"""Tests for Dream driven through AgentLoop._process_system_message."""

import json
from types import SimpleNamespace
from unittest.mock import AsyncMock, MagicMock, patch

import pytest

from nanobot.agent.loop import AgentLoop
from nanobot.agent.runner import AgentRunResult
from nanobot.agent.skills import BUILTIN_SKILLS_DIR
from nanobot.bus.events import InboundMessage
from nanobot.bus.queue import MessageBus
from nanobot.utils.gitstore import LineAge


def _provider(default_model: str, max_tokens: int = 123) -> MagicMock:
    provider = MagicMock()
    provider.get_default_model.return_value = default_model
    provider.generation = SimpleNamespace(
        max_tokens=max_tokens, temperature=0.1, reasoning_effort=None
    )
    return provider


@pytest.fixture
def store(tmp_path):
    from nanobot.agent.memory import MemoryStore

    s = MemoryStore(tmp_path)
    s.write_soul("# Soul\n- Helpful")
    s.write_user("# User\n- Developer")
    s.write_memory("# Memory\n- Project X active")
    return s


@pytest.fixture
def mock_provider():
    return _provider("test-model")


@pytest.fixture
def mock_runner():
    return MagicMock()


@pytest.fixture
def loop(tmp_path, mock_provider, mock_runner):
    loop = AgentLoop(
        bus=MessageBus(),
        provider=mock_provider,
        workspace=tmp_path,
        model="test-model",
        context_window_tokens=1000,
    )
    loop.dream._runner = mock_runner
    return loop


def _make_run_result(
    stop_reason="completed",
    final_content=None,
    tool_events=None,
    usage=None,
):
    return AgentRunResult(
        final_content=final_content or stop_reason,
        stop_reason=stop_reason,
        messages=[],
        tools_used=[],
        usage={},
        tool_events=tool_events or [],
    )


class TestDreamAgentLoopIntegration:
    async def test_completes_goal_state_after_full_backlog(self, loop, mock_runner, store):
        """Goal should be completed after processing all backlog in internal loop."""
        for i in range(6):
            store.append_history(f"event {i}")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        session = loop.sessions.get_or_create("system:dream")
        goal = session.metadata.get("goal_state")
        assert isinstance(goal, dict)
        assert goal["status"] == "completed"
        assert store.get_last_dream_cursor() == 6

    async def test_completes_goal_state_on_finish(self, loop, mock_runner, store):
        """Goal should be marked completed when backlog is fully processed."""
        store.append_history("event 1")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        session = loop.sessions.get_or_create("system:dream")
        goal = session.metadata.get("goal_state")
        assert goal["status"] == "completed"
        assert "completed_at" in goal
        assert "recap" in goal

    async def test_noop_when_no_unprocessed_history(self, loop, mock_runner):
        """Dream should not call runner when there's nothing to process."""
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        result = await loop._process_system_message(msg)
        assert result is None
        mock_runner.run.assert_not_called()

    async def test_calls_runner_for_unprocessed_entries(self, loop, mock_runner, store):
        """Dream should call AgentRunner when there are unprocessed history entries."""
        store.append_history("User prefers dark mode")
        mock_runner.run = AsyncMock(
            return_value=_make_run_result(
                tool_events=[
                    {"name": "edit_file", "status": "ok", "detail": "memory/MEMORY.md"}
                ],
            )
        )
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        mock_runner.run.assert_called_once()
        spec = mock_runner.run.call_args[0][0]
        assert spec.max_iterations == 10
        assert spec.fail_on_tool_error is False

    async def test_advances_dream_cursor(self, loop, mock_runner, store):
        """Dream should advance the cursor after processing."""
        store.append_history("event 1")
        store.append_history("event 2")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        assert store.get_last_dream_cursor() == 2

    async def test_compacts_processed_history(self, loop, mock_runner, store):
        """Dream should compact history after processing."""
        store.append_history("event 1")
        store.append_history("event 2")
        store.append_history("event 3")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        entries = store.read_unprocessed_history(since_cursor=0)
        assert all(e["cursor"] > 0 for e in entries)

    async def test_processes_full_backlog_in_one_call(self, loop, mock_runner, store):
        """Backlog larger than max_batch_size should be fully processed in one call."""
        for i in range(12):
            store.append_history(f"event {i}")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        assert store.get_last_dream_cursor() == 12
        assert mock_runner.run.call_count == 3  # 5 + 5 + 2

    async def test_single_git_commit_for_multi_batch(self, loop, mock_runner, store):
        """Multi-batch run should collapse into exactly one git commit."""
        store.git.init()
        store.git.auto_commit("initial")
        for i in range(12):
            store.append_history(f"event {i}")
        mock_runner.run = AsyncMock(
            return_value=_make_run_result(
                tool_events=[
                    {"name": "edit_file", "status": "ok", "detail": "memory/MEMORY.md"}
                ],
            )
        )
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        commits = store.git.log()
        dream_commits = [c for c in commits if c.message.startswith("dream:")]
        assert len(dream_commits) == 1

    async def test_system_prompt_cached(self, loop, mock_runner, store):
        """Batches within one run should reuse cached system prompt when template mtime unchanged."""
        for i in range(6):
            store.append_history(f"event {i}")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        # Two batches (5 + 1), both should use the same cached prompt
        assert mock_runner.run.call_count == 2
        first_prompt = mock_runner.run.call_args_list[0][0][0].initial_messages[0]["content"]
        second_prompt = mock_runner.run.call_args_list[1][0][0].initial_messages[0]["content"]
        assert second_prompt is first_prompt

    async def test_noop_when_empty_backlog(self, loop, mock_runner, store):
        """Empty backlog should not advance cursor or create a commit."""
        store.git.init()
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        assert store.get_last_dream_cursor() == 0
        commits = store.git.log()
        assert len([c for c in commits if c.message.startswith("dream:")]) == 0


class TestDreamPrompt:
    async def test_prompt_contains_mece_rules(self, loop, mock_runner, store):
        store.append_history("some event")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        system_prompt = spec.initial_messages[0]["content"]
        assert "Do NOT guess paths" in system_prompt
        assert "SOUL.md" in system_prompt
        assert "USER.md" in system_prompt
        assert "MEMORY.md" in system_prompt

    async def test_skill_phase_uses_builtin_skill_creator_path(self, loop, mock_runner, store):
        store.append_history("Repeated workflow one")
        store.append_history("Repeated workflow two")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        system_prompt = spec.initial_messages[0]["content"]
        expected = str(BUILTIN_SKILLS_DIR / "skill-creator" / "SKILL.md")
        assert expected in system_prompt

    async def test_system_prompt_uses_threshold_from_template_var(self, loop, mock_runner, store):
        store.append_history("some event")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        system_msg = spec.initial_messages[0]["content"]
        assert "N>14" in system_msg


class TestDreamPromptCaps:
    async def test_caps_huge_memory_file(self, loop, mock_runner, store):
        store.write_memory("M" * (loop.dream._MEMORY_FILE_MAX_CHARS * 5))
        store.append_history("some event")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        user_msg = spec.initial_messages[1]["content"]
        memory_section = user_msg.split("## Current MEMORY.md")[1].split(
            "## Current SOUL.md"
        )[0]
        assert len(memory_section) < loop.dream._MEMORY_FILE_MAX_CHARS + 500

    async def test_caps_huge_history_entry(self, loop, mock_runner, store):
        store.history_file.write_text(
            json.dumps(
                {
                    "cursor": 1,
                    "timestamp": "2026-04-01 10:00",
                    "content": "H" * (loop.dream._HISTORY_ENTRY_PREVIEW_MAX_CHARS * 8),
                }
            )
            + "\n",
            encoding="utf-8",
        )
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        user_msg = spec.initial_messages[1]["content"]
        history_section = user_msg.split("## Conversation History\n")[1].split(
            "\n\n## Current Date"
        )[0]
        assert len(history_section) < loop.dream._HISTORY_ENTRY_PREVIEW_MAX_CHARS + 500


class TestDreamTools:
    def test_apply_patch_tool_registered(self, loop):
        tool = loop.dream._tools.get("apply_patch")
        assert tool is not None


class TestDreamCaps:
    def test_batch_size_default_is_5(self):
        from nanobot.config.schema import DreamConfig

        assert DreamConfig().max_batch_size == 5

    def test_memory_cap_is_16k(self, loop):
        assert loop.dream._MEMORY_FILE_MAX_CHARS == 16_000


class TestDreamSkipFiltering:
    async def test_skip_entries_removed_from_prompt(self, loop, mock_runner, store):
        store.append_history("- [skip] greeting\n- [permanent] User prefers dark mode")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        user_msg = spec.initial_messages[1]["content"]
        assert "User prefers dark mode" in user_msg
        assert "[skip]" not in user_msg
        assert "greeting" not in user_msg


class TestDreamAgeAnnotations:
    async def test_prompt_includes_line_age_annotations(self, loop, mock_runner, store):
        store.append_history("some event")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        store.git.init()
        store.git.auto_commit("initial memory state")
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        user_msg = spec.initial_messages[1]["content"]
        assert "## Current MEMORY.md" in user_msg

    async def test_annotates_only_memory_not_soul_or_user(self, loop, mock_runner, store):
        store.append_history("some event")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        store.git.init()
        store.git.auto_commit("initial state")
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        user_msg = spec.initial_messages[1]["content"]
        soul_section = user_msg.split("## Current SOUL.md")[1].split(
            "## Current USER.md"
        )[0]
        user_section = user_msg.split("## Current USER.md")[1]
        assert "←" not in soul_section
        assert "←" not in user_section

    async def test_prompt_works_without_git(self, loop, mock_runner, store):
        store.append_history("some event")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        mock_runner.run.assert_called_once()
        spec = mock_runner.run.call_args[0][0]
        user_msg = spec.initial_messages[1]["content"]
        assert "## Current MEMORY.md" in user_msg

    async def test_prompt_carries_age_suffix_for_stale_lines(self, loop, mock_runner, store):
        store.write_memory(
            "# Memory\n- Project X active\n- fresh item\n- edge case line"
        )
        store.append_history("some event")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        fake_ages = [
            LineAge(age_days=30),
            LineAge(age_days=20),
            LineAge(age_days=14),
            LineAge(age_days=5),
        ]
        with patch.object(loop.dream.store.git, "line_ages", return_value=fake_ages):
            msg = InboundMessage(
                channel="system", sender_id="dream", chat_id="dream", content=""
            )
            await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        user_msg = spec.initial_messages[1]["content"]
        memory_section = user_msg.split("## Current MEMORY.md")[1].split(
            "## Current SOUL.md"
        )[0]
        assert "← 30d" in memory_section
        assert "← 20d" in memory_section
        assert "← 14d" not in memory_section
        assert "← 5d" not in memory_section

    async def test_skips_annotation_when_disabled(self, loop, mock_runner, store):
        store.append_history("some event")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        loop.dream.annotate_line_ages = False
        with patch.object(loop.dream.store.git, "line_ages") as mock_line_ages:
            msg = InboundMessage(
                channel="system", sender_id="dream", chat_id="dream", content=""
            )
            await loop._process_system_message(msg)
            mock_line_ages.assert_not_called()
        spec = mock_runner.run.call_args[0][0]
        user_msg = spec.initial_messages[1]["content"]
        assert "←" not in user_msg

    async def test_skips_annotation_on_line_ages_length_mismatch(self, loop, mock_runner, store):
        store.append_history("some event")
        mock_runner.run = AsyncMock(return_value=_make_run_result())
        with patch.object(
            loop.dream.store.git, "line_ages", return_value=[LineAge(age_days=999)]
        ):
            msg = InboundMessage(
                channel="system", sender_id="dream", chat_id="dream", content=""
            )
            await loop._process_system_message(msg)
        spec = mock_runner.run.call_args[0][0]
        user_msg = spec.initial_messages[1]["content"]
        memory_section = user_msg.split("## Current MEMORY.md")[1].split(
            "## Current SOUL.md"
        )[0]
        assert "←" not in memory_section


class TestDreamSessionPersistence:
    async def test_writes_session_on_success(self, loop, mock_runner, store):
        store.append_history("event one")
        store.append_history("event two")
        mock_runner.run = AsyncMock(
            return_value=_make_run_result(
                tool_events=[
                    {"name": "edit_file", "status": "ok", "detail": "memory/MEMORY.md"}
                ],
            )
        )
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        session_path = store.memory_dir / ".dream_session.json"
        assert session_path.exists()
        data = json.loads(session_path.read_text(encoding="utf-8"))
        assert data["batch"]["from_cursor"] == 0
        assert data["batch"]["to_cursor"] == 2
        assert data["batch"]["count"] == 2
        assert data["stop_reason"] == "completed"
        assert data["changelog"] == ["edit_file: memory/MEMORY.md"]
        assert "timestamp" in data
        assert "elapsed_seconds" in data
        assert "messages" in data

    async def test_no_session_record_on_failure(self, loop, mock_runner, store):
        """Failed batch should not write a session record (cursor stays put for retry)."""
        store.append_history("event one")
        mock_runner.run = AsyncMock(side_effect=RuntimeError("LLM error"))
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        session_path = store.memory_dir / ".dream_session.json"
        assert not session_path.exists()
        assert store.get_last_dream_cursor() == 0

    async def test_session_contains_full_messages(self, loop, mock_runner, store):
        store.append_history("event one")
        messages = [
            {"role": "system", "content": "you are a memory bot"},
            {"role": "user", "content": "history here"},
            {"role": "assistant", "content": "I will edit MEMORY.md"},
        ]
        result = _make_run_result()
        result.messages = messages
        mock_runner.run = AsyncMock(return_value=result)
        msg = InboundMessage(
            channel="system", sender_id="dream", chat_id="dream", content=""
        )
        await loop._process_system_message(msg)
        session_path = store.memory_dir / ".dream_session.json"
        data = json.loads(session_path.read_text(encoding="utf-8"))
        assert data["messages"] == messages
        assert data["prompt_chars"] > 0
        assert data["commit_sha"] is None