defmodule Mix.Tasks.Claude.SetupToken do
  use Mix.Task

  @shortdoc "Sets up Claude Code authentication token"

  @moduledoc """
  Sets up a long-lived authentication token for Claude Code SDK.

  This task executes `claude setup-token` and stores the result
  for automatic use by the SDK.

  ## Usage

      $ mix claude.setup_token

  ## Requirements

  - Claude Code CLI installed (`npm install -g @anthropic-ai/claude-code`)
  - Active Claude subscription
  - Interactive terminal access

  ## Options

  - `--force` - Force token refresh even if valid token exists
  - `--clear` - Clear existing authentication

  ## Examples

      # Initial setup
      $ mix claude.setup_token

      # Force refresh
      $ mix claude.setup_token --force

      # Clear authentication
      $ mix claude.setup_token --clear
  """

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

    # Start AuthManager manually if not in supervision tree
    ensure_auth_manager_started()

    # Parse options
    {opts, _args, _invalid} =
      OptionParser.parse(args,
        switches: [force: :boolean, clear: :boolean]
      )

    cond do
      opts[:clear] ->
        clear_auth()

      opts[:force] || !token_exists?() ->
        setup_new_token()

      true ->
        Mix.shell().info("✅ Valid token already exists. Use --force to refresh.")
        show_status()
    end
  end

  defp ensure_auth_manager_started do
    # Check if AuthManager is already running
    case Process.whereis(ClaudeAgentSDK.AuthManager) do
      nil ->
        # Start it manually
        {:ok, _pid} = ClaudeAgentSDK.AuthManager.start_link()
        :ok

      _pid ->
        # Already running
        :ok
    end
  end

  defp token_exists? do
    case ClaudeAgentSDK.AuthManager.get_token() do
      {:ok, _token} -> true
      _ -> false
    end
  end

  defp setup_new_token do
    Mix.shell().info("🔐 Setting up Claude Code authentication...")
    Mix.shell().info("")
    Mix.shell().info("This will:")
    Mix.shell().info("  1. Open your browser for OAuth authentication")
    Mix.shell().info("  2. Generate a long-lived OAuth token (1 year)")
    Mix.shell().info("  3. Store the token for automatic use")
    Mix.shell().info("")
    Mix.shell().info("⚠️  This requires an active Claude subscription")
    Mix.shell().info("")

    case ClaudeAgentSDK.AuthManager.setup_token() do
      {:ok, token} ->
        Mix.shell().info("✅ Authentication successful!")
        Mix.shell().info("")
        Mix.shell().info("Token: #{String.slice(token, 0, 20)}...")
        Mix.shell().info("")

        # Show how to use the token
        if String.starts_with?(token, "sk-ant-oat01-") do
          Mix.shell().info("💡 To use this token manually, set:")
          Mix.shell().info("   export CLAUDE_AGENT_OAUTH_TOKEN=#{token}")
        end

        show_status()

      {:error, reason} ->
        Mix.shell().error("❌ Authentication failed: #{inspect(reason)}")
        Mix.shell().error("")
        Mix.shell().error("Troubleshooting:")

        Mix.shell().error(
          "  • Ensure Claude CLI is installed: npm install -g @anthropic-ai/claude-code"
        )

        Mix.shell().error("  • Verify you have an active Claude subscription")
        Mix.shell().error("  • Check that you're in an interactive terminal")
        Mix.shell().error("")
        Mix.shell().error("Alternative: Set environment variable manually:")
        Mix.shell().error("  export CLAUDE_AGENT_OAUTH_TOKEN=<your-token>")
        Mix.shell().error("  or")
        Mix.shell().error("  export ANTHROPIC_API_KEY=<your-api-key>")
        Mix.raise("Authentication setup failed")
    end
  end

  defp clear_auth do
    Mix.shell().info("🗑️  Clearing authentication...")
    :ok = ClaudeAgentSDK.AuthManager.clear_auth()
    Mix.shell().info("✅ Authentication cleared")
  end

  defp show_status do
    status = ClaudeAgentSDK.AuthManager.status()

    Mix.shell().info("")
    Mix.shell().info("📊 Authentication Status:")
    Mix.shell().info("  Provider: #{status.provider}")
    Mix.shell().info("  Authenticated: #{status.authenticated}")

    if status.expires_at do
      Mix.shell().info("  Expires: #{status.expires_at}")
      Mix.shell().info("  Time remaining: #{status.time_until_expiry_hours} hours")
    end

    Mix.shell().info("")
    Mix.shell().info("✅ Ready to use ClaudeAgentSDK.query/2")
  end
end