import time
import asyncio
from typing import List
from urllib.parse import urlparse
from pathlib import Path
from crawl4ai import AsyncWebCrawler, BrowserConfig, CrawlerRunConfig, CacheMode
from langchain_core.tools import tool

# ─────────────── 重要：計算路徑 ───────────────
# 目前這個檔案 (crawl4ai_batch.py) 所在的目錄
TOOL_DIR = Path(__file__).resolve().parent

# 專案根目錄（假設 tools 資料夾與主程式同級）
PROJECT_ROOT = TOOL_DIR.parent

# 儲存爬取結果的目錄（你可以自由決定放在哪裡）
# 建議選項 A：放在專案根目錄下的 workspace/raw_data
SAVE_DIR = PROJECT_ROOT / "workspace" / "raw_data"

# 建議選項 B：如果你打算讓 deep agent 直接讀取，建議放在 agent_workspace 底下
# SAVE_DIR = PROJECT_ROOT / "agent_workspace" / "raw_data"

# 確保目錄存在
SAVE_DIR.mkdir(parents=True, exist_ok=True)


# ────────────────────────────────────────────────


@tool
async def crawl4ai_batch(urls: List[str]) -> str:
    """
    高性能网页爬虫，支持并行处理多个 URL。
    爬取后的 Markdown 内容将保存到本地 workspace/raw_data 目录中。
    返回执行结果摘要和保存的文件路径列表。
    """
    if not urls:
        return "❌ 错误: 未提供任何 URL。"

    # print(f"🕷️ 正在并行爬取 {len(urls)} 个 URL...")
    # print(f"儲存目錄: {SAVE_DIR}")

    browser_config = BrowserConfig(
        headless=True,
        verbose=False,
        java_script_enabled=True,
        user_agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
                   "AppleWebKit/537.36 (KHTML, like Gecko) "
                   "Chrome/118.0.5993.118 Safari/537.36",
        proxy=None,  # 可选，如果需要代理填 "http://user:pass@ip:port"
    )

    run_config = CrawlerRunConfig(
        cache_mode=CacheMode.BYPASS,
        word_count_threshold=5,
        excluded_tags=["script", "style", "nav", "footer"],
        remove_overlay_elements=True,
        process_iframes=True,
    )

    results_summary = []
    saved_files = []

    try:
        async with AsyncWebCrawler(config=browser_config) as crawler:
            tasks = [crawler.arun(url=url, config=run_config) for url in urls]
            crawl_results = await asyncio.gather(*tasks, return_exceptions=True)

            for i, result in enumerate(crawl_results):
                url = urls[i]

                if isinstance(result, Exception):
                    results_summary.append(f"❌ 抓取失败 {url}: {str(result)}")
                    continue

                if result.success:
                    markdown_content = result.markdown or ""

                    if len(markdown_content) < 500:
                        results_summary.append(f"⏩ 跳过 {url} (内容过短)")
                        continue

                    # 生成檔名
                    parsed = urlparse(url)
                    domain = parsed.netloc.replace("www.", "").replace(".", "_")
                    path_part = parsed.path.strip("/").replace("/", "_")[:50] or "index"
                    filename = f"{int(time.time())}_{domain}_{path_part}.md"

                    # 完整檔案路徑
                    filepath = SAVE_DIR / filename

                    # 寫入檔案
                    with open(filepath, "w", encoding="utf-8") as f:
                        header = f"<!-- Source: {url} -->\n<!-- Saved: {time.strftime('%Y-%m-%d %H:%M:%S')} -->\n\n"
                        f.write(header + markdown_content)

                    saved_files.append(str(filepath))  # 建議轉成字串
                    results_summary.append(f"✅ 成功: {url} → {filepath}")

                else:
                    status = getattr(result, 'status_code', '未知错误')
                    results_summary.append(f"❌ 失败: {url} (状态码: {status})")

    except Exception as e:
        return f"🚨 爬虫系统崩溃: {str(e)}"

    # 回傳給 agent 的結果
    final_output = (
            f"### 批量抓取完成 ###\n"
            f"已成功保存 {len(saved_files)} 个文件。\n"
            f"儲存目錄: {SAVE_DIR}\n"
            f"详情:\n" + "\n".join(results_summary)
    )

    if saved_files:
        final_output += "\n\n已保存的文件列表（可供後續讀取）:\n" + "\n".join(saved_files)

    return final_output