'use client';

import Link from 'next/link';
import { useEffect, useState } from 'react';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { ExternalLink, Gauge, Loader2, Save } from 'lucide-react';
import { useTranslations } from 'next-intl';
import { toast } from 'sonner';

import { useAuth } from '@/components/providers/auth-provider';
import { EmptyStateWithBorder } from '@/components/layout/empty';
import { ErrorInline } from '@/components/layout/error';
import { LoadingStateWithBorder } from '@/components/layout/loading';
import { Button } from '@/components/ui/button';
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from '@/components/ui/card';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select';
import { Switch } from '@/components/ui/switch';
import { OptionService } from '@/lib/services/openflare';

import {
  defaultPerformanceFields,
  entriesFromKeys,
  mapOptionsToFields,
  optionsToMap,
  type PerformanceFields,
  validateCacheFields,
  validateGzipFields,
  validateProxyFields,
  validateRuntimeFields,
} from './components/performance-utils';

const optionsQueryKey = ['openflare', 'options'] as const;

export default function PerformancePage() {
  const t = useTranslations('performance');
  const tc = useTranslations('common');
  const { user, loading: authLoading } = useAuth();
  const queryClient = useQueryClient();
  const [fields, setFields] = useState<PerformanceFields>(
    defaultPerformanceFields,
  );
  const [savingSection, setSavingSection] = useState<string | null>(null);

  const optionsQuery = useQuery({
    queryKey: optionsQueryKey,
    queryFn: () => OptionService.list(),
    enabled: !!user?.is_admin,
  });

  useEffect(() => {
    if (!optionsQuery.data) return;
    setFields(mapOptionsToFields(optionsToMap(optionsQuery.data)));
  }, [optionsQuery.data]);

  const saveMutation = useMutation({
    mutationFn: async ({
      section,
      entries,
      validator,
    }: {
      section: string;
      entries: Array<{ key: string; value: string }>;
      validator?: (fields: PerformanceFields) => void;
    }) => {
      validator?.(fields);
      setSavingSection(section);
      await OptionService.updateBatch(entries);
    },
    onSuccess: async () => {
      toast.success(t('saved'));
      await Promise.all([
        queryClient.invalidateQueries({ queryKey: optionsQueryKey }),
        queryClient.invalidateQueries({
          queryKey: ['openflare', 'config-preview'],
        }),
        queryClient.invalidateQueries({
          queryKey: ['openflare', 'config-versions'],
        }),
      ]);
      setSavingSection(null);
    },
    onError: (error) => {
      setSavingSection(null);
      toast.error(error instanceof Error ? error.message : t('saveFailed'));
    },
  });

  const updateField = <K extends keyof PerformanceFields>(
    key: K,
    value: PerformanceFields[K],
  ) => {
    setFields((prev) => ({ ...prev, [key]: value }));
  };

  if (authLoading) {
    return (
      <div className='py-6 px-1'>
        <LoadingStateWithBorder icon={Gauge} description={t('loadingAuth')} />
      </div>
    );
  }

  if (!user?.is_admin) {
    return (
      <div className='py-6 px-1'>
        <EmptyStateWithBorder
          icon={Gauge}
          title={t('forbiddenTitle')}
          description={t('forbiddenDesc')}
        />
      </div>
    );
  }

  if (optionsQuery.isLoading) {
    return (
      <div className='py-6 px-1'>
        <LoadingStateWithBorder icon={Gauge} description={t('loading')} />
      </div>
    );
  }

  if (optionsQuery.isError) {
    return (
      <div className='py-6 px-1'>
        <ErrorInline
          message={
            optionsQuery.error instanceof Error
              ? optionsQuery.error.message
              : tc('loadFailed')
          }
          onRetry={() => void optionsQuery.refetch()}
        />
      </div>
    );
  }

  return (
    <div className='py-6 px-1 space-y-6'>
      <div className='flex flex-col gap-4 lg:flex-row lg:items-start lg:justify-between'>
        <div className='flex items-center gap-2'>
          <Gauge className='size-5 text-primary' />
          <div>
            <h1 className='text-2xl font-semibold tracking-tight'>
              {t('title')}
            </h1>
            <p className='text-sm text-muted-foreground'>{t('description')}</p>
          </div>
        </div>
        <Button variant='outline' size='sm' asChild>
          <Link href='/config-versions'>
            <ExternalLink className='size-3.5 mr-1' />
            {t('preview')}
          </Link>
        </Button>
      </div>

      <Card className='border-dashed shadow-none'>
        <CardHeader className='flex flex-row items-center justify-between'>
          <div>
            <CardTitle className='text-base'>{t('runtimeTitle')}</CardTitle>
            <CardDescription>{t('runtimeDesc')}</CardDescription>
          </div>
          <Button
            size='sm'
            disabled={savingSection === 'runtime'}
            onClick={() =>
              saveMutation.mutate({
                section: 'runtime',
                validator: (fields) => validateRuntimeFields(fields, t),
                entries: entriesFromKeys(fields, [
                  'openresty_default_server_return_status',
                  'openresty_worker_processes',
                  'openresty_resolvers',
                  'openresty_worker_connections',
                  'openresty_worker_rlimit_nofile',
                  'openresty_events_use',
                  'openresty_events_multi_accept_enabled',
                  'openresty_keepalive_timeout',
                  'openresty_keepalive_requests',
                  'openresty_client_header_timeout',
                  'openresty_client_body_timeout',
                  'openresty_client_max_body_size',
                  'openresty_large_client_header_buffers',
                  'openresty_send_timeout',
                ]),
              })
            }
          >
            {savingSection === 'runtime' ? (
              <Loader2 className='size-4 animate-spin mr-1' />
            ) : (
              <Save className='size-3.5 mr-1' />
            )}
            {tc('save')}
          </Button>
        </CardHeader>
        <CardContent className='grid gap-4 md:grid-cols-2 xl:grid-cols-3'>
          <FieldInput
            label='worker_processes'
            value={fields.openresty_worker_processes}
            onChange={(v) => updateField('openresty_worker_processes', v)}
          />
          <FieldInput
            label='worker_connections'
            value={fields.openresty_worker_connections}
            onChange={(v) => updateField('openresty_worker_connections', v)}
            type='number'
          />
          <FieldInput
            label='worker_rlimit_nofile'
            value={fields.openresty_worker_rlimit_nofile}
            onChange={(v) => updateField('openresty_worker_rlimit_nofile', v)}
            type='number'
          />
          <div className='space-y-1.5'>
            <Label>events use</Label>
            <Select
              value={fields.openresty_events_use}
              onValueChange={(v) => updateField('openresty_events_use', v)}
            >
              <SelectTrigger>
                <SelectValue />
              </SelectTrigger>
              <SelectContent>
                <SelectItem value='epoll'>epoll</SelectItem>
                <SelectItem value='kqueue'>kqueue</SelectItem>
                <SelectItem value='poll'>poll</SelectItem>
                <SelectItem value='select'>select</SelectItem>
              </SelectContent>
            </Select>
          </div>
          <ToggleRow
            label='multi_accept'
            checked={fields.openresty_events_multi_accept_enabled}
            onChange={(v) =>
              updateField('openresty_events_multi_accept_enabled', v)
            }
          />
          <FieldInput
            label='keepalive_timeout'
            value={fields.openresty_keepalive_timeout}
            onChange={(v) => updateField('openresty_keepalive_timeout', v)}
            type='number'
          />
          <FieldInput
            label='client_max_body_size'
            value={fields.openresty_client_max_body_size}
            onChange={(v) => updateField('openresty_client_max_body_size', v)}
          />
          <FieldInput
            label='resolvers'
            value={fields.openresty_resolvers}
            onChange={(v) => updateField('openresty_resolvers', v)}
            placeholder='1.1.1.1 8.8.8.8'
          />
          <FieldInput
            label='default_server_return_status'
            value={fields.openresty_default_server_return_status}
            onChange={(v) =>
              updateField('openresty_default_server_return_status', v)
            }
            type='number'
          />
        </CardContent>
      </Card>

      <Card className='border-dashed shadow-none'>
        <CardHeader className='flex flex-row items-center justify-between'>
          <div>
            <CardTitle className='text-base'>{t('proxyTitle')}</CardTitle>
            <CardDescription>{t('proxyDesc')}</CardDescription>
          </div>
          <Button
            size='sm'
            disabled={savingSection === 'proxy'}
            onClick={() =>
              saveMutation.mutate({
                section: 'proxy',
                validator: (fields) => validateProxyFields(fields, t),
                entries: entriesFromKeys(fields, [
                  'openresty_proxy_connect_timeout',
                  'openresty_proxy_send_timeout',
                  'openresty_proxy_read_timeout',
                  'openresty_websocket_enabled',
                  'openresty_http3_enabled',
                  'openresty_proxy_request_buffering_enabled',
                  'openresty_proxy_buffering_enabled',
                  'openresty_proxy_buffers',
                  'openresty_proxy_buffer_size',
                  'openresty_proxy_busy_buffers_size',
                ]),
              })
            }
          >
            {savingSection === 'proxy' ? (
              <Loader2 className='size-4 animate-spin mr-1' />
            ) : (
              <Save className='size-3.5 mr-1' />
            )}
            {tc('save')}
          </Button>
        </CardHeader>
        <CardContent className='grid gap-4 md:grid-cols-2'>
          <FieldInput
            label='proxy_connect_timeout'
            value={fields.openresty_proxy_connect_timeout}
            onChange={(v) => updateField('openresty_proxy_connect_timeout', v)}
            type='number'
          />
          <FieldInput
            label='proxy_read_timeout'
            value={fields.openresty_proxy_read_timeout}
            onChange={(v) => updateField('openresty_proxy_read_timeout', v)}
            type='number'
          />
          <ToggleRow
            label='websocket'
            checked={fields.openresty_websocket_enabled}
            onChange={(v) => updateField('openresty_websocket_enabled', v)}
          />
          <ToggleRow
            label='http3'
            checked={fields.openresty_http3_enabled}
            onChange={(v) => updateField('openresty_http3_enabled', v)}
          />
          <ToggleRow
            label='proxy_buffering'
            checked={fields.openresty_proxy_buffering_enabled}
            onChange={(v) =>
              updateField('openresty_proxy_buffering_enabled', v)
            }
          />
          <FieldInput
            label='proxy_buffers'
            value={fields.openresty_proxy_buffers}
            onChange={(v) => updateField('openresty_proxy_buffers', v)}
          />
        </CardContent>
      </Card>

      <div className='grid gap-6 xl:grid-cols-2'>
        <Card className='border-dashed shadow-none'>
          <CardHeader className='flex flex-row items-center justify-between'>
            <CardTitle className='text-base'>{t('gzipTitle')}</CardTitle>
            <Button
              size='sm'
              disabled={savingSection === 'gzip'}
              onClick={() =>
                saveMutation.mutate({
                  section: 'gzip',
                  validator: (fields) => validateGzipFields(fields, t),
                  entries: entriesFromKeys(fields, [
                    'openresty_gzip_enabled',
                    'openresty_gzip_min_length',
                    'openresty_gzip_comp_level',
                  ]),
                })
              }
            >
              {tc('save')}
            </Button>
          </CardHeader>
          <CardContent className='space-y-4'>
            <ToggleRow
              label='gzip'
              checked={fields.openresty_gzip_enabled}
              onChange={(v) => updateField('openresty_gzip_enabled', v)}
            />
            <FieldInput
              label='gzip_min_length'
              value={fields.openresty_gzip_min_length}
              onChange={(v) => updateField('openresty_gzip_min_length', v)}
              type='number'
            />
            <FieldInput
              label='gzip_comp_level'
              value={fields.openresty_gzip_comp_level}
              onChange={(v) => updateField('openresty_gzip_comp_level', v)}
              type='number'
            />
          </CardContent>
        </Card>

        <Card className='border-dashed shadow-none'>
          <CardHeader className='flex flex-row items-center justify-between'>
            <div>
              <CardTitle className='text-base'>{t('cacheTitle')}</CardTitle>
              <CardDescription>{t('cacheDesc')}</CardDescription>
            </div>
            <Button
              size='sm'
              disabled={savingSection === 'cache'}
              onClick={() =>
                saveMutation.mutate({
                  section: 'cache',
                  validator: (fields) => validateCacheFields(fields, t),
                  entries: entriesFromKeys(fields, [
                    'openresty_cache_enabled',
                    'openresty_cache_path',
                    'openresty_cache_levels',
                    'openresty_cache_inactive',
                    'openresty_cache_max_size',
                    'openresty_cache_key_template',
                    'openresty_cache_lock_enabled',
                    'openresty_cache_lock_timeout',
                    'openresty_cache_use_stale',
                  ]),
                })
              }
            >
              {tc('save')}
            </Button>
          </CardHeader>
          <CardContent className='space-y-4'>
            <ToggleRow
              label='cache_enabled'
              checked={fields.openresty_cache_enabled}
              onChange={(v) => updateField('openresty_cache_enabled', v)}
            />
            <FieldInput
              label='proxy_cache_path'
              value={fields.openresty_cache_path}
              onChange={(v) => updateField('openresty_cache_path', v)}
              disabled={!fields.openresty_cache_enabled}
            />
            <FieldInput
              label='levels'
              value={fields.openresty_cache_levels}
              onChange={(v) => updateField('openresty_cache_levels', v)}
              disabled={!fields.openresty_cache_enabled}
            />
            <FieldInput
              label='max_size'
              value={fields.openresty_cache_max_size}
              onChange={(v) => updateField('openresty_cache_max_size', v)}
              disabled={!fields.openresty_cache_enabled}
            />
          </CardContent>
        </Card>
      </div>
    </div>
  );
}

function FieldInput({
  label,
  value,
  onChange,
  type = 'text',
  placeholder,
  disabled,
}: {
  label: string;
  value: string;
  onChange: (value: string) => void;
  type?: string;
  placeholder?: string;
  disabled?: boolean;
}) {
  return (
    <div className='space-y-1.5'>
      <Label className='text-xs text-muted-foreground'>{label}</Label>
      <Input
        type={type}
        value={value}
        placeholder={placeholder}
        disabled={disabled}
        onChange={(e) => onChange(e.target.value)}
        className='h-9 text-xs'
      />
    </div>
  );
}

function ToggleRow({
  label,
  checked,
  onChange,
}: {
  label: string;
  checked: boolean;
  onChange: (value: boolean) => void;
}) {
  return (
    <div className='flex items-center justify-between rounded-lg border border-dashed px-3 py-2'>
      <Label className='text-xs'>{label}</Label>
      <Switch checked={checked} onCheckedChange={onChange} />
    </div>
  );
}