import os
from flask import Blueprint, render_template, request, redirect, url_for, flash, current_app
from flask_login import login_required, current_user
from werkzeug.utils import secure_filename
from models import db, Post, Comment
from config import Config

posts_bp = Blueprint('posts', __name__)


def allowed_file(filename):
    """检查文件扩展名是否允许"""
    return '.' in filename and \
           filename.rsplit('.', 1)[1].lower() in Config.ALLOWED_EXTENSIONS


@posts_bp.route('/')
def index():
    """首页 - 显示已审核的帖子流"""
    page = request.args.get('page', 1, type=int)
    
    # 只显示已审核的帖子
    pagination = Post.query.filter_by(is_approved=True)\
        .order_by(Post.created_at.desc())\
        .paginate(page=page, per_page=current_app.config['POSTS_PER_PAGE'], error_out=False)
    
    posts = pagination.items
    
    return render_template('index.html', posts=posts, pagination=pagination)


@posts_bp.route('/post/create', methods=['GET', 'POST'])
@login_required
def create_post():
    """创建帖子"""
    if not current_user.is_approved:
        flash('您的账号尚未通过审核，无法发帖', 'error')
        return redirect(url_for('posts.index'))
    
    if request.method == 'POST':
        description = request.form.get('description')
        image = request.files.get('image')
        
        if not image:
            flash('请上传照片', 'error')
            return render_template('create_post.html')
        
        if not allowed_file(image.filename):
            flash('请上传有效的图片文件（支持 PNG, JPG, JPEG, GIF, WEBP）', 'error')
            return render_template('create_post.html')
        
        # 保存图片
        filename = secure_filename(f"{current_user.username}_{image.filename}")
        # 添加时间戳避免重名
        from datetime import datetime
        timestamp = datetime.now().strftime('%Y%m%d%H%M%S')
        filename = f"{timestamp}_{filename}"
        filepath = os.path.join(Config.UPLOAD_FOLDER, 'posts', filename)
        image.save(filepath)
        
        # 创建帖子
        post = Post(
            user_id=current_user.id,
            image_path=f'posts/{filename}',
            description=description,
            is_approved=False  # 需要审核
        )
        
        db.session.add(post)
        db.session.commit()
        
        flash('帖子已提交，等待管理员审核', 'success')
        return redirect(url_for('posts.index'))
    
    return render_template('create_post.html')


@posts_bp.route('/post/<int:post_id>')
def post_detail(post_id):
    """帖子详情页"""
    post = Post.query.get_or_404(post_id)
    
    # 如果帖子未审核，只有作者和管理员可以查看
    if not post.is_approved:
        if not current_user.is_authenticated or \
           (current_user.id != post.user_id and not current_user.is_admin):
            flash('该帖子正在审核中', 'warning')
            return redirect(url_for('posts.index'))
    
    # 获取评论
    comments = post.comments.order_by(Comment.created_at.desc()).all()
    
    return render_template('post_detail.html', post=post, comments=comments)


@posts_bp.route('/post/<int:post_id>/comment', methods=['POST'])
@login_required
def add_comment(post_id):
    """添加评论"""
    if not current_user.is_approved:
        flash('您的账号尚未通过审核，无法评论', 'error')
        return redirect(url_for('posts.post_detail', post_id=post_id))
    
    post = Post.query.get_or_404(post_id)
    
    if not post.is_approved:
        flash('该帖子正在审核中，无法评论', 'error')
        return redirect(url_for('posts.index'))
    
    content = request.form.get('content')
    
    if not content or not content.strip():
        flash('评论内容不能为空', 'error')
        return redirect(url_for('posts.post_detail', post_id=post_id))
    
    comment = Comment(
        post_id=post_id,
        user_id=current_user.id,
        content=content.strip()
    )
    
    db.session.add(comment)
    db.session.commit()
    
    flash('评论发表成功', 'success')
    return redirect(url_for('posts.post_detail', post_id=post_id))