defmodule Mix.Tasks.Firebird.Target.Verify do
  @moduledoc """
  Verify compiled WASM modules by loading and optionally running smoke tests.

  ## Usage

      # Verify all WASM files in output directory
      mix firebird.target.verify

      # Verify specific directory
      mix firebird.target.verify --dir _build/wasm

      # Verify specific file
      mix firebird.target.verify --file _build/wasm/MyMath.wasm

      # Run with smoke tests (auto-detected from source annotations)
      mix firebird.target.verify --smoke

  ## Output

  Reports for each WASM file:
  - Whether it loads successfully
  - Number and names of exports
  - Smoke test results (if enabled)
  """

  use Mix.Task

  @shortdoc "Verify compiled WASM modules"

  @switches [
    dir: :string,
    file: :string,
    smoke: :boolean,
    json: :boolean,
    verbose: :boolean
  ]

  @aliases [
    d: :dir,
    f: :file,
    v: :verbose
  ]

  @impl Mix.Task
  def run(args) do
    {opts, _rest, _invalid} = OptionParser.parse(args, switches: @switches, aliases: @aliases)

    verbose = Keyword.get(opts, :verbose, false)
    json_mode = Keyword.get(opts, :json, false)

    cond do
      file = Keyword.get(opts, :file) ->
        verify_file(file, verbose, json_mode)

      dir = Keyword.get(opts, :dir) ->
        verify_directory(dir, verbose, json_mode)

      true ->
        # Default: verify _build/wasm
        config = Firebird.Target.Config.from_mix_project()
        verify_directory(config.output_dir, verbose, json_mode)
    end
  end

  defp verify_file(path, _verbose, json_mode) do
    Mix.shell().info("🔍 Verifying #{path}...")

    case File.read(path) do
      {:ok, binary} ->
        {:ok, report} = Firebird.Target.Verify.verify_binary(binary)

        if json_mode do
          Mix.shell().info(Jason.encode!(report, pretty: true))
        else
          Mix.shell().info(Firebird.Target.Verify.format_report(report))
        end

      {:error, reason} ->
        Mix.shell().error("  ❌ Cannot read #{path}: #{reason}")
    end
  end

  defp verify_directory(dir, verbose, json_mode) do
    unless File.dir?(dir) do
      Mix.shell().info(
        "Directory #{dir} does not exist. Run `mix firebird.target.compile` first."
      )

      :ok
    else
      Mix.shell().info("🔍 Verifying WASM modules in #{dir}/")
      Mix.shell().info("")

      case Firebird.Target.Verify.verify_dir(dir) do
        {:ok, reports} ->
          if Enum.empty?(reports) do
            Mix.shell().info("  No WASM files found in #{dir}/")
          else
            if json_mode do
              data =
                Enum.map(reports, fn r ->
                  %{file: r.file, valid: r.result.valid, exports: r.result.export_count}
                end)

              Mix.shell().info(Jason.encode!(data, pretty: true))
            else
              Enum.each(reports, fn r ->
                basename = Path.basename(r.file)
                status = if r.result.valid, do: "✅", else: "❌"
                Mix.shell().info("  #{status} #{basename}")

                if verbose do
                  Mix.shell().info(Firebird.Target.Verify.format_report(r.result))
                else
                  Mix.shell().info("     Exports: #{r.result.export_count}")
                end

                Mix.shell().info("")
              end)

              valid = Enum.count(reports, & &1.result.valid)
              total = length(reports)
              Mix.shell().info("📊 #{valid}/#{total} modules verified successfully")
            end
          end

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