KVideo/lib/player/resolution-probe-utils.ts

import { extractPlaybackQualityLabel } from '@/lib/utils/video';

export interface ResolutionProbeLabel {
  label: string;
  color: string;
  width?: number;
  height?: number;
}

const QUALITY_RANK: Record<string, number> = {
  '4K': 700,
  '2K': 620,
  '1080P': 540,
  '蓝光': 520,
  'HDR': 500,
  '超清': 480,
  '720P': 420,
  'WEB-DL': 380,
  'HDTV': 360,
  '高清': 340,
  '540P': 300,
  'DVD': 280,
  '480P': 260,
  '360P': 220,
  'TS': 120,
  'SD': 100,
};

const DIMENSION_PATTERN = /(\d{3,4})\s*[xX]\s*(\d{3,4})/g;
const HLS_RESOLUTION_PATTERN = /RESOLUTION=(\d+)x(\d+)/gi;
const TEXT_QUALITY_PATTERNS: Array<{ pattern: RegExp; width?: number; height?: number; label: string; color: string }> = [
  { pattern: /(?:^|[^\d])(2160p?|4k|uhd)(?:[^\d]|$)/i, width: 3840, height: 2160, label: '4K', color: 'bg-amber-500' },
  { pattern: /(?:^|[^\d])(1440p?|2k|qhd)(?:[^\d]|$)/i, width: 2560, height: 1440, label: '2K', color: 'bg-emerald-500' },
  { pattern: /(?:^|[^\d])(1080p?|1080i|fhd|fullhd|full-hd)(?:[^\d]|$)/i, width: 1920, height: 1080, label: '1080P', color: 'bg-green-500' },
  { pattern: /(?:^|[^\d])(720p?|hd720)(?:[^\d]|$)/i, width: 1280, height: 720, label: '720P', color: 'bg-teal-500' },
  { pattern: /(?:^|[^\d])540p?(?:[^\d]|$)/i, width: 960, height: 540, label: '540P', color: 'bg-cyan-500' },
  { pattern: /(?:^|[^\d])480p?(?:[^\d]|$)/i, width: 854, height: 480, label: '480P', color: 'bg-sky-500' },
  { pattern: /(?:^|[^\d])360p?(?:[^\d]|$)/i, width: 640, height: 360, label: '360P', color: 'bg-gray-500' },
];

export function getResolutionLabel(width: number, height: number): ResolutionProbeLabel {
  const normalizedWidth = Math.max(width, height);
  const normalizedHeight = Math.min(width, height);

  if (normalizedHeight >= 2160) return { width: normalizedWidth, height: normalizedHeight, label: '4K', color: 'bg-amber-500' };
  if (normalizedHeight >= 1440) return { width: normalizedWidth, height: normalizedHeight, label: '2K', color: 'bg-emerald-500' };
  if (normalizedHeight >= 1080) return { width: normalizedWidth, height: normalizedHeight, label: '1080P', color: 'bg-green-500' };
  if (normalizedHeight >= 720) return { width: normalizedWidth, height: normalizedHeight, label: '720P', color: 'bg-teal-500' };
  if (normalizedHeight >= 540) return { width: normalizedWidth, height: normalizedHeight, label: '540P', color: 'bg-cyan-500' };
  if (normalizedHeight >= 480) return { width: normalizedWidth, height: normalizedHeight, label: '480P', color: 'bg-sky-500' };
  if (normalizedHeight >= 360) return { width: normalizedWidth, height: normalizedHeight, label: '360P', color: 'bg-gray-500' };
  return { width: normalizedWidth, height: normalizedHeight, label: `${normalizedHeight}P`, color: 'bg-gray-500' };
}

function getCandidateRank(candidate: ResolutionProbeLabel): number {
  if (candidate.width && candidate.height) {
    return candidate.width * candidate.height;
  }

  return QUALITY_RANK[candidate.label] || 0;
}

export function chooseHigherQuality(
  current: ResolutionProbeLabel | null,
  candidate: ResolutionProbeLabel | null
): ResolutionProbeLabel | null {
  if (!candidate) return current;
  if (!current) return candidate;
  return getCandidateRank(candidate) > getCandidateRank(current) ? candidate : current;
}

export function extractResolutionHint(...values: Array<string | undefined>): ResolutionProbeLabel | null {
  let best: ResolutionProbeLabel | null = null;

  for (const value of values) {
    if (!value) continue;

    let match: RegExpExecArray | null;
    DIMENSION_PATTERN.lastIndex = 0;
    while ((match = DIMENSION_PATTERN.exec(value)) !== null) {
      const width = Number.parseInt(match[1], 10);
      const height = Number.parseInt(match[2], 10);
      if (width > 0 && height > 0) {
        best = chooseHigherQuality(best, getResolutionLabel(width, height));
      }
    }

    for (const pattern of TEXT_QUALITY_PATTERNS) {
      if (!pattern.pattern.test(value)) continue;
      best = chooseHigherQuality(best, {
        label: pattern.label,
        color: pattern.color,
        width: pattern.width,
        height: pattern.height,
      });
    }

    best = chooseHigherQuality(best, extractPlaybackQualityLabel(value) || null);
  }

  return best;
}

export function parseResolutionFromManifest(content: string, baseUrl?: string): ResolutionProbeLabel | null {
  let best: ResolutionProbeLabel | null = null;

  let match: RegExpExecArray | null;
  HLS_RESOLUTION_PATTERN.lastIndex = 0;
  while ((match = HLS_RESOLUTION_PATTERN.exec(content)) !== null) {
    const width = Number.parseInt(match[1], 10);
    const height = Number.parseInt(match[2], 10);
    if (width > 0 && height > 0) {
      best = chooseHigherQuality(best, getResolutionLabel(width, height));
    }
  }

  const lines = content.split(/\r?\n/);
  for (let index = 0; index < lines.length; index += 1) {
    const line = lines[index].trim();
    if (!line) continue;

    if (line.startsWith('#EXT-X-STREAM-INF') || line.startsWith('#EXT-X-I-FRAME-STREAM-INF')) {
      best = chooseHigherQuality(best, extractResolutionHint(line));
      continue;
    }

    if (line.startsWith('#')) continue;

    const resolvedLine = baseUrl
      ? (() => {
          try {
            return new URL(line, baseUrl).toString();
          } catch {
            return line;
          }
        })()
      : line;

    best = chooseHigherQuality(best, extractResolutionHint(resolvedLine, line));
  }

  return best;
}

export function extractVariantPlaylistUrls(content: string, baseUrl: string): string[] {
  const urls = new Set<string>();
  const lines = content.split(/\r?\n/);

  for (let index = 0; index < lines.length; index += 1) {
    const line = lines[index].trim();
    if (!line) continue;

    if (line.startsWith('#EXT-X-I-FRAME-STREAM-INF') && line.includes('URI="')) {
      const uriMatch = line.match(/URI="([^"]+)"/i);
      if (uriMatch?.[1]) {
        try {
          urls.add(new URL(uriMatch[1], baseUrl).toString());
        } catch {
          // Ignore invalid URIs.
        }
      }
      continue;
    }

    if (!line.startsWith('#EXT-X-STREAM-INF')) continue;

    const candidate = lines[index + 1]?.trim();
    if (!candidate || candidate.startsWith('#')) continue;

    try {
      urls.add(new URL(candidate, baseUrl).toString());
    } catch {
      // Ignore invalid URLs.
    }
  }

  return Array.from(urls);
}