defmodule Mix.Tasks.Check.Install do
  use Mix.Task

  @shortdoc "Builds and installs the check escript globally"

  @moduledoc """
  Builds and installs the al_check escript to ~/.mix/escripts/

  ## Usage

      mix check.install

  The escript will be available globally as the `check` command.

  ## Installation Location

  The escript is installed to:
  - macOS/Linux: `~/.mix/escripts/check`
  - Windows: `%USERPROFILE%/.mix/escripts/check`

  Make sure `~/.mix/escripts` is in your PATH.

  ## Example

      # Install the escript
      mix check.install

      # Then use from anywhere
      check
      check --fast
      check --only test
  """

  @spec run([String.t()]) :: :ok
  def run(_args) do
    # Get the al_check dependency path or current directory
    check_path = get_check_path()

    Mix.shell().info("Building escript in #{check_path}...")

    # Build the escript
    case build_escript(check_path) do
      :ok ->
        Mix.shell().info("Installing escript globally...")

        # Install the escript
        case install_escript(check_path) do
          :ok ->
            Mix.shell().info([
              IO.ANSI.format([:green, "\n✓ Check escript installed successfully!"])
            ])

            Mix.shell().info("You can now run 'check' from anywhere.")
            Mix.shell().info("\nExamples:")
            Mix.shell().info("  check              # Run all checks")
            Mix.shell().info("  check --fast       # Run fast checks only")
            Mix.shell().info("  check --only test  # Run specific checks")

          {:error, reason} ->
            Mix.raise("Failed to install escript: #{reason}")
        end

      {:error, reason} ->
        Mix.raise("Failed to build escript: #{reason}")
    end
  end

  defp get_check_path do
    # If running from a project that has al_check as a dependency
    case Mix.Project.deps_paths()[:al_check] do
      nil ->
        # Running from within al_check itself
        File.cwd!()

      path ->
        # Running from a parent project
        path
    end
  end

  defp build_escript(path) do
    with {_, 0} <- System.cmd("mix", ["deps.get"], cd: path, stderr_to_stdout: true),
         {_, 0} <- System.cmd("mix", ["escript.build"], cd: path, stderr_to_stdout: true) do
      :ok
    else
      {output, _status} -> {:error, output}
    end
  end

  defp install_escript(path) do
    # First, check if escript was built
    escript_path = Path.join([path, "scripts", "check"])

    unless File.exists?(escript_path) do
      {:error, "Escript not found at #{escript_path}"}
    else
      # Install the escript
      case System.cmd("mix", ["escript.install", "--force", escript_path], stderr_to_stdout: true) do
        {_output, 0} ->
          :ok

        {output, _status} ->
          {:error, output}
      end
    end
  end
end