import os
import pandas as pd
from typing import Any, Dict, List, Union
from langchain_community.document_loaders import (
    TextLoader,
    PyPDFLoader,
    UnstructuredWordDocumentLoader,
    UnstructuredPowerPointLoader,
)
from langchain_core.tools import tool


def load_file(file_path: str) -> str:
    """Load a file as str.
    Args:
        file_path: Path to the file.
    Returns:
        str: Content of the file.
    Raises:
        ValueError: If file type is unsupported.
    """
    ext = os.path.splitext(file_path)[-1].lower()
    if ext in (".csv", ".xlsx", ".xls"):
        if ext == ".csv":
            df = pd.read_csv(file_path)
        else:
            df = pd.read_excel(file_path)
        return df
    elif ext in (".txt", ".pdf", ".docx", ".doc", ".pptx", ".ppt"):
        if ext == ".txt":
            loader = TextLoader(file_path, encoding="utf8")
        elif ext == ".pdf":
            loader = PyPDFLoader(file_path)
        elif ext in (".docx", ".doc"):
            loader = UnstructuredWordDocumentLoader(file_path)
        elif ext in (".pptx", ".ppt"):
            loader = UnstructuredPowerPointLoader(file_path)
        docs = loader.load()
        if len(docs) > 0:
            doc = docs[0]
            return doc.page_content
        else:
            return "No content found in the file"
    else:
        raise ValueError(f"Unsupported file extension: {ext}")


@tool
def file_loader_tool(file_path: str) -> str:
    """Loads a file (csv, xlsx, txt, pdf, docx, etc.) and returns its content as a string.
    Args:
        file_path (str): Path to the file to load.
    """
    doc = load_file(file_path)
    return doc


if __name__ == "__main__":
    print(file_loader_tool.invoke("7bd855d8-463d-4ed5-93ca-5fe35145f733.xlsx"))
    print(file_loader_tool.invoke("test.txt"))