import { useMemo } from 'react';
import { ChevronDown, ChevronRight, Check, Minus } from 'lucide-react';
import { useState } from 'react';
import type { Permission } from '@/services/api';
import { getPermissionCategoryLabel, getPermissionActionLabel } from '@/hooks/useRbac';

interface PermissionsMatrixProps {
  permissions: Permission[];
  selectedPermissions: string[];
  onTogglePermission: (permissionSlug: string) => void;
  onToggleCategory: (category: string, permissionSlugs: string[]) => void;
  readOnly?: boolean;
}

export function PermissionsMatrix({
  permissions,
  selectedPermissions,
  onTogglePermission,
  onToggleCategory,
  readOnly = false,
}: PermissionsMatrixProps) {
  const [expandedCategories, setExpandedCategories] = useState<Set<string>>(new Set());

  const permissionsByCategory = useMemo(() => {
    const grouped: Record<string, Permission[]> = {};
    permissions.forEach((perm) => {
      if (!grouped[perm.category]) {
        grouped[perm.category] = [];
      }
      grouped[perm.category].push(perm);
    });
    return grouped;
  }, [permissions]);

  const categories = useMemo(() => Object.keys(permissionsByCategory).sort(), [permissionsByCategory]);

  const toggleCategory = (category: string) => {
    setExpandedCategories((prev) => {
      const newSet = new Set(prev);
      if (newSet.has(category)) {
        newSet.delete(category);
      } else {
        newSet.add(category);
      }
      return newSet;
    });
  };

  const getCategoryStatus = (category: string): 'all' | 'some' | 'none' => {
    const categoryPerms = permissionsByCategory[category];
    const selectedCount = categoryPerms.filter((p) => selectedPermissions.includes(p.slug)).length;
    if (selectedCount === 0) return 'none';
    if (selectedCount === categoryPerms.length) return 'all';
    return 'some';
  };

  const handleCategoryCheckboxClick = (category: string) => {
    if (readOnly) return;
    const categoryPerms = permissionsByCategory[category];
    const slugs = categoryPerms.map((p) => p.slug);
    onToggleCategory(category, slugs);
  };

  return (
    <div className="space-y-2">
      {categories.map((category) => {
        const isExpanded = expandedCategories.has(category);
        const categoryPerms = permissionsByCategory[category];
        const status = getCategoryStatus(category);
        const selectedCount = categoryPerms.filter((p) =>
          selectedPermissions.includes(p.slug)
        ).length;

        return (
          <div
            key={category}
            className="rounded-lg border border-gray-200 dark:border-gray-700"
          >
            {/* Category Header */}
            <button
              type="button"
              className="flex w-full cursor-pointer items-center justify-between p-3 hover:bg-gray-50 dark:hover:bg-gray-700/50 focus:outline-none focus:ring-2 focus:ring-inset focus:ring-blue-500 rounded-t-lg"
              onClick={() => toggleCategory(category)}
              aria-expanded={isExpanded}
              aria-controls={`permissions-${category}`}
            >
              <div className="flex items-center gap-3">
                <span
                  className="flex-shrink-0 text-gray-400"
                  aria-hidden="true"
                >
                  {isExpanded ? (
                    <ChevronDown className="h-5 w-5" />
                  ) : (
                    <ChevronRight className="h-5 w-5" />
                  )}
                </span>
                {!readOnly && (
                  <span
                    onClick={(e) => {
                      e.stopPropagation();
                      handleCategoryCheckboxClick(category);
                    }}
                    onKeyDown={(e) => {
                      if (e.key === 'Enter' || e.key === ' ') {
                        e.preventDefault();
                        e.stopPropagation();
                        handleCategoryCheckboxClick(category);
                      }
                    }}
                    role="checkbox"
                    aria-checked={status === 'all' ? true : status === 'some' ? 'mixed' : false}
                    aria-label={`Toggle all ${category} permissions`}
                    tabIndex={0}
                    className={`flex h-5 w-5 flex-shrink-0 items-center justify-center rounded border cursor-pointer focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-1 ${
                      status === 'all'
                        ? 'border-blue-600 bg-blue-600 text-white'
                        : status === 'some'
                        ? 'border-blue-600 bg-blue-100 text-blue-600 dark:bg-blue-900/20'
                        : 'border-gray-300 bg-white dark:border-gray-600 dark:bg-gray-800'
                    }`}
                  >
                    {status === 'all' && <Check className="h-3.5 w-3.5" aria-hidden="true" />}
                    {status === 'some' && <Minus className="h-3.5 w-3.5" aria-hidden="true" />}
                  </span>
                )}
                <span className="font-medium text-gray-900 dark:text-white">
                  {getPermissionCategoryLabel(category)}
                </span>
              </div>
              <span className="text-sm text-gray-500 dark:text-gray-400">
                {selectedCount} / {categoryPerms.length}
              </span>
            </button>

            {/* Permissions List */}
            {isExpanded && (
              <div
                id={`permissions-${category}`}
                className="border-t border-gray-200 bg-gray-50 p-3 dark:border-gray-700 dark:bg-gray-800/50"
                role="group"
                aria-label={`${getPermissionCategoryLabel(category)} permissions`}
              >
                <div className="grid gap-2 sm:grid-cols-2 lg:grid-cols-3">
                  {categoryPerms.map((perm) => {
                    const isSelected = selectedPermissions.includes(perm.slug);
                    const [, action] = perm.slug.split(':');

                    return (
                      <label
                        key={perm.id}
                        className={`flex cursor-pointer items-start gap-3 rounded-lg p-2 transition-colors ${
                          readOnly
                            ? ''
                            : 'hover:bg-white dark:hover:bg-gray-700'
                        } ${isSelected ? 'bg-blue-50 dark:bg-blue-900/20' : ''}`}
                      >
                        <input
                          type="checkbox"
                          checked={isSelected}
                          onChange={() => !readOnly && onTogglePermission(perm.slug)}
                          disabled={readOnly}
                          className="mt-0.5 h-4 w-4 rounded border-gray-300 text-blue-600 focus:ring-blue-500 disabled:cursor-not-allowed dark:border-gray-600"
                        />
                        <div className="min-w-0 flex-1">
                          <div className="flex items-center gap-2">
                            <span className="text-sm font-medium text-gray-900 dark:text-white">
                              {perm.name}
                            </span>
                            <span
                              className={`rounded px-1.5 py-0.5 text-xs font-medium ${
                                action === 'delete'
                                  ? 'bg-red-100 text-red-700 dark:bg-red-900/20 dark:text-red-400'
                                  : action === 'write'
                                  ? 'bg-yellow-100 text-yellow-700 dark:bg-yellow-900/20 dark:text-yellow-400'
                                  : 'bg-gray-100 text-gray-700 dark:bg-gray-700 dark:text-gray-300'
                              }`}
                            >
                              {getPermissionActionLabel(action)}
                            </span>
                          </div>
                          {perm.description && (
                            <p className="mt-0.5 text-xs text-gray-500 dark:text-gray-400">
                              {perm.description}
                            </p>
                          )}
                          <code className="mt-1 block text-xs text-gray-400 dark:text-gray-500">
                            {perm.slug}
                          </code>
                        </div>
                      </label>
                    );
                  })}
                </div>
              </div>
            )}
          </div>
        );
      })}

      {categories.length === 0 && (
        <div className="py-8 text-center text-gray-500 dark:text-gray-400">
          No permissions available
        </div>
      )}
    </div>
  );
}