import os
import time
from urllib.parse import urlparse

import requests


# --- Configurace ---
API_ENDPOINT = "https://www.googleapis.com/customsearch/v1"
DEFAULT_LOCALE = "cs"   # language for results
DEFAULT_NUM = 10         # how many results to fetch (max 10 per API call)
RATE_SECONDS = 5.0       # wait time between API requests
last_api_call = 0.0      # remember when we last called the API


def _throttle_api():
    """
    Pause if the last API call was too recent.

    This is a super basic rate limiter: we allow one request every 5 seconds.
    It helps to not run through your daily quota too fast.
    """
    global last_api_call
    now = time.time()
    wait = RATE_SECONDS - (now - last_api_call)

    if wait > 0:
        time.sleep(wait)
    last_api_call = time.time()


def favicon_from_link(link):
    try:
        u = urlparse(link)
        scheme = u.scheme or "https"
        netloc = u.netloc
        if not netloc and u.path:
            # Handle URLs without a scheme like: example.com/path
            netloc = u.path.split("/")[0]
        if not netloc:
            return ""
        return f"{scheme}://{netloc}/favicon.ico"
    except Exception:
        return ""


def _cse_request(q, num=DEFAULT_NUM, hl=DEFAULT_LOCALE):
    """Call the Custom Search API and return the JSON data.

    Requires two env variables in your .env file:
      - GOOGLE_DEVELOPER_KEY (your API key)
      - GOOGLE_CSE_ID (your search engine ID)
    """
    api_key = os.environ.get("GOOGLE_DEVELOPER_KEY")
    cse_id = os.environ.get("GOOGLE_CSE_ID")
    if not api_key:
        raise RuntimeError("GOOGLE_DEVELOPER_KEY není nastaven v .env")
    if not cse_id:
        raise RuntimeError("GOOGLE_CSE_ID (Programmable Search Engine ID) není nastaven v .env")

    _throttle_api()
    params = {
        "key": api_key,
        "cx": cse_id,
        "q": q,
        "num": min(max(num, 1), 10),  # API allows up to 10 per call
        "hl": hl,
        "safe": "off",
    }
    resp = requests.get(API_ENDPOINT, params=params, timeout=15)
    if resp.status_code != 200:
        # Try to extract a nice error message from API response
        try:
            data = resp.json()
            msg = data.get("error", {}).get("message") or resp.text
        except Exception:
            msg = resp.text
        raise RuntimeError(f"Google CSE API chyba ({resp.status_code}): {msg}")
    return resp.json()


def get_google_first_page(query):
    """Return a list of results for a query using the Custom Search API.

    Each item has: position, title, link, snippet, icon
    """
    data = _cse_request(query, num=DEFAULT_NUM, hl=DEFAULT_LOCALE)
    items = data.get("items", []) or []

    results = []
    for i, item in enumerate(items, start=1):
        link = item.get("link") or item.get("formattedUrl") or ""
        title = item.get("title") or item.get("htmlTitle") or ""
        snippet = item.get("snippet") or item.get("htmlSnippet") or ""
        results.append({
            "position": i,
            "title": title,
            "link": link,
            "snippet": snippet,
            "icon": favicon_from_link(link),
        })
    return results