[JET-2027] deref 抽象 (#6)

config/dev.exs

@@ -1,3 +1,5 @@
 import Config
 
+config :resource_kit, ResourceKit.Deref, adapter: ResourceKit.Deref.Local
+
 config :resource_kit, ResourceKitCLI.Endpoint, server: true

config/test.exs

@@ -1,5 +1,8 @@
 import Config
 
+config :resource_kit, ResourceKit.Deref,
+  adapter: {ResourceKit.Deref.Local, directory: "test/fixtures"}
+
 config :resource_kit, ResourceKit.Repo,
   hostname: "localhost",
   database: "resource_kit_test",

lib/resource_kit.ex

@@ -1,7 +1,7 @@
 defmodule ResourceKit do
   @moduledoc false
 
-  defdelegate insert(action, params), to: ResourceKit.Action.Insert, as: :run
+  defdelegate insert(action, params, opts), to: ResourceKit.Action.Insert, as: :run
 
-  defdelegate list(action, params), to: ResourceKit.Action.List, as: :run
+  defdelegate list(action, params, opts), to: ResourceKit.Action.List, as: :run
 end

lib/resource_kit/action/skeleton.ex

@@ -55,23 +55,29 @@ defmodule ResourceKit.Action.Skeleton do
       alias ResourceKit.Pipeline.Compile.Token, as: CompileToken
       alias ResourceKit.Pipeline.Execute.Token, as: ExecuteToken
 
-      def run(action, params) do
-        with {:ok, %{action: action, references: references}} <- __compile__(action) do
-          __execute__(action, references, params)
+      def run(action, params, opts) do
+        with {:ok, %{action: action, references: references}} <- __compile__(action, opts) do
+          __execute__(action, references, params, opts)
         end
       end
 
-      defp __compile__(action) do
-        %CompileToken{action: action}
+      defp __compile__(action, opts) do
+        root = Keyword.fetch!(opts, :root)
+        context = %CompileToken.Context{root: root, current: root}
+
+        %CompileToken{action: action, context: context}
         |> Pluggable.run([&__MODULE__.compile(&1, [])])
         |> case do
           %CompileToken{halted: false} = token -> {:ok, token.assigns}
           %CompileToken{errors: [reason]} -> {:error, reason}
         end
       end
 
-      defp __execute__(action, references, params) do
-        %ExecuteToken{action: action, references: references, params: params}
+      defp __execute__(action, references, params, opts) do
+        root = Keyword.fetch!(opts, :root)
+        context = %ExecuteToken.Context{root: root, current: root}
+
+        %ExecuteToken{action: action, references: references, params: params, context: context}
         |> Pluggable.run([&__MODULE__.execute(&1, [])])
         |> case do
           %ExecuteToken{halted: false} = token -> ExecuteToken.fetch_assign(token, :result)

lib/resource_kit/deref.ex

@@ -0,0 +1,67 @@
+defmodule ResourceKit.Deref do
+  @moduledoc """
+  A behavior definition that developers can use to implement their own dereferencing logic.
+
+  ## Options
+
+    * `adapter` - A module that implemented the deref behaviour. Or `{adapter, opts}` if the adapter has options.
+  """
+
+  alias ResourceKit.Types
+
+  alias ResourceKit.Deref.Context
+  alias ResourceKit.Schema.Ref
+
+  @conf Application.compile_env(:resource_kit, [__MODULE__, :adapter], ResourceKit.Deref.Local)
+  @adapter if is_tuple(@conf), do: elem(@conf, 0), else: @conf
+  @opts if is_tuple(@conf), do: elem(@conf, 1), else: []
+
+  @callback resolve(ref :: Ref.t(), ctx :: Context.t()) ::
+              {:ok, Ref.t()} | {:error, Types.error()}
+
+  @callback fetch(ref :: Ref.t(), ctx :: Context.t()) ::
+              {:ok, Types.json_value()} | {:error, Types.error()}
+
+  defmacro __using__(_args) do
+    quote location: :keep do
+      @behaviour unquote(__MODULE__)
+
+      import unquote(__MODULE__)
+
+      @impl unquote(__MODULE__)
+      def resolve(ref, ctx) do
+        unquote(__MODULE__).absolute(ref, ctx)
+      end
+
+      defoverridable resolve: 2
+    end
+  end
+
+  defguard is_absolute(term) when is_struct(term, Ref) and is_binary(term.uri.scheme)
+
+  @spec absolute(ref :: Ref.t(), ctx :: Context.t()) :: {:ok, Ref.t()} | {:error, Types.error()}
+  def absolute(ref, ctx)
+
+  def absolute(%Ref{} = ref, %Context{}) when is_absolute(ref) do
+    {:ok, ref}
+  end
+
+  def absolute(%Ref{uri: uri}, %Context{current: %Ref{uri: current}}) do
+    {:ok, %Ref{uri: %{current | path: Path.expand(uri.path, current.path)}}}
+  end
+
+  @spec resolve(ref :: Ref.t(), ctx :: Context.t()) :: {:ok, Ref.t()} | {:error, Types.error()}
+  def resolve(ref, ctx) do
+    @adapter.resolve(ref, put_options(ctx))
+  end
+
+  @spec fetch(ref :: Ref.t(), ctx :: Context.t()) ::
+          {:ok, Types.json_value()} | {:error, Types.error()}
+  def fetch(ref, ctx) do
+    @adapter.fetch(ref, put_options(ctx))
+  end
+
+  defp put_options(ctx) do
+    %{ctx | opts: @opts}
+  end
+end

lib/resource_kit/deref/context.ex

@@ -0,0 +1,12 @@
+defmodule ResourceKit.Deref.Context do
+  @moduledoc false
+
+  use TypedStruct
+
+  alias ResourceKit.Schema.Ref
+
+  typedstruct do
+    field :current, Ref.t(), enforce: true
+    field :opts, keyword(), default: []
+  end
+end

lib/resource_kit/deref/local.ex

@@ -0,0 +1,41 @@
+defmodule ResourceKit.Deref.Local do
+  @moduledoc """
+  A deref implementation that loads a JSON document from a local directory.
+
+  ## Options
+
+    * `directory` - The root directory from which to load JSON documents. Defaults to `File.cwd/0`.
+  """
+
+  use ResourceKit.Deref
+
+  alias ResourceKit.Deref.Context
+  alias ResourceKit.Schema.Ref
+
+  @impl ResourceKit.Deref
+  def fetch(%Ref{uri: %URI{} = uri}, %Context{opts: opts}) do
+    directory = Keyword.get_lazy(opts, :directory, &File.cwd!/0)
+    file = uri.path |> Path.relative() |> Path.expand(directory)
+
+    with {:ok, content} <- fetch_file(file),
+         {:ok, value} <- decode_json(content) do
+      {:ok, value}
+    else
+      {:error, message} -> {:error, {message, path: uri.path}}
+    end
+  end
+
+  defp fetch_file(path) do
+    case File.read(path) do
+      {:ok, content} -> {:ok, content}
+      {:error, reason} -> {:error, "#{reason}"}
+    end
+  end
+
+  defp decode_json(content) do
+    case Jason.decode(content) do
+      {:ok, value} -> {:ok, value}
+      {:error, reason} -> {:error, Exception.message(reason)}
+    end
+  end
+end

lib/resource_kit/json_pointer/utils.ex

@@ -24,7 +24,10 @@ defmodule ResourceKit.JSONPointer.Utils do
   def resolve(parent, [], ctx), do: {:ok, parent, ctx}
 
   def resolve(parent, [key | rest], ctx) when is_map(parent) do
-    case Map.fetch(parent, key) do
+    parent
+    |> stringify_keys()
+    |> Map.fetch(key)
+    |> case do
       {:ok, data} -> resolve(data, rest, push_token(ctx, key))
       :error -> {:error, {@key_not_exists, location: encode_location(ctx), key: key}}
     end
@@ -43,6 +46,16 @@ defmodule ResourceKit.JSONPointer.Utils do
     end
   end
 
+  defp stringify_keys(data) when is_struct(data) do
+    data
+    |> Map.from_struct()
+    |> stringify_keys()
+  end
+
+  defp stringify_keys(data) do
+    JetExt.Map.stringify_keys(data)
+  end
+
   # leading zeros are not allowed for index
   defp parse_index(<<?0, _x, _rest::binary>> = index) do
     {:error, {@index_has_leading_zeros, index: index}}

lib/resource_kit/pipeline/compile/deref.ex

@@ -15,6 +15,7 @@ defmodule ResourceKit.Pipeline.Compile.Deref do
 
   import ResourceKit.Guards
 
+  alias ResourceKit.Deref.Context, as: DerefContext
   alias ResourceKit.Pipeline.Compile.Token
   alias ResourceKit.Schema.Ref
 
@@ -24,33 +25,33 @@ defmodule ResourceKit.Pipeline.Compile.Deref do
   @impl Pluggable
   def call(%Token{halted: true} = token, _opts), do: token
 
-  def call(%Token{action: action} = token, _opts) do
-    with {:ok, action} <- deref_schema(action),
-         {:ok, action} <- deref_returning_schema(action) do
+  def call(%Token{action: action, context: ctx} = token, _opts) do
+    with {:ok, action} <- deref_schema(action, ctx),
+         {:ok, action} <- deref_returning_schema(action, ctx) do
       Token.put_assign(token, :action, action)
     else
       {:error, reason} ->
         Token.put_error(token, reason)
     end
   end
 
-  defp deref_schema(%{"schema" => ref} = action) when is_ref(ref) do
+  defp deref_schema(%{"schema" => ref} = action, ctx) when is_ref(ref) do
     with {:ok, ref} <- cast_ref(ref),
-         {:ok, schema} <- ResourceKit.Utils.deref(ref) do
+         {:ok, schema} <- ResourceKit.Deref.fetch(ref, %DerefContext{current: ctx.current}) do
       {:ok, Map.put(action, "schema", schema)}
     end
   end
 
-  defp deref_schema(action), do: {:ok, action}
+  defp deref_schema(action, _ctx), do: {:ok, action}
 
-  defp deref_returning_schema(%{"returning_schema" => ref} = action) when is_ref(ref) do
+  defp deref_returning_schema(%{"returning_schema" => ref} = action, ctx) when is_ref(ref) do
     with {:ok, ref} <- cast_ref(ref),
-         {:ok, returning} <- ResourceKit.Utils.deref(ref) do
+         {:ok, returning} <- ResourceKit.Deref.fetch(ref, %DerefContext{current: ctx.current}) do
       {:ok, Map.put(action, "returning_schema", returning)}
     end
   end
 
-  defp deref_returning_schema(action), do: {:ok, action}
+  defp deref_returning_schema(action, _ctx), do: {:ok, action}
 
   defp cast_ref(ref) do
     ref |> Ref.changeset() |> Ecto.Changeset.apply_action(:insert)

lib/resource_kit/pipeline/compile/preload_reference.ex

@@ -10,6 +10,7 @@ defmodule ResourceKit.Pipeline.Compile.PreloadReference do
 
   @behaviour Pluggable
 
+  alias ResourceKit.Deref.Context, as: DerefContext
   alias ResourceKit.Pipeline.Compile.Token
   alias ResourceKit.Schema.Column
   alias ResourceKit.Schema.Ref
@@ -21,10 +22,10 @@ defmodule ResourceKit.Pipeline.Compile.PreloadReference do
   @impl Pluggable
   def call(%Token{halted: true} = token, _opts), do: token
 
-  def call(%Token{} = token, _opts) do
+  def call(%Token{context: context} = token, _opts) do
     action = Token.fetch_assign!(token, :action)
 
-    case preload_schema(action.schema) do
+    case preload_schema(action.schema, context) do
       {:ok, schema, references} ->
         token
         |> Token.put_assign(:action, %{action | schema: schema})
@@ -35,10 +36,10 @@ defmodule ResourceKit.Pipeline.Compile.PreloadReference do
     end
   end
 
-  defp preload_schema(%Schema{} = schema, references \\ %{}) do
+  defp preload_schema(%Schema{} = schema, context, references \\ %{}) do
     schema.columns
     |> Enum.reduce_while({:ok, [], references}, fn column, {:ok, columns, references} ->
-      case preload_column(column, references) do
+      case preload_column(column, context, references) do
         {:ok, column, references} -> {:cont, {:ok, [column | columns], references}}
         {:error, reason} -> {:halt, {:error, reason}}
       end
@@ -49,31 +50,39 @@ defmodule ResourceKit.Pipeline.Compile.PreloadReference do
     end
   end
 
-  defp preload_column(column, references)
+  defp preload_column(column, context, references)
 
-  defp preload_column(%Column.Literal{} = column, references), do: {:ok, column, references}
+  defp preload_column(%Column.Literal{} = column, _context, references),
+    do: {:ok, column, references}
 
-  defp preload_column(column, references)
+  defp preload_column(column, context, references)
        when is_struct(column, Column.Belongs) or is_struct(column, Column.Has) do
     with {:ok, schema, references} <-
-           resolve_association_schema(column.association_schema, references),
-         {:ok, _schema, references} <- preload_schema(schema, references) do
+           resolve_association_schema(column.association_schema, context, references),
+         {:ok, _schema, references} <-
+           preload_schema(schema, update_context(column.association_schema, context), references) do
       {:ok, column, references}
     end
   end
 
-  defp resolve_association_schema(%Ref{} = ref, references) do
-    case resolve(ref, references) do
+  defp resolve_association_schema(%Ref{} = ref, context, references) do
+    case resolve(ref, context, references) do
       {:ok, schema} -> {:ok, schema, Map.put_new(references, ref, schema)}
       {:error, reason} -> {:error, reason}
     end
   end
 
-  defp resolve_association_schema(schema, references), do: {:ok, schema, references}
+  defp resolve_association_schema(schema, _context, references), do: {:ok, schema, references}
 
-  defp resolve(ref, references) do
+  defp update_context(%Ref{uri: uri}, context) do
+    %{context | current: uri}
+  end
+
+  defp update_context(_schema, context), do: context
+
+  defp resolve(ref, context, references) do
     with :error <- Map.fetch(references, ref) do
-      ResourceKit.Utils.resolve_association_schema(ref)
+      ResourceKit.Utils.resolve_association_schema(ref, %DerefContext{current: context.current})
     end
   end
 end

lib/resource_kit/pipeline/compile/token.ex

@@ -1,9 +1,16 @@
 defmodule ResourceKit.Pipeline.Compile.Token do
   @moduledoc false
 
+  use TypedStruct
   use ResourceKit.Pipeline.Token
 
+  typedstruct module: Context do
+    field :root, URI.t(), enforce: true
+    field :current, URI.t(), enforce: true
+  end
+
   token do
     field :action, map(), enforce: true
+    field :context, Context.t(), enforce: true
   end
 end