import { type ClassValue, clsx } from "clsx";
import { twMerge } from "tailwind-merge";

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs));
}

export function formatDuration(seconds: number): string {
  const h = Math.floor(seconds / 3600);
  const m = Math.floor((seconds % 3600) / 60);
  const s = Math.floor(seconds % 60);
  const frames = Math.floor((seconds % 1) * 24); // rough
  if (h > 0) return `${h}:${String(m).padStart(2, "0")}:${String(s).padStart(2, "0")}`;
  return `${String(m).padStart(2, "0")}:${String(s).padStart(2, "0")}`;
}

export function formatTimecode(seconds: number, fps: number = 24): string {
  const h = Math.floor(seconds / 3600);
  const m = Math.floor((seconds % 3600) / 60);
  const s = Math.floor(seconds % 60);
  const f = Math.floor((seconds % 1) * fps);
  if (h > 0) {
    return `${String(h).padStart(2, "0")}:${String(m).padStart(2, "0")}:${String(s).padStart(2, "0")}:${String(f).padStart(2, "0")}`;
  }
  return `${String(m).padStart(2, "0")}:${String(s).padStart(2, "0")}:${String(f).padStart(2, "0")}`;
}

export function frameToTimecode(frame: number, fps: number): string {
  return formatTimecode(frame / fps, fps);
}

export function formatFileSize(bytes: number | bigint): string {
  const b = typeof bytes === "bigint" ? Number(bytes) : bytes;
  if (b < 1024) return `${b} B`;
  if (b < 1024 * 1024) return `${(b / 1024).toFixed(1)} KB`;
  if (b < 1024 * 1024 * 1024) return `${(b / 1024 / 1024).toFixed(1)} MB`;
  return `${(b / 1024 / 1024 / 1024).toFixed(2)} GB`;
}

export function formatRelativeDate(date: Date | string): string {
  const d = typeof date === "string" ? new Date(date) : date;
  const now = new Date();
  const diff = now.getTime() - d.getTime();
  const minutes = Math.floor(diff / 60000);
  const hours = Math.floor(diff / 3600000);
  const days = Math.floor(diff / 86400000);

  if (minutes < 1) return "just now";
  if (minutes < 60) return `${minutes}m ago`;
  if (hours < 24) return `${hours}h ago`;
  if (days < 7) return `${days}d ago`;
  return d.toLocaleDateString("en-US", { month: "short", day: "numeric" });
}

export function getInitials(name: string | null | undefined): string {
  if (!name) return "?";
  return name
    .split(" ")
    .map((n) => n[0])
    .join("")
    .toUpperCase()
    .slice(0, 2);
}

export function slugify(text: string): string {
  return text
    .toLowerCase()
    .replace(/[^\w\s-]/g, "")
    .replace(/[\s_-]+/g, "-")
    .replace(/^-+|-+$/g, "");
}

export function versionLabel(n: number): string {
  return `v${String(n).padStart(3, "0")}`;
}