import logging
from datetime import datetime, timezone

from fastapi import APIRouter, Depends, HTTPException

from app.middleware.auth import get_current_user
from app.models.chat import ChatSession, ChatMessage
from app.models.report import Report
from app.models.user import User
from app.schemas.chat import ChatMessageRequest, ChatSessionResponse, ChatMessageResponse
from app.services.ai_service import chat_with_ai
from app.utils.helpers import parse_object_id

logger = logging.getLogger(__name__)

router = APIRouter()


@router.post("/{report_id}/message")
async def send_message(
    report_id: str,
    req: ChatMessageRequest,
    user: User = Depends(get_current_user),
):
    """发送消息并获取 AI 回复"""
    oid = parse_object_id(report_id)
    report = await Report.get(oid)
    if not report or report.user_id != user.id:
        raise HTTPException(status_code=404, detail="报告不存在")

    # Get or create chat session
    session = await ChatSession.find_one(
        ChatSession.user_id == user.id,
        ChatSession.report_id == report.id,
    )
    if not session:
        session = ChatSession(user_id=user.id, report_id=report.id)
        await session.insert()

    # Add user message
    user_msg = ChatMessage(role="user", content=req.content)
    session.messages.append(user_msg)

    # Get AI response
    history = [{"role": m.role, "content": m.content} for m in session.messages[:-1]]
    try:
        ai_response = await chat_with_ai(report, user, history, req.content)
    except Exception:
        logger.exception("AI 对话失败 report_id=%s", report_id)
        raise HTTPException(status_code=502, detail="AI 对话服务暂时不可用，请稍后重试")

    # Add AI message
    ai_msg = ChatMessage(role="assistant", content=ai_response)
    session.messages.append(ai_msg)
    session.updated_at = datetime.now(timezone.utc)
    await session.save()

    return {
        "user_message": {"role": "user", "content": req.content, "timestamp": user_msg.timestamp.isoformat()},
        "ai_message": {"role": "assistant", "content": ai_response, "timestamp": ai_msg.timestamp.isoformat()},
    }


@router.get("/{report_id}/history")
async def get_chat_history(
    report_id: str, user: User = Depends(get_current_user)
):
    """获取聊天历史"""
    oid = parse_object_id(report_id)
    report = await Report.get(oid)
    if not report or report.user_id != user.id:
        raise HTTPException(status_code=404, detail="报告不存在")

    session = await ChatSession.find_one(
        ChatSession.user_id == user.id,
        ChatSession.report_id == report.id,
    )

    if not session:
        return {"messages": [], "quick_questions": _get_quick_questions()}

    return {
        "messages": [
            {"role": m.role, "content": m.content, "timestamp": m.timestamp.isoformat()}
            for m in session.messages
        ],
        "quick_questions": _get_quick_questions(),
    }


def _get_quick_questions() -> list[str]:
    return [
        "这个指标偏高会影响宝宝吗？",
        "我需要注意什么饮食？",
        "什么时候需要复查？",
        "这个结果严重吗？",
        "有什么改善建议？",
    ]