from tools.base_tool import BaseTool
import requests
import base64
import tempfile
from urllib.parse import urljoin


class GetAttachmentTool(BaseTool):
    name = "get_attachment"
    description = """
    Downloads an attachment linked to the current GAIA task.
    Supported formats for response are: URL, DATA_URL, LOCAL_FILE_PATH, or TEXT.
    """

    inputs = {
        "fmt": {
            "type": "string",
            "description": "Choose response format: URL, DATA_URL, LOCAL_FILE_PATH, or TEXT.",
            "nullable": True,
            "default": "URL",
        }
    }
    output_type = "string"

    def __init__(self, evaluation_api: str | None = None, task_id: str | None = None, **kwargs):
        # Default GAIA evaluation API endpoint
        self.evaluation_api = evaluation_api or "https://agents-course-unit4-scoring.hf.space/"
        self.task_id = task_id
        super().__init__(**kwargs)

    def attachment_for(self, task_id: str | None):
        """Set the current GAIA task ID."""
        self.task_id = task_id

    def forward(self, fmt: str = "URL") -> str:
        fmt = fmt.upper()
        assert fmt in {"URL", "DATA_URL", "LOCAL_FILE_PATH", "TEXT"}

        if not self.task_id:
            return "No task_id provided to fetch the attachment."

        file_url = urljoin(self.evaluation_api, f"files/{self.task_id}")

        if fmt == "URL":
            return file_url

        # Download the file
        resp = requests.get(file_url)
        if 400 <= resp.status_code < 500:
            raise ValueError(f"Failed to retrieve attachment: {resp.status_code} {resp.reason}")

        resp.raise_for_status()
        content_type = resp.headers.get("content-type", "text/plain")

        if fmt == "TEXT":
            if content_type.startswith("text/"):
                return resp.text
            else:
                raise ValueError(f"Cannot extract text from content-type: {content_type}")

        if fmt == "DATA_URL":
            b64 = base64.b64encode(resp.content).decode("utf-8")
            return f"data:{content_type};base64,{b64}"

        if fmt == "LOCAL_FILE_PATH":
            with tempfile.NamedTemporaryFile(delete=False) as tmp_file:
                tmp_file.write(resp.content)
                return tmp_file.name

        raise ValueError(f"Unsupported format: {fmt}")