/**
 * Visual mini-DAG diagram showing block relationships.
 * Displays parent blocks → current block → child blocks.
 */

import { Link } from 'react-router-dom';
import { ArrowDown, Box, Layers } from 'lucide-react';
import { truncateHash } from '../lib/utils';
import { cn } from '../lib/utils';

interface BlockRelationshipDiagramProps {
  currentHash: string;
  parentHashes: string[];
  childrenHashes: string[];
  isChainBlock?: boolean;
  mergeSetBlues?: string[];
  mergeSetReds?: string[];
}

export default function BlockRelationshipDiagram({
  currentHash,
  parentHashes,
  childrenHashes,
  isChainBlock = true,
  mergeSetBlues = [],
  mergeSetReds = [],
}: BlockRelationshipDiagramProps) {
  // Determine selected parent (first one by convention)
  const selectedParent = parentHashes[0];
  const otherParents = parentHashes.slice(1);

  return (
    <div className="relative overflow-hidden rounded-2xl border border-gray-700/50 bg-gray-900/40 backdrop-blur-xl p-6">
      {/* Background gradient */}
      <div className="absolute inset-0 bg-gradient-to-br from-synor-500/5 via-transparent to-violet-500/5" />

      <div className="relative">
        {/* Header */}
        <div className="flex items-center gap-2 mb-6">
          <Layers size={18} className="text-synor-400" />
          <h3 className="font-semibold">Block Relationships</h3>
        </div>

        <div className="flex flex-col items-center gap-3">
          {/* Parent Blocks */}
          {parentHashes.length > 0 && (
            <>
              <div className="flex items-center gap-3 flex-wrap justify-center">
                {selectedParent && (
                  <BlockNode
                    hash={selectedParent}
                    type="parent"
                    isSelected
                    label="Selected Parent"
                  />
                )}
                {otherParents.map((hash) => (
                  <BlockNode
                    key={hash}
                    hash={hash}
                    type="parent"
                    label="Parent"
                  />
                ))}
              </div>

              {/* Arrow down */}
              <div className="flex flex-col items-center">
                <div className="w-px h-4 bg-gradient-to-b from-synor-500/50 to-synor-500" />
                <ArrowDown size={16} className="text-synor-400 -mt-1" />
              </div>
            </>
          )}

          {/* Current Block - Highlighted */}
          <div className="relative">
            {/* Glow effect */}
            <div className="absolute inset-0 -m-2 rounded-2xl bg-synor-500/20 blur-xl" />

            <div
              className={cn(
                'relative px-6 py-4 rounded-xl border-2 bg-gray-800/80 backdrop-blur',
                isChainBlock
                  ? 'border-synor-500 shadow-[0_0_30px_rgba(124,58,237,0.3)]'
                  : 'border-blue-500 shadow-[0_0_30px_rgba(59,130,246,0.3)]'
              )}
            >
              <div className="flex items-center gap-3">
                <div
                  className={cn(
                    'p-2 rounded-lg',
                    isChainBlock ? 'bg-synor-500/20' : 'bg-blue-500/20'
                  )}
                >
                  <Box
                    size={24}
                    className={isChainBlock ? 'text-synor-400' : 'text-blue-400'}
                  />
                </div>
                <div>
                  <div className="text-xs text-gray-400 mb-0.5">Current Block</div>
                  <div className="font-mono text-sm font-medium">
                    {truncateHash(currentHash, 8, 8)}
                  </div>
                </div>
              </div>

              {/* Chain block indicator */}
              {isChainBlock && (
                <div className="absolute -top-2 -right-2 px-2 py-0.5 bg-synor-500 text-white text-xs font-medium rounded-full">
                  Chain
                </div>
              )}
            </div>
          </div>

          {/* Arrow down to children */}
          {childrenHashes.length > 0 && (
            <>
              <div className="flex flex-col items-center">
                <ArrowDown size={16} className="text-synor-400" />
                <div className="w-px h-4 bg-gradient-to-b from-synor-500 to-synor-500/50" />
              </div>

              {/* Child Blocks */}
              <div className="flex items-center gap-3 flex-wrap justify-center">
                {childrenHashes.map((hash) => (
                  <BlockNode key={hash} hash={hash} type="child" label="Child" />
                ))}
              </div>
            </>
          )}

          {/* Merge set info */}
          {(mergeSetBlues.length > 0 || mergeSetReds.length > 0) && (
            <div className="mt-4 pt-4 border-t border-gray-700/50 w-full">
              <div className="flex items-center gap-4 justify-center text-sm">
                {mergeSetBlues.length > 0 && (
                  <div className="flex items-center gap-2">
                    <div className="w-3 h-3 rounded-full bg-blue-500" />
                    <span className="text-gray-400">
                      {mergeSetBlues.length} blue merge
                    </span>
                  </div>
                )}
                {mergeSetReds.length > 0 && (
                  <div className="flex items-center gap-2">
                    <div className="w-3 h-3 rounded-full bg-red-500" />
                    <span className="text-gray-400">
                      {mergeSetReds.length} red merge
                    </span>
                  </div>
                )}
              </div>
            </div>
          )}
        </div>
      </div>
    </div>
  );
}

interface BlockNodeProps {
  hash: string;
  type: 'parent' | 'child';
  isSelected?: boolean;
  label: string;
}

function BlockNode({ hash, type, isSelected, label }: BlockNodeProps) {
  return (
    <Link
      to={`/block/${hash}`}
      className={cn(
        'group relative px-4 py-2.5 rounded-lg border transition-all duration-200',
        'hover:scale-105 hover:shadow-lg',
        isSelected
          ? 'bg-amber-900/30 border-amber-600/50 hover:border-amber-500'
          : type === 'parent'
          ? 'bg-gray-800/50 border-gray-600/50 hover:border-gray-500'
          : 'bg-gray-800/50 border-gray-600/50 hover:border-gray-500'
      )}
    >
      <div className="text-xs text-gray-500 mb-0.5">{label}</div>
      <div className="font-mono text-sm text-gray-300 group-hover:text-white transition-colors">
        {truncateHash(hash, 6, 6)}
      </div>

      {/* Selected indicator */}
      {isSelected && (
        <div className="absolute -top-1.5 -right-1.5 w-3 h-3 rounded-full bg-amber-500 border-2 border-gray-900" />
      )}
    </Link>
  );
}