# -*- coding: utf-8 -*-
"""可用性检测与去重"""

import requests
from concurrent.futures import ThreadPoolExecutor, as_completed


def check_url(url, timeout=5):
    """检测 URL 是否可用"""
    try:
        resp = requests.get(url, timeout=timeout, stream=True, headers={
            "User-Agent": "Mozilla/5.0 (APTV-Live-Source-Builder)"
        })
        return resp.status_code == 200
    except Exception:
        return False


def filter_available(channels, timeout=5, max_workers=20):
    """并发过滤可用源"""
    if not channels:
        return []

    results = []
    with ThreadPoolExecutor(max_workers=max_workers) as executor:
        future_map = {
            executor.submit(check_url, ch["url"], timeout): ch
            for ch in channels
        }
        for future in as_completed(future_map):
            ch = future_map[future]
            try:
                ok = future.result()
            except Exception:
                ok = False
            if ok:
                results.append(ch)
    return results


def dedup(channels):
    """按 URL 和频道名去重"""
    seen_urls = set()
    seen_names = set()
    result = []
    for ch in channels:
        url = ch["url"]
        name = ch["name"]
        if url in seen_urls:
            continue
        if name in seen_names:
            continue
        seen_urls.add(url)
        seen_names.add(name)
        result.append(ch)
    return result