'use client';

import React, { useEffect, useRef } from 'react';
import { cn } from '@/lib/utils';

// ---------------------------------------------------------------------------
// Types
// ---------------------------------------------------------------------------

export type LogLevel = 'info' | 'success' | 'warning' | 'error';

export interface LogEntry {
  timestamp: string;
  message: string;
  level: LogLevel;
}

export interface DeployLogViewerProps {
  logs: LogEntry[];
  maxHeight?: string;
  className?: string;
}

// ---------------------------------------------------------------------------
// Level colors
// ---------------------------------------------------------------------------

const levelStyles: Record<LogLevel, string> = {
  info: 'text-gray-400',
  success: 'text-emerald-400',
  warning: 'text-amber-400',
  error: 'text-red-400',
};

const levelBadge: Record<LogLevel, string> = {
  info: 'text-gray-500',
  success: 'text-emerald-500',
  warning: 'text-amber-500',
  error: 'text-red-500',
};

const levelPrefix: Record<LogLevel, string> = {
  info: '○',
  success: '✓',
  warning: '⚠',
  error: '✗',
};

// ---------------------------------------------------------------------------
// Component
// ---------------------------------------------------------------------------

export function DeployLogViewer({
  logs,
  maxHeight = '320px',
  className,
}: DeployLogViewerProps) {
  const bottomRef = useRef<HTMLDivElement>(null);
  const containerRef = useRef<HTMLDivElement>(null);

  // Auto-scroll to bottom on new logs
  useEffect(() => {
    if (bottomRef.current) {
      bottomRef.current.scrollIntoView({ behavior: 'smooth' });
    }
  }, [logs.length]);

  const formatTime = (ts: string) => {
    try {
      const d = new Date(ts);
      return d.toLocaleTimeString('en-US', {
        hour12: false,
        hour: '2-digit',
        minute: '2-digit',
        second: '2-digit',
      });
    } catch {
      return '--:--:--';
    }
  };

  return (
    <div
      className={cn(
        'relative rounded-xl border border-gray-800 bg-gray-900 overflow-hidden',
        className,
      )}
    >
      {/* Header */}
      <div className="flex items-center gap-2 border-b border-gray-800 px-4 py-2">
        <div className="flex gap-1.5">
          <div className="h-3 w-3 rounded-full bg-red-500/70" />
          <div className="h-3 w-3 rounded-full bg-amber-500/70" />
          <div className="h-3 w-3 rounded-full bg-emerald-500/70" />
        </div>
        <span className="ml-2 text-xs font-medium text-gray-500">
          Deploy Log
        </span>
        <span className="ml-auto text-xs text-gray-600">
          {logs.length} entries
        </span>
      </div>

      {/* Log content */}
      <div
        ref={containerRef}
        className="overflow-y-auto p-4 font-mono text-sm leading-relaxed"
        style={{ maxHeight }}
      >
        {logs.length === 0 && (
          <div className="flex items-center gap-2 text-gray-600">
            <span className="inline-block h-2 w-2 animate-pulse rounded-full bg-gray-600" />
            Waiting for deploy to start…
          </div>
        )}

        {logs.map((entry, i) => (
          <div
            key={i}
            className={cn(
              'flex gap-3 py-0.5 transition-opacity duration-300',
              i === logs.length - 1 ? 'opacity-100' : 'opacity-90',
            )}
          >
            {/* Timestamp */}
            <span className="shrink-0 text-gray-600 select-none">
              {formatTime(entry.timestamp)}
            </span>

            {/* Level indicator */}
            <span
              className={cn('shrink-0 w-4 text-center', levelBadge[entry.level])}
            >
              {levelPrefix[entry.level]}
            </span>

            {/* Message */}
            <span className={cn(levelStyles[entry.level])}>
              {entry.message}
            </span>
          </div>
        ))}

        {/* Cursor blink at bottom */}
        {logs.length > 0 && (
          <div className="mt-1 flex items-center gap-1 text-gray-600">
            <span className="inline-block h-3.5 w-1.5 animate-pulse bg-indigo-500/70" />
          </div>
        )}

        <div ref={bottomRef} />
      </div>
    </div>
  );
}