# -*- coding: utf-8 -*-
"""
个人博客 - Flask 应用入口
"""
import os
import re
from datetime import datetime
from flask import Flask, render_template, abort
import markdown

app = Flask(__name__)

BASE_DIR = os.path.dirname(os.path.abspath(__file__))
POSTS_DIR = os.path.join(BASE_DIR, 'posts')


def parse_front_matter(text):
    """解析 Markdown 文件的 YAML front matter（简单实现）"""
    meta = {}
    body = text
    match = re.match(r'^---\s*\n(.*?)\n---\s*\n(.*)$', text, re.DOTALL)
    if match:
        raw_meta, body = match.group(1), match.group(2)
        for line in raw_meta.strip().splitlines():
            if ':' in line:
                key, value = line.split(':', 1)
                meta[key.strip()] = value.strip()
    return meta, body


def load_posts():
    """加载所有文章，返回按日期倒序的列表"""
    posts = []
    if not os.path.isdir(POSTS_DIR):
        return posts
    for filename in os.listdir(POSTS_DIR):
        if not filename.endswith('.md'):
            continue
        slug = filename[:-3]
        path = os.path.join(POSTS_DIR, filename)
        with open(path, 'r', encoding='utf-8') as f:
            raw = f.read()
        meta, body = parse_front_matter(raw)
        posts.append({
            'slug': slug,
            'title': meta.get('title', slug),
            'date': meta.get('date', ''),
            'summary': meta.get('summary', ''),
            'content': body,
        })
    posts.sort(key=lambda p: p['date'], reverse=True)
    return posts


def get_post(slug):
    """根据 slug 获取单篇文章"""
    for post in load_posts():
        if post['slug'] == slug:
            return post
    return None


@app.route('/')
def index():
    """首页：文章列表"""
    posts = load_posts()
    return render_template('index.html', posts=posts)


@app.route('/post/<slug>')
def post_detail(slug):
    """文章详情页"""
    post = get_post(slug)
    if not post:
        abort(404)
    html_content = markdown.markdown(
        post['content'],
        extensions=['fenced_code', 'codehilite', 'tables']
    )
    return render_template('post.html', post=post, content=html_content)


@app.route('/about')
def about():
    """关于页面"""
    return render_template('about.html')


@app.errorhandler(404)
def not_found(e):
    return render_template('404.html'), 404


if __name__ == '__main__':
    app.run(debug=True, host='127.0.0.1', port=5000)