# main.py

import pymysql
import time
from dotenv import load_dotenv
import os
import requests
import logging
import hashlib

# Load environment variables from .env file
load_dotenv()

logging.basicConfig(
    filename='download.log',
    level=logging.INFO,
    format='%(asctime)s [%(levelname)s] %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S'
)
logger = logging.getLogger(__name__)


def get_file_hash(filename):
    if os.path.isfile(filename) is False:
        return None

    # make a hash object
    h_sha256 = hashlib.sha256()

    # open file for reading in binary mode
    with open(filename, "rb") as file:
        # read file in chunks and update hash
        chunk = 0
        while chunk != b"":
            chunk = file.read(1024)
            h_sha256.update(chunk)

    # return the hex digest
    return h_sha256.hexdigest()


def connect_to_mysql():
    try:
        connection = pymysql.connect(
            host=os.getenv('MYSQL_HOST'),
            port=int(os.getenv('MYSQL_PORT')),
            user=os.getenv('MYSQL_USER'),
            password=os.getenv('MYSQL_PASSWORD'),
            database=os.getenv('MYSQL_DATABASE'),
            cursorclass=pymysql.cursors.DictCursor
        )
        if connection.open:
            return connection
    except pymysql.Error as e:
        logger.error(f"Error: {e}")
        return None

def fetch_oldest_video(connection):
    try:
        with connection.cursor() as cursor:
            query = "SELECT * FROM tp_videos WHERE download_status = 0 ORDER BY create_time LIMIT 1;"
            cursor.execute(query)
            result = cursor.fetchone()
            return result
    except pymysql.Error as e:
        logger.error(f"Error fetching data: {e}")
        return None

def fetch_same_video(connection, video_hash):
    try:
        with connection.cursor() as cursor:
            sql = "SELECT * FROM tp_videos WHERE video_hash = %s ORDER BY id DESC LIMIT 1"
        
        # 执行 SQL 查询
            cursor.execute(sql, (video_hash,))
            result = cursor.fetchone()
            return result
    except pymysql.Error as e:
        logger.error(f"Error fetching data: {e}")
        return None

def save_download_success(connection, id_, video_hash, is_same=False):
    try:
        with connection.cursor() as cursor:
            query = "UPDATE tp_videos SET download_status=2, video_hash=%s, video_status=%s WHERE id=%s;"
            if is_same:
                cursor.execute(query, (video_hash, 4, id_))
            else:
                cursor.execute(query, (video_hash, 1, id_))
            connection.commit()
    except pymysql.Error as e:
        with connection.cursor() as cursor:
            query = "UPDATE tp_videos SET download_status=3 WHERE id=%s;"
            cursor.execute(query, (id_))
            connection.commit()
        logger.error(f"更新失败： {e}")
    except Exception as e1:
        logger.error(f"更新失败： {e1}")

def save_download_error(connection, id_):
    try:
        with connection.cursor() as cursor:
            query = "UPDATE tp_videos SET download_status=3 WHERE id=%s;"
            cursor.execute(query, (id_, ))
            connection.commit()
    except pymysql.Error as e:
        logger.error(f"更新失败： {e}")


def download_video(video_data):
    download_path = video_data.get('video_path', '')
    file_name = video_data.get('video_name', '')
    ftp_path = video_data.get('ftp_path', '')

    if download_path and file_name and ftp_path:

        try:
            # 发送带有流式传输的 GET 请求
            response = requests.get(ftp_path, stream=True)
            # 检查响应状态码是否为 200
            if response.status_code == 200:
                with open(download_path, 'wb') as file:
                    # 逐块写入文件
                    for chunk in response.iter_content(chunk_size=8192):
                        if chunk:
                            file.write(chunk)

                logger.info(f"下载完成: {download_path}")                

            else:
                logger.error(f"下载失败:状态码:{response.status_code}")
        except requests.RequestException as e:
            logger.error(f"下载失败: {e}")
            raise requests.RequestException(f"下载失败: {e}")
        except IOError as e:
            logger.error(f"文件操作失败: {e}")
            raise IOError(f"文件操作失败: {e}")

def main():
    count = 0
    try:
        while True:
            connection = connect_to_mysql()
            if not connection:
                time.sleep(10)
                continue 
            video_data = fetch_oldest_video(connection)
            if video_data and video_data.get('id', None):
                logger.info(str(video_data))

                # video_url = video_data['url']  # Assuming URL is in the 'url' column
                try:
                    download_video(video_data)
                except Exception as e:
                    logger.error(f"保存异常{e}")
                    save_download_error(connection, video_data['id'])
                else:
                    download_path = video_data.get('video_path', '')
                    video_hash = get_file_hash(download_path)
                    same_rsult = fetch_same_video(connection, video_hash)
                    if same_rsult:
                        try:
                            os.remove(download_path)
                            logger.info(f"删除重复视频:{download_path}")
                        except Exception as e:
                            logger.error(f"删除重复视频失败，原因为：{e}")

                        save_download_success(connection, video_data['id'], video_hash, is_same=True)
                    else:
                       save_download_success(connection, video_data['id'], video_hash, is_same=False) 
                time.sleep(2)
            else:
                print("No videos to download. Waiting...")
                time.sleep(5)
            count += 1
            # if count == 500:
            #     logger.info(f"重启")
            #     break
    except KeyboardInterrupt:
        logger.info("Stopping the downloader.")
    finally:
        connection.close()

if __name__ == "__main__":
    main()