import random
from httpcore import TimeoutException
from huggingface_hub import list_models
from langchain_community.tools import DuckDuckGoSearchRun
from langchain_core.tools import Tool

from selenium import webdriver
driver = webdriver.Chrome()
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

import os
try:
    from langchain_tavily import TavilySearch
    tavily_api_key = os.getenv("TAVILY_API_KEY")
    if tavily_api_key:
        tavilytool = TavilySearch(
            max_results=2,
            search_depth="advanced",   # deep crawl mode
            include_raw_content=True,  # returns full page text, not just snippets
            tavily_api_key=tavily_api_key
        )
    else:
        tavilytool = None
except ImportError:
    tavilytool = None



class ToolRegistry:
    """
    A registry that defines and exposes all LangChain tools.
    Import this class in downstream code and access tools via class methods or attributes.
    """

    # ------------------------------------------------------------------ #
    #  Internal implementations                                           #
    # ------------------------------------------------------------------ #

    @staticmethod
    def _weather_info(location: str) -> str:
        """Fetches dummy weather information for a given location."""
        weather_conditions = [
            {"condition": "Rainy",  "temp_c": 15},
            {"condition": "Clear",  "temp_c": 25},
            {"condition": "Windy",  "temp_c": 20},
        ]
        data = random.choice(weather_conditions)
        return f"Weather in {location}: {data['condition']}, {data['temp_c']}°C"

    @staticmethod
    def _get_hub_stats(author: str) -> str:
        """Fetches the most downloaded model from a specific author on the Hugging Face Hub."""
        try:
            models = list(list_models(author=author, sort="downloads", limit=1))
            if models:
                model = models[0]
                return (
                    f"The most downloaded model by {author} is {model.id} "
                    f"with {model.downloads:,} downloads."
                )
            return f"No models found for author {author}."
        except Exception as e:
            return f"Error fetching models for {author}: {str(e)}"
        
    @staticmethod
    def _browse_url(url: str) -> str:
        """Opens a URL and returns the page text"""
        try:
            driver.get(url)
            WebDriverWait(driver, 20).until(EC.presence_of_all_elements_located(("tag name", "body")))
            return driver.find_element("tag name", "body").text[:3000]
        except TimeoutException as e:
            return f"Timeout loading {url}: {str(e)}. Current URL: {driver.current_url}"     

    @staticmethod
    def _click_element(selector: str) -> str:
        """Clicks an element by CSS selector"""
        try:
            element = WebDriverWait(driver, 20).until(
                EC.element_to_be_clickable(("css selector", selector))
            )
            element.click()
            return f"Clicked {selector}"
        except TimeoutException as e:
            return f"Timeout clicking {selector}: {str(e)}. Current URL: {driver.current_url}"
    # ------------------------------------------------------------------ #
    #  Tool factories                                                      #
    # ------------------------------------------------------------------ #

    @classmethod
    def weather_info_tool(cls) -> Tool:
        """Returns a LangChain Tool for fetching weather information."""
        return Tool(
            name="WeatherInfoTool",
            func=cls._weather_info,
            description="Retrieves weather information for a given location.",
        )

    @classmethod
    def hub_stats_tool(cls) -> Tool:
        """Returns a LangChain Tool for fetching Hugging Face Hub stats."""
        return Tool(
            name="get_hub_stats",
            func=cls._get_hub_stats,
            description=(
                "Fetches the most downloaded model from a specific author "
                "on the Hugging Face Hub."
            ),
        )

    @classmethod
    def duck_duck_go_search_tool(cls) -> DuckDuckGoSearchRun:
        """Returns a LangChain DuckDuckGo search tool."""
        return DuckDuckGoSearchRun()

    @classmethod
    def tavily_search_tool(cls) -> TavilySearch:
        """Returns a LangChain Tavily search tool."""
        if tavilytool is None:
            raise ValueError("Tavily tool not available. Please install langchain-tavily and set TAVILY_API_KEY environment variable.")
        return tavilytool
    
    # ------------------------------------------------------------------ #
    #  Convenience: get all tools at once                                  #
    # ------------------------------------------------------------------ #

    @classmethod
    def get_all_tools(cls) -> list[Tool]:
        """Returns a list of all registered tools — ready to pass to an agent."""
        return [
            cls.weather_info_tool(),
            cls.hub_stats_tool(),
            cls.duck_duck_go_search_tool(),
        ]