from __future__ import annotations

from datetime import UTC, date, datetime, time, timedelta
from io import BytesIO

from fastapi import APIRouter, Depends, HTTPException, Query, status
from fastapi.responses import StreamingResponse
from openpyxl import Workbook
from openpyxl.styles import Alignment, Font, PatternFill
from openpyxl.worksheet.table import Table, TableStyleInfo
from pydantic import BaseModel, Field
from sqlalchemy import func, select
from sqlalchemy.exc import IntegrityError
from sqlalchemy.orm import Session

from app.api.pagination import page_result
from app.core.database import get_db
from app.core.dependencies import get_current_admin, get_current_user
from app.core.responses import api_success
from app.models.admin import Admin
from app.models.chat import ChatMessage, ChatSession
from app.models.feedback import MessageFeedback
from app.models.user import User
from app.services.admin_service import OperationLogService
from app.services.admin_permission_service import require_permission

router = APIRouter()


class FeedbackCreate(BaseModel):
    messageId: int = Field(gt=0)
    content: str = Field(min_length=1, max_length=200)


@router.post("")
def create_feedback(payload: FeedbackCreate, db: Session = Depends(get_db), user: User = Depends(get_current_user)) -> dict:
    message = db.scalar(select(ChatMessage).where(ChatMessage.id == payload.messageId, ChatMessage.user_id == user.id))
    if message is None or message.role != "assistant" or message.message_status != "FINISHED":
        raise HTTPException(status_code=404, detail="反馈的回答不存在")
    content = payload.content.strip()
    if not content:
        raise HTTPException(status_code=400, detail="请填写反馈内容")
    existing = db.scalar(select(MessageFeedback).where(MessageFeedback.user_id == user.id, MessageFeedback.message_id == message.id))
    if existing:
        raise HTTPException(status_code=409, detail="这条回答已经反馈过了")
    item = MessageFeedback(user_id=user.id, session_id=message.session_id, message_id=message.id, content=content)
    db.add(item)
    try:
        db.commit()
    except IntegrityError as exc:
        db.rollback()
        raise HTTPException(status_code=409, detail="这条回答已经反馈过了") from exc
    db.refresh(item)
    return api_success({"id": item.id})


@router.get("/admin/list")
def feedback_list(readStatus: str = Query(default="all", pattern="^(all|read|unread)$"), startDate: date | None = None, endDate: date | None = None, page: int = Query(default=1, ge=1), pageSize: int = Query(default=20, ge=10, le=100), db: Session = Depends(get_db), _admin: Admin = Depends(get_current_admin)) -> dict:
    require_permission(_admin, "feedback.view")
    query = _feedback_query(readStatus, startDate, endDate)
    total = db.scalar(select(func.count()).select_from(query.order_by(None).subquery())) or 0
    rows = db.execute(query.order_by(MessageFeedback.created_at.desc()).offset((page - 1) * pageSize).limit(pageSize)).all()
    return api_success(page_result([_summary(row[0], row[1], row[2]) for row in rows], total=total, page=page, page_size=pageSize))


@router.get("/admin/export")
def export_feedback(
    startDate: date,
    endDate: date,
    readStatus: str = Query(default="all", pattern="^(all|read|unread)$"),
    db: Session = Depends(get_db),
    admin: Admin = Depends(get_current_admin),
) -> StreamingResponse:
    require_permission(admin, "feedback.export")
    if endDate < startDate:
        raise HTTPException(status_code=400, detail="结束日期不能早于开始日期")
    if endDate - startDate > timedelta(days=366):
        raise HTTPException(status_code=400, detail="单次导出时间范围不能超过 366 天")
    rows = db.execute(_feedback_query(readStatus, startDate, endDate).order_by(MessageFeedback.created_at.desc()).limit(100001)).all()
    if len(rows) > 100000:
        raise HTTPException(status_code=400, detail="导出数据超过 10 万条，请缩小时间范围")
    workbook = _feedback_workbook(rows)
    stream = BytesIO()
    workbook.save(stream)
    stream.seek(0)
    OperationLogService.write(db, admin_id=admin.id, module="feedback", action="export")
    db.commit()
    filename = f"feedback_{startDate:%Y%m%d}_{endDate:%Y%m%d}.xlsx"
    return StreamingResponse(
        stream,
        media_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
    )


@router.get("/admin/{feedback_id}")
def feedback_detail(feedback_id: int, db: Session = Depends(get_db), admin: Admin = Depends(get_current_admin)) -> dict:
    require_permission(admin, "feedback.detail")
    row = db.execute(select(MessageFeedback, User, ChatMessage, ChatSession).join(User, User.id == MessageFeedback.user_id).join(ChatMessage, ChatMessage.id == MessageFeedback.message_id).join(ChatSession, ChatSession.id == MessageFeedback.session_id).where(MessageFeedback.id == feedback_id)).first()
    if row is None:
        raise HTTPException(status_code=404, detail="反馈不存在")
    feedback, user, target, session = row
    if not feedback.is_read:
        feedback.is_read = 1
        feedback.read_by = admin.id
        feedback.read_at = datetime.now(UTC).replace(tzinfo=None)
        db.commit()
    messages = db.scalars(select(ChatMessage).where(ChatMessage.session_id == feedback.session_id, ChatMessage.id <= target.id).order_by(ChatMessage.id.asc()).limit(200)).all()
    return api_success({**_summary(feedback, user, target), "sessionTitle": session.title, "messages": [{"id": m.id, "role": m.role, "content": m.content, "createdAt": m.created_at, "isTarget": m.id == target.id} for m in messages]})


@router.delete("/admin/{feedback_id}")
def delete_feedback(feedback_id: int, db: Session = Depends(get_db), admin: Admin = Depends(get_current_admin)) -> dict:
    require_permission(admin, "feedback.delete")
    item = db.get(MessageFeedback, feedback_id)
    if item is None:
        raise HTTPException(status_code=404, detail="反馈不存在")
    db.delete(item)
    OperationLogService.write(db, admin_id=admin.id, module="feedback", action="delete", target_id=feedback_id)
    db.commit()
    return api_success()


def _summary(item: MessageFeedback, user: User, message: ChatMessage) -> dict:
    return {"id": item.id, "userId": user.id, "userName": user.name, "userPhone": user.phone, "messageId": message.id, "messageContent": message.content, "content": item.content, "isRead": bool(item.is_read), "createdAt": item.created_at}


def _feedback_query(read_status: str, start_date: date | None, end_date: date | None):
    query = (
        select(MessageFeedback, User, ChatMessage, ChatSession)
        .join(User, User.id == MessageFeedback.user_id)
        .join(ChatMessage, ChatMessage.id == MessageFeedback.message_id)
        .join(ChatSession, ChatSession.id == MessageFeedback.session_id)
    )
    if read_status != "all":
        query = query.where(MessageFeedback.is_read == (1 if read_status == "read" else 0))
    if start_date is not None:
        query = query.where(MessageFeedback.created_at >= datetime.combine(start_date, time.min))
    if end_date is not None:
        query = query.where(MessageFeedback.created_at < datetime.combine(end_date + timedelta(days=1), time.min))
    return query


def _feedback_workbook(rows: list[tuple]) -> Workbook:
    workbook = Workbook()
    sheet = workbook.active
    sheet.title = "反馈记录"
    sheet.sheet_view.showGridLines = False
    headers = ["序号", "状态", "用户姓名", "手机号", "反馈内容", "会话标题", "消息ID", "对应AI回答", "提交时间", "阅读时间"]
    sheet.append(headers)
    for index, (feedback, user, message, session) in enumerate(rows, start=1):
        sheet.append([
            index,
            "已读" if feedback.is_read else "未读",
            _excel_safe_text(user.name),
            _excel_safe_text(user.phone),
            _excel_safe_text(feedback.content),
            _excel_safe_text(session.title),
            message.id,
            _excel_safe_text(message.content),
            feedback.created_at,
            feedback.read_at,
        ])
    header_fill = PatternFill("solid", fgColor="1F6F5F")
    for cell in sheet[1]:
        cell.fill = header_fill
        cell.font = Font(color="FFFFFF", bold=True)
        cell.alignment = Alignment(horizontal="center", vertical="center")
    sheet.freeze_panes = "A2"
    sheet.auto_filter.ref = f"A1:J{max(1, sheet.max_row)}"
    widths = [8, 10, 16, 16, 38, 24, 12, 70, 20, 20]
    for index, width in enumerate(widths, start=1):
        sheet.column_dimensions[chr(64 + index)].width = width
    for row in sheet.iter_rows(min_row=2):
        row[4].alignment = Alignment(vertical="top", wrap_text=True)
        row[7].alignment = Alignment(vertical="top", wrap_text=True)
        for cell in (row[8], row[9]):
            cell.number_format = "yyyy-mm-dd hh:mm:ss"
    if sheet.max_row > 1:
        table = Table(displayName="FeedbackRecords", ref=f"A1:J{sheet.max_row}")
        table.tableStyleInfo = TableStyleInfo(name="TableStyleMedium2", showRowStripes=True, showFirstColumn=False, showLastColumn=False)
        sheet.add_table(table)
    return workbook


def _excel_safe_text(value: object | None) -> str:
    text_value = str(value or "")
    return f"'{text_value}" if text_value.startswith(("=", "+", "-", "@")) else text_value