import requests
import io
import base64
import openai
from openai import OpenAI
from smolagents import tool
import os
import pandas as pd
import functools
from typing import List, Optional, Dict, Any
import sys

import av
from yt_dlp import YoutubeDL

from PIL import Image
import wikipediaapi
import tempfile

model_id = "gpt-4.1"


@tool
def read_image(query: str, img_url: str) -> str:
    """
    Use a visual question answering (VQA) model to generate a response to a query based on an image.

    Args:
        query (str): A natural language question about the image.
        img_url (str): The URL of the image to analyze.

    Returns:
        str: A response generated by the VQA model based on the provided image and question.
    """
    client = OpenAI()
    response = client.responses.create(
        model=model_id,
        input=[
            {
                "role": "user",
                "content": [
                    {"type": "input_text", "text": query},
                    {
                        "type": "input_image",
                        "image_url": img_url,
                    },
                ],
            }
        ],
    )
    return response.output_text


@tool
def read_code(file_url: str) -> str:
    """
    Read the contents of a code file such as py file instead of executing it. Use this tool to analyze a code snippet.

    Args:
        file_url (str): The URL of the code file to retrieve.

    Returns:
        str: The content of the file as a string.
    """
    response = requests.get(file_url)
    response.raise_for_status()
    return response.text


@tool
def transcribe_audio(file_url: str, file_name: str) -> str:
    """
    Download and transcribe an audio file using transcription model.

    Args:
        file_url (str): Direct URL to the audio file (e.g., .mp3, .wav).
        file_name (str): Filename including extension, used to determine format.

    Returns:
        str: The transcribed text from the audio file.
    """
    # Download audio content
    response = requests.get(file_url)
    response.raise_for_status()

    # Extract extension (fallback to mp3 if missing)
    extension = file_name.split(".")[-1].lower() or "mp3"

    # Wrap bytes in a file-like object with a valid name
    audio_file = io.BytesIO(response.content)
    audio_file.name = f"audio.{extension}"

    # Create OpenAI client and transcribe
    client = OpenAI()
    transcription = client.audio.transcriptions.create(
        model="gpt-4o-transcribe", file=audio_file
    )

    return transcription.text


### set of functions for youtube video processing
def _pytube_buffer(url: str) -> Optional[io.BytesIO]:
    try:
        from pytube import YouTube

        yt = YouTube(url)
        stream = (
            yt.streams.filter(progressive=True, file_extension="mp4")
            .order_by("resolution")
            .desc()
            .first()
        )
        if stream is None:  # no progressive stream
            raise RuntimeError("No MP4 with audio found")
        buf = io.BytesIO()
        stream.stream_to_buffer(buf)  # PyTube’s built-in helper
        buf.seek(0)
        return buf
    except Exception as e:
        print(f"[youtube_to_buffer] PyTube failed → {e}", file=sys.stderr)
        return None  # trigger fallback


def _ytdlp_buffer(url: str) -> io.BytesIO:
    """
    Return a BytesIO containing some MP4 video stream for `url`.
    Works whether YouTube serves a progressive file or separate A/V.
    """
    ydl_opts = {
        "quiet": True,
        "skip_download": True,
        "format": "bestvideo[ext=mp4]/best[ext=mp4]/best",
    }
    with YoutubeDL(ydl_opts) as ydl:
        info = ydl.extract_info(url, download=False)
        if "entries" in info:  # playlists
            info = info["entries"][0]

    if "url" in info:
        video_urls = [info["url"]]

    elif "requested_formats" in info:
        video_urls = [
            fmt["url"]
            for fmt in info["requested_formats"]
            if fmt.get("vcodec") != "none"  # keep only video
        ]
        if not video_urls:
            raise RuntimeError("yt-dlp returned audio-only formats")

    else:
        raise RuntimeError("yt-dlp could not extract a stream URL")

    buf = io.BytesIO()
    for direct_url in video_urls:
        with requests.get(direct_url, stream=True) as r:
            r.raise_for_status()
            for chunk in r.iter_content(chunk_size=1 << 16):
                buf.write(chunk)

    buf.seek(0)
    return buf


@functools.lru_cache(maxsize=8)  # tiny cache so repeat calls are fast
def youtube_to_buffer(url: str) -> io.BytesIO:
    """

    Return a BytesIO containing a single progressive MP4
    (H.264 + AAC) – the safest thing PyAV can open everywhere.
    """
    ydl_opts = {
        "quiet": True,
        "skip_download": True,
        # progressive (has both audio+video) • mp4 • h264
        "format": (
            "best[ext=mp4][vcodec^=avc1][acodec!=none]"
            "/best[ext=mp4][acodec!=none]"  # fallback: any prog-MP4
        ),
    }

    with YoutubeDL(ydl_opts) as ydl:
        info = ydl.extract_info(url, download=False)
        if "entries" in info:  # playlists → first entry
            info = info["entries"][0]

    direct_url = info.get("url")
    if not direct_url:
        raise RuntimeError("yt-dlp could not find a progressive MP4 track")

    # Stream it straight into RAM
    buf = io.BytesIO()
    with requests.get(direct_url, stream=True) as r:
        r.raise_for_status()
        for chunk in r.iter_content(chunk_size=1 << 17):  # 128 kB
            buf.write(chunk)

    buf.seek(0)
    return buf


def sample_frames(video_bytes: io.BytesIO, n_frames: int = 6) -> List[Image.Image]:
    """Decode `n_frames` uniformly spaced RGB frames as PIL images."""
    container = av.open(video_bytes, metadata_errors="ignore")
    video = container.streams.video[0]
    total = video.frames or 0

    # If PyAV couldn't count frames (‐1), fall back to timestamp spacing
    step = max(1, total // n_frames) if total else 30

    frames: list[Image.Image] = []
    for i, frame in enumerate(container.decode(video=0)):
        if i % step == 0:
            frames.append(frame.to_image())
        if len(frames) >= n_frames:
            break
    container.close()
    return frames


def pil_to_data_url(img: Image.Image, quality: int = 80) -> str:
    buf = io.BytesIO()
    img.save(buf, format="JPEG", quality=quality, optimize=True)
    b64 = base64.b64encode(buf.getvalue()).decode()
    return f"data:image/jpeg;base64,{b64}"


def save_audio_stream_to_temp_wav_file(video_bytes: io.BytesIO) -> Optional[str]:
    """
    Extracts the audio stream from video_bytes, saves it as a temporary WAV file,
    and returns the path to the file.
    Returns None if no audio stream is found or an error occurs.
    """
    try:
        video_bytes.seek(0)  # Ensure buffer is at the beginning
        input_container = av.open(video_bytes, metadata_errors="ignore")

        if not input_container.streams.audio:
            print("No audio streams found in the video.", file=sys.stderr)
            return None
        input_audio_stream = input_container.streams.audio[0]

        # Create a temporary file with .wav suffix
        # delete=False because we need to pass the path to another process (Whisper)
        # and we will manually delete it later.
        with tempfile.NamedTemporaryFile(delete=False, suffix=".wav") as tmp_file:
            temp_audio_file_path = tmp_file.name

        output_container = av.open(temp_audio_file_path, mode="w", format="wav")

        # For WAV, a common codec is pcm_s16le (16-bit signed PCM).
        # Use the input stream's sample rate.
        # Determine channel layout (e.g., 'stereo', 'mono')
        channel_layout = "stereo"  # Default
        if (
            hasattr(input_audio_stream.codec_context, "layout")
            and input_audio_stream.codec_context.layout
        ):
            channel_layout = input_audio_stream.codec_context.layout.name
        elif (
            hasattr(input_audio_stream.codec_context, "channels")
            and input_audio_stream.codec_context.channels == 1
        ):
            channel_layout = "mono"

        output_audio_stream = output_container.add_stream(
            "pcm_s16le",
            rate=input_audio_stream.codec_context.sample_rate,
            layout=channel_layout,
        )

        for frame in input_container.decode(input_audio_stream):
            # PyAV decodes audio into AudioFrame objects.
            # These frames need to be encoded by the output stream's codec.
            for packet in output_audio_stream.encode(frame):
                output_container.mux(packet)

        # Flush any remaining frames from the encoder
        for packet in output_audio_stream.encode():
            output_container.mux(packet)

        output_container.close()
        input_container.close()
        return temp_audio_file_path

    except Exception as e:
        print(f"Error extracting audio to temp WAV file: {e}", file=sys.stderr)
        # Clean up if temp file path was assigned and file exists
        if "temp_audio_file_path" in locals() and os.path.exists(temp_audio_file_path):
            os.remove(temp_audio_file_path)
        return None


@tool
def run_video(query: str, url: str) -> str:
    """
    Get a YouTube video from url and return an answer to a natural-language query using the video.

    Args:
        query (str):  A natural-language question whose answer is expected to be found in the visual content of the video.
        url (str): Fully qualified URL of the YouTube video to analyze.

    Returns:
        str: A response generated by the VQA model based on the provided video and question.
    """
    n_frames = 4
    buff = youtube_to_buffer(url)
    if buff is None:
        return "Error: Could not download or buffer the video."

    # 1. Sample visual frames
    frames = sample_frames(buff, n_frames=n_frames)
    buff.seek(0)  # Reset buffer pointer for audio extraction

    # 2. Extract and Transcribe Audio
    transcript = "[Audio could not be processed]"
    audio_file_path = None
    try:
        audio_file_path = save_audio_stream_to_temp_wav_file(buff)
        if audio_file_path:
            with open(audio_file_path, "rb") as audio_data:
                # Make sure you have the OpenAI client initialized, e.g., client = openai.OpenAI()
                transcription_response = openai.audio.transcriptions.create(
                    model="gpt-4o-transcribe", file=audio_data
                )
                transcript = transcription_response.text
        else:
            transcript = "[No audio stream found or error during extraction]"
            print(
                "No audio file path returned, skipping transcription.", file=sys.stderr
            )
    except Exception as e:
        print(f"Error during audio transcription: {e}", file=sys.stderr)
        transcript = f"[Error during audio transcription: {e}]"
    finally:
        if audio_file_path and os.path.exists(audio_file_path):
            os.remove(audio_file_path)  # Clean up the temporary audio file

    # 3. Prepare content for the AI model (text query, transcript, and images)
    prompt_text = f"Original Query: {query}\n\nVideo Transcript:\n{transcript}\n\nKey Visual Frames (analyze these along with the transcript to answer the query):"

    content = [{"type": "text", "text": prompt_text}]

    for img in frames:
        content.append(
            {
                "type": "image_url",
                "image_url": {"url": pil_to_data_url(img)},
            }
        )

    # 4. Send to AI model
    try:
        resp = openai.chat.completions.create(
            model=model_id,
            messages=[{"role": "user", "content": content}],
            temperature=0.1,
        )
        result = resp.choices[0].message.content.strip()
    except Exception as e:
        print(f"Error calling OpenAI API: {e}", file=sys.stderr)
        result = f"[Error processing with AI model: {e}]"

    return result


## Read video only, ignore audio
# @tool
# def run_video(query: str, url: str) -> str:
#     """
#     Get a YouTube video from url and return an answer to a natural-language query using the video.

#     Args:
#         query (str):  A natural-language question whose answer is expected to be found in the visual content of the video.
#         url (str): Fully qualified URL of the YouTube video to analyze.

#     Returns:
#         str: A response generated by the VQA model based on the provided video and question.
#     """
#     buff = youtube_to_buffer(url)
#     n_frames = 8
#     frames = sample_frames(buff, n_frames=n_frames)

#     content = [{"type": "text", "text": query}] + [
#         {
#             "type": "image_url",
#             "image_url": {"url": pil_to_data_url(img)},
#         }
#         for img in frames
#     ]

#     resp = openai.chat.completions.create(
#         model="gpt-4.1-mini",
#         messages=[{"role": "user", "content": content}],
#         temperature=0.1,
#     )
#     return resp.choices[0].message.content.strip()


# Helper functions for processing different file types
def process_image(response, filename, content_type):
    """Process image files - convert to base64 data URL for vision models"""
    img_data = base64.b64encode(response.content).decode("utf-8")
    data_url = f"data:{content_type};base64,{img_data}"

    return {
        "file_type": "image",
        "filename": filename,
        "content_type": content_type,
        "data_url": data_url,
    }


def process_audio(response, filename, content_type):
    """Process audio files - either return data URL or save to temp file for processing"""
    audio_data = base64.b64encode(response.content).decode("utf-8")
    data_url = f"data:{content_type};base64,{audio_data}"

    # For compatibility with audio processing tools, save to temp file
    audio_file = io.BytesIO(response.content)
    extension = os.path.splitext(filename)[1].lower() or ".mp3"
    audio_file.name = f"audio{extension}"  # Some libraries need filename

    return {
        "file_type": "audio",
        "filename": filename,
        "content_type": content_type,
        "data_url": data_url,
        "audio_buffer": audio_file,  # Include buffer for processing
    }


def process_video(response, filename, content_type):
    """Process video files - save to buffer and extract frames"""
    video_buffer = io.BytesIO(response.content)

    # Option to extract frames - similar to what run_video does
    try:
        frames = sample_frames(video_buffer, n_frames=4)  # Reuse existing function
        frame_urls = [pil_to_data_url(img) for img in frames]
        frame_extraction_success = True
    except Exception:
        frame_urls = []
        frame_extraction_success = False

    return {
        "file_type": "video",
        "filename": filename,
        "content_type": content_type,
        "video_buffer": video_buffer,
        "frame_urls": frame_urls,
        "frames_extracted": frame_extraction_success,
    }


def process_tabular(response, filename, content_type):
    """Process spreadsheet files using pandas"""
    excel_buffer = io.BytesIO(response.content)

    try:
        # Determine format based on extension
        if filename.lower().endswith(".csv"):
            df = pd.read_csv(excel_buffer)
        else:  # Excel formats
            df = pd.read_excel(excel_buffer)

        return {
            "file_type": "tabular",
            "filename": filename,
            "content_type": content_type,
            "data": df.to_dict(orient="records"),
            "columns": df.columns.tolist(),
            "shape": df.shape,
        }
    except Exception as e:
        # Fallback if parsing fails
        return {
            "file_type": "tabular",
            "filename": filename,
            "content_type": content_type,
            "error": f"Failed to parse tabular data: {e}",
            "raw_data": base64.b64encode(response.content).decode("utf-8"),
        }


def process_text(response, filename, content_type):
    """Process text files (code, plain text, etc.)"""
    try:
        text_content = response.text
        return {
            "file_type": "text",
            "filename": filename,
            "content_type": content_type,
            "content": text_content,
            "extension": os.path.splitext(filename)[
                1
            ],  # Useful for syntax highlighting
        }
    except Exception as e:
        return {
            "file_type": "text",
            "filename": filename,
            "content_type": content_type,
            "error": f"Failed to decode text: {e}",
            "raw_data": base64.b64encode(response.content).decode("utf-8"),
        }


def process_json(response, filename, content_type):
    """Process JSON data"""
    try:
        json_data = response.json()
        return {
            "file_type": "json",
            "filename": filename,
            "content_type": content_type,
            "data": json_data,
        }
    except Exception:
        # Try as text if JSON parsing fails
        return process_text(response, filename, content_type)


def process_pdf(response, filename, content_type):
    """Process PDF files - return as binary with metadata"""
    # Simple version - just return binary for now
    # Could be enhanced with PDF text extraction libraries
    pdf_data = base64.b64encode(response.content).decode("utf-8")

    return {
        "file_type": "pdf",
        "filename": filename,
        "content_type": content_type,
        "data": pdf_data,
    }


def process_binary(response, filename, content_type):
    """Process other binary files (fallback handler)"""
    binary_data = base64.b64encode(response.content).decode("utf-8")

    return {
        "file_type": "binary",
        "filename": filename,
        "content_type": content_type,
        "data": binary_data,
    }


@tool
def fetch_task_files(url: str) -> Dict[str, Any]:
    """
    Download and process files from a given URL. This tool detects the file type and returns the data in a suitable format for further processing.

    For different file types, this tool returns:

    - Images: Returns a data_url that can be directly used with the read_image tool
      Example: result = fetch_task_files(url); then use read_image(question, result["data_url"])

    - Audio: Returns audio data that can be used with the transcribe_audio tool
      Example: result = fetch_task_files(url); then use transcribe_audio(result["data_url"], result["filename"])

    - Video: Returns frame extractions and a video buffer for processing with run_video
      Example: result = fetch_task_files(url); you can access frames via result["frame_urls"]

    - Tabular data (Excel/CSV): Returns parsed data as records, column names, and dimensions
      Example: result = fetch_task_files(url); then analyze data with result["data"] and result["columns"]

    - Text/Code: Returns the content as text for analysis
      Example: result = fetch_task_files(url); then access text via result["content"]

    - PDFs & other files: Returns encoded file data for processing

    All responses include metadata like file_type, filename, and content_type to help determine how to handle the file.

    Args:
        url (str): Direct URL to the file to download. For task files, construct using the API base URL
                  and the task ID (e.g., "https://agents-course-unit4-scoring.hf.space/files/{task_id}")

    Returns:
        dict: A dictionary with file data and metadata structured for the specific file type
    """
    files_url = url
    print(f"Fetching file from: {files_url}")

    try:
        response = requests.get(files_url, timeout=15)
        response.raise_for_status()

        # Extract metadata
        content_type = response.headers.get("Content-Type", "").lower()
        filename = response.headers.get("content-disposition", "")
        if "filename=" in filename:
            filename = filename.split("filename=")[-1].strip('"')
        else:
            filename = "file.bin"  # Default filename

        print(f"Received file: {filename}, type: {content_type}")

        # Route to appropriate helper based on content type or file extension
        if "image/" in content_type or any(
            filename.lower().endswith(ext) for ext in [".png", ".jpg", ".jpeg", ".gif"]
        ):
            return process_image(response, filename, content_type)

        elif "audio/" in content_type or any(
            filename.lower().endswith(ext) for ext in [".mp3", ".wav", ".ogg"]
        ):
            return process_audio(response, filename, content_type)

        elif "video/" in content_type or any(
            filename.lower().endswith(ext) for ext in [".mp4", ".avi", ".mov"]
        ):
            return process_video(response, filename, content_type)

        elif (
            "spreadsheet" in content_type
            or "excel" in content_type
            or any(filename.lower().endswith(ext) for ext in [".xlsx", ".xls", ".csv"])
        ):
            return process_tabular(response, filename, content_type)

        elif (
            "text/" in content_type
            or "code" in content_type
            or any(
                filename.lower().endswith(ext)
                for ext in [".txt", ".py", ".js", ".html", ".md"]
            )
        ):
            return process_text(response, filename, content_type)

        elif "application/json" in content_type or filename.lower().endswith(".json"):
            return process_json(response, filename, content_type)

        elif "application/pdf" in content_type or filename.lower().endswith(".pdf"):
            return process_pdf(response, filename, content_type)

        else:
            # Default fallback for binary files
            return process_binary(response, filename, content_type)

    except requests.exceptions.RequestException as e:
        print(f"Error fetching url: {files_url} - {e}")
        return {"error": f"Error fetching files: {e}"}
    except Exception as e:
        print(f"An unexpected error occurred fetching files from url: {files_url}- {e}")
        return {"error": f"An unexpected error occurred: {e}"}


@tool
def search_wikipedia(query: str) -> str:
    """
    get the contents of wikipedia page retrieved by search query.

    Args:
        query (str):  A search term to search within wikipedia. Ideally it should be one word or a group of few words.

    Returns:
        str: The text content of wikipedia page
    """
    get_wiki = wikipediaapi.Wikipedia(
        language="en",
        user_agent="test_tokki",
        extract_format=wikipediaapi.ExtractFormat.WIKI,
    )
    page_content = get_wiki.page(query)
    text_content = page_content.text

    cutoff = 25000
    text_content = " ".join(text_content.split(" ")[:cutoff])
    return text_content


if __name__ == "__main__":
    # Simple test for fetch_task_files with direct URLs
    api_base = "https://agents-course-unit4-scoring.hf.space"
    test_urls = [
        f"{api_base}/files/cca530fc-4052-43b2-b130-b30968d8aa44",
        f"{api_base}/files/99c9cc74-fdc8-46c6-8f8d-3ce2d3bfeea3",
        f"{api_base}/files/7bd855d8-463d-4ed5-93ca-5fe35145f733",
    ]

    for url in test_urls:
        print(
            "=" * 20
            + " "
            + f"Testing fetch_task_files with URL: {url}"
            + " "
            + "=" * 20
        )

        result = fetch_task_files(url)
        print(f"File type: {result.get('file_type')}")
        print(f"Filename: {result.get('filename')}")