import { zodResolver } from '@hookform/resolvers/zod'
import { PermissionAction } from '@supabase/shared-types/out/constants'
import { useEffect, useState } from 'react'
import { useForm } from 'react-hook-form'
import { toast } from 'sonner'
import {
  Button,
  Card,
  CardContent,
  CardFooter,
  Form,
  FormControl,
  FormField,
  FormInputGroupInput,
  InputGroup,
  InputGroupAddon,
  InputGroupText,
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from 'ui'
import { GenericSkeletonLoader, ShimmeringLoader } from 'ui-patterns'
import { FormItemLayout } from 'ui-patterns/form/FormItemLayout/FormItemLayout'
import * as z from 'zod'

import { ScaffoldSection, ScaffoldSectionTitle } from '@/components/layouts/Scaffold'
import AlertError from '@/components/ui/AlertError'
import NoPermission from '@/components/ui/NoPermission'
import { UpgradeToPro } from '@/components/ui/UpgradeToPro'
import { useAuthConfigQuery } from '@/data/auth/auth-config-query'
import { useAuthConfigUpdateMutation } from '@/data/auth/auth-config-update-mutation'
import { useMaxConnectionsQuery } from '@/data/database/max-connections-query'
import { useCheckEntitlements } from '@/hooks/misc/useCheckEntitlements'
import { useAsyncCheckPermissions } from '@/hooks/misc/useCheckPermissions'
import { useSelectedProjectQuery } from '@/hooks/misc/useSelectedProject'
import { IS_PLATFORM } from '@/lib/constants'

const FormSchema = z.object({
  API_MAX_REQUEST_DURATION: z.coerce
    .number()
    .min(5, 'Must be 5 or larger')
    .max(30, 'Must be a value no greater than 30'),
  DB_MAX_POOL_SIZE: z.coerce.number().min(1),
  DB_MAX_POOL_SIZE_UNIT: z.enum(['percent', 'connections']),
})

export const DatabaseFormSchema = z
  .object({
    DB_MAX_POOL_SIZE: z.coerce.number().min(1),
    DB_MAX_POOL_SIZE_UNIT: z.enum(['percent', 'connections']),
  })
  .superRefine((data, ctx) => {
    if (data.DB_MAX_POOL_SIZE_UNIT === 'percent') {
      if (data.DB_MAX_POOL_SIZE < 1 || data.DB_MAX_POOL_SIZE > 100) {
        ctx.addIssue({
          code: z.ZodIssueCode.custom,
          path: ['DB_MAX_POOL_SIZE'],
          message: 'Percentage must be between 1 and 100',
        })
      }
    }
  })

export const PerformanceSettingsForm = () => {
  const { data: project } = useSelectedProjectQuery()
  const { hasAccess: hasAccessToPerformance, isLoading: isLoadingEntitlement } =
    useCheckEntitlements('auth.performance_settings')
  const { can: canReadConfig } = useAsyncCheckPermissions(
    PermissionAction.READ,
    'custom_config_gotrue'
  )
  const { can: canUpdateConfig } = useAsyncCheckPermissions(
    PermissionAction.UPDATE,
    'custom_config_gotrue'
  )

  const [isUpdatingRequestDurationForm, setIsUpdatingRequestDurationForm] = useState(false)
  const [isUpdatingDatabaseForm, setIsUpdatingDatabaseForm] = useState(false)

  const {
    data: authConfig,
    error: authConfigError,
    isError,
    isLoading: isLoadingAuthConfig,
  } = useAuthConfigQuery({ projectRef: project?.ref })

  const { data: maxConnData, isLoading: isLoadingMaxConns } = useMaxConnectionsQuery({
    projectRef: project?.ref,
    connectionString: project?.connectionString,
  })
  const maxConnectionLimit = maxConnData?.maxConnections ?? 60

  const promptUpgrade = IS_PLATFORM && !isLoadingEntitlement && !hasAccessToPerformance

  const { mutate: updateAuthConfig } = useAuthConfigUpdateMutation()

  const requestDurationForm = useForm({
    resolver: zodResolver(
      z.object({ API_MAX_REQUEST_DURATION: FormSchema.shape.API_MAX_REQUEST_DURATION })
    ),
    defaultValues: { API_MAX_REQUEST_DURATION: 10 },
  })

  const databaseForm = useForm({
    resolver: zodResolver(DatabaseFormSchema),
    defaultValues: {
      DB_MAX_POOL_SIZE: 10,
      DB_MAX_POOL_SIZE_UNIT: 'connections',
    },
  })

  const chosenUnit = databaseForm.watch('DB_MAX_POOL_SIZE_UNIT')

  const onSubmitRequestDurationForm = (values: any) => {
    if (!project?.ref) return console.error('Project ref is required')
    if (!hasAccessToPerformance) return

    setIsUpdatingRequestDurationForm(true)

    updateAuthConfig(
      { projectRef: project?.ref, config: values },
      {
        onError: (error) => {
          toast.error(`Failed to update request duration settings: ${error?.message}`)
          setIsUpdatingRequestDurationForm(false)
        },
        onSuccess: () => {
          toast.success('Successfully updated request duration settings')
          setIsUpdatingRequestDurationForm(false)
        },
      }
    )
  }

  const onSubmitDatabaseForm = (values: any) => {
    if (!project?.ref) return console.error('Project ref is required')

    setIsUpdatingDatabaseForm(true)

    const config = {
      DB_MAX_POOL_SIZE: values.DB_MAX_POOL_SIZE,
      DB_MAX_POOL_SIZE_UNIT: values.DB_MAX_POOL_SIZE_UNIT,
    }

    updateAuthConfig(
      { projectRef: project?.ref, config },
      {
        onError: () => {
          setIsUpdatingDatabaseForm(false)
        },
        onSuccess: () => {
          toast.success('Successfully updated connection settings')
          setIsUpdatingDatabaseForm(false)
        },
      }
    )
  }

  useEffect(() => {
    if (authConfig) {
      if (!isUpdatingRequestDurationForm) {
        requestDurationForm.reset({
          API_MAX_REQUEST_DURATION: authConfig?.API_MAX_REQUEST_DURATION ?? 10,
        })
      }

      if (!isUpdatingDatabaseForm) {
        databaseForm.reset({
          DB_MAX_POOL_SIZE:
            authConfig?.DB_MAX_POOL_SIZE !== null ? (authConfig?.DB_MAX_POOL_SIZE ?? 10) : 10,
          DB_MAX_POOL_SIZE_UNIT:
            authConfig?.DB_MAX_POOL_SIZE_UNIT !== null
              ? authConfig?.DB_MAX_POOL_SIZE_UNIT
              : 'connections',
        })
      }
    }
  }, [authConfig, isUpdatingRequestDurationForm, isUpdatingDatabaseForm])

  if (isError) {
    return (
      <ScaffoldSection isFullWidth>
        <AlertError error={authConfigError} subject="Failed to retrieve auth configuration" />
      </ScaffoldSection>
    )
  }

  if (!canReadConfig) {
    return (
      <ScaffoldSection isFullWidth>
        <NoPermission resourceText="view auth configuration settings" />
      </ScaffoldSection>
    )
  }

  if (isLoadingAuthConfig || isLoadingEntitlement) {
    return (
      <ScaffoldSection isFullWidth>
        <GenericSkeletonLoader />
      </ScaffoldSection>
    )
  }

  return (
    <>
      <ScaffoldSection isFullWidth>
        {promptUpgrade && (
          <UpgradeToPro
            source="authPerformance"
            featureProposition="configure advanced Auth server settings"
            primaryText="Only available on the Pro Plan and above"
            secondaryText="Upgrade to the Pro Plan to configure Auth server performance settings."
          />
        )}
      </ScaffoldSection>

      <ScaffoldSection isFullWidth>
        <ScaffoldSectionTitle className="mb-4">Request duration</ScaffoldSectionTitle>

        <Form {...requestDurationForm}>
          <form onSubmit={requestDurationForm.handleSubmit(onSubmitRequestDurationForm)}>
            <Card>
              <CardContent className="pt-6">
                <FormField
                  control={requestDurationForm.control}
                  name="API_MAX_REQUEST_DURATION"
                  render={({ field }) => (
                    <FormItemLayout
                      layout="flex-row-reverse"
                      label="Maximum allowed duration for an Auth request"
                      description={
                        <p className="text-balance">
                          Requests that exceed this time limit are terminated to help manage server
                          load.
                        </p>
                      }
                    >
                      <div className="flex flex-col gap-2">
                        <div className="relative">
                          <FormControl>
                            <InputGroup>
                              <FormInputGroupInput
                                type="number"
                                min={5}
                                max={30}
                                {...field}
                                disabled={!canUpdateConfig || promptUpgrade}
                              />
                              <InputGroupAddon align="inline-end">
                                <InputGroupText>seconds</InputGroupText>
                              </InputGroupAddon>
                            </InputGroup>
                          </FormControl>
                        </div>

                        <p className="text-xs text-right text-foreground-muted">
                          10+ seconds recommended
                        </p>
                      </div>
                    </FormItemLayout>
                  )}
                />
              </CardContent>

              <CardFooter className="justify-end space-x-2">
                {requestDurationForm.formState.isDirty && (
                  <Button type="default" onClick={() => requestDurationForm.reset()}>
                    Cancel
                  </Button>
                )}
                <Button
                  type={promptUpgrade ? 'default' : 'primary'}
                  htmlType="submit"
                  disabled={
                    !canUpdateConfig ||
                    isUpdatingRequestDurationForm ||
                    !requestDurationForm.formState.isDirty ||
                    promptUpgrade
                  }
                  loading={isUpdatingRequestDurationForm}
                >
                  Save changes
                </Button>
              </CardFooter>
            </Card>
          </form>
        </Form>
      </ScaffoldSection>

      <ScaffoldSection isFullWidth>
        <ScaffoldSectionTitle className="mb-4">Connection management</ScaffoldSectionTitle>

        <Form {...databaseForm}>
          <form onSubmit={databaseForm.handleSubmit(onSubmitDatabaseForm)} className="space-y-4">
            <Card>
              <CardContent className="pt-6 flex flex-col gap-4">
                <FormField
                  control={databaseForm.control}
                  name="DB_MAX_POOL_SIZE_UNIT"
                  render={({ field }) => (
                    <FormItemLayout
                      layout="flex-row-reverse"
                      label="Allocation strategy"
                      description={
                        <p className="text-balance">
                          Choose whether to allocate a percentage or a fixed number of connections
                          to the Auth server. We recommend a percentage, as it scales automatically
                          with your instance size.
                        </p>
                      }
                    >
                      <FormControl>
                        <Select
                          value={field.value}
                          onValueChange={(value) => {
                            const values = databaseForm.getValues()
                            field.onChange(value)

                            if (values.DB_MAX_POOL_SIZE_UNIT !== value) {
                              const currentValue = values.DB_MAX_POOL_SIZE!

                              let preservedPoolSize: number
                              if (value === 'percent') {
                                // convert from absolute number to roughly the same percentage
                                preservedPoolSize = Math.ceil(
                                  (Math.min(maxConnectionLimit, currentValue) /
                                    maxConnectionLimit) *
                                    100
                                )
                              } else {
                                // convert from percentage to roughly the same connection number
                                preservedPoolSize = Math.floor(
                                  maxConnectionLimit * (Math.min(100, currentValue) / 100)
                                )
                              }

                              databaseForm.setValue('DB_MAX_POOL_SIZE', preservedPoolSize)
                            }
                          }}
                        >
                          <SelectTrigger size="small" disabled={!canUpdateConfig || promptUpgrade}>
                            <SelectValue>
                              {field.value === 'percent' ? 'Percentage' : 'Absolute'}
                            </SelectValue>
                          </SelectTrigger>
                          <SelectContent align="end">
                            <SelectItem value="connections" className="text-xs">
                              Absolute number of connections
                            </SelectItem>
                            <SelectItem value="percent" className="text-xs">
                              Percent of max connections
                            </SelectItem>
                          </SelectContent>
                        </Select>
                      </FormControl>
                    </FormItemLayout>
                  )}
                />
              </CardContent>
              <CardContent>
                <FormField
                  control={databaseForm.control}
                  name="DB_MAX_POOL_SIZE"
                  render={({ field }) => (
                    <FormItemLayout
                      layout="flex-row-reverse"
                      label="Maximum connections"
                      description={
                        <p className="text-balance">
                          The maximum number of connections the Auth server can use under peak load.{' '}
                          <em className="text-foreground-light font-medium not-italic">
                            Connections are not reserved
                          </em>{' '}
                          and are returned to Postgres after a short idle period.
                        </p>
                      }
                    >
                      <div className="flex flex-col gap-2">
                        <div className="relative">
                          <FormControl>
                            <InputGroup>
                              <FormInputGroupInput
                                type="number"
                                {...field}
                                disabled={!canUpdateConfig || promptUpgrade}
                              />
                              <InputGroupAddon align="inline-end">
                                <InputGroupText>
                                  {chosenUnit === 'percent' ? '%' : 'connections'}
                                </InputGroupText>
                              </InputGroupAddon>
                            </InputGroup>
                          </FormControl>
                        </div>
                        {isLoadingMaxConns ? (
                          <ShimmeringLoader className="py-2 w-16 ml-auto" />
                        ) : (
                          <p className="text-xs text-right text-foreground-muted">
                            <span className="text-foreground-light">
                              {chosenUnit === 'percent'
                                ? Math.floor(
                                    maxConnectionLimit * (Math.min(100, field.value!) / 100)
                                  ).toString()
                                : Math.min(maxConnectionLimit, field.value!)}
                            </span>{' '}
                            / {maxConnectionLimit}
                          </p>
                        )}
                      </div>
                    </FormItemLayout>
                  )}
                />
              </CardContent>

              <CardFooter className="justify-end space-x-2">
                {databaseForm.formState.isDirty && (
                  <Button type="default" onClick={() => databaseForm.reset()}>
                    Cancel
                  </Button>
                )}
                <Button
                  type={promptUpgrade ? 'default' : 'primary'}
                  htmlType="submit"
                  disabled={
                    !canUpdateConfig || isUpdatingDatabaseForm || !databaseForm.formState.isDirty
                  }
                  loading={isUpdatingDatabaseForm}
                >
                  Save changes
                </Button>
              </CardFooter>
            </Card>
          </form>
        </Form>
      </ScaffoldSection>
    </>
  )
}