defmodule Pier.OpenApi.Tasks.Compile do
  alias Pier.OpenApi.Blueprint
  alias Pier.OpenApi.Schema.Operation
  require Logger

  def build(%Blueprint{} = blueprint, _opts) do
    types =
      Enum.map(blueprint.definitions, fn definition -> {definition.module_name, definition} end)

    for {_module_name, definition} <- types do
      parameters =
        quote do
          defstruct unquote(definition.parameters)
        end

      module =
        quote do
          defmodule unquote(definition.module_name) do
            unquote(parameters)
          end
        end

      code = Macro.to_string(module) |> Code.format_string!()
      :ok = File.mkdir_p("lib/generated/types")
      File.touch("lib/generated/types/#{Macro.underscore(definition.name)}.ex")
      File.write!("lib/generated/types/#{Macro.underscore(definition.name)}.ex", code)
    end

    modules = Enum.map(blueprint.modules, fn module -> {module.module_name, module} end)

    for {name, module} <- modules do
      # search for all function definitions in the paths variable"

      functions =
        Enum.filter(blueprint.paths, fn {_, functions} ->
          tags =
            Enum.map(functions, fn func ->
              [tag | _] = func.tags
              String.downcase(tag)
            end)

          Enum.any?(tags, fn tag ->
            tag == String.downcase(module.tag)
          end)
        end)
        |> List.flatten()

      built_functions = Enum.map(functions, &build_functions/1)

      # Logger.debug("built_functions size: #{length(built_functions)}")
      built_functions = List.flatten(built_functions)

      body =
        quote do
          @moduledoc unquote(module.description)
          unquote_splicing(built_functions)
        end

      module_code =
        quote do
          defmodule unquote(name) do
            unquote(body)
          end
        end

      bin =
        module_code
        |> Macro.to_string()
        |> Code.format_string!()

      try do
        File.write!("lib/generated/#{String.downcase(module.file_name)}.ex", bin)
      rescue
        e -> IO.inspect(e)
      end
    end

    {:ok, blueprint}
  end

  defp build_functions({_path, funcs}) do
    body = fn %Operation{} = operation ->
      if operation.params != nil do
        quote do
          def unquote(String.to_atom(operation.function_name))(opts \\ []) do
            optional_params = unquote(operation.params)

            path =
              Pier.Request.generate_base_url(unquote(operation.path))
              |> Pier.Request.add_path_params(optional_params, opts)
              |> Pier.Request.add_query_params(optional_params, opts)

            headers = Pier.Request.build_headers([], optional_params, opts)
            Pier.Request.build(unquote(operation.method), path, headers)
          end
        end
      else
        quote do
          def unquote(String.to_atom(operation.function_name))(opts \\ []) do
            path =
              Pier.Request.generate_base_url(unquote(operation.path))
              |> Pier.Request.add_path_params(%{}, opts)
              |> Pier.Request.add_query_params(%{}, opts)

            headers = Pier.Request.build_headers([], %{}, opts)
            Pier.Request.build(unquote(operation.method), path, headers)
          end
        end
      end
    end

    Enum.map(funcs, body)
  end
end