defp mock_categories do
    [
      %{
        id: "1",
        name: "Art Prints",
        slug: "art-prints",
        product_count: 5,
        image_url: "/mockups/mountain-sunrise-print-2-thumb.jpg"
      },
      %{
        id: "2",
        name: "Apparel",
        slug: "apparel",
        product_count: 4,
        image_url: "/mockups/forest-silhouette-tshirt-1-thumb.jpg"
      },
      %{
        id: "3",
        name: "Homewares",
        slug: "homewares",
        product_count: 3,
        image_url: "/mockups/fern-leaf-mug-1-thumb.jpg"
      },
      %{
        id: "4",
        name: "Stationery",
        slug: "stationery",
        product_count: 2,
        image_url: "/mockups/autumn-leaves-notebook-1-thumb.jpg"
      },
      %{
        id: "5",
        name: "Accessories",
        slug: "accessories",
        product_count: 2,
        image_url: "/mockups/monstera-leaf-phone-case-1-thumb.jpg"
      }
    ]
  end
end