# router_messages.py
from fastapi import APIRouter, HTTPException, Depends
from pydantic import BaseModel
import time
import uuid
import subprocess
import os
import 数据库连接 as db
from notifications import add_notification
from models import PrivateMessage
from 安全认证 import require_auth, is_admin

router = APIRouter()

# ==========================================
# 新增：系统公告请求体模型
# ==========================================
class SystemAnnouncement(BaseModel):
    admin_account: str
    content: str

# ==========================================
# 新增：发布系统公告接口 (仅限管理员，使用JWT验证)
# ==========================================
@router.post("/api/system/announcement")
async def publish_announcement(ann: SystemAnnouncement, current_user: str = Depends(require_auth)):
    # 🔒 P0安全修复：使用环境变量配置的管理员列表
    if not is_admin(current_user):
        raise HTTPException(status_code=403, detail="无权发布系统公告，仅管理员可操作")
    
    # 查询管理员信息
    users_db = db.load_data("users.json", default_data={})
    admin_info = users_db.get(current_user, {})
    
    announcements_db = db.load_data("announcements.json", default_data=[])
    
    new_ann = {
        "id": f"sys_{int(time.time())}_{uuid.uuid4().hex[:6]}",
        "type": "system",
        "from_user": current_user,  # 使用真实的管理员账号
        "from_name": admin_info.get("name", current_user),  # 使用真实昵称，fallback 为账号
        "from_avatar": admin_info.get("avatarDataUrl", ""),  # 使用真实头像
        "content": ann.content,
        "created_at": int(time.time())
    }
    
    announcements_db.append(new_ann)
    db.save_data("announcements.json", announcements_db)
    return {"status": "success"}


# ==========================================
# 管理员调试：执行 Python 脚本
# ==========================================
class AdminScriptRequest(BaseModel):
    admin_account: str
    script_name: str

# 🔒 P0安全修复：脚本白名单（仅允许执行指定的脚本）
# 警告：添加新脚本前请确保其安全性
ALLOWED_SCRIPTS = {
    "密码迁移.py",      # 用户密码哈希化迁移
    "测试脚本.py",      # 接口测试工具
    "迁移_余额合并.py",  # 一次性余额合并迁移（执行后可移除）
}

@router.post("/api/admin/run-script")
async def run_admin_script(req: AdminScriptRequest, current_user: str = Depends(require_auth)):
    """
    管理员专属：执行指定的 Python 脚本
    🔒 P0安全修复：白名单 + 路径穿越防护
    """
    # 🔒 P0安全修复：使用环境变量配置的管理员列表
    if not is_admin(current_user):
        raise HTTPException(status_code=403, detail="无权执行此操作，仅管理员可操作")
    
    script_name = req.script_name.strip()
    if not script_name:
        raise HTTPException(status_code=400, detail="脚本名称不能为空")
    
    # 🔒 P0安全修复：路径穿越攻击防护
    if ".." in script_name or "/" in script_name or "\\" in script_name:
        raise HTTPException(status_code=400, detail="🚨 安全拦截：脚本名称包含非法字符")
    
    # 🔒 P0安全修复：白名单检查
    if script_name not in ALLOWED_SCRIPTS:
        raise HTTPException(
            status_code=403, 
            detail=f"🚨 安全拦截：脚本 [{script_name}] 不在白名单中。允许的脚本: {list(ALLOWED_SCRIPTS)}"
        )
    
    # 获取当前工作目录
    current_dir = os.path.dirname(os.path.abspath(__file__))
    script_path = os.path.join(current_dir, script_name)
    
    # 检查文件是否存在
    if not os.path.exists(script_path):
        return {
            "status": "error",
            "output": f"❌ 脚本文件不存在: {script_name}\n\n白名单脚本: {list(ALLOWED_SCRIPTS)}"
        }
    
    try:
        # 执行脚本，设置超时 60 秒
        result = subprocess.run(
            ["python", script_path],
            capture_output=True,
            text=True,
            timeout=60,
            cwd=current_dir,
            encoding="utf-8"
        )
        
        output = ""
        if result.stdout:
            output += f"📝 标准输出:\n{result.stdout}\n"
        if result.stderr:
            output += f"\n⚠️ 错误输出:\n{result.stderr}"
        if not output:
            output = "✅ 脚本执行完成，无输出"
            
        return {
            "status": "success" if result.returncode == 0 else "error",
            "return_code": result.returncode,
            "output": output
        }
        
    except subprocess.TimeoutExpired:
        return {
            "status": "error",
            "output": "❌ 脚本执行超时 (60秒)"
        }
    except Exception as e:
        return {
            "status": "error",
            "output": f"❌ 执行异常: {str(e)}"
        }

# ==========================================
# 原有功能：私信与聊天
# ==========================================
@router.post("/api/messages/private")
async def send_private_message(msg: PrivateMessage):
    chats_db = db.load_data("chats.json", default_data={})
    conv_id = f"{min(msg.sender, msg.receiver)}_{max(msg.sender, msg.receiver)}"
    if conv_id not in chats_db: chats_db[conv_id] = []
    
    chat_msg = {"id": f"chat_{int(time.time())}_{uuid.uuid4().hex[:6]}", "sender": msg.sender, "receiver": msg.receiver, "content": msg.content, "created_at": int(time.time()), "is_read": False}
    chats_db[conv_id].append(chat_msg)
    db.save_data("chats.json", chats_db)
    
    add_notification(msg.receiver, {"type": "private", "from_user": msg.sender, "content": msg.content})
    return {"status": "success"}

@router.get("/api/chats/{account}")
async def get_chat_list(account: str):
    chats_db = db.load_data("chats.json", default_data={})
    users_db = db.load_data("users.json", default_data={})
    
    chat_list = []
    for conv_id, msgs in chats_db.items():
        if account in conv_id:
            other_account = conv_id.replace(account, "").replace("_", "")
            if not msgs: continue
            last_msg = msgs[-1]
            unread_count = sum(1 for m in msgs if m["receiver"] == account and not m.get("is_read"))
            other_user = users_db.get(other_account, {})
            chat_list.append({
                "account": other_account,
                "name": other_user.get("name", other_account),
                "avatar": other_user.get("avatarDataUrl", ""),
                "last_message": last_msg["content"],
                "last_time": last_msg["created_at"],
                "unread_count": unread_count
            })
            
    chat_list.sort(key=lambda x: x["last_time"], reverse=True)
    return {"status": "success", "data": chat_list}

@router.get("/api/chats/{account}/{target_account}")
async def get_chat_history(account: str, target_account: str):
    chats_db = db.load_data("chats.json", default_data={})
    conv_id = f"{min(account, target_account)}_{max(account, target_account)}"
    msgs = chats_db.get(conv_id, [])
    
    now = int(time.time())
    seven_days = 7 * 24 * 3600
    valid_msgs = []
    modified = False
    
    for m in msgs:
        if not m.get("is_read") or (now - m.get("created_at", 0) < seven_days):
            valid_msgs.append(m)
        else:
            modified = True
            
        # 本次访问即为已读
        if m["receiver"] == account and not m.get("is_read"): 
            m["is_read"] = True
            modified = True
            
    if modified or len(valid_msgs) != len(msgs): 
        chats_db[conv_id] = valid_msgs
        db.save_data("chats.json", chats_db)
        
    return {"status": "success", "data": valid_msgs}

# ==========================================
# 改造：获取通知列表 (加入系统公告懒加载注入)
# 使用 atomic_update 避免并发覆盖问题
# 🔥 性能优化：先用只读方式检查是否有实际变更，避免无意义的写入和HF上传
# ==========================================
@router.get("/api/messages/{account}")
async def get_messages(account: str, count_only: bool = False, current_user: str = Depends(require_auth)):
    # 🔥 count_only 模式：轻量级轮询，只返回未读数，不标记已读
    if count_only:
        messages_db = db.load_data("messages.json", default_data={})
        user_msgs = messages_db.get(account, [])
        
        now = int(time.time())
        seven_days = 7 * 24 * 3600
        
        # 只统计未过期的未读消息
        unread = sum(1 for m in user_msgs 
                     if not m.get("is_read") 
                     and (now - m.get("created_at", 0) < seven_days))
        return {"status": "success", "unread_count": unread}
    
    # 公告是只读的，先加载
    announcements_db = db.load_data("announcements.json", default_data=[])
    
    # 🔥 性能优化：先用只读方式检查是否有实际变更需要写入
    messages_db = db.load_data("messages.json", default_data={})
    user_msgs = messages_db.get(account, [])
    
    now = int(time.time())
    seven_days = 7 * 24 * 3600
    
    # 检查三个条件判断是否需要写入
    # 1. 是否有新公告需要注入
    user_msg_ids = {m.get("id") for m in user_msgs}
    has_new_announcements = any(
        ann.get("id") not in user_msg_ids 
        for ann in announcements_db
    )
    
    # 2. 是否有未读消息需要标记已读
    has_unread = any(not m.get("is_read") for m in user_msgs)
    
    # 3. 是否有已读超过7天的消息需要清理
    has_expired = any(
        m.get("is_read") and (now - m.get("created_at", 0) >= seven_days)
        for m in user_msgs
    )
    
    needs_update = has_new_announcements or has_unread or has_expired
    
    # 🔥 修复：在标记已读之前先计算真实的未读数
    unread_before_mark = sum(1 for m in user_msgs 
                              if not m.get("is_read") 
                              and (now - m.get("created_at", 0) < seven_days))
    
    if not needs_update:
        # 无变更，直接返回只读数据，不触发写入和HF上传
        return {
            "status": "success",
            "data": user_msgs,
            "unread_count": unread_before_mark  # 🔥 修复：返回真实的未读数
        }
    
    # 有变更需要写入，使用 atomic_update 保证并发安全
    result_container = [None]
    
    def updater(data):
        user_msgs = data.get(account, [])
        
        # --- 核心改造区：瞬间比对并注入全局公告 ---
        user_msg_ids = {m.get("id") for m in user_msgs}
        
        injected = False
        for ann in announcements_db:
            if ann.get("id") not in user_msg_ids:
                new_sys_msg = dict(ann)
                new_sys_msg["is_read"] = False
                new_sys_msg["receiver"] = account
                user_msgs.append(new_sys_msg)
                injected = True
        
        if injected:
            # 重新按照时间倒序排列，让新公告置顶
            user_msgs.sort(key=lambda x: x.get("created_at", 0), reverse=True)
        # ----------------------------------------
        
        now = int(time.time())
        seven_days = 7 * 24 * 3600
        valid = []
        
        # 如果注入了新公告，则判定为需要回写数据库保存
        modified = injected
        
        for m in user_msgs:
            if not m.get("is_read") or (now - m.get("created_at", 0) < seven_days):
                valid.append(m)
            else:
                modified = True
            
            # 本次访问即为已读 - 将所有未读消息标记为已读
            if not m.get("is_read"):
                m["is_read"] = True
                modified = True
        # 原地修改 data，atomic_update 会自动保存
        data[account] = valid
        
        # 通过闭包返回结果
        result_container[0] = {
            "status": "success",
            "data": valid,
            "unread_count": unread_before_mark  # 🔥 修复：返回标记已读前的真实未读数
        }
    
    db.atomic_update("messages.json", updater, default_data={})
    
    return result_container[0]

@router.post("/api/messages/{account}/read")
async def mark_messages_read(account: str):
    """
    标记消息为已读（原子操作，并发安全）
    """
    def updater(data):
        user_msgs = data.get(account, [])
        modified = False
        for m in user_msgs:
            if not m.get("is_read"):
                m["is_read"] = True
                modified = True
        
        # 原地修改 data，atomic_update 会自动保存
        if modified:
            data[account] = user_msgs
    
    db.atomic_update("messages.json", updater, default_data={})
    
    return {"status": "success"}