import os
import io
import time
import zipfile
import requests
from pathlib import Path

API_BASE = "https://mineru.net/api/v4"
DEFAULT_MINERU_FIELDS = {
    "return_middle_json": "false",
    "return_model_output": "false",
    "return_md": "true",
    "return_images": "false",
    "end_page_id": "99999",
    "parse_method": "auto",
    "start_page_id": "0",
    "lang_list": "ch",
    "output_dir": "./output",
    "server_url": "string",
    "return_content_list": "false",
    "backend": "hybrid-auto-engine",
    "table_enable": "true",
    "response_format_zip": "false",
    "formula_enable": "true",
}

class MinerUClient:
    def __init__(self, token: str | None = None):
        self.token = token or ""
        self.headers = {
            "Content-Type": "application/json"
        }
        if self.token:
            self.headers["Authorization"] = f"Bearer {self.token}"
        self.result = None

    def parse_file(self, file_path: str, model_version="vlm"):
        """上传单个文件到 MinerU 并启动解析"""
        if os.getenv("MinerU_URL"):
            return self.parse_file_api(file_path)

        resp = requests.post(
            f"{API_BASE}/file-urls/batch",
            headers=self.headers,
            json={"files": [{"name": os.path.basename(file_path)}], "model_version": model_version}
        )
        resp.raise_for_status()
        data = resp.json()["data"]
        batch_id = data["batch_id"]
        upload_url = data["file_urls"][0]

        print(f"[INFO] 上传文件: {file_path}")
        with open(file_path, "rb") as f:
            put_resp = requests.put(upload_url, data=f)
            put_resp.raise_for_status()

        print(f"[INFO] 等待 MinerU 解析文件 {os.path.basename(file_path)} ...")
        while True:
            res = requests.get(
                f"{API_BASE}/extract-results/batch/{batch_id}",
                headers=self.headers
            ).json()
            states = [r["state"] for r in res["data"]["extract_result"]]
            if all(s == "done" for s in states):
                print(f"[INFO] 文件解析完成: {os.path.basename(file_path)}")
                self.result = res
                return res
            elif any(s == "failed" for s in states):
                raise RuntimeError(f"[INFO] MinerU 解析失败: {file_path}")
            time.sleep(10)

    def parse_file_api(self, file_path: str, fields: dict | None = None):
        """通过本地/私有 MinerU API 解析文件（/file_parse）。"""
        api_url = os.getenv("MinerU_URL")
        if not api_url:
            raise RuntimeError("MinerU_URL 未配置")

        data = {**DEFAULT_MINERU_FIELDS, **(fields or {})}
        file_name = os.path.basename(file_path)
        with open(file_path, "rb") as f:
            files = {
                "files": (file_name, f, "application/octet-stream")
            }
            resp = requests.post(api_url, data=data, files=files, headers={"accept": "application/json"})
            resp.raise_for_status()
            self.result = resp.json()
            return self.result

    def download_result(self, save_dir="mineru_result"):
        """下载并解压 MinerU 结果"""
        if os.getenv("MinerU_URL"):
            raise RuntimeError("MinerU_URL 模式不支持下载 zip 结果")

        zip_url = self.result["data"]["extract_result"][0]["full_zip_url"]
        print(f"[INFO] 下载解析结果: {zip_url}")
        res = requests.get(zip_url)
        res.raise_for_status()
        zf = zipfile.ZipFile(io.BytesIO(res.content))
        os.makedirs(save_dir, exist_ok=True)
        zf.extractall(save_dir)
        print(f"[INFO] 已解压到 {save_dir}/")
        return save_dir


# ✅ 新增函数：统一批量解析接口
def extract_texts_with_mineru(input_dir: str, save_dir: str = "./mineru_result") -> str:
    """
    批量调用 MinerU 解析 input_dir 下的所有文件，并合并结果为纯文本。
    返回合并后的文本文件路径。
    """
    mineru_token = os.getenv("MinerU_API_KEY")  # 可从环境变量读取
    client = MinerUClient(token=mineru_token)

    input_path = Path(input_dir)
    os.makedirs(save_dir, exist_ok=True)
    output_file = Path(save_dir) / "all_knowledge.txt"

    print(f"[INFO] 开始批量解析目录: {input_path}")
    all_texts = []

    for file in input_path.iterdir():
        if not file.is_file():
            continue
        if file.suffix.lower() not in [".pdf", ".docx", ".xlsx", ".pptx", ".txt"]:
            print(f"[INFO] 跳过不支持的文件类型: {file.name}")
            continue

        try:
            # 调用 MinerU 解析
            client.parse_file(str(file))
            result_dir = client.download_result(save_dir)

            # 查找 full.md 文件
            for md_path in Path(result_dir).rglob("full.md"):
                with open(md_path, "r", encoding="utf-8") as f:
                    content = f.read().strip()
                    all_texts.append(f"\n# {file.name}\n{content}")

        except Exception as e:
            print(f"[INFO] 解析失败: {file.name} ({type(e).__name__}: {e})")

    # 合并所有内容
    if all_texts:
        with open(output_file, "w", encoding="utf-8") as f:
            f.write("\n\n".join(all_texts))
        print(f"[INFO] 已合并所有 MinerU 输出 -> {output_file}")
    else:
        print(f"[INFO] 未成功解析任何文件。")

    return str(output_file)