import re
import json
import time
import shutil
from datetime import datetime, timezone
from pathlib import Path

from flask import (
    Flask,
    render_template,
    request,
    redirect,
    url_for,
    send_from_directory,
    abort,
    jsonify,
    session,
    flash,
)
from werkzeug.utils import secure_filename
from bs4 import BeautifulSoup

import config
from helpers import (
    allowed_file,
    load_index,
    save_index,
    fix_image_paths,
    extract_summary,
    extract_thumbnail,
    render_markdown,
    generate_static_page,
)

app = Flask(__name__)
app.config.from_object(config)

# 确保必要的目录存在
for dir_path in [
    config.UPLOAD_FOLDER,
    config.GENERATED_FOLDER,
    config.POSTS_DATA_FOLDER,
    config.INDEX_FILE.parent,
    config.UPLOAD_FOLDER / "editor_uploads",
]:
    dir_path.mkdir(parents=True, exist_ok=True)

# 如果索引文件不存在，创建空列表
if not config.INDEX_FILE.exists():
    with open(config.INDEX_FILE, "w", encoding="utf-8") as f:
        json.dump([], f, ensure_ascii=False, indent=2)


@app.context_processor
def inject_user_status():
    """向所有模板注入登录状态"""
    return {"logged_in": "user" in session}


# ==================== 登录 / 登出相关路由 ====================


@app.route("/login", methods=["GET", "POST"])
def login():
    """密码登录（无需用户名）"""
    if request.method == "GET":
        return render_template("login.html")

    password = request.form.get("password", "")
    if password == config.PASSWORD:
        session["user"] = True
        flash("登录成功", "success")
        return redirect(url_for("index"))
    else:
        flash("密码错误", "danger")
        return render_template("login.html")


@app.route("/logout")
def logout():
    session.pop("user", None)
    flash("已登出", "info")
    return redirect(url_for("index"))


# ==================== 编辑器相关路由 ====================


@app.route("/editor", methods=["GET", "POST"])
def editor():
    """Markdown 编辑器页面：创建新文章（需要登录）"""
    if "user" not in session:
        flash("请先登录", "warning")
        return redirect(url_for("login"))

    if request.method == "GET":
        return render_template("editor.html")

    # POST：保存文章
    title = request.form.get("title", "").strip()
    if not title:
        flash("标题不能为空", "danger")
        return redirect(url_for("editor"))

    md_content = request.form.get("content", "")
    if not md_content.strip():
        flash("内容不能为空", "danger")
        return redirect(url_for("editor"))

    # 生成唯一文章 ID
    post_id = str(int(time.time() * 1000))

    # 确保文章数据目录存在
    posts_data_dir = config.POSTS_DATA_FOLDER / post_id
    posts_data_dir.mkdir(parents=True, exist_ok=True)

    # 保存 Markdown 文件
    md_path = posts_data_dir / "content.md"
    with open(md_path, "w", encoding="utf-8") as f:
        f.write(md_content)

    # 修正图片路径（允许 http、/ 开头路径保持原样）
    fixed_md = fix_image_paths(md_content, post_id)

    # 渲染 HTML
    html_body = render_markdown(fixed_md)

    # 提取摘要与缩略图
    summary = extract_summary(html_body)
    thumbnail = extract_thumbnail(html_body)

    # 生成日期（精确到分钟）
    date_iso = datetime.now(timezone.utc).replace(second=0, microsecond=0).isoformat()

    # 生成静态页面
    generate_static_page(post_id, title, html_body, date_iso, thumbnail)

    # 更新索引
    index = load_index()
    index.append(
        {
            "id": post_id,
            "title": title,
            "date": date_iso,
            "summary": summary,
            "thumbnail": thumbnail,
        }
    )
    index.sort(key=lambda p: p.get("date", ""), reverse=True)
    save_index(index)

    flash("文章发布成功", "success")
    return redirect(url_for("index"))


@app.route("/editor/upload-image", methods=["POST"])
def editor_upload_image():
    """处理编辑器中的图片上传，返回 Markdown 图片代码"""
    if "user" not in session:
        return jsonify({"success": False, "error": "需要登录"}), 403

    if "image" not in request.files:
        return jsonify({"success": False, "error": "没有选择图片"}), 400

    file = request.files["image"]
    if file.filename == "":
        return jsonify({"success": False, "error": "文件名为空"}), 400

    # 只允许图片类型
    if not allowed_file(file.filename):
        return jsonify({"success": False, "error": "不支持的文件类型"}), 400

    # 保存到 editor_uploads 目录
    editor_uploads_dir = config.UPLOAD_FOLDER / "editor_uploads"
    editor_uploads_dir.mkdir(parents=True, exist_ok=True)

    safe_name = secure_filename(file.filename)
    timestamp = str(int(time.time() * 1000))
    new_name = f"{timestamp}_{safe_name}"
    file_path = editor_uploads_dir / new_name
    file.save(str(file_path))

    # 生成可访问 URL 和 Markdown 片段
    image_url = f"/static/uploads/posts/editor_uploads/{new_name}"
    markdown_code = f"![{safe_name}]({image_url})"

    return jsonify(
        {
            "success": True,
            "url": image_url,
            "markdown": markdown_code,
        }
    )


# ==================== 路由 ====================


@app.route("/")
def index():
    """首页：瀑布流文章列表（展示完整博文）"""
    posts = load_index()
    # 按日期倒序排列
    posts.sort(key=lambda p: p.get("date", ""), reverse=True)

    # 为每篇文章获取内容
    for post in posts:
        post_id = post.get("id", "")
        content = ""

        # 优先从原始 Markdown 文件渲染内容（即使 generated 文件不存在也能显示）
        md_path = config.POSTS_DATA_FOLDER / post_id / "content.md"
        if md_path.exists():
            try:
                with open(md_path, "r", encoding="utf-8") as f:
                    md_content = f.read()
                fixed_md = fix_image_paths(md_content, post_id)
                html_body = render_markdown(fixed_md)
                content = html_body
            except Exception:
                content = ""
        else:
            # 回退到生成的静态 HTML 文件
            generated_path = config.GENERATED_FOLDER / f"{post_id}.html"
            if generated_path.exists():
                try:
                    with open(generated_path, "r", encoding="utf-8") as f:
                        html_content = f.read()
                    soup = BeautifulSoup(html_content, "html.parser")
                    card_summary = soup.find("div", class_="card-summary")
                    if card_summary:
                        content = card_summary.decode_contents()
                except Exception:
                    content = ""

        post["content"] = content

    return render_template("index.html", posts=posts)


@app.route("/upload", methods=["GET", "POST"])
def upload():
    """上传文章（原始文件上传，需要登录）"""
    # 登录检查
    if "user" not in session:
        flash("请先登录", "warning")
        return redirect(url_for("login"))

    if request.method == "GET":
        return render_template("upload.html")

    # POST 处理
    title = request.form.get("title", "").strip()
    if not title:
        return "标题不能为空", 400

    markdown_file = request.files.get("markdown_file")
    if not markdown_file or markdown_file.filename == "":
        return "请选择 Markdown 文件", 400

    if not allowed_file(markdown_file.filename):
        return "不支持的文件类型，请上传 .md 文件", 400

    # 生成唯一 ID
    post_id = str(int(time.time() * 1000))

    # 创建目录
    upload_dir = config.UPLOAD_FOLDER / post_id
    upload_dir.mkdir(parents=True, exist_ok=True)

    posts_data_dir = config.POSTS_DATA_FOLDER / post_id
    posts_data_dir.mkdir(parents=True, exist_ok=True)

    # 保存 Markdown 文件
    md_path = posts_data_dir / "content.md"
    markdown_file.save(str(md_path))

    # 处理图片上传
    images = request.files.getlist("images")
    for img in images:
        if img and img.filename:
            filename = secure_filename(img.filename)
            if filename:
                img.save(str(upload_dir / filename))

    # 读取 Markdown 内容
    with open(md_path, "r", encoding="utf-8") as f:
        md_content = f.read()

    # 修正图片路径
    fixed_md = fix_image_paths(md_content, post_id)

    # 渲染 HTML
    html_body = render_markdown(fixed_md)

    # 提取摘要
    summary = extract_summary(html_body)

    # 提取缩略图
    thumbnail = extract_thumbnail(html_body)

    # 生成日期（精确到分钟）
    date_iso = datetime.now(timezone.utc).replace(second=0, microsecond=0).isoformat()

    # 生成静态页面
    generate_static_page(post_id, title, html_body, date_iso, thumbnail)

    # 更新索引
    index = load_index()
    index.append(
        {
            "id": post_id,
            "title": title,
            "date": date_iso,
            "summary": summary,
            "thumbnail": thumbnail,
        }
    )
    # 按日期倒序排序
    index.sort(key=lambda p: p.get("date", ""), reverse=True)
    save_index(index)

    return redirect(url_for("index"))


@app.route("/post/<post_id>")
def view_post(post_id: str):
    """查看文章详情"""
    # 安全验证：只允许字母数字和下划线
    if not re.match(r"^[a-zA-Z0-9_]+$", post_id):
        abort(404)

    try:
        return send_from_directory(
            config.GENERATED_FOLDER,
            f"{post_id}.html",
        )
    except FileNotFoundError:
        abort(404)


@app.route("/admin")
def admin():
    """管理页面"""
    posts = load_index()
    return render_template("admin.html", posts=posts)


@app.route("/admin/delete/<post_id>", methods=["POST"])
def delete_post(post_id: str):
    """删除文章"""
    # 安全验证
    if not re.match(r"^[a-zA-Z0-9_]+$", post_id):
        abort(404)

    # 删除生成的静态文件
    generated_file = config.GENERATED_FOLDER / f"{post_id}.html"
    if generated_file.exists():
        generated_file.unlink()

    # 删除 posts_data 目录
    posts_data_dir = config.POSTS_DATA_FOLDER / post_id
    if posts_data_dir.exists():
        shutil.rmtree(posts_data_dir)

    # 删除上传的图片目录
    upload_dir = config.UPLOAD_FOLDER / post_id
    if upload_dir.exists():
        shutil.rmtree(upload_dir)

    # 从索引中移除
    index = load_index()
    index = [p for p in index if p["id"] != post_id]
    save_index(index)

    return redirect(url_for("admin"))


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


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5000, debug=True)