'use client';

import { useState } from 'react';
import { Check, ChevronsUpDown } from 'lucide-react';
import { useQuery } from '@tanstack/react-query';

import { Button } from '@/components/ui/button';
import {
  Command,
  CommandEmpty,
  CommandGroup,
  CommandInput,
  CommandItem,
  CommandList,
} from '@/components/ui/command';
import { Popover, PopoverContent, PopoverTrigger } from '@/components/ui/popover';
import { useDebounce } from '@/hooks/use-debounce';
import { apiFetch } from '@/lib/api/client';
import { cn } from '@/lib/utils';

interface TemplateOption {
  id: string;
  name: string;
  templateType?: string;
  isActive?: boolean;
}

interface DocumentTemplatePickerProps {
  value: string | null;
  onChange: (templateId: string | null) => void;
  /** Optional filter by templateType (e.g. 'eoi', 'contract'). */
  templateType?: string;
  placeholder?: string;
  disabled?: boolean;
}

export function DocumentTemplatePicker({
  value,
  onChange,
  templateType,
  placeholder = 'Select template...',
  disabled,
}: DocumentTemplatePickerProps) {
  const [open, setOpen] = useState(false);
  const [search, setSearch] = useState('');
  const debounced = useDebounce(search, 300);

  const { data } = useQuery<{ data: TemplateOption[] }>({
    queryKey: ['document-template-picker', debounced, templateType ?? ''],
    queryFn: () => {
      const params = new URLSearchParams({
        search: debounced,
        page: '1',
        limit: '10',
        order: 'desc',
        isActive: 'true',
      });
      if (templateType) params.set('templateType', templateType);
      return apiFetch(`/api/v1/document-templates?${params.toString()}`);
    },
    enabled: open,
  });

  const options = data?.data ?? [];

  const selectedLabel = (() => {
    if (!value) return placeholder;
    const match = options.find((o) => o.id === value);
    return match?.name ?? `Template ${value.slice(0, 8)}`;
  })();

  return (
    <Popover open={open} onOpenChange={setOpen} modal>
      <PopoverTrigger asChild>
        <Button
          variant="outline"
          role="combobox"
          disabled={disabled}
          className={cn('w-full justify-between', !value && 'text-muted-foreground')}
        >
          <span className="truncate">{selectedLabel}</span>
          <ChevronsUpDown className="ml-2 h-4 w-4 shrink-0 opacity-50" aria-hidden />
        </Button>
      </PopoverTrigger>
      <PopoverContent className="w-[320px] p-0" align="start">
        <Command shouldFilter={false}>
          <CommandInput placeholder="Search templates…" value={search} onValueChange={setSearch} />
          <CommandList>
            <CommandEmpty>No templates found.</CommandEmpty>
            <CommandGroup>
              {options.map((t) => (
                <CommandItem
                  key={t.id}
                  value={t.id}
                  onSelect={() => {
                    onChange(t.id);
                    setOpen(false);
                  }}
                >
                  <Check
                    className={cn('mr-2 h-4 w-4', value === t.id ? 'opacity-100' : 'opacity-0')}
                  />
                  <span className="truncate">
                    {t.name}
                    {t.templateType ? (
                      <span className="ml-2 text-xs text-muted-foreground">
                        {t.templateType.replace(/_/g, ' ')}
                      </span>
                    ) : null}
                  </span>
                </CommandItem>
              ))}
            </CommandGroup>
          </CommandList>
        </Command>
      </PopoverContent>
    </Popover>
  );
}
