from __future__ import annotations

"""Comprehensive, **key‑free** toolset for the LangGraph agent.
Every tool is fully self‑contained and safe to run inside a public
Hugging Face Space – no private API keys required.
Capabilities covered (GAIA L1):
• general web search  • Wikipedia summary  • light image inspection
• basic math          • current time        • YouTube video metadata
• inspect Excel files
"""

import datetime
import io
import math
import pathlib
import re
import statistics
from typing import List, Dict, Any

import pandas as pd
import requests
from bs4 import BeautifulSoup
from langchain.tools import tool, BaseTool
from PIL import Image
from pytube import YouTube


# ---------------------------------------------------------------------------
# Helper utilities -----------------------------------------------------------
# ---------------------------------------------------------------------------

def _html_text(soup: BeautifulSoup) -> str:
    return re.sub(r"\s+", " ", soup.get_text(" ").strip())


# ---------------------------------------------------------------------------
# Time & math ----------------------------------------------------------------
# ---------------------------------------------------------------------------

@tool
def get_current_time() -> str:
    """Return the current UTC time (ISO‑8601)."""
    return datetime.datetime.utcnow().isoformat()


@tool
def calculator(expression: str) -> str:
    """Evaluate an arithmetic **expression** (e.g. "2 + 2*3").
    Supported tokens: numbers, + ‑ * / ** % ( ), and constants/funcs from math.*
    Returns the result or an error message.
    """

    allowed_names = {
        k: v for k, v in math.__dict__.items() if not k.startswith("__")
    }
    try:
        result = eval(expression, {"__builtins__": {}}, allowed_names)
        return str(result)
    except Exception as exc:  # pylint: disable=broad-except
        return f"Error: {exc}"


# ---------------------------------------------------------------------------
# Web search & Wikipedia -----------------------------------------------------
# ---------------------------------------------------------------------------

_DDG_URL = "https://duckduckgo.com/html/"
_WIKI_API = "https://en.wikipedia.org/api/rest_v1/page/summary/{}"


@tool
def web_search(query: str, max_results: int = 6) -> List[Dict[str, str]]:
    """Return *max_results* DuckDuckGo hits for **query**.
    Each hit is a dict with keys: title, url, snippet.
    """
    params = {"q": query, "s": "0"}
    html = requests.post(_DDG_URL, data=params, timeout=10).text
    soup = BeautifulSoup(html, "lxml")

    results = []
    for a in soup.select("a.result__a", limit=max_results):
        title = _html_text(a)
        url = a["href"]
        snippet_tag = a.find_parent(class_="result").select_one(".result__snippet")
        snippet = _html_text(snippet_tag) if snippet_tag else ""
        results.append({"title": title, "url": url, "snippet": snippet})
    return results


@tool
def wikipedia_summary(title: str) -> str:
    """Return the lead paragraph of a Wikipedia page by **title**."""
    url = _WIKI_API.format(requests.utils.quote(title))
    resp = requests.get(url, timeout=10)
    if resp.status_code != 200:
        return f"Error: page '{title}' not found."
    data = resp.json()
    return data.get("extract", "No extract available.")


# ---------------------------------------------------------------------------
# YouTube metadata -----------------------------------------------------------
# ---------------------------------------------------------------------------

@tool
def youtube_info(url: str) -> Dict[str, Any]:
    """Fetch basic metadata (title, length, author, views) of a YouTube video."""
    try:
        yt = YouTube(url)
    except Exception as exc:  # pylint: disable=broad-except
        return {"error": str(exc)}
    return {
        "title": yt.title,
        "author": yt.author,
        "length_sec": yt.length,
        "views": yt.views,
    }


# ---------------------------------------------------------------------------
# Image inspection -----------------------------------------------------------
# ---------------------------------------------------------------------------

@tool
def image_info(path: str) -> Dict[str, Any]:
    """Return basic stats for an image file at **path** (W×H, mode, format, mean
    pixel value per channel)."""
    p = pathlib.Path(path)
    if not p.exists():
        return {"error": "file not found"}

    try:
        with Image.open(p) as im:
            pixels = list(im.getdata())
    except Exception as exc:  # pylint: disable=broad-except
        return {"error": str(exc)}

    # Flatten tuples (RGB) into list of channels
    if isinstance(pixels[0], (tuple, list)):
        channels = list(zip(*pixels))
        means = [statistics.mean(c) for c in channels]
    else:
        means = [statistics.mean(pixels)]

    return {
        "width": im.width,
        "height": im.height,
        "format": im.format,
        "mode": im.mode,
        "mean_pixel": means,
    }


# ---------------------------------------------------------------------------
# Excel inspection -----------------------------------------------------------
# ---------------------------------------------------------------------------

@tool
def excel_preview(path: str, sheet: str | int = 0, nrows: int = 5) -> str:
    """Return the first *nrows* rows of an Excel sheet as a markdown table."""
    p = pathlib.Path(path)
    if not p.exists():
        return "Error: file not found."

    try:
        df = pd.read_excel(p, sheet_name=sheet, engine="openpyxl", nrows=nrows)
    except Exception as exc:  # pylint: disable=broad-except
        return f"Error: {exc}"

    return df.to_markdown(index=False)


# ---------------------------------------------------------------------------
# Export list ----------------------------------------------------------------
# ---------------------------------------------------------------------------

TOOLS: List[BaseTool] = [
    get_current_time,
    calculator,
    web_search,
    wikipedia_summary,
    youtube_info,
    image_info,
    excel_preview,
]