# routes/posts.py

from flask import Blueprint, request, jsonify, abort
from extensions    import db
from models.post   import Post
from models.behavior import Behavior
from utils.Fpost import Fpost
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from config import Config
import json

posts_bp = Blueprint('posts', __name__)

def safe_log(user_id, log_type, message, ip):
    user_id=1
    """安全的日志记录函数，不会影响主业务逻辑"""
    try:
        engine = create_engine(Config.SQLURL)
        SessionLocal = sessionmaker(bind=engine)
        session = SessionLocal()
        f = Fpost(session)
        f.recordlog(user_id, log_type, message, ip)
    except Exception as e:
        # 方法一：简单打印错误信息
        print(f"[safe_log] 记录日志失败：{e}")
        traceback.print_exc()  # 打印完整的堆栈跟踪

        # 方法二：使用 logging 模块（推荐）
        logger.exception("safe_log: 记录日志时发生异常")
    finally:
        # 确保 session 一定关闭
        try:
            session.close()
        except Exception:
            pass

@posts_bp.route('', methods=['POST'])
def create_post():
    user_id = None
    try:
        # 获取文本字段
        user_id = request.form.get('user_id')
        title = request.form.get('title')
        content = request.form.get('content')
        status = request.form.get('status', 'published')
        topic_id = request.form.get('topic_id')
        media_count = int(request.form.get('media_count', 0))
        
        if not user_id or not title or not content:
            safe_log(int(user_id) if user_id else 0, 'error', '创建帖子失败：缺少必要字段', request.remote_addr)
            return jsonify({'error': '缺少必要字段'}), 400
        
        # 获取上传的文件
        files = []
        for i in range(media_count):
            file_key = f'media_{i}'
            if file_key in request.files:
                files.append(request.files[file_key])
        
        # 使用 Fpost 创建帖子
        fpost = Fpost(db.session)
        new_post = fpost.create_post_with_files(
            user_id=int(user_id),
            title=title,
            content=content,
            topic_id=int(topic_id) if topic_id else None,
            status=status,
            files=files
        )
        
        safe_log(int(user_id), 'behavior', f'成功创建帖子，帖子ID: {new_post.id}，标题: {title}', request.remote_addr)
        return jsonify({'id': new_post.id}), 201
        
    except Exception as e:
        safe_log(int(user_id) if user_id else 0, 'error', f'创建帖子时发生异常: {str(e)}', request.remote_addr)
        return jsonify({'error': str(e)}), 500

@posts_bp.route('', methods=['GET'])
def list_posts():
    """
    获取帖子列表，支持：
      - GET /posts              返回所有已发布帖子
      - GET /posts?user_id=123  返回指定用户 user_id 的所有帖子
    """
    user_id = None
    try:
        user_id = request.args.get('user_id', type=int)
        query = Post.query
        if user_id is not None:
            query = query.filter_by(user_id=user_id)
        else:
            query = query.filter_by(status='published')

        posts = query.all()
        
        log_msg = f'获取帖子列表成功，共{len(posts)}个帖子'
        if user_id:
            log_msg += f'，用户ID: {user_id}'
        safe_log(user_id if user_id else 0, 'access', log_msg, request.remote_addr)

        return jsonify([{
            'id': p.id,
            'title': p.title,
            'status': p.status,
            'heat': p.heat,
            'created_at': p.created_at.isoformat()
        } for p in posts])
        
    except Exception as e:
        safe_log(user_id if user_id else 0, 'error', f'获取帖子列表时发生异常: {str(e)}', request.remote_addr)
        return jsonify({'error': str(e)}), 500

@posts_bp.route('/<int:post_id>', methods=['GET'])
def get_post(post_id):
    try:
        post = Post.query.get_or_404(post_id)
        safe_log(0, 'access', f'获取帖子详情成功，帖子ID: {post_id}，标题: {post.title}', request.remote_addr)
        
        return jsonify({
            'id': post.id,
            'user_id': post.user_id,
            'topic_id': post.topic_id,
            'title': post.title,
            'content': post.content,
            'media_urls': post.media_urls,
            'status': post.status,
            'heat': post.heat,
            'created_at': post.created_at.isoformat(),
            'updated_at': post.updated_at.isoformat()
        })
        
    except Exception as e:
        safe_log(0, 'error', f'获取帖子详情时发生异常，帖子ID: {post_id}，错误: {str(e)}', request.remote_addr)
        return jsonify({'error': str(e)}), 500

@posts_bp.route('/<int:post_id>', methods=['PUT'])
def update_post(post_id):
    """
    修改帖子字段（可选字段：title, content, topic_id, media_urls, status）
    支持FormData和JSON两种格式
    """
    try:
        fpost = Fpost(db.session)
        
        # 检查是否是FormData请求
        if request.content_type and 'multipart/form-data' in request.content_type:
            # FormData请求
            title = request.form.get('title')
            content = request.form.get('content')
            status = request.form.get('status')
            topic_id = request.form.get('topic_id')
            media_count = int(request.form.get('media_count', 0))
            existing_media_urls_str = request.form.get('existing_media_urls')
            
            # 解析现有媒体URLs
            existing_media_urls = None
            if existing_media_urls_str:
                try:
                    existing_media_urls = json.loads(existing_media_urls_str)
                except:
                    existing_media_urls = None
            
            # 获取新上传的文件
            files = []
            for i in range(media_count):
                file_key = f'media_{i}'
                if file_key in request.files:
                    files.append(request.files[file_key])
            
            # 更新帖子
            updated_post = fpost.update_post_with_files(
                post_id=post_id,
                title=title,
                content=content,
                topic_id=int(topic_id) if topic_id else None,
                status=status,
                files=files if files else None,
                existing_media_urls=existing_media_urls
            )
            
        else:
            # JSON请求（保持原有逻辑）
            post = Post.query.get_or_404(post_id)
            data = request.get_json() or {}
            for key in ('title', 'content', 'topic_id', 'media_urls', 'status'):
                if key in data:
                    setattr(post, key, data[key])
            db.session.commit()
            updated_post = post
        
        if not updated_post:
            safe_log(0, 'error', f'更新帖子失败，帖子不存在，帖子ID: {post_id}', request.remote_addr)
            return jsonify({'error': '帖子不存在'}), 404
        
        safe_log(0, 'behavior', f'更新帖子成功，帖子ID: {post_id}', request.remote_addr)
        return '', 204
        
    except Exception as e:
        safe_log(0, 'error', f'更新帖子时发生异常，帖子ID: {post_id}，错误: {str(e)}', request.remote_addr)
        return jsonify({'error': str(e)}), 500

@posts_bp.route('/<int:post_id>', methods=['DELETE'])
def delete_post(post_id):
    try:
        post = Post.query.get_or_404(post_id)
        db.session.delete(post)
        db.session.commit()
        safe_log(0, 'behavior', f'删除帖子成功，帖子ID: {post_id}', request.remote_addr)
        return '', 204
        
    except Exception as e:
        safe_log(0, 'error', f'删除帖子时发生异常，帖子ID: {post_id}，错误: {str(e)}', request.remote_addr)
        return jsonify({'error': str(e)}), 500

@posts_bp.route('/<int:post_id>/<action>', methods=['POST'])
def post_action(post_id, action):
    """
    支持的 action: like, favorite, view, share
    对于 like 和 favorite，保证每个用户每帖只做一次。
    """
    user_id = None
    try:
        if action not in ('like', 'favorite', 'view', 'share'):
            abort(400, 'Invalid action')

        data = request.get_json() or {}
        user_id = data.get('user_id')
        if not user_id:
            safe_log(0, 'error', f'执行帖子操作失败，缺少用户ID，帖子ID: {post_id}，操作: {action}', request.remote_addr)
            abort(400, 'user_id required')

        # 对 like/favorite 做去重检查
        if action in ('like', 'favorite'):
            exists = Behavior.query.filter_by(
                user_id=user_id,
                post_id=post_id,
                type=action
            ).first()
            if exists:
                safe_log(user_id, 'error', f'重复执行帖子操作，帖子ID: {post_id}，操作: {action}', request.remote_addr)
                return jsonify({'error': f'already {action}d'}), 400

        # 创建行为记录
        beh = Behavior(user_id=user_id, post_id=post_id, type=action)
        db.session.add(beh)

        # 更新热度
        post = Post.query.get_or_404(post_id)
        post.heat += 1

        db.session.commit()
        safe_log(user_id, 'behavior', f'执行帖子操作成功，帖子ID: {post_id}，操作: {action}', request.remote_addr)
        return '', 201
        
    except Exception as e:
        safe_log(user_id if user_id else 0, 'error', f'执行帖子操作时发生异常，帖子ID: {post_id}，操作: {action}，错误: {str(e)}', request.remote_addr)
        return jsonify({'error': str(e)}), 500

@posts_bp.route('/<int:post_id>/like', methods=['DELETE'])
def unlike(post_id):
    user_id = None
    try:
        user_id = request.get_json(silent=True) and request.get_json().get('user_id')
        if not user_id:
            safe_log(0, 'error', f'取消点赞失败，缺少用户ID，帖子ID: {post_id}', request.remote_addr)
            abort(400, 'user_id required')
            
        # 查找已有的 like 行为
        beh = Behavior.query.filter_by(
            user_id=user_id,
            post_id=post_id,
            type='like'
        ).first()
        if not beh:
            safe_log(user_id, 'error', f'取消点赞失败，用户尚未点赞，帖子ID: {post_id}', request.remote_addr)
            return jsonify({'error': 'not liked yet'}), 400

        db.session.delete(beh)
        # 更新热度，确保不降到负数
        post = Post.query.get_or_404(post_id)
        post.heat = max(post.heat - 1, 0)
        db.session.commit()
        safe_log(user_id, 'behavior', f'取消点赞成功，帖子ID: {post_id}', request.remote_addr)
        return '', 204
        
    except Exception as e:
        safe_log(user_id if user_id else 0, 'error', f'取消点赞时发生异常，帖子ID: {post_id}，错误: {str(e)}', request.remote_addr)
        return jsonify({'error': str(e)}), 500

@posts_bp.route('/<int:post_id>/favorite', methods=['DELETE'])
def unfavorite(post_id):
    user_id = None
    try:
        user_id = request.get_json(silent=True) and request.get_json().get('user_id')
        if not user_id:
            safe_log(0, 'error', f'取消收藏失败，缺少用户ID，帖子ID: {post_id}', request.remote_addr)
            abort(400, 'user_id required')
            
        # 查找已有的 favorite 行为
        beh = Behavior.query.filter_by(
            user_id=user_id,
            post_id=post_id,
            type='favorite'
        ).first()
        if not beh:
            safe_log(user_id, 'error', f'取消收藏失败，用户尚未收藏，帖子ID: {post_id}', request.remote_addr)
            return jsonify({'error': 'not favorited yet'}), 400

        db.session.delete(beh)
        # 更新热度
        post = Post.query.get_or_404(post_id)
        post.heat = max(post.heat - 1, 0)
        db.session.commit()
        safe_log(user_id, 'behavior', f'取消收藏成功，帖子ID: {post_id}', request.remote_addr)
        return '', 204
        
    except Exception as e:
        safe_log(user_id if user_id else 0, 'error', f'取消收藏时发生异常，帖子ID: {post_id}，错误: {str(e)}', request.remote_addr)
        return jsonify({'error': str(e)}), 500

@posts_bp.route('/<int:post_id>/like/status', methods=['GET'])
def has_liked(post_id):
    """
    检查指定 user_id 是否对 post_id 点过赞。
    GET /posts/<post_id>/like/status?user_id=123
    返回 { "liked": true } 或 { "liked": false }
    """
    user_id = None
    try:
        user_id = request.args.get('user_id', type=int)
        if not user_id:
            safe_log(0, 'error', f'检查点赞状态失败，缺少用户ID，帖子ID: {post_id}', request.remote_addr)
            abort(400, 'user_id required')

        exists = Behavior.query.filter_by(
            user_id=user_id,
            post_id=post_id,
            type='like'
        ).first() is not None
        
        safe_log(user_id, 'access', f'检查点赞状态成功，帖子ID: {post_id}，结果: {exists}', request.remote_addr)
        return jsonify({'liked': exists}), 200
        
    except Exception as e:
        safe_log(user_id if user_id else 0, 'error', f'检查点赞状态时发生异常，帖子ID: {post_id}，错误: {str(e)}', request.remote_addr)
        return jsonify({'error': str(e)}), 500