defmodule Mix.Tasks.Firebird.Inspect do
  @moduledoc """
  Inspect a WASM module and display its exports.

  ## Usage

      mix firebird.inspect fixtures/math.wasm
      mix firebird.inspect fixtures/go_math.wasm --wasi
      mix firebird.inspect fixtures/math.wasm --generate MyApp.Math
      mix firebird.inspect fixtures/math.wasm --generate MyApp.Math --style wasm_module

  ## Options

  - `--wasi` - Enable WASI support (required for Go/TinyGo modules)
  - `--generate MODULE` - Generate an Elixir module wrapper
  - `--style module|wasm_module` - Module style (default: module)
  """

  use Mix.Task

  @shortdoc "Inspect a WASM module's exports and types"

  @switches [
    wasi: :boolean,
    generate: :string,
    style: :string
  ]

  @impl Mix.Task
  def run(args) do
    Mix.Task.run("app.start")

    {opts, rest, _} = OptionParser.parse(args, switches: @switches)

    case rest do
      [path] ->
        wasi = Keyword.get(opts, :wasi, false)

        case Firebird.Inspector.inspect_file(path, wasi: wasi) do
          {:ok, info} ->
            if gen_name = Keyword.get(opts, :generate) do
              style =
                case Keyword.get(opts, :style, "module") do
                  "wasm_module" -> :wasm_module
                  _ -> :module
                end

              code = Firebird.Inspector.generate_module(gen_name, path, wasi: wasi, style: style)
              Mix.shell().info(code)
            else
              print_info(path, info)
            end

          {:error, reason} ->
            Mix.shell().error("Error: #{inspect(reason)}")
        end

      _ ->
        Mix.shell().info(@moduledoc)
    end
  end

  defp print_info(path, info) do
    Mix.shell().info("🔍 WASM Module: #{path}")
    Mix.shell().info("   Size: #{info.size_bytes} bytes")
    Mix.shell().info("   Exports: #{info.export_count} total (#{info.function_count} functions)")
    Mix.shell().info("")

    if length(info.functions) > 0 do
      Mix.shell().info("   Functions:")

      for f <- info.functions do
        params = Enum.join(Enum.map(f.params, &to_string/1), ", ")
        results = Enum.join(Enum.map(f.results, &to_string/1), ", ")
        sig = "(#{params}) -> #{results}"
        Mix.shell().info("     #{f.name}#{sig}")
      end
    end

    if length(info.memories) > 0 do
      Mix.shell().info("")
      Mix.shell().info("   Memories:")

      for m <- info.memories do
        Mix.shell().info("     #{m.name}: #{m.min_pages} pages (#{m.min_pages * 64}KB)")
      end
    end

    if length(info.globals) > 0 do
      Mix.shell().info("")
      Mix.shell().info("   Globals:")

      for g <- info.globals do
        Mix.shell().info("     #{g.name}: #{g.type} (#{g.mutability})")
      end
    end
  end
end