"""
CoinGecko -- free public API, no key required (300 calls/min).
"""
import httpx

BASE = "https://api.coingecko.com/api/v3"


def run(params: dict) -> dict:
    mode = params.get("mode", "markets")

    if mode == "trending":
        resp = httpx.get(f"{BASE}/search/trending", timeout=15.0)
        resp.raise_for_status()
        coins = resp.json().get("coins", [])
        results = [
            {
                "name": c["item"]["name"],
                "symbol": c["item"]["symbol"],
                "market_cap_rank": c["item"]["market_cap_rank"],
            }
            for c in coins
        ]
        return {"mode": "trending", "count": len(results), "results": results}

    if mode == "ohlc":
        coin_id = params.get("coin_id")
        if not coin_id:
            raise ValueError("coin_id is required for mode='ohlc'")
        days = int(params.get("days", 30))
        resp = httpx.get(
            f"{BASE}/coins/{coin_id}/ohlc", params={"vs_currency": "usd", "days": days}, timeout=15.0
        )
        resp.raise_for_status()
        candles = resp.json()
        results = [{"time": c[0], "open": c[1], "high": c[2], "low": c[3], "close": c[4]} for c in candles]
        return {"mode": "ohlc", "coin_id": coin_id, "count": len(results), "results": results}

    # default: markets
    per_page = int(params.get("per_page", 100))
    resp = httpx.get(
        f"{BASE}/coins/markets",
        params={"vs_currency": "usd", "order": "market_cap_desc", "per_page": min(per_page, 250), "page": 1},
        timeout=15.0,
    )
    resp.raise_for_status()
    coins = resp.json()
    results = [
        {
            "id": c["id"],
            "symbol": c["symbol"],
            "price": c["current_price"],
            "market_cap": c["market_cap"],
            "volume_24h": c["total_volume"],
            "change_24h_pct": c["price_change_percentage_24h"],
            "change_7d_pct": c.get("price_change_percentage_7d_in_currency"),
        }
        for c in coins
    ]
    return {"mode": "markets", "count": len(results), "results": results}