#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
学术论文批量下载工具 (Academic Paper Downloader)
支持HTTP(S)/HTTPS重试、大文件分块下载、进度显示、日志记录

创建时间：2026-04-14
最后更新：2026-04-14
"""

import urllib.request
import ssl
import os
import sys
import io
import time
import json
from pathlib import Path
from urllib.error import URLError, HTTPError
from datetime import datetime

# Force UTF-8 encoding for console output
sys.stdout = io.TextIOWrapper(sys.stdout, encoding="utf-8")

# =============================================================================
# 配置区域
# =============================================================================

# 基础目录
BASE_DIR = r"D:\TC_UP\2023card\projects\openclaw\教育AI研究\高等教育AI专题\文献库"
LOG_DIR = os.path.join(BASE_DIR, "logs")
CONFIG_DIR = os.path.join(BASE_DIR, "configs")
os.makedirs(LOG_DIR, exist_ok=True)
os.makedirs(CONFIG_DIR, exist_ok=True)


# 下载配置
class DownloadConfig:
    """下载配置"""

    def __init__(self):
        self.timeout = 300  # 5分钟
        self.retry_count = 3
        self.retry_delay = 5  # 秒
        self.chunk_size = 8192  # 8KB per chunk
        self.user_agent = "Mozilla/5.0 (compatible; AcademicPaperDownloader/1.0)"

    def set_timeout(self, seconds):
        """设置超时时间"""
        self.timeout = seconds

    def set_retry(self, count, delay):
        """设置重试次数和延迟"""
        self.retry_count = count
        self.retry_delay = delay


# SSL上下文
SSL_CONTEXT = ssl._create_default_https_context()

# =============================================================================
# 日志系统
# =============================================================================


class DownloadLogger:
    """下载日志记录器"""

    def __init__(self, log_file):
        self.log_file = os.path.join(LOG_DIR, log_file)
        self.records = []
        self._load_existing_logs()

    def _load_existing_logs(self):
        """加载已有日志"""
        if os.path.exists(self.log_file):
            try:
                with open(self.log_file, "r", encoding="utf-8") as f:
                    for line in f:
                        if line.strip():
                            try:
                                self.records.append(json.loads(line))
                            except:
                                pass
            except:
                pass

    def log(self, paper_name, url, status, size_mb, error=None):
        """记录下载日志"""
        record = {
            "timestamp": datetime.now().isoformat(),
            "paper": paper_name,
            "url": url,
            "status": status,  # 'success' or 'failed'
            "size_mb": size_mb,
            "error": error,
        }
        self.records.append(record)
        self._save_log()

    def _save_log(self):
        """保存日志到文件"""
        with open(self.log_file, "w", encoding="utf-8") as f:
            for record in self.records:
                f.write(json.dumps(record, ensure_ascii=False) + "\n")

    def get_stats(self):
        """获取统计信息"""
        total = len(self.records)
        success = len([r for r in self.records if r["status"] == "success"])
        failed = len([r for r in self.records if r["status"] == "failed"])
        total_size = sum(
            [r.get("size_mb", 0) for r in self.records if r["status"] == "success"]
        )

        return {
            "total": total,
            "success": success,
            "failed": failed,
            "success_rate": f"{(success / total * 100):.1f}%",
            "total_size_mb": f"{total_size:.2f}",
            "avg_size_mb": f"{(total_size / success if success > 0 else 0):.2f}",
        }


# =============================================================================
# 核心下载器
# =============================================================================


class PaperDownloader:
    """学术论文下载器"""

    def __init__(self, config):
        self.config = config
        self.logger = DownloadLogger("paper_downloads.log")

    def download_with_retry(self, url, filepath, paper_name=""):
        """带重试机制的下载"""
        filename = os.path.basename(filepath)

        for attempt in range(self.config.retry_count):
            try:
                print(f"\n📥 尝试 {attempt + 1}/{self.config.retry_count}: {filename}")
                return self._download(url, filepath, paper_name)

            except (URLError, HTTPError) as e:
                print(f"❌ 尝试 {attempt + 1}/{self.config.retry_count} 失败: {e}")

                if attempt < self.config.retry_count - 1:
                    print(f"⏳ {self.config.retry_delay} 秒后重试...")
                    time.sleep(self.config.retry_delay)
                else:
                    # 最后一次失败，记录日志
                    self.logger.log(
                        paper_name or filename, url, "failed", 0, error=str(e)
                    )
                    return False

    def _download(self, url, filepath, paper_name=""):
        """实际下载方法，支持分块下载"""
        try:
            print(f"📥 开始下载: {paper_name or os.path.basename(filepath)}")

            req = urllib.request.Request(
                url, headers={"User-Agent": self.config.user_agent}
            )

            with urllib.request.urlopen(
                req, context=SSL_CONTEXT, timeout=self.config.timeout
            ) as response:
                total_size = int(response.headers.get("content-length", 0))
                total_mb = total_size / (1024 * 1024)

                print(f"📊 文件大小: {total_mb:.2f} MB")

                # 创建目录
                os.makedirs(os.path.dirname(filepath), exist_ok=True)

                downloaded = 0
                start_time = time.time()

                with open(filepath, "wb") as f:
                    while downloaded < total_size:
                        chunk = response.read(self.config.chunk_size)
                        if not chunk:
                            break
                        f.write(chunk)
                        downloaded += len(chunk)

                        # 进度显示
                        percent = (downloaded / total_size) * 100
                        downloaded_mb = downloaded / (1024 * 1024)
                        elapsed = time.time() - start_time

                        # 进度条
                        progress_bar = "█" * int(percent / 5)
                        print(
                            f"\r进度: {percent:5.1f}% [{progress_bar:20}] {downloaded_mb:.2f}/{total_mb:.2f}MB {elapsed:.0f}s",
                            end="",
                        )

                print()  # 换行

                # 记录成功日志
                self.logger.log(
                    paper_name or os.path.basename(filepath), url, "success", total_mb
                )

                print(
                    f"\n✅ 下载成功: {paper_name or os.path.basename(filepath)} ({total_mb:.2f} MB)"
                )
                return True

        except Exception as e:
            print(f"\n❌ 下载失败: {e}")
            return False


# =============================================================================
# 配置文件管理
# =============================================================================


def load_config(config_file):
    """从JSON文件加载配置"""
    config_path = os.path.join(CONFIG_DIR, config_file)

    if not os.path.exists(config_path):
        print(f"⚠️  配置文件不存在: {config_file}")
        return None

    try:
        with open(config_path, "r", encoding="utf-8") as f:
            config_data = json.load(f)
            print(f"✅ 已加载配置: {config_file}")
            print(f"📋 论文数量: {len(config_data.get('papers', []))}")
            return config_data
    except Exception as e:
        print(f"❌ 加载配置失败: {e}")
        return None


def create_sample_config():
    """创建示例配置文件（使用英文以避免编码问题）"""
    sample_config = {
        "name": "Academic Paper Downloader Configuration Sample",
        "description": "Configuration file for batch downloading academic papers",
        "papers": [
            {
                "name": "Teaching CS50 with AI (SIGCSE 2024)",
                "url": "https://cs.harvard.edu/malan/publications/V1fp0567-liu.pdf",
                "filename": "Teaching_CS50_with_AI_SIGCSE2024.pdf",
                "enabled": True,
            },
            {
                "name": "Improving AI in CS50 (SIGCSE 2025)",
                "url": "https://cs.harvard.edu/malan/publications/fp0627-liu.pdf",
                "filename": "Improving_AI_in_CS50_SIGCSE2025.pdf",
                "enabled": True,
            },
        ],
    }

    sample_path = os.path.join(CONFIG_DIR, "sample_config.json")

    try:
        with open(sample_path, "w", encoding="utf-8") as f:
            json.dump(sample_data, f, ensure_ascii=False, indent=2)
        print("Sample config created successfully: " + sample_path)
        return sample_path
    except Exception as e:
        print(f"❌ 创建示例配置失败: {e}")
        return None


# =============================================================================
# 主命令
# =============================================================================


def download_from_config(config_file):
    """从配置文件批量下载"""
    config_data = load_config(config_file)

    if not config_data:
        return

    downloader = PaperDownloader(DownloadConfig())
    papers = config_data.get("papers", [])
    enabled_papers = [p for p in papers if p.get("enabled", True)]

    if not enabled_papers:
        print("⚠️  没有启用的论文可下载")
        return

    print(f"\n{'=' * 50}")
    print(f"准备下载 {len(enabled_papers)} 篇论文...\n")

    success_count = 0
    failed_count = 0

    for idx, paper in enumerate(enabled_papers, 1):
        print(
            f"\n[{'=' * 40}/{len(enabled_papers)}] {paper.get('name', 'Unknown Paper')}"
        )

        url = paper.get("url")
        filename = paper.get("filename", f"paper_{idx}.pdf")
        filepath = os.path.join(BASE_DIR, filename)
        name = paper.get("name", "Unknown Paper")

        if downloader.download_with_retry(url, filepath, name):
            success_count += 1
        else:
            failed_count += 1

    print(f"\n{'=' * 50}")
    print(f"✅ 成功: {success_count}")
    print(f"❌ 失败: {failed_count}")

    # 显示统计
    stats = downloader.logger.get_stats()
    print(f"\n📊 下载统计:")
    print(f"总论文数: {stats['total']}")
    print(f"成功率: {stats['success_rate']}")
    print(f"总下载大小: {stats['total_size_mb']} MB")
    print(f"平均大小: {stats['avg_size_mb']} MB")


def download_single(url, filename=None):
    """单篇论文下载"""
    if not filename:
        # 从URL提取文件名
        filename = url.split("/")[-1]
        if not filename.endswith(".pdf"):
            filename = filename + ".pdf"

    filepath = os.path.join(BASE_DIR, filename)
    paper_name = os.path.splitext(filename)[0]

    downloader = PaperDownloader(DownloadConfig())
    downloader.download_with_retry(url, filepath, paper_name)

    # 显示统计
    stats = downloader.logger.get_stats()
    print(f"\n📊 当前下载统计:")
    print(f"总下载次数: {stats['total']}")
    print(f"成功率: {stats['success_rate']}")
    print(f"总下载大小: {stats['total_size_mb']} MB")


def show_logs():
    """显示下载日志"""
    stats = DownloadLogger("paper_downloads.log").get_stats()

    print(f"\n📊 下载日志统计:")
    print(f"{'=' * 40}")
    print(f"总下载次数: {stats['total']}")
    print(f"成功次数: {stats['success']}")
    print(f"失败次数: {stats['failed']}")
    print(f"成功率: {stats['success_rate']}")
    print(f"总下载大小: {stats['total_size_mb']} MB")
    print(f"平均大小: {stats['avg_size_mb']} MB")
    print(f"日志文件: {os.path.join(LOG_DIR, 'paper_downloads.log')}")


def clear_logs():
    """清除日志"""
    log_file = os.path.join(LOG_DIR, "paper_downloads.log")

    try:
        if os.path.exists(log_file):
            os.remove(log_file)
            print(f"✅ 日志已清除: {log_file}")
        else:
            print("⚠️  日志文件不存在")
    except Exception as e:
        print(f"❌ 清除日志失败: {e}")


# =============================================================================
# 主程序
# =============================================================================


def print_help():
    """显示帮助信息"""
    help_text = """
学术论文批量下载工具 (Academic Paper Downloader)

使用方法:
    python paper_downloader.py <command> [options]

命令:
    download <url>                    下载单篇论文
    config <config.json>              从配置文件批量下载
    logs                            显示下载日志统计
    clear                           清除下载日志
    create-sample                    创建示例配置文件
    help                            显示此帮助信息

选项:
    --timeout <seconds>              设置超时时间（默认: 300秒）
    --retry <count>                  设置重试次数（默认: 3次）
    --chunk-size <bytes>             设置分块大小（默认: 8192字节）
    --no-progress                     不显示进度条

示例:
    # 下载单篇论文
    python paper_downloader.py download https://cs.harvard.edu/malan/publications/V1fp0567-liu.pdf

    # 从配置文件批量下载
    python paper_downloader.py config my_papers.json

    # 创建示例配置文件
    python paper_downloader.py create-sample

    # 查看下载日志
    python paper_downloader.py logs

    # 清除下载日志
    python paper_downloader.py clear

配置文件格式:
    {
        "name": "论文集合名称",
        "papers": [
            {
                "name": "论文标题",
                "url": "论文URL",
                "filename": "保存的文件名.pdf",
                "enabled": true
            }
        ]
    }

作者: Sisyphus
版本: 1.0.0
更新: 2026-04-14
"""
    print(help_text)


def main():
    """主函数"""
    if len(sys.argv) < 2:
        print_help()
        return

    command = sys.argv[1].lower()

    # 解析选项
    options = {"timeout": 300, "retry": 3, "chunk_size": 8192, "no_progress": False}

    args = sys.argv[2:]
    i = 0
    while i < len(args):
        if args[i] == "--timeout":
            if i + 1 < len(args):
                options["timeout"] = int(args[i + 1])
                i += 2
        elif args[i] == "--retry":
            if i + 1 < len(args):
                options["retry"] = int(args[i + 1])
                i += 2
        elif args[i] == "--chunk-size":
            if i + 1 < len(args):
                options["chunk_size"] = int(args[i + 1])
                i += 2
        elif args[i] == "--no-progress":
            options["no_progress"] = True
            i += 1
        else:
            print(f"⚠️ 未知选项: {args[i]}")
            i += 1

    # 应用配置
    config = DownloadConfig()
    if options["timeout"]:
        config.set_timeout(options["timeout"])
    if options["retry"]:
        config.set_retry(
            options["retry"], options.get("retry_delay", config.retry_delay)
        )
    if options["chunk_size"]:
        config.chunk_size = options["chunk_size"]
    if options["no_progress"]:
        config.user_agent = (
            "Mozilla/5.0 (compatible; AcademicPaperDownloader/1.0) (No Progress)"
        )

    # 执行命令
    try:
        if command == "download":
            if len(args) > i:
                download_single(args[i])
            else:
                print("❌ 请提供论文URL")

        elif command == "config":
            if len(args) > i:
                download_from_config(args[i])
            else:
                print("❌ 请提供配置文件路径")

        elif command == "logs":
            show_logs()

        elif command == "clear":
            clear_logs()

        elif command == "create-sample":
            create_sample_config()

        elif command == "help":
            print_help()

        else:
            print(f"❌ 未知命令: {command}")
            print_help()

    except KeyboardInterrupt:
        print("\n\n⚠️ 下载已中断")
    except Exception as e:
        print(f"\n❌ 发生错误: {e}")


if __name__ == "__main__":
    main()