'use client';

import { useState } from 'react';
import {
  AlertCircle,
  CalendarDays,
  CheckCircle2,
  Clock3,
  Loader2,
  Plus,
  RotateCcw,
  XCircle,
} from 'lucide-react';

import { Button } from '@/components/ui/button';
import { cn } from '@/lib/utils';
import type {
  TicketExtensionRequest,
  TicketExtensionRequestsResponse,
} from '@/types';
import { formatDate } from '@/utils/date';

import { useTicketExtensionRequestQuery } from '../../../hooks/useTicketQueries';
import { ExtensionRequestHistoryDialog } from './ExtensionRequestHistoryDialog';
import { RequestExtensionForm } from './RequestExtensionForm';

interface DetailRowProps {
  label: string;
  value: string;
  children?: React.ReactNode;
  className?: string;
}

function DetailRow({ label, value, children, className }: DetailRowProps) {
  return (
    <div className={cn('space-y-1 px-3 py-2.5', className)}>
      <p className="text-[11px] font-medium text-muted-foreground">{label}</p>
      <div className="flex items-center justify-between gap-3">
        <p className="text-sm font-medium">{value}</p>
        {children}
      </div>
    </div>
  );
}

const statusConfig = {
  pending: {
    title: 'Request Pending',
    description: 'This extension request is waiting for manager approval.',
    icon: Clock3,
    className:
      'border-amber-200 bg-amber-50 text-amber-700 dark:border-amber-900/60 dark:bg-amber-950/30 dark:text-amber-300',
  },
  approved: {
    title: 'Request Approved',
    description: 'This extension request was approved by the manager.',
    icon: CheckCircle2,
    className:
      'border-emerald-200 bg-emerald-50 text-emerald-700 dark:border-emerald-900/60 dark:bg-emerald-950/30 dark:text-emerald-300',
  },
  rejected: {
    title: 'Request Rejected',
    description: 'This extension request was rejected by the manager.',
    icon: AlertCircle,
    className:
      'border-red-200 bg-red-50 text-red-700 dark:border-red-900/60 dark:bg-red-950/30 dark:text-red-300',
  },
  cancelled: {
    title: 'Request Cancelled',
    description: 'This extension request was cancelled.',
    icon: XCircle,
    className: 'border-border bg-muted/50 text-muted-foreground',
  },
} satisfies Record<
  TicketExtensionRequest['status'],
  {
    title: string;
    description: string;
    icon: typeof Clock3;
    className: string;
  }
>;

export function getLatestRequest(response: TicketExtensionRequestsResponse) {
  return response.items.reduce<TicketExtensionRequest | null>(
    (latest, item) => {
      if (!latest) return item;
      return new Date(item.requested_at) > new Date(latest.requested_at)
        ? item
        : 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)));
}

export function ExtensionRequestDetails({
  request,
  requests,
  onRequestAnother,
}: {
  request: TicketExtensionRequest;
  requests: TicketExtensionRequest[];
  onRequestAnother?: () => void;
}) {
  const config = statusConfig[request.status];
  const StatusIcon = config.icon;
  const extensionDays = getExtensionDays(request);

  return (
    <div className="space-y-4">
      <div className={cn('flex gap-3 rounded-lg border p-4', config.className)}>
        <StatusIcon className="mt-0.5 size-5 shrink-0" />
        <div className="space-y-1">
          <p className="text-sm font-semibold">{config.title}</p>
          <p className="text-xs leading-relaxed">{config.description}</p>
        </div>
      </div>

      <section className="space-y-2">
        <p className="text-xs font-semibold">Request Details</p>
        <div className="divide-y overflow-hidden rounded-lg border">
          <DetailRow
            label="Requested On"
            value={formatDate(request.requested_at)}
          />
          <DetailRow
            label="Requested By"
            value={request.requested_by?.name ?? 'Assigned worker'}
          />
          <DetailRow
            label="Requested Due Date"
            value={formatDate(request.requested_due_at)}
          >
            {extensionDays > 0 ? (
              <span className="shrink-0 rounded-full bg-primary/10 px-2 py-0.5 text-[10px] font-semibold text-primary">
                +{extensionDays} {extensionDays === 1 ? 'Day' : 'Days'}
              </span>
            ) : null}
          </DetailRow>
          <DetailRow label="Reason for Extension" value={request.reason} />
        </div>
      </section>

      {request.resolved_at || request.resolved_by ? (
        <section className="space-y-2">
          <p className="text-xs font-semibold">Manager Response</p>
          <div className="divide-y overflow-hidden rounded-lg border">
            {request.resolved_at ? (
              <DetailRow
                label="Responded On"
                value={formatDate(request.resolved_at)}
              />
            ) : null}
            {request.resolved_by ? (
              <DetailRow
                label="Resolved By"
                value={`${request.resolved_by.name} · ${request.resolved_by.role.name}`}
              />
            ) : null}
            {request.status === 'approved' ? (
              <DetailRow
                label="Approved Due Date"
                value={formatDate(request.requested_due_at)}
              />
            ) : null}
            {request.decision_note ? (
              <DetailRow
                label="Manager Comments"
                value={request.decision_note}
              />
            ) : null}
          </div>
        </section>
      ) : null}

      <section className="space-y-2">
        <p className="text-xs font-semibold">Original Due Date</p>
        <div className="rounded-lg border">
          <DetailRow
            label="Original schedule"
            value={formatDate(request.current_due_at)}
          >
            <CalendarDays className="size-4 text-muted-foreground" />
          </DetailRow>
        </div>
      </section>

      <div className="space-y-2">
        <ExtensionRequestHistoryDialog requests={requests} />
        {request.status !== 'pending' && onRequestAnother ? (
          <Button type="button" className="w-full" onClick={onRequestAnother}>
            <Plus />
            Request Another Extension
          </Button>
        ) : null}
      </div>
    </div>
  );
}

export function TicketExtensionRequestPanel({
  ticketId,
  assignmentId,
  dueAt,
  canRequest,
}: {
  ticketId: string;
  assignmentId: number;
  dueAt: string | null;
  canRequest: boolean;
}) {
  const [isRequestFormOpen, setIsRequestFormOpen] = useState(false);
  const extensionRequestQuery = useTicketExtensionRequestQuery(
    ticketId,
    assignmentId,
  );

  if (extensionRequestQuery.isLoading) {
    return (
      <div className="flex min-h-40 items-center justify-center text-muted-foreground">
        <Loader2 className="size-5 animate-spin" />
        <span className="ml-2 text-sm">Loading extension request...</span>
      </div>
    );
  }

  if (extensionRequestQuery.isError) {
    return (
      <div className="space-y-3 rounded-lg border border-destructive/30 bg-destructive/5 p-4">
        <p className="text-sm text-destructive">
          Extension request details could not be loaded.
        </p>
        <Button
          type="button"
          size="sm"
          variant="outline"
          onClick={() => extensionRequestQuery.refetch()}
        >
          <RotateCcw />
          Try Again
        </Button>
      </div>
    );
  }

  const latestRequest = extensionRequestQuery.data
    ? getLatestRequest(extensionRequestQuery.data)
    : null;

  if (!latestRequest) {
    if (!canRequest) {
      return (
        <p className="text-sm text-muted-foreground">
          No extension request history is available for this ticket lot.
        </p>
      );
    }

    return (
      <RequestExtensionForm
        ticketId={ticketId}
        assignmentId={assignmentId}
        currentDueAt={dueAt}
      />
    );
  }

  if (isRequestFormOpen && latestRequest.status !== 'pending') {
    return (
      <div className="space-y-4">
        <Button
          type="button"
          variant="ghost"
          size="sm"
          onClick={() => setIsRequestFormOpen(false)}
        >
          Back to latest request
        </Button>
        <RequestExtensionForm
          ticketId={ticketId}
          assignmentId={assignmentId}
          currentDueAt={dueAt}
        />
      </div>
    );
  }

  return (
    <ExtensionRequestDetails
      request={latestRequest}
      requests={extensionRequestQuery.data?.items ?? []}
      onRequestAnother={
        canRequest ? () => setIsRequestFormOpen(true) : undefined
      }
    />
  );
}