"""Hidden Gems Tool - Find undervalued Hugging Face models."""

import os
import json
from typing import Optional
from urllib.request import urlopen, Request
from urllib.error import HTTPError


def find_hidden_gems(
    limit: int = 100,
    min_downloads: int = 100,
    top: int = 20,
    pipeline_tag: Optional[str] = None,
    sort_by: str = "ratio"
) -> str:
    """
    Find hidden gem models with high likes-to-downloads ratios.
    
    Args:
        limit: Number of models to fetch from API (default: 100)
        min_downloads: Minimum downloads to filter out very new models (default: 100)
        top: Number of top results to return (default: 20)
        pipeline_tag: Filter by pipeline tag like "text-generation", "image-to-text" (optional)
        sort_by: Sort results by "ratio" (default), "likes", "downloads", or "trending"
    
    Returns:
        JSON string with list of hidden gem models ranked by score
    """
    # Build API URL
    api_url = f"https://huggingface.co/api/models?limit={limit}"
    if pipeline_tag:
        api_url += f"&pipeline_tag={pipeline_tag}"
    
    # Fetch models
    headers = {}
    token = os.environ.get("HF_TOKEN")
    if token:
        headers["Authorization"] = f"Bearer {token}"
    
    try:
        req = Request(api_url, headers=headers)
        with urlopen(req, timeout=60) as response:
            models = json.loads(response.read().decode("utf-8"))
    except HTTPError as e:
        return json.dumps({"error": f"API error: {e.code} - {e.reason}"})
    except Exception as e:
        return json.dumps({"error": f"Failed to fetch models: {str(e)}"})
    
    # Calculate hidden gem scores
    results = []
    for model in models:
        likes = model.get("likes")
        downloads = model.get("downloads")
        
        if likes is None or downloads is None:
            continue
        if downloads < min_downloads:
            continue
        
        ratio = likes / downloads if downloads > 0 else 0
        
        results.append({
            "id": model.get("id"),
            "likes": likes,
            "downloads": downloads,
            "ratio": round(ratio, 6),
            "pipeline_tag": model.get("pipeline_tag") or "unknown",
            "library_name": model.get("library_name") or "unknown",
            "createdAt": model.get("createdAt") or "unknown",
            "trendingScore": model.get("trendingScore") or 0,
            "tags": model.get("tags", [])
        })
    
    # Sort results
    sort_key = {
        "likes": "likes",
        "downloads": "downloads",
        "trending": "trendingScore"
    }.get(sort_by, "ratio")
    
    results.sort(key=lambda x: x[sort_key], reverse=True)
    
    # Take top N
    top_results = results[:top]
    
    return json.dumps({
        "count": len(results),
        "showing": len(top_results),
        "filters": {
            "min_downloads": min_downloads,
            "pipeline_tag": pipeline_tag,
            "sort_by": sort_by
        },
        "gems": top_results
    }, indent=2)


def get_model_details(model_id: str) -> str:
    """
    Get detailed information about a specific Hugging Face model.
    
    Args:
        model_id: The model ID (e.g., "microsoft/DialoGPT-medium")
    
    Returns:
        JSON string with detailed model information
    """
    api_url = f"https://huggingface.co/api/models/{model_id}"
    
    headers = {}
    token = os.environ.get("HF_TOKEN")
    if token:
        headers["Authorization"] = f"Bearer {token}"
    
    try:
        req = Request(api_url, headers=headers)
        with urlopen(req, timeout=30) as response:
            model = json.loads(response.read().decode("utf-8"))
    except HTTPError as e:
        if e.code == 404:
            return json.dumps({"error": f"Model '{model_id}' not found"})
        return json.dumps({"error": f"API error: {e.code} - {e.reason}"})
    except Exception as e:
        return json.dumps({"error": f"Failed to fetch model: {str(e)}"})
    
    # Calculate hidden gem score
    likes = model.get("likes", 0)
    downloads = model.get("downloads", 0)
    ratio = likes / downloads if downloads > 0 else 0
    
    result = {
        "id": model.get("id"),
        "likes": likes,
        "downloads": downloads,
        "hidden_gem_score": round(ratio, 6),
        "pipeline_tag": model.get("pipeline_tag") or "unknown",
        "library_name": model.get("library_name") or "unknown",
        "tags": model.get("tags", []),
        "createdAt": model.get("createdAt"),
        "lastModified": model.get("lastModified"),
        "cardExists": model.get("cardExists", False),
        "widgetData": model.get("widgetData", []),
        "siblings": [s.get("rfilename") for s in model.get("siblings", [])[:10]],
        "description": (model.get("cardData") or {}).get("tags", [])
    }
    
    return json.dumps(result, indent=2)