'use client';

import { useState } from 'react';
import { ChevronDown, ChevronRight, Folder, FolderOpen } from 'lucide-react';

import { cn } from '@/lib/utils';
import type { FileRow } from '@/components/files/file-grid';

interface FolderNode {
  name: string;
  fullPath: string;
  children: Record<string, FolderNode>;
}

function buildFolderTree(files: FileRow[]): FolderNode {
  const root: FolderNode = { name: '', fullPath: '', children: {} };

  for (const file of files) {
    const parts = file.storagePath ? file.storagePath.split('/').slice(0, -1) : [];
    if (parts.length <= 1) continue; // skip files directly in root/port folder

    let node = root;
    let accumulated = '';
    for (const part of parts.slice(1)) { // skip portSlug prefix
      accumulated = accumulated ? `${accumulated}/${part}` : part;
      if (!node.children[part]) {
        node.children[part] = { name: part, fullPath: accumulated, children: {} };
      }
      node = node.children[part]!;
    }
  }

  return root;
}

interface FolderNodeComponentProps {
  node: FolderNode;
  currentFolder: string;
  onFolderSelect: (path: string) => void;
  depth?: number;
}

function FolderNodeComponent({
  node,
  currentFolder,
  onFolderSelect,
  depth = 0,
}: FolderNodeComponentProps) {
  const [expanded, setExpanded] = useState(true);
  const hasChildren = Object.keys(node.children).length > 0;
  const isSelected = currentFolder === node.fullPath;

  return (
    <div>
      <button
        type="button"
        onClick={() => {
          onFolderSelect(node.fullPath);
          if (hasChildren) setExpanded((v) => !v);
        }}
        className={cn(
          'flex w-full items-center gap-1.5 rounded px-2 py-1 text-left text-sm hover:bg-muted/60 transition-colors',
          isSelected && 'bg-muted font-medium',
        )}
        style={{ paddingLeft: `${depth * 12 + 8}px` }}
      >
        {hasChildren ? (
          expanded ? (
            <ChevronDown className="h-3.5 w-3.5 shrink-0 text-muted-foreground" />
          ) : (
            <ChevronRight className="h-3.5 w-3.5 shrink-0 text-muted-foreground" />
          )
        ) : (
          <span className="w-3.5" />
        )}
        {isSelected ? (
          <FolderOpen className="h-4 w-4 shrink-0 text-primary" />
        ) : (
          <Folder className="h-4 w-4 shrink-0 text-muted-foreground" />
        )}
        <span className="truncate">{node.name}</span>
      </button>

      {hasChildren && expanded && (
        <div>
          {Object.values(node.children).map((child) => (
            <FolderNodeComponent
              key={child.fullPath}
              node={child}
              currentFolder={currentFolder}
              onFolderSelect={onFolderSelect}
              depth={depth + 1}
            />
          ))}
        </div>
      )}
    </div>
  );
}

interface FolderTreeProps {
  files: (FileRow & { storagePath: string })[];
  currentFolder: string;
  onFolderSelect: (path: string) => void;
}

export function FolderTree({ files, currentFolder, onFolderSelect }: FolderTreeProps) {
  const tree = buildFolderTree(files);

  return (
    <div className="space-y-0.5">
      <button
        type="button"
        onClick={() => onFolderSelect('')}
        className={cn(
          'flex w-full items-center gap-1.5 rounded px-2 py-1 text-left text-sm hover:bg-muted/60 transition-colors',
          currentFolder === '' && 'bg-muted font-medium',
        )}
      >
        <span className="w-3.5" />
        {currentFolder === '' ? (
          <FolderOpen className="h-4 w-4 shrink-0 text-primary" />
        ) : (
          <Folder className="h-4 w-4 shrink-0 text-muted-foreground" />
        )}
        <span>All Files</span>
      </button>

      {Object.values(tree.children).map((child) => (
        <FolderNodeComponent
          key={child.fullPath}
          node={child}
          currentFolder={currentFolder}
          onFolderSelect={onFolderSelect}
        />
      ))}
    </div>
  );
}