import json
from pathlib import Path
from unittest.mock import AsyncMock, MagicMock

import pytest

from nanobot.agent.context import ContextBuilder
from nanobot.agent.loop import AgentLoop
from nanobot.bus.events import InboundMessage
from nanobot.bus.queue import MessageBus
from nanobot.session.manager import Session


def _mk_loop() -> AgentLoop:
    loop = AgentLoop.__new__(AgentLoop)
    from nanobot.config.schema import AgentDefaults

    loop.max_tool_result_chars = AgentDefaults().max_tool_result_chars
    return loop


def _make_full_loop(tmp_path: Path) -> AgentLoop:
    provider = MagicMock()
    provider.get_default_model.return_value = "test-model"
    return AgentLoop(bus=MessageBus(), provider=provider, workspace=tmp_path, model="test-model")


def test_save_turn_skips_multimodal_user_when_only_runtime_context() -> None:
    loop = _mk_loop()
    session = Session(key="test:runtime-only")
    runtime = ContextBuilder._RUNTIME_CONTEXT_TAG + "\nCurrent Time: now (UTC)"

    loop._save_turn(
        session,
        [{"role": "user", "content": [{"type": "text", "text": runtime}]}],
        skip=0,
    )
    assert session.messages == []


def test_save_turn_keeps_image_placeholder_with_path_after_runtime_strip() -> None:
    loop = _mk_loop()
    session = Session(key="test:image")
    runtime = ContextBuilder._RUNTIME_CONTEXT_TAG + "\nCurrent Time: now (UTC)"

    loop._save_turn(
        session,
        [{
            "role": "user",
            "content": [
                {"type": "text", "text": runtime},
                {"type": "image_url", "image_url": {"url": "data:image/png;base64,abc"}, "_meta": {"path": "/media/feishu/photo.jpg"}},
            ],
        }],
        skip=0,
    )
    assert session.messages[0]["content"] == [{"type": "text", "text": "[image: /media/feishu/photo.jpg]"}]


def test_save_turn_keeps_image_placeholder_without_meta() -> None:
    loop = _mk_loop()
    session = Session(key="test:image-no-meta")
    runtime = ContextBuilder._RUNTIME_CONTEXT_TAG + "\nCurrent Time: now (UTC)"

    loop._save_turn(
        session,
        [{
            "role": "user",
            "content": [
                {"type": "text", "text": runtime},
                {"type": "image_url", "image_url": {"url": "data:image/png;base64,abc"}},
            ],
        }],
        skip=0,
    )
    assert session.messages[0]["content"] == [{"type": "text", "text": "[image]"}]


def test_save_turn_keeps_tool_results_under_16k() -> None:
    loop = _mk_loop()
    session = Session(key="test:tool-result")
    content = "x" * 12_000

    loop._save_turn(
        session,
        [{"role": "tool", "tool_call_id": "call_1", "name": "read_file", "content": content}],
        skip=0,
    )

    assert session.messages[0]["content"] == content


def test_restore_runtime_checkpoint_rehydrates_completed_and_pending_tools() -> None:
    loop = _mk_loop()
    session = Session(
        key="test:checkpoint",
        metadata={
            AgentLoop._RUNTIME_CHECKPOINT_KEY: {
                "assistant_message": {
                    "role": "assistant",
                    "content": "working",
                    "tool_calls": [
                        {
                            "id": "call_done",
                            "type": "function",
                            "function": {"name": "read_file", "arguments": "{}"},
                        },
                        {
                            "id": "call_pending",
                            "type": "function",
                            "function": {"name": "exec", "arguments": "{}"},
                        },
                    ],
                },
                "completed_tool_results": [
                    {
                        "role": "tool",
                        "tool_call_id": "call_done",
                        "name": "read_file",
                        "content": "ok",
                    }
                ],
                "pending_tool_calls": [
                    {
                        "id": "call_pending",
                        "type": "function",
                        "function": {"name": "exec", "arguments": "{}"},
                    }
                ],
            }
        },
    )

    restored = loop._restore_runtime_checkpoint(session)

    assert restored is True
    assert session.metadata.get(AgentLoop._RUNTIME_CHECKPOINT_KEY) is None
    assert session.messages[0]["role"] == "assistant"
    assert session.messages[1]["tool_call_id"] == "call_done"
    assert session.messages[2]["tool_call_id"] == "call_pending"
    assert "interrupted before this tool finished" in session.messages[2]["content"].lower()


def test_restore_runtime_checkpoint_dedupes_overlapping_tail() -> None:
    loop = _mk_loop()
    session = Session(
        key="test:checkpoint-overlap",
        messages=[
            {
                "role": "assistant",
                "content": "working",
                "tool_calls": [
                    {
                        "id": "call_done",
                        "type": "function",
                        "function": {"name": "read_file", "arguments": "{}"},
                    },
                    {
                        "id": "call_pending",
                        "type": "function",
                        "function": {"name": "exec", "arguments": "{}"},
                    },
                ],
            },
            {
                "role": "tool",
                "tool_call_id": "call_done",
                "name": "read_file",
                "content": "ok",
            },
        ],
        metadata={
            AgentLoop._RUNTIME_CHECKPOINT_KEY: {
                "assistant_message": {
                    "role": "assistant",
                    "content": "working",
                    "tool_calls": [
                        {
                            "id": "call_done",
                            "type": "function",
                            "function": {"name": "read_file", "arguments": "{}"},
                        },
                        {
                            "id": "call_pending",
                            "type": "function",
                            "function": {"name": "exec", "arguments": "{}"},
                        },
                    ],
                },
                "completed_tool_results": [
                    {
                        "role": "tool",
                        "tool_call_id": "call_done",
                        "name": "read_file",
                        "content": "ok",
                    }
                ],
                "pending_tool_calls": [
                    {
                        "id": "call_pending",
                        "type": "function",
                        "function": {"name": "exec", "arguments": "{}"},
                    }
                ],
            }
        },
    )

    restored = loop._restore_runtime_checkpoint(session)

    assert restored is True
    assert session.metadata.get(AgentLoop._RUNTIME_CHECKPOINT_KEY) is None
    assert len(session.messages) == 3
    assert session.messages[0]["role"] == "assistant"
    assert session.messages[1]["tool_call_id"] == "call_done"
    assert session.messages[2]["tool_call_id"] == "call_pending"


@pytest.mark.asyncio
async def test_process_message_persists_user_message_before_turn_completes(tmp_path: Path) -> None:
    loop = _make_full_loop(tmp_path)
    loop.consolidator.maybe_consolidate_by_tokens = AsyncMock(return_value=False)  # type: ignore[method-assign]
    loop._run_agent_loop = AsyncMock(side_effect=RuntimeError("boom"))  # type: ignore[method-assign]

    msg = InboundMessage(channel="feishu", sender_id="u1", chat_id="c1", content="persist me")
    with pytest.raises(RuntimeError, match="boom"):
        await loop._process_message(msg)

    loop.sessions.invalidate("feishu:c1")
    persisted = loop.sessions.get_or_create("feishu:c1")
    assert [m["role"] for m in persisted.messages] == ["user"]
    assert persisted.messages[0]["content"] == "persist me"
    assert persisted.metadata.get(AgentLoop._PENDING_USER_TURN_KEY) is True
    assert persisted.updated_at >= persisted.created_at


@pytest.mark.asyncio
async def test_process_message_does_not_duplicate_early_persisted_user_message(tmp_path: Path) -> None:
    loop = _make_full_loop(tmp_path)
    loop.consolidator.maybe_consolidate_by_tokens = AsyncMock(return_value=False)  # type: ignore[method-assign]
    loop._run_agent_loop = AsyncMock(return_value=(
        "done",
        None,
        [
            {"role": "system", "content": "system"},
            {"role": "user", "content": "hello"},
            {"role": "assistant", "content": "done"},
        ],
        "stop",
        False,
    ))  # type: ignore[method-assign]

    result = await loop._process_message(
        InboundMessage(channel="feishu", sender_id="u1", chat_id="c2", content="hello")
    )

    assert result is not None
    assert result.content == "done"
    session = loop.sessions.get_or_create("feishu:c2")
    assert [
        {k: v for k, v in m.items() if k in {"role", "content"}}
        for m in session.messages
    ] == [
        {"role": "user", "content": "hello"},
        {"role": "assistant", "content": "done"},
    ]
    assert AgentLoop._PENDING_USER_TURN_KEY not in session.metadata


@pytest.mark.asyncio
async def test_next_turn_after_crash_closes_pending_user_turn_before_new_input(tmp_path: Path) -> None:
    loop = _make_full_loop(tmp_path)
    loop.consolidator.maybe_consolidate_by_tokens = AsyncMock(return_value=False)  # type: ignore[method-assign]
    loop.provider.chat_with_retry = AsyncMock(return_value=MagicMock())  # unused because _run_agent_loop is stubbed

    session = loop.sessions.get_or_create("feishu:c3")
    session.add_message("user", "old question")
    session.metadata[AgentLoop._PENDING_USER_TURN_KEY] = True
    loop.sessions.save(session)

    loop._run_agent_loop = AsyncMock(return_value=(
        "new answer",
        None,
        [
            {"role": "system", "content": "system"},
            {"role": "user", "content": "old question"},
            {"role": "assistant", "content": "Error: Task interrupted before a response was generated."},
            {"role": "user", "content": "new question"},
            {"role": "assistant", "content": "new answer"},
        ],
        "stop",
        False,
    ))  # type: ignore[method-assign]

    result = await loop._process_message(
        InboundMessage(channel="feishu", sender_id="u1", chat_id="c3", content="new question")
    )

    assert result is not None
    assert result.content == "new answer"
    session = loop.sessions.get_or_create("feishu:c3")
    assert [
        {k: v for k, v in m.items() if k in {"role", "content"}}
        for m in session.messages
    ] == [
        {"role": "user", "content": "old question"},
        {"role": "assistant", "content": "Error: Task interrupted before a response was generated."},
        {"role": "user", "content": "new question"},
        {"role": "assistant", "content": "new answer"},
    ]
    assert AgentLoop._PENDING_USER_TURN_KEY not in session.metadata


def _cross_channel_messages(
    source_channel: str = "websocket",
    source_chat_id: str = "ws-uuid-123",
    target_channel: str = "feishu",
    target_chat_id: str = "ou_abc123",
) -> list[dict]:
    """Build a message list with a cross-channel message tool call."""
    return [
        {"role": "user", "content": "send report to feishu"},
        {
            "role": "assistant",
            "content": "",
            "tool_calls": [
                {
                    "id": "call_x1",
                    "type": "function",
                    "function": {
                        "name": "message",
                        "arguments": json.dumps({
                            "content": "Report: audit complete",
                            "channel": target_channel,
                            "chat_id": target_chat_id,
                        }),
                    },
                }
            ],
        },
        {
            "role": "tool",
            "tool_call_id": "call_x1",
            "name": "message",
            "content": f"Message sent to {target_channel}:{target_chat_id}",
        },
        {"role": "assistant", "content": "Done, sent to feishu."},
    ]


def test_cross_channel_message_persisted_in_target_session(tmp_path: Path) -> None:
    loop = _make_full_loop(tmp_path)
    source_key = "websocket:ws-uuid-123"
    target_key = "feishu:ou_abc123"

    # Pre-create the target session (simulate an existing feishu conversation)
    target_session = loop.sessions.get_or_create(target_key)
    target_session.add_message("user", "hello from feishu")
    loop.sessions.save(target_session)

    source_session = loop.sessions.get_or_create(source_key)
    msgs = _cross_channel_messages()
    loop._save_turn(source_session, msgs, skip=1)  # skip user message

    # Source session has its own messages
    source_session = loop.sessions.get_or_create(source_key)
    assert len(source_session.messages) >= 2  # assistant + tool + final

    # Target session now has the cross-channel message appended
    loop.sessions.invalidate(target_key)
    target = loop.sessions.get_or_create(target_key)
    cross_msg = [m for m in target.messages if m.get("_cross_channel")]
    assert len(cross_msg) == 1
    assert cross_msg[0]["content"] == "Report: audit complete"
    assert cross_msg[0]["role"] == "assistant"


def test_cross_channel_same_session_not_duplicated(tmp_path: Path) -> None:
    loop = _make_full_loop(tmp_path)
    key = "feishu:ou_same"

    session = loop.sessions.get_or_create(key)
    # message tool call targeting the same session — should NOT create a duplicate
    msgs = [
        {"role": "user", "content": "hello"},
        {
            "role": "assistant",
            "content": "",
            "tool_calls": [
                {
                    "id": "call_s1",
                    "type": "function",
                    "function": {
                        "name": "message",
                        "arguments": json.dumps({
                            "content": "same channel msg",
                            "channel": "feishu",
                            "chat_id": "ou_same",
                        }),
                    },
                }
            ],
        },
        {"role": "tool", "tool_call_id": "call_s1", "name": "message", "content": "ok"},
    ]
    loop._save_turn(session, msgs, skip=1)

    # No _cross_channel entries should exist
    assert all(not m.get("_cross_channel") for m in session.messages)


def test_cross_channel_target_session_not_exist(tmp_path: Path) -> None:
    loop = _make_full_loop(tmp_path)
    source_session = loop.sessions.get_or_create("websocket:ws-xyz")

    msgs = _cross_channel_messages(
        target_channel="feishu", target_chat_id="ou_nonexistent"
    )
    loop._save_turn(source_session, msgs, skip=1)

    # Target session was never created, so no error should occur
    assert "feishu:ou_nonexistent" not in loop.sessions._cache


def test_cross_channel_non_message_tools_ignored(tmp_path: Path) -> None:
    loop = _make_full_loop(tmp_path)
    source_session = loop.sessions.get_or_create("websocket:ws-abc")
    target_session = loop.sessions.get_or_create("feishu:ou_tgt")
    target_session.add_message("user", "hi")
    loop.sessions.save(target_session)

    msgs = [
        {"role": "user", "content": "do stuff"},
        {
            "role": "assistant",
            "content": "",
            "tool_calls": [
                {
                    "id": "call_e1",
                    "type": "function",
                    "function": {
                        "name": "exec",
                        "arguments": json.dumps({"command": "echo hi"}),
                    },
                }
            ],
        },
        {"role": "tool", "tool_call_id": "call_e1", "name": "exec", "content": "hi"},
    ]
    loop._save_turn(source_session, msgs, skip=1)

    # exec tool should NOT produce cross-channel entries
    target = loop.sessions.get_or_create("feishu:ou_tgt")
    cross_msgs = [m for m in target.messages if m.get("_cross_channel")]
    assert len(cross_msgs) == 0