"""Tests for gateway /compress user-facing messaging."""

from datetime import datetime
from unittest.mock import MagicMock, patch

import pytest

from gateway.config import GatewayConfig, Platform, PlatformConfig
from gateway.platforms.base import MessageEvent
from gateway.session import SessionEntry, SessionSource, build_session_key


def _make_source() -> SessionSource:
    return SessionSource(
        platform=Platform.TELEGRAM,
        user_id="u1",
        chat_id="c1",
        user_name="tester",
        chat_type="dm",
    )


def _make_event(text: str = "/compress") -> MessageEvent:
    return MessageEvent(text=text, source=_make_source(), message_id="m1")


def _make_history() -> list[dict[str, str]]:
    return [
        {"role": "user", "content": "one"},
        {"role": "assistant", "content": "two"},
        {"role": "user", "content": "three"},
        {"role": "assistant", "content": "four"},
    ]


def _make_runner(history: list[dict[str, str]]):
    from gateway.run import GatewayRunner

    runner = object.__new__(GatewayRunner)
    runner.config = GatewayConfig(
        platforms={Platform.TELEGRAM: PlatformConfig(enabled=True, token="***")}
    )
    session_entry = SessionEntry(
        session_key=build_session_key(_make_source()),
        session_id="sess-1",
        created_at=datetime.now(),
        updated_at=datetime.now(),
        platform=Platform.TELEGRAM,
        chat_type="dm",
    )
    runner.session_store = MagicMock()
    runner.session_store.get_or_create_session.return_value = session_entry
    runner.session_store.load_transcript.return_value = history
    runner.session_store.rewrite_transcript = MagicMock()
    runner.session_store.update_session = MagicMock()
    runner.session_store._save = MagicMock()
    return runner


@pytest.mark.asyncio
async def test_compress_command_reports_noop_without_success_banner():
    history = _make_history()
    runner = _make_runner(history)
    agent_instance = MagicMock()
    agent_instance.shutdown_memory_provider = MagicMock()
    agent_instance.close = MagicMock()
    agent_instance._cached_system_prompt = ""
    agent_instance.tools = None
    agent_instance.context_compressor.has_content_to_compress.return_value = True
    agent_instance.session_id = "sess-1"
    agent_instance._compress_context.return_value = (list(history), "")

    def _estimate(messages, **_kwargs):
        assert messages == history
        return 100

    with (
        patch("gateway.run._resolve_runtime_agent_kwargs", return_value={"api_key": "test-key"}),
        patch("gateway.run._resolve_gateway_model", return_value="test-model"),
        patch("run_agent.AIAgent", return_value=agent_instance),
        patch("agent.model_metadata.estimate_request_tokens_rough", side_effect=_estimate),
    ):
        result = await runner._handle_compress_command(_make_event())

    assert "No changes from compression" in result
    assert "Compressed:" not in result
    assert "Approx request size: ~100 tokens (unchanged)" in result
    agent_instance.shutdown_memory_provider.assert_called_once()
    agent_instance.close.assert_called_once()


@pytest.mark.asyncio
async def test_compress_command_explains_when_token_estimate_rises():
    history = _make_history()
    compressed = [
        history[0],
        {"role": "assistant", "content": "Dense summary that still counts as more tokens."},
        history[-1],
    ]
    runner = _make_runner(history)
    agent_instance = MagicMock()
    agent_instance.shutdown_memory_provider = MagicMock()
    agent_instance.close = MagicMock()
    agent_instance._cached_system_prompt = ""
    agent_instance.tools = None
    agent_instance.context_compressor.has_content_to_compress.return_value = True
    agent_instance.session_id = "sess-1"
    agent_instance._compress_context.return_value = (compressed, "")

    def _estimate(messages, **_kwargs):
        if messages == history:
            return 100
        if messages == compressed:
            return 120
        raise AssertionError(f"unexpected transcript: {messages!r}")

    with (
        patch("gateway.run._resolve_runtime_agent_kwargs", return_value={"api_key": "test-key"}),
        patch("gateway.run._resolve_gateway_model", return_value="test-model"),
        patch("run_agent.AIAgent", return_value=agent_instance),
        patch("agent.model_metadata.estimate_request_tokens_rough", side_effect=_estimate),
    ):
        result = await runner._handle_compress_command(_make_event())

    assert "Compressed: 4 → 3 messages" in result
    assert "Approx request size: ~100 → ~120 tokens" in result
    assert "denser summaries" in result
    agent_instance.shutdown_memory_provider.assert_called_once()
    agent_instance.close.assert_called_once()


@pytest.mark.asyncio
async def test_compress_command_appends_warning_when_compression_aborts():
    """When the auxiliary summariser fails and the compressor ABORTS (returns
    messages unchanged), /compress must append a visible ⚠️ warning to its
    reply telling the user nothing was dropped and how to retry. Otherwise
    the failure is silently logged and the user has no idea why nothing
    happened."""
    history = _make_history()
    # Abort path: compressor returns the input messages unchanged.
    compressed = list(history)
    runner = _make_runner(history)
    agent_instance = MagicMock()
    agent_instance.shutdown_memory_provider = MagicMock()
    agent_instance.close = MagicMock()
    agent_instance._cached_system_prompt = ""
    agent_instance.tools = None
    agent_instance.context_compressor.has_content_to_compress.return_value = True
    # Simulate compression aborting (force=True bypassed cooldown but the
    # aux LLM is genuinely broken).
    agent_instance.context_compressor._last_compress_aborted = True
    agent_instance.context_compressor._last_summary_fallback_used = False
    agent_instance.context_compressor._last_summary_dropped_count = 0
    agent_instance.context_compressor._last_summary_error = (
        "404 model not found: gemini-3-flash-preview"
    )
    agent_instance.session_id = "sess-1"
    agent_instance._compress_context.return_value = (compressed, "")

    def _estimate(messages, **_kwargs):
        if messages == history:
            return 100
        if messages == compressed:
            return 100
        raise AssertionError(f"unexpected transcript: {messages!r}")

    with (
        patch("gateway.run._resolve_runtime_agent_kwargs", return_value={"api_key": "***"}),
        patch("gateway.run._resolve_gateway_model", return_value="test-model"),
        patch("run_agent.AIAgent", return_value=agent_instance),
        patch("agent.model_metadata.estimate_request_tokens_rough", side_effect=_estimate),
    ):
        result = await runner._handle_compress_command(_make_event())

    # A clearly-marked warning must be appended.
    assert "⚠️" in result
    assert "Compression aborted" in result
    # Underlying error must surface so users can fix their config.
    assert "404 model not found" in result
    # User must be told nothing was dropped — the whole point of the
    # new behavior is no silent data loss.
    assert "No messages were dropped" in result
    agent_instance.shutdown_memory_provider.assert_called_once()
    agent_instance.close.assert_called_once()


@pytest.mark.asyncio
async def test_compress_command_surfaces_aux_model_failure_even_when_recovered():
    """When the user's configured ``auxiliary.compression.model`` errors out
    but compression recovers by retrying on the main model, /compress must
    STILL inform the user.  Silent recovery hides broken config the user
    needs to fix."""
    history = _make_history()
    # Compressed transcript — normal successful compression, no placeholder.
    compressed = [
        history[0],
        {"role": "assistant", "content": "summary via main model"},
        history[-1],
    ]
    runner = _make_runner(history)
    agent_instance = MagicMock()
    agent_instance.shutdown_memory_provider = MagicMock()
    agent_instance.close = MagicMock()
    agent_instance._cached_system_prompt = ""
    agent_instance.tools = None
    agent_instance.context_compressor.has_content_to_compress.return_value = True
    # Fallback placeholder was NOT used — recovery succeeded.
    agent_instance.context_compressor._last_compress_aborted = False
    agent_instance.context_compressor._last_summary_fallback_used = False
    agent_instance.context_compressor._last_summary_dropped_count = 0
    agent_instance.context_compressor._last_summary_error = None
    # But the configured aux model DID fail before the retry succeeded.
    agent_instance.context_compressor._last_aux_model_failure_model = (
        "gemini-3-flash-preview"
    )
    agent_instance.context_compressor._last_aux_model_failure_error = (
        "404 model not found: gemini-3-flash-preview"
    )
    agent_instance.session_id = "sess-1"
    agent_instance._compress_context.return_value = (compressed, "")

    def _estimate(messages, **_kwargs):
        if messages == history:
            return 100
        if messages == compressed:
            return 60
        raise AssertionError(f"unexpected transcript: {messages!r}")

    with (
        patch("gateway.run._resolve_runtime_agent_kwargs", return_value={"api_key": "***"}),
        patch("gateway.run._resolve_gateway_model", return_value="test-model"),
        patch("run_agent.AIAgent", return_value=agent_instance),
        patch("agent.model_metadata.estimate_request_tokens_rough", side_effect=_estimate),
    ):
        result = await runner._handle_compress_command(_make_event())

    # Compression succeeded
    assert "Compressed:" in result
    # No ⚠️ warning (that's reserved for dropped-turns case)
    assert "⚠️" not in result
    # But there IS an info note about the broken aux model
    assert "ℹ️" in result
    assert "gemini-3-flash-preview" in result
    assert "404" in result
    assert "auxiliary.compression.model" in result
    # The user's context is explicitly called out as intact
    assert "intact" in result
    agent_instance.shutdown_memory_provider.assert_called_once()
    agent_instance.close.assert_called_once()
