'use client'

import * as React from 'react'
import { CheckIcon, ChevronsUpDown } from 'lucide-react'
import { cn } from '@/lib/utils'
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 { ScrollArea } from '@/components/ui/scroll-area'
import { COUNTRIES } from '@/lib/countries'

// Build sorted country list from the canonical COUNTRIES source
const countryList = Object.entries(COUNTRIES)
  .map(([code, info]) => ({ code, name: info.name }))
  .sort((a, b) => a.name.localeCompare(b.name))

/** Renders a country flag image from flagcdn.com CDN */
function CountryFlagImg({ code, size = 20, className }: { code: string; size?: number; className?: string }) {
  return (
    <img
      src={`https://flagcdn.com/w${size}/${code.toLowerCase()}.png`}
      srcSet={`https://flagcdn.com/w${size * 2}/${code.toLowerCase()}.png 2x`}
      width={size}
      height={Math.round(size * 0.75)}
      alt={code}
      className={cn('inline-block rounded-[2px]', className)}
      loading="lazy"
    />
  )
}

export type Country = { code: string; name: string }

interface CountrySelectProps {
  value?: string
  onChange?: (value: string) => void
  placeholder?: string
  disabled?: boolean
  className?: string
}

const CountrySelect = React.forwardRef<HTMLButtonElement, CountrySelectProps>(
  ({ value, onChange, placeholder = 'Select country...', disabled, className }, ref) => {
    const [open, setOpen] = React.useState(false)
    const selectedCountry = countryList.find((c) => c.code === value)

    return (
      <Popover open={open} onOpenChange={setOpen}>
        <PopoverTrigger asChild>
          <Button
            ref={ref}
            variant="outline"
            role="combobox"
            aria-expanded={open}
            className={cn('w-full justify-between font-normal', className)}
            disabled={disabled}
          >
            {selectedCountry ? (
              <span className="flex items-center gap-2">
                <CountryFlagImg code={selectedCountry.code} size={20} />
                <span>{selectedCountry.name}</span>
              </span>
            ) : (
              <span className="text-muted-foreground">{placeholder}</span>
            )}
            <ChevronsUpDown className="ml-2 h-4 w-4 shrink-0 opacity-50" />
          </Button>
        </PopoverTrigger>
        <PopoverContent className="w-[--radix-popover-trigger-width] p-0" align="start">
          <Command>
            <CommandInput placeholder="Search country..." />
            <CommandList>
              <ScrollArea className="h-72">
                <CommandEmpty>No country found.</CommandEmpty>
                <CommandGroup>
                  {countryList.map((country) => (
                    <CommandItem
                      key={country.code}
                      value={country.name}
                      onSelect={() => {
                        onChange?.(country.code)
                        setOpen(false)
                      }}
                      className="gap-2"
                    >
                      <CountryFlagImg code={country.code} size={20} />
                      <span className="flex-1">{country.name}</span>
                      <CheckIcon
                        className={cn(
                          'ml-auto h-4 w-4',
                          value === country.code ? 'opacity-100' : 'opacity-0'
                        )}
                      />
                    </CommandItem>
                  ))}
                </CommandGroup>
              </ScrollArea>
            </CommandList>
          </Command>
        </PopoverContent>
      </Popover>
    )
  }
)
CountrySelect.displayName = 'CountrySelect'

export { CountrySelect, countryList as countries, CountryFlagImg }