feat: datasheet upload and auto-retrieve

- store datasheet PDFs on the server
- download PDF automatically when given a link

lib/components_elixir/datasheet_downloader.ex

@@ -0,0 +1,137 @@
+defmodule ComponentsElixir.DatasheetDownloader do
+  @moduledoc """
+  Module for downloading datasheet PDFs from URLs.
+  """
+
+  require Logger
+
+  @doc """
+  Downloads a PDF from the given URL and saves it to the datasheets folder.
+  Returns {:ok, filename} on success or {:error, reason} on failure.
+  """
+  def download_pdf_from_url(url) when is_binary(url) do
+    with {:ok, %URI{scheme: scheme}} when scheme in ["http", "https"] <- validate_url(url),
+         {:ok, filename} <- generate_filename(url),
+         {:ok, response} <- fetch_pdf(url),
+         :ok <- validate_pdf_content(response.body),
+         :ok <- save_file(filename, response.body) do
+      {:ok, filename}
+    else
+      {:error, reason} -> {:error, reason}
+      error -> {:error, "Unexpected error: #{inspect(error)}"}
+    end
+  end
+
+  def download_pdf_from_url(_), do: {:error, "Invalid URL"}
+
+  defp validate_url(url) do
+    case URI.parse(url) do
+      %URI{scheme: scheme} when scheme in ["http", "https"] ->
+        {:ok, URI.parse(url)}
+      _ ->
+        {:error, "Invalid URL scheme. Only HTTP and HTTPS are supported."}
+    end
+  end
+
+  defp generate_filename(url) do
+    # Try to extract a meaningful filename from the URL
+    uri = URI.parse(url)
+    original_filename =
+      case Path.basename(uri.path || "") do
+        "" -> "datasheet"
+        basename ->
+          # Remove extension and sanitize
+          basename
+          |> Path.rootname()
+          |> sanitize_filename()
+      end
+
+    # Create a unique filename with timestamp
+    timestamp = System.unique_integer([:positive])
+    filename = "#{timestamp}_#{original_filename}.pdf"
+    {:ok, filename}
+  end
+
+  defp sanitize_filename(filename) do
+    filename
+    |> String.replace(~r/[^\w\-_]/, "_")  # Replace non-word chars with underscores
+    |> String.replace(~r/_+/, "_")        # Replace multiple underscores with single
+    |> String.trim("_")                   # Remove leading/trailing underscores
+    |> String.slice(0, 50)                # Limit length
+    |> case do
+      "" -> "datasheet"
+      name -> name
+    end
+  end
+
+  defp fetch_pdf(url) do
+    case Req.get(url,
+      redirect: true,
+      max_redirects: 5,
+      receive_timeout: 30_000,
+      headers: [
+        {"User-Agent", "ComponentSystem/1.0 DatasheetDownloader"}
+      ]
+    ) do
+      {:ok, %Req.Response{status: 200} = response} ->
+        {:ok, response}
+      {:ok, %Req.Response{status: status}} ->
+        {:error, "HTTP error: #{status}"}
+      {:error, reason} ->
+        Logger.error("Failed to download PDF from #{url}: #{inspect(reason)}")
+        {:error, "Download failed: #{inspect(reason)}"}
+    end
+  end
+
+  defp validate_pdf_content(body) do
+    # Check if the response body looks like a PDF (starts with %PDF)
+    case body do
+      <<"%PDF", _rest::binary>> ->
+        :ok
+      _ ->
+        {:error, "Downloaded content is not a valid PDF file"}
+    end
+  end
+
+  defp save_file(filename, content) do
+    uploads_dir = Application.get_env(:components_elixir, :uploads_dir)
+    datasheets_dir = Path.join([uploads_dir, "datasheets"])
+    file_path = Path.join(datasheets_dir, filename)
+
+    # Ensure the datasheets directory exists
+    case File.mkdir_p(datasheets_dir) do
+      :ok ->
+        case File.write(file_path, content) do
+          :ok ->
+            Logger.info("Successfully saved datasheet: #{filename}")
+            :ok
+          {:error, reason} ->
+            Logger.error("Failed to save datasheet file: #{inspect(reason)}")
+            {:error, "Failed to save file: #{inspect(reason)}"}
+        end
+      {:error, reason} ->
+        Logger.error("Failed to create datasheets directory: #{inspect(reason)}")
+        {:error, "Failed to create directory: #{inspect(reason)}"}
+    end
+  end
+
+  @doc """
+  Deletes a datasheet file from the filesystem.
+  """
+  def delete_datasheet_file(nil), do: :ok
+  def delete_datasheet_file(""), do: :ok
+
+  def delete_datasheet_file(filename) do
+    uploads_dir = Application.get_env(:components_elixir, :uploads_dir)
+    file_path = Path.join([uploads_dir, "datasheets", filename])
+
+    case File.rm(file_path) do
+      :ok ->
+        Logger.info("Deleted datasheet file: #{filename}")
+        :ok
+      {:error, reason} ->
+        Logger.warning("Failed to delete datasheet file #{filename}: #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
+end

lib/components_elixir/inventory.ex

@@ -320,6 +320,30 @@ defmodule ComponentsElixir.Inventory do
     |> Repo.insert()
   end
 
+  @doc """
+  Creates a component and downloads datasheet from URL if provided.
+  """
+  def create_component_with_datasheet(attrs \\ %{}) do
+    # If a datasheet_url is provided, download it
+    updated_attrs =
+      case Map.get(attrs, "datasheet_url") do
+        url when is_binary(url) and url != "" ->
+          case ComponentsElixir.DatasheetDownloader.download_pdf_from_url(url) do
+            {:ok, filename} ->
+              Map.put(attrs, "datasheet_filename", filename)
+            {:error, _reason} ->
+              # Continue without datasheet file if download fails
+              attrs
+          end
+        _ ->
+          attrs
+      end
+
+    %Component{}
+    |> Component.changeset(updated_attrs)
+    |> Repo.insert()
+  end
+
   @doc """
   Updates a component.
   """
@@ -329,6 +353,34 @@ defmodule ComponentsElixir.Inventory do
     |> Repo.update()
   end
 
+  @doc """
+  Updates a component and downloads datasheet from URL if provided.
+  """
+  def update_component_with_datasheet(%Component{} = component, attrs) do
+    # If a datasheet_url is provided and changed, download it
+    updated_attrs =
+      case Map.get(attrs, "datasheet_url") do
+        url when is_binary(url) and url != "" and url != component.datasheet_url ->
+          case ComponentsElixir.DatasheetDownloader.download_pdf_from_url(url) do
+            {:ok, filename} ->
+              # Delete old datasheet file if it exists
+              if component.datasheet_filename do
+                ComponentsElixir.DatasheetDownloader.delete_datasheet_file(component.datasheet_filename)
+              end
+              Map.put(attrs, "datasheet_filename", filename)
+            {:error, _reason} ->
+              # Keep existing filename if download fails
+              attrs
+          end
+        _ ->
+          attrs
+      end
+
+    component
+    |> Component.changeset(updated_attrs)
+    |> Repo.update()
+  end
+
   @doc """
   Deletes a component.
   """

lib/components_elixir/inventory/component.ex

@@ -18,6 +18,7 @@ defmodule ComponentsElixir.Inventory.Component do
     field :legacy_position, :string
     field :count, :integer, default: 0
     field :datasheet_url, :string
+    field :datasheet_filename, :string
     field :image_filename, :string
 
     belongs_to :category, Category
@@ -29,7 +30,7 @@ defmodule ComponentsElixir.Inventory.Component do
   @doc false
   def changeset(component, attrs) do
     component
-    |> cast(attrs, [:name, :description, :keywords, :position, :count, :datasheet_url, :image_filename, :category_id, :storage_location_id])
+    |> cast(attrs, [:name, :description, :keywords, :position, :count, :datasheet_url, :datasheet_filename, :image_filename, :category_id, :storage_location_id])
     |> validate_required([:name, :category_id])
     |> validate_length(:name, min: 1, max: 255)
     |> validate_length(:description, max: 2000)
@@ -59,6 +60,14 @@ defmodule ComponentsElixir.Inventory.Component do
     |> cast(attrs, [:image_filename])
   end
 
+  @doc """
+  Changeset for updating component datasheet.
+  """
+  def datasheet_changeset(component, attrs) do
+    component
+    |> cast(attrs, [:datasheet_filename])
+  end
+
   defp validate_url(changeset, field) do
     validate_change(changeset, field, fn ^field, url ->
       if url && url != "" do
@@ -78,6 +87,12 @@ defmodule ComponentsElixir.Inventory.Component do
   def has_image?(%__MODULE__{image_filename: filename}) when is_binary(filename), do: true
   def has_image?(_), do: false
 
+  @doc """
+  Returns true if the component has a datasheet file.
+  """
+  def has_datasheet?(%__MODULE__{datasheet_filename: filename}) when is_binary(filename), do: true
+  def has_datasheet?(_), do: false
+
   @doc """
   Returns the search text for this component.
   """