# router_posts.py
# ==========================================
# 💬 讨论区路由模块
# ==========================================
# 作用：处理讨论区内容的增删改查和互动功能
# 关联文件：
#   - 数据库连接.py (JSON数据库读写 posts.json)
#   - models.py (PostCreate, PostUpdate, PostInteraction)
# 前端调用：
#   - 讨论区列表组件.js (获取帖子列表)
#   - 讨论区发布组件.js (发布新帖子)
#   - 讨论区详情组件.js (帖子详情、互动操作)
# ==========================================

from fastapi import APIRouter, HTTPException
import 数据库连接 as db
from models import PostCreate, PostUpdate, PostInteraction
import time
import uuid

# 创建子路由实例
router = APIRouter()


# ==========================================
# 📖 获取讨论区列表
# ==========================================
@router.get("/api/posts")
async def get_posts(sort: str = "time", page: int = 1, page_size: int = 20):
    """
    获取讨论区帖子列表
    
    查询参数：
        - sort: 排序方式 (time=最新, hot=最热)
        - page: 页码
        - page_size: 每页数量
    """
    posts_db = db.load_data("posts.json", default_data=[])
    
    # 排序
    if sort == "hot":
        # 最热：按点赞+收藏加权排序
        posts_db.sort(key=lambda x: x.get("likes", 0) * 2 + x.get("favorites", 0), reverse=True)
    else:
        # 最新：按创建时间倒序
        posts_db.sort(key=lambda x: x.get("createdAt", 0), reverse=True)
    
    # 分页
    start = (page - 1) * page_size
    end = start + page_size
    paginated = posts_db[start:end]
    
    return {
        "status": "success",
        "data": paginated,
        "total": len(posts_db),
        "page": page,
        "page_size": page_size
    }


# ==========================================
# 📖 获取单个帖子详情
# ==========================================
@router.get("/api/posts/{post_id}")
async def get_post_detail(post_id: str):
    """
    获取帖子详情
    """
    posts_db = db.load_data("posts.json", default_data=[])
    
    post = next((p for p in posts_db if p.get("id") == post_id), None)
    if not post:
        raise HTTPException(status_code=404, detail="帖子不存在")
    
    # 增加浏览量
    post["views"] = post.get("views", 0) + 1
    db.save_data("posts.json", posts_db)
    
    return {"status": "success", "data": post}


# ==========================================
# ✏️ 发布新帖子
# ==========================================
@router.post("/api/posts")
async def create_post(post_data: PostCreate):
    """
    发布新帖子
    """
    posts_db = db.load_data("posts.json", default_data=[])
    users_db = db.load_data("users.json", default_data={})
    
    # 获取作者信息
    author_info = users_db.get(post_data.author, {})
    
    # 构建新帖子对象
    new_post = {
        "id": f"post_{uuid.uuid4().hex[:12]}",
        "type": "discussion",
        "title": post_data.title,
        "content": post_data.content,
        "coverImage": post_data.coverImage,
        "images": post_data.images or [],
        
        # 作者信息快照
        "author": post_data.author,
        "authorName": author_info.get("name", post_data.author),
        "authorAvatar": author_info.get("avatarDataUrl", ""),
        
        # 互动数据初始化
        "likes": 0,
        "favorites": 0,
        "comments": 0,
        "views": 0,
        
        # 点赞/收藏用户列表（用于判断当前用户是否已操作）
        "likedBy": [],
        "favoritedBy": [],
        
        # 打赏数据
        "tip_board": [],
        "totalTips": 0,
        
        # 时间戳
        "createdAt": int(time.time()),
        "updatedAt": int(time.time())
    }
    
    posts_db.insert(0, new_post)  # 插入到列表头部
    db.save_data("posts.json", posts_db)
    
    return {"status": "success", "data": new_post}


# ==========================================
# ✏️ 更新帖子
# ==========================================
@router.put("/api/posts/{post_id}")
async def update_post(post_id: str, update_data: PostUpdate, author: str = None):
    """
    更新帖子内容
    """
    posts_db = db.load_data("posts.json", default_data=[])
    
    post_idx = next((i for i, p in enumerate(posts_db) if p.get("id") == post_id), None)
    if post_idx is None:
        raise HTTPException(status_code=404, detail="帖子不存在")
    
    post = posts_db[post_idx]
    
    # 权限校验：只有作者可以修改
    if author and post.get("author") != author:
        raise HTTPException(status_code=403, detail="无权修改此帖子")
    
    # 更新字段
    for k, v in update_data.dict(exclude_unset=True).items():
        if v is not None:
            post[k] = v
    
    post["updatedAt"] = int(time.time())
    db.save_data("posts.json", posts_db)
    
    return {"status": "success", "data": post}


# ==========================================
# 🗑️ 删除帖子
# ==========================================
@router.delete("/api/posts/{post_id}")
async def delete_post(post_id: str, author: str = None):
    """
    删除帖子
    """
    posts_db = db.load_data("posts.json", default_data=[])
    
    post_idx = next((i for i, p in enumerate(posts_db) if p.get("id") == post_id), None)
    if post_idx is None:
        raise HTTPException(status_code=404, detail="帖子不存在")
    
    post = posts_db[post_idx]
    
    # 权限校验
    if author and post.get("author") != author:
        raise HTTPException(status_code=403, detail="无权删除此帖子")
    
    posts_db.pop(post_idx)
    db.save_data("posts.json", posts_db)
    
    return {"status": "success", "message": "帖子已删除"}


# ==========================================
# ❤️ 点赞/收藏操作
# ==========================================
@router.post("/api/posts/interaction")
async def toggle_interaction(req: PostInteraction):
    """
    点赞或收藏帖子
    
    请求参数：
        - post_id: 帖子ID
        - user_id: 用户账号
        - action_type: like / favorite
        - is_active: True=添加, False=取消
    """
    posts_db = db.load_data("posts.json", default_data=[])
    users_db = db.load_data("users.json", default_data={})
    
    post_idx = next((i for i, p in enumerate(posts_db) if p.get("id") == req.post_id), None)
    if post_idx is None:
        raise HTTPException(status_code=404, detail="帖子不存在")
    
    post = posts_db[post_idx]
    
    if req.action_type == "like":
        liked_by = post.get("likedBy", [])
        if req.is_active and req.user_id not in liked_by:
            liked_by.append(req.user_id)
            post["likes"] = post.get("likes", 0) + 1
        elif not req.is_active and req.user_id in liked_by:
            liked_by.remove(req.user_id)
            post["likes"] = max(0, post.get("likes", 0) - 1)
        post["likedBy"] = liked_by
        
    elif req.action_type == "favorite":
        favorited_by = post.get("favoritedBy", [])
        if req.is_active and req.user_id not in favorited_by:
            favorited_by.append(req.user_id)
            post["favorites"] = post.get("favorites", 0) + 1
            # 同步到用户收藏列表
            user = users_db.get(req.user_id, {})
            user_favs = user.get("favorited_posts", [])
            if req.post_id not in user_favs:
                user_favs.append(req.post_id)
                user["favorited_posts"] = user_favs
                users_db[req.user_id] = user
                db.save_data("users.json", users_db)
        elif not req.is_active and req.user_id in favorited_by:
            favorited_by.remove(req.user_id)
            post["favorites"] = max(0, post.get("favorites", 0) - 1)
            # 从用户收藏列表移除
            user = users_db.get(req.user_id, {})
            user_favs = user.get("favorited_posts", [])
            if req.post_id in user_favs:
                user_favs.remove(req.post_id)
                user["favorited_posts"] = user_favs
                users_db[req.user_id] = user
                db.save_data("users.json", users_db)
        post["favoritedBy"] = favorited_by
    
    db.save_data("posts.json", posts_db)
    
    return {
        "status": "success",
        "data": {
            "likes": post.get("likes", 0),
            "favorites": post.get("favorites", 0),
            "isLiked": req.user_id in post.get("likedBy", []),
            "isFavorited": req.user_id in post.get("favoritedBy", [])
        }
    }


# ==========================================
# 📊 获取用户的帖子列表
# ==========================================
@router.get("/api/posts/user/{account}")
async def get_user_posts(account: str):
    """
    获取指定用户发布的帖子
    """
    posts_db = db.load_data("posts.json", default_data=[])
    
    user_posts = [p for p in posts_db if p.get("author") == account]
    user_posts.sort(key=lambda x: x.get("createdAt", 0), reverse=True)
    
    return {"status": "success", "data": user_posts}