#!/usr/bin/env python3
"""
Hugo Frontmatter 转换脚本
将 YAML 格式 (---) 转换为 TOML 格式 (+++)
"""

import os
import re
import sys
from pathlib import Path

import yaml  # pip install pyyaml
import tomli_w  # pip install tomli-w


def yaml_to_toml_frontmatter(content: str) -> str:
    """
    将 YAML frontmatter 转换为 TOML frontmatter
    """
    # 匹配 YAML frontmatter: ---\n...\n---
    yaml_pattern = r'^---\s*\n(.*?)\n---\s*\n'
    match = re.match(yaml_pattern, content, re.DOTALL)

    if not match:
        return None  # 不是 YAML frontmatter 格式

    yaml_content = match.group(1)
    body_content = content[match.end():]

    # 解析 YAML
    try:
        data = yaml.safe_load(yaml_content)
        if data is None:
            data = {}
    except yaml.YAMLError as e:
        raise ValueError(f"YAML 解析错误: {e}")

    # 转换为 TOML
    # tomli_w 需要 dict，且不支持 None 值，需要处理
    def clean_for_toml(obj):
        if isinstance(obj, dict):
            return {k: clean_for_toml(v) for k, v in obj.items() if v is not None}
        elif isinstance(obj, list):
            return [clean_for_toml(item) for item in obj if item is not None]
        elif obj is None:
            return ""
        return obj

    clean_data = clean_for_toml(data)

    # 生成 TOML
    try:
        toml_bytes = tomli_w.dumps(clean_data)
        toml_str = toml_bytes.decode('utf-8') if isinstance(toml_bytes, bytes) else toml_bytes
    except Exception as e:
        raise ValueError(f"TOML 生成错误: {e}")

    # 组合新的 frontmatter
    new_content = f"+++\n{toml_str}+++\n{body_content}"

    return new_content


def process_file(file_path: Path, dry_run: bool = False) -> bool:
    """
    处理单个文件
    返回: 是否进行了转换
    """
    try:
        content = file_path.read_text(encoding='utf-8')
    except Exception as e:
        print(f"❌ 读取失败: {file_path} - {e}")
        return False

    # 检查是否是 YAML frontmatter (--- 开头)
    if not content.startswith('---'):
        # 检查是否是 TOML frontmatter (+++ 开头)，跳过
        if content.startswith('+++'):
            print(f"⏭️  跳过 (已是 TOML): {file_path}")
        else:
            print(f"⏭️  跳过 (无 frontmatter): {file_path}")
        return False

    # 转换
    try:
        new_content = yaml_to_toml_frontmatter(content)
        if new_content is None:
            print(f"⏭️  跳过 (格式不匹配): {file_path}")
            return False
    except ValueError as e:
        print(f"❌ 转换失败: {file_path} - {e}")
        return False

    # 写入文件
    if not dry_run:
        try:
            # 备份原文件
            backup_path = file_path.with_suffix(file_path.suffix + '.bak')
            file_path.rename(backup_path)

            # 写入新内容
            file_path.write_text(new_content, encoding='utf-8')

            # 删除备份（可选，注释掉这行会保留备份）
            # backup_path.unlink()

            print(f"✅ 已转换: {file_path}")
        except Exception as e:
            print(f"❌ 写入失败: {file_path} - {e}")
            return False
    else:
        print(f"[预览] 将转换: {file_path}")
        # 打印前 500 字符预览
        preview = new_content[:500] + "..." if len(new_content) > 500 else new_content
        print(preview)
        print("-" * 50)

    return True


def main():
    # 配置
    content_dir = Path("content")  # Hugo content 目录
    dry_run = False  # 设为 True 预览而不实际修改

    # 检查命令行参数
    if len(sys.argv) > 1:
        if sys.argv[1] in ['--dry-run', '-n', '--preview']:
            dry_run = True
            print("🔍 预览模式 (不会实际修改文件)")
        else:
            content_dir = Path(sys.argv[1])

    if not content_dir.exists():
        print(f"❌ 目录不存在: {content_dir}")
        sys.exit(1)

    # 查找所有 markdown 文件
    md_extensions = {'.md', '.markdown', '.mdown', '.mkd'}
    md_files = [
        f for f in content_dir.rglob('*')
        if f.is_file() and f.suffix.lower() in md_extensions
    ]

    print(f"📁 扫描目录: {content_dir.absolute()}")
    print(f"📄 找到 {len(md_files)} 个 Markdown 文件\n")

    converted = 0
    skipped = 0
    failed = 0

    for file_path in md_files:
        result = process_file(file_path, dry_run)
        if result:
            converted += 1
        elif result is False:
            # 区分失败和跳过
            pass

    print(f"\n{'='*50}")
    print(f"处理完成:")
    print(f"  - 转换: {converted} 个文件")
    print(f"  - 跳过: {len(md_files) - converted} 个文件")

    if dry_run:
        print(f"\n💡 这是预览模式，实际运行请去掉 --dry-run 参数")


if __name__ == "__main__":
    main()