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

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

export function formatDuration(nanoseconds: number): string {
  const ms = nanoseconds / 1_000_000;
  
  if (ms < 1) {
    return `${(nanoseconds / 1000).toFixed(0)}μs`;
  }
  if (ms < 1000) {
    return `${ms.toFixed(1)}ms`;
  }
  if (ms < 60000) {
    return `${(ms / 1000).toFixed(2)}s`;
  }
  return `${(ms / 60000).toFixed(1)}m`;
}

export function formatTime(timestamp: string): string {
  const date = new Date(timestamp);
  const now = new Date();
  const diff = now.getTime() - date.getTime();
  
  // Within last hour, show relative time
  if (diff < 3600000) {
    const minutes = Math.floor(diff / 60000);
    if (minutes < 1) {
      return 'just now';
    }
    return `${minutes}m ago`;
  }
  
  // Today, show time only
  if (date.toDateString() === now.toDateString()) {
    return date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit', second: '2-digit' });
  }
  
  // Show date and time
  return date.toLocaleString([], {
    month: 'short',
    day: 'numeric',
    hour: '2-digit',
    minute: '2-digit',
  });
}

export function formatBytes(bytes: number): string {
  if (bytes === 0) return '0 B';
  
  const k = 1024;
  const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
  const i = Math.floor(Math.log(bytes) / Math.log(k));
  
  return `${parseFloat((bytes / Math.pow(k, i)).toFixed(2))} ${sizes[i]}`;
}

export function formatNumber(num: number): string {
  if (num >= 1_000_000) {
    return `${(num / 1_000_000).toFixed(1)}M`;
  }
  if (num >= 1_000) {
    return `${(num / 1_000).toFixed(1)}K`;
  }
  return num.toString();
}

export function truncate(str: string, length: number): string {
  if (str.length <= length) return str;
  return str.slice(0, length) + '...';
}

export function generateId(): string {
  return Math.random().toString(36).substr(2, 9);
}