"""
技术论坛 - 后台管理系统 (重构版 + 登录验证)
"""

from flask import Flask, render_template, jsonify, request, redirect, url_for, session, make_response
from flask_cors import CORS
import jwt
import datetime
import os
from functools import wraps
from pathlib import Path

# 导入配置和模型
import sys
sys.path.insert(0, str(Path(__file__).parent.parent))
from config import SECRET_KEY, ADMIN_USERNAME, ADMIN_PASSWORD, DATABASE_PATH, ADMIN_PORT
from models import Database, UserModel, PostModel, ReplyModel, TopicModel

app = Flask(__name__)
CORS(app)
app.secret_key = SECRET_KEY

# 初始化数据库
db = Database(DATABASE_PATH)
user_model = UserModel(db)
post_model = PostModel(db)
reply_model = ReplyModel(db)
topic_model = TopicModel(db)

# ============ 登录验证装饰器 ============

def admin_required(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        # 检查 session
        if not session.get('admin_logged_in'):
            # 检查 Authorization header
            token = request.headers.get('Authorization', '').replace('Bearer ', '')
            if token:
                try:
                    data = jwt.decode(token, SECRET_KEY, algorithms=['HS256'])
                    if data.get('admin'):
                        return f(*args, **kwargs)
                except:
                    pass
            
            # API请求返回401，页面请求跳转登录
            if request.path.startswith('/api/'):
                return jsonify({'error': '请先登录', 'code': 401}), 401
            return redirect('/login')
        return f(*args, **kwargs)
    return decorated_function

# ============ 登录相关 ============

@app.route('/login')
def login_page():
    return render_template('login.html')

@app.route('/api/login', methods=['POST'])
def api_login():
    data = request.json
    
    username = data.get('username', '').strip()
    password = data.get('password', '')
    
    if not username or not password:
        return jsonify({'error': '请输入用户名和密码'}), 400
    
    if username != ADMIN_USERNAME or password != ADMIN_PASSWORD:
        return jsonify({'error': '用户名或密码错误'}), 400
    
    # 设置session
    session['admin_logged_in'] = True
    session['admin_username'] = username
    
    # 生成token（可选，用于API调用）
    token = jwt.encode({
        'admin': True,
        'username': username,
        'exp': datetime.datetime.utcnow() + datetime.timedelta(hours=24)
    }, SECRET_KEY, algorithm='HS256')
    
    return jsonify({
        'success': True,
        'token': token,
        'message': '登录成功'
    })

@app.route('/api/logout', methods=['POST'])
def api_logout():
    session.pop('admin_logged_in', None)
    session.pop('admin_username', None)
    return jsonify({'success': True, 'message': '已退出登录'})

@app.route('/api/check-auth')
def api_check_auth():
    if session.get('admin_logged_in'):
        return jsonify({
            'logged_in': True,
            'username': session.get('admin_username')
        })
    return jsonify({'logged_in': False})

# ============ 页面路由 ============

@app.route('/')
@admin_required
def index():
    return render_template('index.html')

@app.route('/users')
@admin_required
def users_page():
    return render_template('users.html')

@app.route('/posts')
@admin_required
def posts_page():
    return render_template('posts.html')

@app.route('/topics')
@admin_required
def topics_page():
    return render_template('topics.html')

# ============ API路由 ============

@app.route('/api/stats')
@admin_required
def api_stats():
    users = user_model.get_all()
    posts, posts_total = post_model.get_all()
    topics = topic_model.get_all()
    
    # 统计回复数
    total_replies = 0
    for post in posts:
        total_replies += len(reply_model.get_by_post(post['id']))
    
    today = datetime.datetime.now().strftime('%Y-%m-%d')
    today_posts = sum(1 for p in posts if p.get('created_at', '').startswith(today))
    today_users = sum(1 for u in users if u.get('created_at', '').startswith(today))
    
    # 帖子类型统计
    discussion_count = sum(1 for p in posts if p.get('type') == 'discussion')
    share_count = sum(1 for p in posts if p.get('type') == 'share')
    
    return jsonify({
        'users_count': len(users),
        'posts_count': posts_total,
        'topics_count': len(topics),
        'messages_count': total_replies,
        'today_posts': today_posts,
        'today_users': today_users,
        'discussion_count': discussion_count,
        'share_count': share_count,
    })

@app.route('/api/users')
@admin_required
def api_users():
    users = user_model.get_all()
    
    user_list = []
    for user in users:
        user_list.append({
            'id': user['id'],
            'username': user.get('username', ''),
            'email': user.get('email', ''),
            'phone': user.get('phone', ''),
            'posts_count': user_model.get_posts_count(user['id']),
            'replies_count': user_model.get_replies_count(user['id']),
            'created_at': user.get('created_at', ''),
        })
    
    return jsonify(user_list)

@app.route('/api/users/<user_id>', methods=['DELETE'])
@admin_required
def api_delete_user(user_id):
    user_model.delete(user_id)
    return jsonify({'success': True})

@app.route('/api/posts')
@admin_required
def api_posts():
    post_type = request.args.get('type')
    
    posts, total = post_model.get_all(post_type)
    
    post_list = []
    for post in posts:
        author = user_model.get_by_id(post['author_id']) or {}
        post_list.append({
            'id': post['id'],
            'title': post['title'],
            'type': post['type'],
            'author': author.get('username', '未知'),
            'author_id': post['author_id'],
            'likes': len(post['likes']),
            'replies': len(reply_model.get_by_post(post['id'])),
            'views': post['views'],
            'is_pinned': post['is_pinned'],
            'created_at': post['created_at'],
        })
    
    return jsonify(post_list)

@app.route('/api/posts/<post_id>')
@admin_required
def api_post_detail(post_id):
    post = post_model.get_by_id(post_id)
    if not post:
        return jsonify({'error': '帖子不存在'}), 404
    
    author = user_model.get_by_id(post['author_id']) or {}
    
    # 获取回复
    replies = reply_model.get_by_post(post_id)
    reply_list = []
    for reply in replies:
        reply_author = user_model.get_by_id(reply['author_id']) or {}
        reply_list.append({
            'id': reply['id'],
            'content': reply['content'][:100] + '...' if len(reply['content']) > 100 else reply['content'],
            'author': reply_author.get('username', '未知'),
            'likes': len(reply['likes']),
            'created_at': reply['created_at'],
        })
    
    return jsonify({
        'id': post_id,
        'title': post['title'],
        'content': post['content'],
        'type': post['type'],
        'author': author.get('username', '未知'),
        'tags': post['tags'],
        'likes': len(post['likes']),
        'replies': reply_list,
        'views': post['views'],
        'is_pinned': post['is_pinned'],
        'created_at': post['created_at'],
    })

@app.route('/api/posts/<post_id>', methods=['DELETE'])
@admin_required
def api_delete_post(post_id):
    post_model.delete(post_id)
    return jsonify({'success': True})

@app.route('/api/posts/<post_id>/pin', methods=['POST'])
@admin_required
def api_pin_post(post_id):
    new_pin = post_model.toggle_pin(post_id)
    return jsonify({
        'success': True,
        'is_pinned': new_pin
    })

@app.route('/api/topics')
@admin_required
def api_topics():
    topics = topic_model.get_all()
    
    topic_list = []
    for topic in topics:
        author = user_model.get_by_id(topic['author_id']) or {}
        topic_list.append({
            'id': topic['id'],
            'name': topic['name'],
            'icon': topic.get('icon', '🔧'),
            'author': author.get('username', '未知'),
            'sub_topics_count': len(topic_model.get_sub_topics(topic['id'])),
            'questions_count': len(topic_model.get_questions(topic['id'])),
            'followers_count': len(topic['followers']),
            'created_at': topic['created_at'],
        })
    
    return jsonify(topic_list)

@app.route('/api/topics/<topic_id>')
@admin_required
def api_topic_detail(topic_id):
    topic = topic_model.get_by_id(topic_id)
    if not topic:
        return jsonify({'error': '主题不存在'}), 404
    
    author = user_model.get_by_id(topic['author_id']) or {}
    
    return jsonify({
        'id': topic_id,
        'name': topic['name'],
        'description': topic.get('description', ''),
        'icon': topic.get('icon', '🔧'),
        'author': author.get('username', '未知'),
        'sub_topics': topic_model.get_sub_topics(topic_id),
        'questions': topic_model.get_questions(topic_id),
        'followers_count': len(topic['followers']),
        'created_at': topic['created_at'],
    })

@app.route('/api/topics/<topic_id>', methods=['DELETE'])
@admin_required
def api_delete_topic(topic_id):
    topic_model.delete(topic_id)
    return jsonify({'success': True})

@app.route('/api/tags')
@admin_required
def api_tags():
    tags = post_model.get_tags_stats()
    return jsonify([{'name': t[0], 'count': t[1]} for t in tags[:20]])

# ============ 健康检查（无需登录） ============

@app.route('/api/health')
def api_health():
    return jsonify({'status': 'ok', 'service': 'tech-forum-admin', 'port': ADMIN_PORT})

if __name__ == '__main__':
    print("=" * 50)
    print("技术论坛 - 后台管理系统")
    print("=" * 50)
    print(f"访问地址: http://localhost:{ADMIN_PORT}")
    print(f"默认账号: {ADMIN_USERNAME}")
    print(f"默认密码: {ADMIN_PASSWORD}")
    print("=" * 50)
    
    app.run(host='0.0.0.0', port=ADMIN_PORT, debug=True)