"""Tests for context & token visualization (Track: context_token_viz_20260301)."""
from typing import Generator
from unittest.mock import patch
import pytest

import ai_client
from ai_client import _add_bleed_derived, get_history_bleed_stats
from gui_2 import App


@pytest.fixture
def app_instance() -> Generator[App, None, None]:
 with (
  patch('gui_2.load_config', return_value={'gui': {'show_windows': {}}}),
  patch('gui_2.save_config'),
  patch('gui_2.project_manager'),
  patch('gui_2.session_logger'),
  patch('gui_2.immapp.run'),
  patch.object(App, '_load_active_project'),
  patch.object(App, '_fetch_models'),
  patch.object(App, '_load_fonts'),
  patch.object(App, '_post_init')
 ):
  yield App()


# --- _add_bleed_derived unit tests ---

def test_add_bleed_derived_aliases() -> None:
 base = {"provider": "test", "limit": 1000, "current": 400, "percentage": 40.0}
 result = _add_bleed_derived(base)
 assert result["estimated_prompt_tokens"] == 400
 assert result["max_prompt_tokens"] == 1000
 assert result["utilization_pct"] == 40.0


def test_add_bleed_derived_headroom() -> None:
 base = {"provider": "test", "limit": 1000, "current": 400, "percentage": 40.0}
 result = _add_bleed_derived(base)
 assert result["headroom_tokens"] == 600


def test_add_bleed_derived_would_trim_false() -> None:
 base = {"provider": "test", "limit": 100000, "current": 10000, "percentage": 10.0}
 result = _add_bleed_derived(base)
 assert result["would_trim"] is False


def test_add_bleed_derived_would_trim_true() -> None:
 base = {"provider": "test", "limit": 100000, "current": 90000, "percentage": 90.0}
 result = _add_bleed_derived(base)
 assert result["would_trim"] is True  # headroom = 10000 < 20000


def test_add_bleed_derived_breakdown() -> None:
 base = {"provider": "test", "limit": 10000, "current": 5000, "percentage": 50.0}
 result = _add_bleed_derived(base, sys_tok=500, tool_tok=2500)
 assert result["system_tokens"] == 500
 assert result["tools_tokens"] == 2500
 assert result["history_tokens"] == 2000  # 5000 - 500 - 2500


def test_add_bleed_derived_history_clamped_to_zero() -> None:
 """history_tokens should not go negative when sys+tool > current."""
 base = {"provider": "test", "limit": 1000, "current": 100, "percentage": 10.0}
 result = _add_bleed_derived(base, sys_tok=200, tool_tok=2500)
 assert result["history_tokens"] == 0


def test_add_bleed_derived_headroom_clamped_to_zero() -> None:
 base = {"provider": "test", "limit": 1000, "current": 1100, "percentage": 110.0}
 result = _add_bleed_derived(base)
 assert result["headroom_tokens"] == 0


# --- get_history_bleed_stats returns all required keys ---

REQUIRED_KEYS = [
 "provider", "limit", "current", "percentage",
 "estimated_prompt_tokens", "max_prompt_tokens", "utilization_pct",
 "headroom_tokens", "would_trim", "system_tokens", "tools_tokens", "history_tokens",
]

def test_get_history_bleed_stats_returns_all_keys_unknown_provider() -> None:
 """Fallback path (unknown provider) must still return all derived keys."""
 original = ai_client._provider
 try:
  ai_client._provider = "unknown_test_provider"
  stats = get_history_bleed_stats()
  for key in REQUIRED_KEYS:
   assert key in stats, f"Missing key: {key}"
 finally:
  ai_client._provider = original


# --- App initialization ---

def test_app_token_stats_initialized_empty(app_instance: App) -> None:
 assert app_instance._token_stats == {}


def test_app_last_stable_md_initialized_empty(app_instance: App) -> None:
 assert app_instance._last_stable_md == ""


def test_app_has_render_token_budget_panel(app_instance: App) -> None:
 assert callable(getattr(app_instance, "_render_token_budget_panel", None))


def test_render_token_budget_panel_empty_stats_no_crash(app_instance: App) -> None:
 """With empty _token_stats, _render_token_budget_panel must not raise."""
 app_instance._token_stats = {}
 # We can't render ImGui in tests, so just verify the guard condition logic
 # by checking the method exists and _token_stats is empty (early-return path)
 assert not app_instance._token_stats  # falsy — method would return early