from langchain_core.tools import tool
import datetime
import requests
import openai
import os
import tempfile
import pandas as pd
from urllib.parse import urlparse, parse_qs
from openai import OpenAI
from youtube_transcript_api import YouTubeTranscriptApi
from youtube_transcript_api._errors import TranscriptsDisabled, NoTranscriptFound, VideoUnavailable
from pytube import extract
from openai import OpenAI
from bs4 import BeautifulSoup
from io import BytesIO
from PyPDF2 import PdfReader

@tool
def add(a: float, b: float) -> float:
    """ Adds two numbers.
    Args:
        a (float): first number
        b (float): second number
    """
    return a + b

@tool
def subtract(a: float, b: float) -> int:
    """ Subtracts two numbers.
    Args:
        a (float): first number
        b (float): second number
    """
    return a - b

@tool
def multiply(a: float, b: float) -> float:
    """ Multiplies two numbers.
    Args:
        a (float): first number
        b (float): second number
    """
    return a * b
    
@tool
def divide(a: float, b: float) -> float:
    """ Divides two numbers.
    Args:
        a (float): first number
        b (float): second number
    """
    if b == 0:
        raise ValueError("Cannot divide by zero.")
    return a / b

@tool
def power(a: float, b: float) -> float:
    """ Calculates the power of two numbers.
    Args:
        a (float): first number
        b (float): second number
    """
    return a**b

calculator_basic = [add, subtract, multiply, divide, power]


@tool
def current_date(_) -> str :
    """ Returns the current date in YYYY-MM-DD format """
    return datetime.datetime.now().strftime("%Y-%m-%d")

@tool
def day_of_week(_) -> str :
    """ Returns the current day of the week (e.g., Monday, Tuesday) """
    return datetime.datetime.now().strftime("%A")

@tool
def days_until(date_str: str) -> str :
    """ Returns the number of days from today until a given date (input format: YYYY-MM-DD) """
    try:
        future_date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
        today = datetime.date.today()

        delta_days = (future_date - today).days
        return f"{delta_days} days until {date_str}"
    except Exception as e:
        return f"Error parsing date: {str(e)}"

datetime_tools = [current_date, day_of_week, days_until]


@tool
def transcribe_audio(audio_file: str, file_extension: str) -> str:
    """ Transcribes an audio file to text
    Args:
        audio_file (str): local file path to the audio file (.mp3, .m4a, etc.)
        file_extension (str): file extension of the audio, e.g. mp3
    Returns:
        str: The transcribed text from the audio.
    """
    try:
        response = requests.get(audio_file)  # download the audio_file
        response.raise_for_status()  # check if the http request was successful
        
        # clean file extension and save to disk
        file_extension = file_extension.replace('.','')
        filename = f'tmp.{file_extension}'
        with open(filename, 'wb') as file:  # opens a new file for writing with a name like, e.g. tmp.mp3
            file.write(response.content)    # write(w) the binary(b) contents (audio file) to disk
        
        # transcribe audio with OpenAI Whisper
        client = OpenAI()
        
        # read(r) the audio file from disk in binary(b) mode "rb"; the "with" block ensures the file is automatically closed afterward
        with open(filename, "rb") as audio_content:
            transcription = client.audio.transcriptions.create(
                model="whisper-1",
                file=audio_content
            )
        return transcription.text

    except Exception as e:
        return f"transcribe_audio failed: {e}"

@tool
def transcribe_youtube(youtube_url: str) -> str:
    """ Transcribes a YouTube video
    Args:
        youtube_url (str): youtube video's url
    Returns:
        str: The transcribed text from the video.
    """
    try:
        query = urlparse(youtube_url).query
        video_id = parse_qs(query)['v'][0]
    except Exception:
        return "invalid YouTube URL"
        
    try:
        transcript_list = YouTubeTranscriptApi.list_transcripts(video_id)
        transcript = transcript_list.find_transcript(['en']).fetch()
        # keep only text
        text = '\n'.join([t['text'] for t in transcript])
        return text

    except (TranscriptsDisabled, NoTranscriptFound, VideoUnavailable) as e:
        return f"transcript unavailable: {str(e)}"
    
    except Exception as e:
        return f"transcribe_youtube failed: {e}"

@tool
def query_image(query: str, image_url: str) -> str:
    """ Ask anything about an image using a Vision Language Model
    Args:
        query (str): the query about the image, e.g. how many animals are on the image?
        image_url (str): the image's URL
    """
    try:
        client = OpenAI()
        response = client.responses.create(
            model="gpt-4o-mini",
            input=[
                {
                    "role": "user",
                    "content": [
                        {"type": "input_text", "text": query},
                        {"type": "input_image","image_url": image_url},
                    ],
                }
            ],
        )
        return response.output_text

    except Exception as e:
        return f"query_image failed: {e}"

@tool
def webpage_content(url: str) -> str:
    """ Fetch text from a webpage or PDF file.
    Args:
        url (str): The URL of the webpage to fetch.
    Returns:
        str: Extracted text.
    """
    try:
        response = requests.get(url)
        response.raise_for_status()

        content_type = response.headers.get("Content-Type", "")

        # PDF file
        if "pdf" in content_type:
            pdf_content = BytesIO(response.content)
            reader = PdfReader(pdf_content)
            return "\n".join(page.extract_text() or "" for page in reader.pages)

        # HTML file
        soup = BeautifulSoup(response.text, "html.parser")
        body = soup.body
        return body.get_text(separator="\n", strip=True) if body else soup.get_text(strip=True)

    except Exception as e:
        return f"webpage_content failed: {e}"

@tool
def read_excel(file_url: str) -> str:
    """ Reads an Excel file from a URL and returns the content as CSV text.
    Args:
        file_url (str): URL to the Excel file (.xlsx, .xls)
    Returns:
        str: Content of the Excel file as CSV text.
    """
    try:
        response = requests.get(file_url)
        response.raise_for_status()

        excel_content = BytesIO(response.content)
        df = pd.read_excel(excel_content)
        
        return df.to_csv(index=False)  # convert dataframe to CSV string for easy processing

    except Exception as e:
        return f"read_excel failed: {str(e)}"