"use client"

import * as React from "react"
import { type Row } from "@tanstack/react-table"
import { Loader, Mail, AlertCircle, XCircle } from "lucide-react"
import { toast } from "sonner"

import { useMediaQuery } from "@/hooks/use-media-query"
import { Button } from "@/components/ui/button"
import {
  Dialog,
  DialogClose,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
} from "@/components/ui/dialog"
import {
  Drawer,
  DrawerClose,
  DrawerContent,
  DrawerDescription,
  DrawerFooter,
  DrawerHeader,
  DrawerTitle,
  DrawerTrigger,
} from "@/components/ui/drawer"
import {
  Alert,
  AlertTitle,
  AlertDescription
} from "@/components/ui/alert"

import { VendorCandidates } from "@/db/schema/vendors"
import { bulkUpdateVendorCandidateStatus } from "../service"
import { useSession } from "next-auth/react" // next-auth 세션 훅

interface InviteCandidatesDialogProps
  extends React.ComponentPropsWithoutRef<typeof Dialog> {
  candidates: Row<VendorCandidates>["original"][]
  showTrigger?: boolean
  onSuccess?: () => void
}

export function InviteCandidatesDialog({
  candidates,
  showTrigger = true,
  onSuccess,
  ...props
}: InviteCandidatesDialogProps) {
  const [isInvitePending, startInviteTransition] = React.useTransition()
  const isDesktop = useMediaQuery("(min-width: 640px)")
  const { data: session, status } = useSession()

  // 후보자를 상태별로 분류
  const discardedCandidates = candidates.filter(candidate => candidate.status === "DISCARDED")
  const nonDiscardedCandidates = candidates.filter(candidate => candidate.status !== "DISCARDED")
  
  // 이메일 유무에 따라 초대 가능한 후보자 분류 (DISCARDED가 아닌 후보자 중에서)
  const candidatesWithEmail = nonDiscardedCandidates.filter(candidate => candidate.contactEmail)
  const candidatesWithoutEmail = nonDiscardedCandidates.filter(candidate => !candidate.contactEmail)

  // 각 카테고리 수
  const invitableCount = candidatesWithEmail.length
  const hasUninvitableCandidates = candidatesWithoutEmail.length > 0
  const hasDiscardedCandidates = discardedCandidates.length > 0

  function onInvite() {
    startInviteTransition(async () => {
      // 이메일이 있고 DISCARDED가 아닌 후보자만 상태 업데이트

      if (!session?.user?.id) {
        toast.error("인증 오류. 로그인 정보를 찾을 수 없습니다.")
        return
      }

      const { error } = await bulkUpdateVendorCandidateStatus({
        ids: candidatesWithEmail.map((candidate) => candidate.id),
        status: "INVITED",
      })

      if (error) {
        toast.error(error)
        return
      }

      props.onOpenChange?.(false)
      
      if (invitableCount === 0) {
        toast.warning("No invitation sent - no eligible candidates with email addresses")
      } else {
        let skipMessage = ""
        
        if (hasUninvitableCandidates && hasDiscardedCandidates) {
          skipMessage = ` ${candidatesWithoutEmail.length} candidates without email and ${discardedCandidates.length} discarded candidates were skipped.`
        } else if (hasUninvitableCandidates) {
          skipMessage = ` ${candidatesWithoutEmail.length} candidates without email were skipped.`
        } else if (hasDiscardedCandidates) {
          skipMessage = ` ${discardedCandidates.length} discarded candidates were skipped.`
        }
        
        toast.success(`Invitation emails sent to ${invitableCount} candidates.${skipMessage}`)
      }
      
      onSuccess?.()
    })
  }

  // 초대 버튼 비활성화 조건
  const disableInviteButton = isInvitePending || invitableCount === 0
  
  const DialogComponent = (
    <>
      <div className="space-y-4">
        {/* 이메일 없는 후보자 알림 */}
        {hasUninvitableCandidates && (
          <Alert>
            <AlertCircle className="h-4 w-4" />
            <AlertTitle>Missing Email Addresses</AlertTitle>
            <AlertDescription>
              {candidatesWithoutEmail.length} candidate{candidatesWithoutEmail.length > 1 ? 's' : ''} {candidatesWithoutEmail.length > 1 ? 'don&apos;t' : 'doesn&apos;t'} have email addresses and won&apos;t receive invitations.
            </AlertDescription>
          </Alert>
        )}
        
        {/* 폐기된 후보자 알림 */}
        {hasDiscardedCandidates && (
          <Alert variant="destructive">
            <XCircle className="h-4 w-4" />
            <AlertTitle>Discarded Candidates</AlertTitle>
            <AlertDescription>
              {discardedCandidates.length} candidate{discardedCandidates.length > 1 ? 's have' : ' has'} been discarded and won&apos;t receive invitations.
            </AlertDescription>
          </Alert>
        )}
        
        <DialogDescription>
          {invitableCount > 0 ? (
            <>
              This will send invitation emails to{" "}
              <span className="font-medium">{invitableCount}</span>
              {invitableCount === 1 ? " candidate" : " candidates"} and change their status to INVITED.
            </>
          ) : (
            <>
              No candidates can be invited because none of the selected candidates have valid email addresses or they have been discarded.
            </>
          )}
        </DialogDescription>
      </div>
    </>
  )
  
  if (isDesktop) {
    return (
      <Dialog {...props}>
        {showTrigger ? (
          <DialogTrigger asChild>
            <Button variant="outline" size="sm" className="gap-2">
              <Mail className="size-4" aria-hidden="true" />
              Invite ({candidates.length})
            </Button>
          </DialogTrigger>
        ) : null}
        <DialogContent>
          <DialogHeader>
            <DialogTitle>Send invitations?</DialogTitle>
          </DialogHeader>
          {DialogComponent}
          <DialogFooter className="gap-2 sm:space-x-0">
            <DialogClose asChild>
              <Button variant="outline">Cancel</Button>
            </DialogClose>
            <Button
              aria-label="Invite selected vendors"
              variant="default"
              onClick={onInvite}
              disabled={disableInviteButton}
            >
              {isInvitePending && (
                <Loader
                  className="mr-2 size-4 animate-spin"
                  aria-hidden="true"
                />
              )}
              Send Invitations
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    )
  }

  return (
    <Drawer {...props}>
      {showTrigger ? (
        <DrawerTrigger asChild>
          <Button variant="outline" size="sm" className="gap-2">
            <Mail className="size-4" aria-hidden="true" />
            Invite ({candidates.length})
          </Button>
        </DrawerTrigger>
      ) : null}
      <DrawerContent>
        <DrawerHeader>
          <DrawerTitle>Send invitations?</DrawerTitle>
        </DrawerHeader>
        {DialogComponent}
        <DrawerFooter className="gap-2 sm:space-x-0">
          <DrawerClose asChild>
            <Button variant="outline">Cancel</Button>
          </DrawerClose>
          <Button
            aria-label="Invite selected vendors"
            variant="default"
            onClick={onInvite}
            disabled={disableInviteButton}
          >
            {isInvitePending && (
              <Loader className="mr-2 size-4 animate-spin" aria-hidden="true" />
            )}
            Send Invitations
          </Button>
        </DrawerFooter>
      </DrawerContent>
    </Drawer>
  )
}