defmodule CljElixir.Phase5Test do
  use ExUnit.Case, async: false

  # Helper to compile and evaluate CljElixir code
  defp eval!(source) do
    case CljElixir.Compiler.eval_string(source) do
      {:ok, result, _bindings} -> result
      {:error, errors} -> raise "CljElixir eval error: #{inspect(errors)}"
    end
  end

  # ==========================================================================
  # GenServer integration
  # ==========================================================================

  describe "GenServer - simple counter" do
    test "define and use a counter GenServer" do
      eval!("""
      (defmodule TestCounter
        (use GenServer)

        (defn init [initial]
          #el[:ok initial])

        (defn handle-call
          ([:get _from state]
            #el[:reply state state])
          ([:increment _from state]
            #el[:reply :ok (+ state 1)])))
      """)

      {:ok, pid} = GenServer.start_link(TestCounter, 0)
      assert GenServer.call(pid, :get) == 0
      assert GenServer.call(pid, :increment) == :ok
      assert GenServer.call(pid, :get) == 1
      GenServer.stop(pid)
    end
  end

  describe "GenServer - handle_cast" do
    test "cast resets state" do
      eval!("""
      (defmodule TestCaster
        (use GenServer)

        (defn init [initial]
          #el[:ok initial])

        (defn handle-call
          ([:get _from state]
            #el[:reply state state]))

        (defn handle-cast
          ([:reset _state]
            #el[:noreply 0])))
      """)

      {:ok, pid} = GenServer.start_link(TestCaster, 42)
      assert GenServer.call(pid, :get) == 42
      GenServer.cast(pid, :reset)
      Process.sleep(50)
      assert GenServer.call(pid, :get) == 0
      GenServer.stop(pid)
    end
  end

  describe "GenServer - handle_info" do
    test "handle-info receives plain messages" do
      eval!("""
      (defmodule TestInfoHandler
        (use GenServer)

        (defn init [initial]
          #el[:ok initial])

        (defn handle-call
          ([:get _from state]
            #el[:reply state state]))

        (defn handle-info
          ([:bump state]
            #el[:noreply (+ state 1)])))
      """)

      {:ok, pid} = GenServer.start_link(TestInfoHandler, 0)
      send(pid, :bump)
      Process.sleep(50)
      assert GenServer.call(pid, :get) == 1
      GenServer.stop(pid)
    end
  end

  # ==========================================================================
  # ChatRoom pattern: spawn + send + receive loop
  # ==========================================================================

  describe "ChatRoom pattern" do
    test "spawn + send + receive loop" do
      eval!("""
      (defmodule TestChatLoop
        (defn loop [state]
          (receive
            [:ping pid]
              (do
                (send pid #el[:pong state])
                (TestChatLoop/loop (+ state 1)))
            [:get pid]
              (do
                (send pid #el[:count state])
                (TestChatLoop/loop state))
            :stop
              :stopped
            :after 5000
              :timeout)))
      """)

      pid = spawn(fn -> TestChatLoop.loop(0) end)

      send(pid, {:ping, self()})
      assert_receive {:pong, 0}, 1000

      send(pid, {:ping, self()})
      assert_receive {:pong, 1}, 1000

      send(pid, {:get, self()})
      assert_receive {:count, 2}, 1000

      send(pid, :stop)
      Process.sleep(50)
      refute Process.alive?(pid)
    end
  end
end