# 工具函数

import os
import re
import requests
from tqdm import tqdm
from config import USER_AGENT, COOKIE, CHUNK_SIZE, DOWNLOAD_DIR


def extract_bv_from_url(url):
    """
    从分享链接中提取BV号
    :param url: 视频分享链接
    :return: BV号
    """
    pattern = r"BV[0-9A-Za-z]+"
    match = re.search(pattern, url)
    if match:
        return match.group(0)
    else:
        raise ValueError("无法从链接中提取BV号")


def get_video_info(bv_id):
    """
    获取视频信息
    :param bv_id: BV号
    :return: 视频信息字典
    """
    url = f"https://api.bilibili.com/x/web-interface/view?bvid={bv_id}"
    headers = {
        "User-Agent": USER_AGENT,
        "Cookie": COOKIE
    }
    response = requests.get(url, headers=headers)
    response.raise_for_status()
    data = response.json()
    if data.get("code") != 0:
        raise Exception(f"获取视频信息失败: {data.get('message')}")
    return data.get("data", {})


def get_play_urls(bv_id, cid):
    """
    获取视频播放链接
    :param bv_id: BV号
    :param cid: 视频cid
    :return: 包含视频和音频链接的字典
    """
    from config import API_URL
    
    params = {
        "bvid": bv_id,
        "cid": cid,
        "qn": 80,
        "type": "",
        "otype": "json",
        "fourk": 1,
        "fnval": 16
    }
    
    headers = {
        "User-Agent": USER_AGENT,
        "Cookie": COOKIE,
        "Referer": "https://www.bilibili.com/",
        "Origin": "https://www.bilibili.com"
    }
    
    response = requests.get(API_URL, params=params, headers=headers)
    response.raise_for_status()
    data = response.json()
    
    if data.get("code") != 0:
        raise Exception(f"获取播放链接失败: {data.get('message')}")
    
    play_urls = {
        "video": [],
        "audio": []
    }
    
    video_info = data.get("data", {}).get("dash", {}).get("video", [])
    audio_info = data.get("data", {}).get("dash", {}).get("audio", [])
    
    if not video_info:
        durl = data.get("data", {}).get("durl", [])
        for item in durl:
            play_urls["video"].append({
                "url": item.get("url"),
                "quality": 80,
                "codec": "h264"
            })
    else:
        for item in video_info:
            play_urls["video"].append({
                "url": item.get("baseUrl"),
                "quality": item.get("id"),
                "codec": item.get("codecs")
            })
    
    if not audio_info and video_info:
        for item in video_info:
            play_urls["audio"].append({
                "url": item.get("baseUrl"),
                "quality": item.get("id"),
                "codec": item.get("codecs")
            })
    else:
        for item in audio_info:
            play_urls["audio"].append({
                "url": item.get("baseUrl"),
                "quality": item.get("id"),
                "codec": item.get("codecs")
            })
    
    print(f"获取到视频流数量: {len(play_urls['video'])}")
    print(f"获取到音频流数量: {len(play_urls['audio'])}")
    
    return play_urls


def sanitize_filename(filename):
    """
    清理文件名，移除非法字符
    :param filename: 原始文件名
    :return: 清理后的文件名
    """
    illegal_chars = r"[<>:/\\|?*]"
    return re.sub(illegal_chars, "_", filename)


def download_file(url, save_path):
    """
    下载文件
    :param url: 文件下载链接
    :param save_path: 保存路径
    :return: 保存路径
    """
    os.makedirs(os.path.dirname(save_path), exist_ok=True)
    
    headers = {
        "User-Agent": USER_AGENT,
        "Cookie": COOKIE,
        "Referer": "https://www.bilibili.com/"
    }
    
    response = requests.get(url, headers=headers, stream=True)
    response.raise_for_status()
    total_size = int(response.headers.get("content-length", 0))
    
    with open(save_path, "wb") as file, tqdm(
        desc=os.path.basename(save_path),
        total=total_size,
        unit="iB",
        unit_scale=True,
        unit_divisor=1024,
    ) as bar:
        for chunk in response.iter_content(chunk_size=CHUNK_SIZE):
            size = file.write(chunk)
            bar.update(size)
    
    return save_path


def download_audio_video(video_url, audio_url, save_dir, video_title):
    """
    下载视频和音频
    :param video_url: 视频流链接
    :param audio_url: 音频流链接
    :param save_dir: 保存目录
    :param video_title: 视频标题
    :return: 视频和音频保存路径
    """
    sanitized_title = sanitize_filename(video_title)
    
    video_path = os.path.join(save_dir, f"{sanitized_title}_video.mp4")
    audio_path = os.path.join(save_dir, f"{sanitized_title}_audio.mp4")
    
    print(f"正在下载视频: {video_title}")
    download_file(video_url, video_path)
    
    print(f"正在下载音频: {video_title}")
    download_file(audio_url, audio_path)
    
    return video_path, audio_path


def merge_audio_video(video_path, audio_path, output_path):
    """
    合并音视频
    :param video_path: 视频文件路径
    :param audio_path: 音频文件路径
    :param output_path: 输出文件路径
    :return: 输出文件路径
    """
    import subprocess
    
    os.makedirs(os.path.dirname(output_path), exist_ok=True)
    
    print(f"正在合并音视频: {os.path.basename(output_path)}")
    
    # 尝试使用FFmpeg合并音视频
    cmd = [
        "ffmpeg",
        "-i", video_path,
        "-i", audio_path,
        "-c:v", "copy",
        "-c:a", "aac",
        "-strict", "experimental",
        "-y",
        output_path
    ]
    
    try:
        # 尝试执行FFmpeg命令（使用字节模式避免编码问题）
        result = subprocess.run(
            cmd,
            check=True,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE
        )
        print("音视频合并完成")
    except subprocess.CalledProcessError as e:
        # FFmpeg失败，尝试使用其他方法
        print(f"FFmpeg合并失败: {e.stderr}")
        print("尝试使用备用方法...")
        
        # 备用方法：使用Python的shutil复制文件
        # 这里只是一个占位符，实际需要更复杂的实现
        # 但至少可以让用户知道问题所在
        raise Exception(
            "音视频合并失败，请确保已安装FFmpeg并添加到系统路径\n"
            "或尝试安装MoviePy: pip install moviepy"
        )
    except FileNotFoundError:
        raise Exception(
            "FFmpeg未找到，请安装FFmpeg并添加到系统路径\n"
            "下载地址: https://ffmpeg.org/download.html"
        )
    
    return output_path


def cleanup_files(*file_paths):
    """
    清理临时文件
    :param file_paths: 要清理的文件路径
    """
    for file_path in file_paths:
        if os.path.exists(file_path):
            try:
                os.remove(file_path)
                print(f"已清理临时文件: {os.path.basename(file_path)}")
            except Exception as e:
                print(f"清理临时文件失败: {e}")