'use client';

import { useState } from 'react';
import {
  ArrowRight,
  CalendarClock,
  Check,
  Clock3,
  Loader2,
  X,
} from 'lucide-react';

import { Button } from '@/components/ui/button';
import { Label } from '@/components/ui/label';
import { Textarea } from '@/components/ui/textarea';
import type {
  TicketDetail,
  TicketExtensionRequest,
  TicketExtensionRequestsResponse,
} from '@/types';
import { formatDate } from '@/utils/date';

import {
  useReviewTicketExtensionMutation,
  useTicketExtensionRequestQuery,
} from '../../../hooks/useTicketQueries';
import { TicketActionCard } from './TicketActionCard';

const MAX_NOTE_LENGTH = 300;

function getPendingRequest(response: TicketExtensionRequestsResponse) {
  return response.items
    .filter((request) => request.status === 'pending')
    .reduce<TicketExtensionRequest | null>((latest, request) => {
      if (!latest) return request;
      return new Date(request.requested_at) > new Date(latest.requested_at)
        ? request
        : latest;
    }, null);
}

function getExtensionDays(request: TicketExtensionRequest) {
  const difference =
    new Date(request.requested_due_at).getTime() -
    new Date(request.current_due_at).getTime();
  return Math.max(0, Math.ceil(difference / (24 * 60 * 60 * 1000)));
}

function Requester({ request }: { request: TicketExtensionRequest }) {
  const name = request.requested_by?.name ?? 'Assigned worker';
  const initials = name
    .split(/\s+/)
    .slice(0, 2)
    .map((part) => part[0]?.toUpperCase())
    .join('');

  return (
    <div className="grid grid-cols-2 gap-3 rounded-lg bg-muted/40 p-3">
      <div className="flex items-center gap-2">
        <span className="flex size-8 shrink-0 items-center justify-center rounded-full bg-primary/15 text-xs font-semibold text-primary">
          {initials || 'W'}
        </span>
        <div className="min-w-0">
          <p className="text-[11px] text-muted-foreground">Requested By</p>
          <p className="truncate text-sm font-medium">{name}</p>
        </div>
      </div>
      <div>
        <p className="text-[11px] text-muted-foreground">Requested On</p>
        <p className="text-sm font-medium">
          {formatDate(request.requested_at)}
        </p>
      </div>
    </div>
  );
}

function ExtensionReviewForm({
  ticket,
  request,
}: {
  ticket: TicketDetail;
  request: TicketExtensionRequest;
}) {
  const [note, setNote] = useState('');
  const [selectedAction, setSelectedAction] = useState<
    'approve' | 'reject' | null
  >(null);
  const assignmentId = ticket.worker?.assignment_id as number;
  const reviewMutation = useReviewTicketExtensionMutation(
    ticket.id,
    assignmentId,
    ticket.defect_class,
  );
  const extensionDays = getExtensionDays(request);

  const submitDecision = async (action: 'approve' | 'reject') => {
    setSelectedAction(action);
    try {
      await reviewMutation.mutateAsync({ action, note: note.trim() });
    } finally {
      setSelectedAction(null);
    }
  };

  return (
    <TicketActionCard icon={CalendarClock} title="Extension Request Details">
      <div className="space-y-4">
        <Requester request={request} />

        <section className="space-y-2">
          <p className="text-xs font-semibold">Request Summary</p>
          <div className="grid grid-cols-[minmax(0,1fr)_auto_minmax(0,1fr)] items-start gap-3 rounded-lg border p-3">
            <div>
              <p className="text-[11px] text-muted-foreground">
                Current Due Date
              </p>
              <p className="text-xs font-medium">
                {formatDate(request.current_due_at)}
              </p>
            </div>
            <ArrowRight className="mt-6 size-4 text-muted-foreground" />
            <div>
              <p className="text-[11px] text-muted-foreground">
                Requested Due Date
              </p>
              <p className="text-xs font-medium">
                {formatDate(request.requested_due_at)}
              </p>
              {extensionDays > 0 ? (
                <span className="mt-1 inline-flex rounded-full bg-emerald-100 px-2 py-0.5 text-[10px] font-semibold text-emerald-700 dark:bg-emerald-950/50 dark:text-emerald-300">
                  +{extensionDays} {extensionDays === 1 ? 'Day' : 'Days'}
                </span>
              ) : null}
            </div>
          </div>
          <div className="rounded-lg border p-3">
            <p className="text-[11px] text-muted-foreground">Reason</p>
            <p className="mt-1 text-sm leading-relaxed">{request.reason}</p>
          </div>
        </section>

        <div className="space-y-2">
          <Label htmlFor="extension-manager-note">
            Add Manager Comments{' '}
            <span className="text-muted-foreground">(Optional)</span>
          </Label>
          <div className="relative">
            <Textarea
              id="extension-manager-note"
              value={note}
              onChange={(event) =>
                setNote(event.target.value.slice(0, MAX_NOTE_LENGTH))
              }
              placeholder="Add a note explaining your decision..."
              disabled={reviewMutation.isPending}
              className="min-h-24 resize-none pb-8"
            />
            <span className="pointer-events-none absolute right-3 bottom-2 text-xs text-muted-foreground">
              {note.length} / {MAX_NOTE_LENGTH}
            </span>
          </div>
        </div>

        <div className="grid grid-cols-2 gap-3">
          <Button
            type="button"
            variant="outline"
            className="border-destructive/40 text-destructive hover:bg-destructive/5 hover:text-destructive"
            disabled={reviewMutation.isPending}
            onClick={() => submitDecision('reject')}
          >
            {selectedAction === 'reject' ? (
              <Loader2 className="animate-spin" />
            ) : (
              <X />
            )}
            Reject Request
          </Button>
          <Button
            type="button"
            disabled={reviewMutation.isPending}
            onClick={() => submitDecision('approve')}
          >
            {selectedAction === 'approve' ? (
              <Loader2 className="animate-spin" />
            ) : (
              <Check />
            )}
            Approve Extension
          </Button>
        </div>
      </div>
    </TicketActionCard>
  );
}

export function ReviewExtensionRequestAction({
  ticket,
}: {
  ticket: TicketDetail;
}) {
  const assignmentId = ticket.worker?.assignment_id;
  const extensionRequestQuery = useTicketExtensionRequestQuery(
    ticket.id,
    assignmentId,
  );

  if (!assignmentId || extensionRequestQuery.isError) {
    return null;
  }

  if (extensionRequestQuery.isLoading) {
    return (
      <TicketActionCard icon={Clock3} title="Extension Request">
        <div className="flex items-center justify-center py-8 text-muted-foreground">
          <Loader2 className="mr-2 size-4 animate-spin" />
          <span className="text-sm">Checking for requests...</span>
        </div>
      </TicketActionCard>
    );
  }

  const pendingRequest = extensionRequestQuery.data
    ? getPendingRequest(extensionRequestQuery.data)
    : null;

  if (!pendingRequest) return null;

  return <ExtensionReviewForm ticket={ticket} request={pendingRequest} />;
}