from flask import Flask, request, render_template, jsonify, send_file
from pymongo import MongoClient
import yt_dlp
import os
import json
import threading
from datetime import datetime
import humanize
import time

# Initialize Flask app
app = Flask(__name__)

# MongoDB connection
try:
    client = MongoClient('mongodb://localhost:2641/')
    db = client['youtube_downloader']
    videos_collection = db['videos']
except Exception as e:
    print(f"MongoDB connection error: {e}")
    videos_collection = None

# 确保下载目录存在
DOWNLOAD_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'downloads')
os.makedirs(DOWNLOAD_DIR, exist_ok=True)

class VideoDownloader:
    def __init__(self):
        self.current_downloads = 0
        self.max_concurrent = 2  # 最大并发下载数
        self.progress = {}
        self.download_queue = []

    def process_queue(self):
        while self.download_queue and self.current_downloads < self.max_concurrent:
            url, video_id = self.download_queue.pop(0)
            self.current_downloads += 1
            thread = threading.Thread(
                target=self._download_video,
                args=(url, video_id)
            )
            thread.start()

    def queue_download(self, url):
        video_id = str(datetime.now().timestamp())
        self.progress[video_id] = {'status': 'queued'}
        self.download_queue.append((url, video_id))
        self.process_queue()
        return video_id

    def _download_video(self, url, video_id):
        try:
            def progress_hook(d):
                if d['status'] == 'downloading':
                    total_bytes = d.get('total_bytes', 0)
                    downloaded_bytes = d.get('downloaded_bytes', 0)
                    speed = d.get('speed', 0)
                    
                    self.progress[video_id] = {
                        'status': 'downloading',
                        'downloaded_bytes': downloaded_bytes,
                        'total_bytes': total_bytes,
                        'speed': speed,
                        'percentage': (downloaded_bytes / total_bytes * 100) if total_bytes else 0,
                        'file_size': humanize.naturalsize(total_bytes) if total_bytes else 'Unknown',
                        'download_speed': humanize.naturalsize(speed) + '/s' if speed else 'Unknown'
                    }
                elif d['status'] == 'finished':
                    self.progress[video_id]['status'] = 'processing'

            # 添加cookies文件路径
            COOKIES_FILE = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'youtube.cookies')

            ydl_opts = {
                'format': 'bestvideo[ext=mp4][vcodec^=avc1]+bestaudio[ext=m4a]/best[ext=mp4]/best',  # 指定兼容的编码格式
                'outtmpl': os.path.join(DOWNLOAD_DIR, '%(title)s.%(ext)s'),
                'progress_hooks': [progress_hook],
                'no_warnings': True,
                'quiet': True,
                'extract_flat': False,
                'no_check_certificates': True,
                'ignoreerrors': True,
                'nocheckcertificate': True,
                'prefer_insecure': True,
                'geo_bypass': True,
                'geo_bypass_country': 'US',
                'retries': 10,
                'fragment_retries': 10,
                'skip_unavailable_fragments': True,
                'force_generic_extractor': False,
                'merge_output_format': 'mp4',
                'http_chunk_size': 10485760,
                'cookiefile': COOKIES_FILE,
                'keepvideo': False,  # 合并后删除原始文件
                'writethumbnail': True,  # 下载缩略图
                'headers': {
                    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
                    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
                    'Accept-Language': 'en-us,en;q=0.5',
                    'Sec-Fetch-Mode': 'navigate'
                }
            }

            with yt_dlp.YoutubeDL(ydl_opts) as ydl:
                try:
                    # 先获取视频信息
                    info_dict = ydl.extract_info(url, download=False)
                    if info_dict is None:
                        raise Exception("Could not extract video information")
                    
                    # 确保是单个视频而不是播放列表
                    if 'entries' in info_dict:
                        info = info_dict['entries'][0]
                    else:
                        info = info_dict

                    # 预先检查文件是否存在
                    filename = ydl.prepare_filename(info)
                    # 确保使用绝对路径
                    if not os.path.isabs(filename):
                        filename = os.path.join(DOWNLOAD_DIR, filename)
                    
                    base, ext = os.path.splitext(filename)
                    existing_file = None

                    # 检查所有可能的扩展名
                    for possible_ext in [ext, '.mp4', '.webm', '.mkv']:
                        possible_file = base + possible_ext
                        if os.path.exists(possible_file):
                            print(f"Found existing file: {possible_file}")  # 调试信息
                            existing_file = possible_file
                            break

                    if existing_file:
                        # 文件已存在，直接使用
                        filename = existing_file
                        print(f"Using existing file: {filename}")
                        
                        # 获取文件大小
                        file_size = os.path.getsize(filename)
                        
                        # 首先更新为下载中状态
                        self.progress[video_id] = {
                            'status': 'downloading',
                            'downloaded_bytes': file_size,
                            'total_bytes': file_size,
                            'speed': 0,
                            'percentage': 100,
                            'file_size': humanize.naturalsize(file_size),
                            'download_speed': '0 MB/s'
                        }
                        
                        # 短暂延迟以确保前端能看到状态变化
                        time.sleep(0.5)
                        
                        # 更新为处理中状态
                        self.progress[video_id]['status'] = 'processing'
                        time.sleep(0.5)
                        
                        # 构建完整的video_data
                        video_data = {
                            '_id': video_id,
                            'title': info.get('title', 'Unknown Title'),
                            'duration': info.get('duration', 0),
                            'uploader': info.get('uploader', 'Unknown Uploader'),
                            'description': info.get('description', ''),
                            'filename': os.path.basename(filename),
                            'file_path': filename,
                            'file_size': humanize.naturalsize(file_size),
                            'download_date': datetime.now(),
                            'thumbnail': info.get('thumbnail', ''),
                            'webpage_url': info.get('webpage_url', url)
                        }
                        
                        # 更数据库
                        if videos_collection is not None:
                            videos_collection.update_one(
                                {'_id': video_id},
                                {'$set': video_data},
                                upsert=True
                            )
                        
                        # 最后更新为完成状态
                        self.progress[video_id] = {
                            'status': 'completed',
                            'video_info': video_data,
                            'downloaded_bytes': file_size,
                            'total_bytes': file_size,
                            'percentage': 100,
                            'file_size': humanize.naturalsize(file_size)
                        }
                    else:
                        # 文件不存在，进行下载
                        print(f"No existing file found, downloading: {url}")  # 调试信息
                        info = ydl.extract_info(url, download=True)
                        filename = ydl.prepare_filename(info)
                        if not os.path.isabs(filename):
                            filename = os.path.join(DOWNLOAD_DIR, filename)
                        
                        # 再次检查文件否存在（以防扩展名变化）
                        if not os.path.exists(filename):
                            base, _ = os.path.splitext(filename)
                            for ext in ['.mp4', '.webm', '.mkv']:
                                alt_filename = base + ext
                                if os.path.exists(alt_filename):
                                    filename = alt_filename
                                    break

                    if not os.path.exists(filename):
                        raise Exception("Downloaded file not found")
                    
                    # Get file size
                    file_size = os.path.getsize(filename)
                    
                    video_data = {
                        '_id': video_id,
                        'title': info.get('title', 'Unknown Title'),
                        'duration': info.get('duration', 0),
                        'uploader': info.get('uploader', 'Unknown Uploader'),
                        'description': info.get('description', ''),
                        'filename': os.path.basename(filename),
                        'file_path': filename,
                        'file_size': humanize.naturalsize(file_size),
                        'download_date': datetime.now(),
                        'thumbnail': info.get('thumbnail', ''),
                        'webpage_url': info.get('webpage_url', url)
                    }
                    
                    if videos_collection is not None:
                        videos_collection.update_one(
                            {'_id': video_id},
                            {'$set': video_data},
                            upsert=True
                        )
                    
                    self.progress[video_id] = {
                        'status': 'completed',
                        'video_info': video_data
                    }
                    
                except Exception as e:
                    raise Exception(f"Download failed: {str(e)}")

        except Exception as e:
            self.progress[video_id] = {
                'status': 'error',
                'error': str(e)
            }
        finally:
            self.current_downloads -= 1
            self.process_queue()

downloader = VideoDownloader()

@app.route('/')
def index():
    videos = []
    if videos_collection is not None:
        videos = list(videos_collection.find().sort('download_date', -1))
    return render_template('index.html', videos=videos)

@app.route('/download', methods=['POST'])
def download():
    url = request.json.get('url')
    if not url:
        return jsonify({'error': 'No URL provided'}), 400
    
    video_id = downloader.queue_download(url)
    return jsonify({'video_id': video_id})

@app.route('/progress/<video_id>')
def get_progress(video_id):
    return jsonify(downloader.progress.get(video_id, {'status': 'not_found'}))

@app.route('/video/<path:filename>')
def serve_video(filename):
    return send_file(
        os.path.join(DOWNLOAD_DIR, filename),
        mimetype='video/mp4'
    )

if __name__ == '__main__':
    app.run(debug=True)