"""Read-only statistics endpoints backed by Redis."""
import json
from urllib.parse import unquote, urlsplit, parse_qs
from flask import render_template, jsonify
from adlist.services import redis_client


def collect_stats():
    stats_data, target_ips, url_requests, user_agents, client_ips = {}, {}, {}, {}, {}
    for key in redis_client.scan_iter("stats:*"):
        key_str = key.decode()
        value = (redis_client.get(key) or b"0").decode()
        if key_str.startswith("stats:target_ips:"):
            target_ips[key_str.split(":", 2)[2]] = value
        elif key_str.startswith("stats:url_requests:"):
            url_requests[unquote(key_str.split(":", 2)[2])] = value
        elif key_str.startswith("stats:user_agents:"):
            user_agents[unquote(key_str.split(":", 2)[2])] = value
        elif key_str.startswith("stats:client_ips:"):
            client_ips[key_str.split(":", 2)[2]] = value
        else:
            stats_data[key_str] = value

    recent = []
    for item in redis_client.lrange("recent_converts", 0, 99):
        try:
            row = json.loads(item.decode())
            params = parse_qs(urlsplit(row.get("url", "")).query)
            row["source_url"] = params.get("url", [""])[0]
            row["target_ip"] = params.get("ip", ["127.0.0.1"])[0]
            recent.append(row)
        except (ValueError, TypeError, AttributeError):
            continue

    total_time = float(redis_client.get("stats:processing_time_total") or 0)
    count_time = int(redis_client.get("stats:processing_time_count") or 0)
    total_size = int(redis_client.get("stats:content_size_total") or 0)
    count_size = int(redis_client.get("stats:content_size_count") or 0)
    detailed = {
        "processing_time_total_sec": total_time,
        "processing_time_count": count_time,
        "processing_time_avg_sec": total_time / count_time if count_time else 0,
        "processing_time_min_sec": float(redis_client.get("stats:processing_time_min") or 0),
        "processing_time_max_sec": float(redis_client.get("stats:processing_time_max") or 0),
        "content_size_total_bytes": total_size,
        "content_size_count": count_size,
        "content_size_avg_bytes": total_size / count_size if count_size else 0,
    }
    return {
        **stats_data,
        "target_ips": target_ips,
        "url_requests": url_requests,
        "user_agents": user_agents,
        "client_ips": client_ips,
        "recent_converts": recent,
        "detailed_stats": detailed,
    }


def stats():
    data = collect_stats()
    return render_template(
        "stats.html",
        stats=data,
        target_ips=data["target_ips"],
        url_requests=data["url_requests"],
        user_agents=data["user_agents"],
        client_ips=data["client_ips"],
        recent=data["recent_converts"],
        detailed=data["detailed_stats"],
        raw_json=json.dumps(data, indent=2),
    )


def stats_json():
    return jsonify(collect_stats())