'use client'

import { useState, useEffect, useRef } from 'react'
import { useTranslations } from 'next-intl'
import { useForm } from 'react-hook-form'
import { zodResolver } from '@hookform/resolvers/zod'
import { z } from 'zod'
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'
import { Loader2, ArrowRight, ArrowLeft, CheckCircle2, AlertTriangle } from 'lucide-react'
import type { EntityType } from '@/types'
import type { CompanyLookupResult } from '@/lib/company-lookup/types'
import { normalizeOrgNumber } from '@/lib/company-lookup/normalize-org-number'

const schema = z.object({
  company_name: z.string().min(1, 'Företagsnamn krävs'),
  org_number: z.string()
    .min(1, 'Organisationsnummer krävs')
    .refine(
      (val) => normalizeOrgNumber(val) !== null,
      'Ogiltigt organisationsnummer. Kontrollera att du angett ett giltigt 10- eller 12-siffrigt organisationsnummer.',
    ),
  address_line1: z.string().optional(),
  postal_code: z.string().optional(),
  city: z.string().optional(),
})

type FormData = z.infer<typeof schema>

interface Step2Props {
  initialData: Partial<FormData>
  entityType?: EntityType
  ticEnabled?: boolean
  onTicLookup?: (result: CompanyLookupResult | null) => void
  onNext: (data: FormData) => void
  onBack: () => void
  isSaving: boolean
  orgNumberLocked?: boolean
  // Orgnr we already trust without a Lens call — typically because it came
  // from BankID CompanyRoles which confirms the user has a director role at
  // this company. When set and the form's orgnr matches, Step 2 skips the
  // debounced `/lookup` to avoid burning a Lens call on something we know
  // exists. The guard clears as soon as the user edits the field.
  preverifiedOrgNumber?: string | null
}

export default function Step2CompanyDetails({
  initialData,
  entityType,
  ticEnabled,
  onTicLookup,
  onNext,
  onBack,
  isSaving,
  orgNumberLocked,
  preverifiedOrgNumber,
}: Step2Props) {
  const t = useTranslations('onboarding')
  const {
    register,
    handleSubmit,
    watch,
    setValue,
    formState: { errors },
  } = useForm<FormData>({
    resolver: zodResolver(schema),
    mode: 'onTouched',
    defaultValues: {
      company_name: initialData.company_name || '',
      org_number: initialData.org_number || '',
      address_line1: initialData.address_line1 || '',
      postal_code: initialData.postal_code || '',
      city: initialData.city || '',
    },
  })

  const [isLooking, setIsLooking] = useState(false)
  const [lookupError, setLookupError] = useState<string | null>(null)
  const [lookupDone, setLookupDone] = useState<CompanyLookupResult | null>(null)
  const [existingOwn, setExistingOwn] = useState<{ id: string; name: string } | null>(null)
  const abortRef = useRef<AbortController | null>(null)
  const dupAbortRef = useRef<AbortController | null>(null)
  // Tracks an orgnr that's been pre-verified (BankID CompanyRoles match) so
  // the client-side Lens lookup is skipped for that exact value. Cleared
  // (set to null) the moment the user edits the org number — a different
  // orgnr is no longer covered by the BankID confirmation and needs a real
  // lookup.
  const prefetchedForOrgRef = useRef<string | null>(
    preverifiedOrgNumber ? normalizeOrgNumber(preverifiedOrgNumber) : null,
  )

  const orgNumber = watch('org_number')

  // Soft, account-scoped duplicate warning: if THIS user already has a
  // (non-archived) company with the same org number, surface a non-blocking
  // note. Org-number reuse is allowed (see lib/company/actions.ts), so this
  // never disables submit. The endpoint is RLS-scoped to the caller's own
  // companies, so it can't reveal or count another account's.
  useEffect(() => {
    if (!orgNumber || normalizeOrgNumber(orgNumber) === null) {
      setExistingOwn(null)
      return
    }
    const timer = setTimeout(() => {
      dupAbortRef.current?.abort()
      const controller = new AbortController()
      dupAbortRef.current = controller
      fetch(`/api/company/check-org-number?org_number=${encodeURIComponent(orgNumber)}`, {
        signal: controller.signal,
      })
        .then(async (res) => {
          if (controller.signal.aborted || !res.ok) return
          const { data } = await res.json()
          setExistingOwn(data?.companies?.[0] ?? null)
        })
        .catch(() => {
          // Advisory only — never blocks creation.
        })
    }, 500)
    return () => {
      clearTimeout(timer)
      dupAbortRef.current?.abort()
    }
  }, [orgNumber])

  useEffect(() => {
    if (!ticEnabled || !orgNumber || normalizeOrgNumber(orgNumber) === null) {
      return
    }

    // Server already fetched this orgnr (BankID deep-link). Don't burn a
    // second TIC call to re-confirm what we already have in `initialLookup`.
    // Once the user edits the field, normalizeOrgNumber(orgNumber) will
    // diverge from the prefetched value and the lookup re-arms.
    const normalized = normalizeOrgNumber(orgNumber)
    if (prefetchedForOrgRef.current && normalized === prefetchedForOrgRef.current) {
      return
    }
    // Any subsequent edit invalidates the prefetched-match guard for good.
    prefetchedForOrgRef.current = null

    setLookupError(null)
    setLookupDone(null)

    const timer = setTimeout(() => {
      // Abort any in-flight request
      abortRef.current?.abort()
      const controller = new AbortController()
      abortRef.current = controller

      setIsLooking(true)

      fetch(`/api/extensions/ext/tic/lookup?org_number=${encodeURIComponent(orgNumber)}`, {
        signal: controller.signal,
      })
        .then(async (res) => {
          if (controller.signal.aborted) return

          if (res.status === 403) {
            // Extension disabled — silently ignore
            return
          }
          if (res.status === 404) {
            setLookupError(t('step2_lookup_not_found'))
            onTicLookup?.(null)
            return
          }
          if (!res.ok) {
            setLookupError(t('step2_lookup_failed'))
            onTicLookup?.(null)
            return
          }

          const { data } = (await res.json()) as { data: CompanyLookupResult }

          // Guard: only apply if org_number still matches (user may have changed it)
          if (controller.signal.aborted) return

          setLookupDone(data)
          onTicLookup?.(data)

          // Auto-fill from TIC — overwrite since user just entered a new org number
          if (data.companyName) setValue('company_name', data.companyName)
          if (data.address?.street) setValue('address_line1', data.address.street)
          if (data.address?.postalCode) setValue('postal_code', data.address.postalCode)
          if (data.address?.city) setValue('city', data.address.city)
        })
        .catch((err) => {
          if ((err as Error).name === 'AbortError') return
          setLookupError(t('step2_lookup_failed'))
          onTicLookup?.(null)
        })
        .finally(() => {
          if (!controller.signal.aborted) setIsLooking(false)
        })
    }, 500)

    return () => {
      clearTimeout(timer)
      abortRef.current?.abort()
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [ticEnabled, orgNumber])

  const isAB = entityType === 'aktiebolag'

  return (
    <div className="space-y-6">
      <Card>
        <CardHeader>
          <CardTitle>{t('step2_card_title')}</CardTitle>
          <CardDescription>
            {ticEnabled
              ? t('step2_card_desc_tic')
              : isAB
                ? t('step2_card_desc_ab')
                : t('step2_card_desc_ef')}
          </CardDescription>
        </CardHeader>
        <CardContent>
          <form onSubmit={handleSubmit(onNext, (errs) => {
            const fields = Object.keys(errs).join(', ')
            console.error('[onboarding] step 2 validation failed:', fields, errs)
            fetch('/api/log', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ message: 'step 2 validation failed', extra: { fields } }) }).catch(() => {})
          })} className="space-y-4">
            <div className="space-y-2">
              <Label htmlFor="org_number">
                {t('step2_org_number_label')}
              </Label>
              <Input
                id="org_number"
                placeholder={isAB ? 'XXXXXX-XXXX' : t('step2_org_number_placeholder_ef')}
                {...register('org_number')}
                readOnly={orgNumberLocked}
                className={orgNumberLocked ? 'bg-muted cursor-not-allowed' : undefined}
              />
              {errors.org_number && (
                <p className="text-sm text-destructive">{errors.org_number.message}</p>
              )}
              <p className="text-xs text-muted-foreground">
                {isAB
                  ? t('step2_org_help_ab')
                  : t('step2_org_help_ef')}
              </p>
              {ticEnabled && isLooking && (
                <div className="flex items-center gap-2 text-sm text-muted-foreground">
                  <Loader2 className="h-3.5 w-3.5 animate-spin" />
                  {t('step2_fetching_details')}
                </div>
              )}
              {ticEnabled && lookupDone && !lookupDone.isCeased && (
                <div className="flex items-center gap-2 text-sm text-primary">
                  <CheckCircle2 className="h-3.5 w-3.5" />
                  {lookupDone.companyName}
                </div>
              )}
              {ticEnabled && lookupDone?.isCeased && (
                <div className="flex items-center gap-2 text-sm text-destructive">
                  <AlertTriangle className="h-3.5 w-3.5" />
                  {t('step2_ceased_inline', { companyName: lookupDone.companyName })}
                </div>
              )}
              {ticEnabled && lookupError && (
                <p className="text-xs text-muted-foreground">{lookupError}</p>
              )}
              {existingOwn && (
                <div className="flex items-start gap-2 rounded-md bg-warning/15 px-3 py-2 text-sm text-warning-foreground">
                  <AlertTriangle className="h-4 w-4 mt-0.5 flex-shrink-0 text-warning" />
                  <span>{t('step2_company_exists_own', { name: existingOwn.name })}</span>
                </div>
              )}
            </div>

            <div className="space-y-2">
              <Label htmlFor="company_name">
                {isAB ? t('step2_company_name_ab') : t('step2_company_name_ef')}
              </Label>
              <Input
                id="company_name"
                placeholder={isAB ? t('step2_company_name_placeholder_ab') : t('step2_company_name_placeholder_ef')}
                {...register('company_name')}
              />
              {errors.company_name && (
                <p className="text-sm text-destructive">{errors.company_name.message}</p>
              )}
            </div>

            <div className="pt-4 border-t">
              <h3 className="font-medium mb-4">{t('step2_address_heading')}</h3>

              <div className="space-y-4">
                <div className="space-y-2">
                  <Label htmlFor="address_line1">{t('step2_street_address')}</Label>
                  <Input
                    id="address_line1"
                    placeholder={t('step2_street_placeholder')}
                    {...register('address_line1')}
                  />
                </div>

                <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
                  <div className="space-y-2">
                    <Label htmlFor="postal_code">{t('step2_postal_code')}</Label>
                    <Input
                      id="postal_code"
                      placeholder="123 45"
                      {...register('postal_code')}
                    />
                  </div>
                  <div className="space-y-2">
                    <Label htmlFor="city">{t('step2_city')}</Label>
                    <Input
                      id="city"
                      placeholder="Stockholm"
                      {...register('city')}
                    />
                  </div>
                </div>
              </div>
            </div>

            <div className="flex flex-col-reverse sm:flex-row sm:justify-between gap-3 pt-4">
              <Button
                type="button"
                variant="ghost"
                onClick={onBack}
                disabled={isSaving}
                className="w-full sm:w-auto"
              >
                <ArrowLeft className="mr-2 h-4 w-4" />
                {t('back')}
              </Button>
              <Button
                type="submit"
                disabled={isSaving}
                className="w-full sm:w-auto"
              >
                {isSaving ? (
                  <>
                    <Loader2 className="mr-2 h-4 w-4 animate-spin" />
                    {t('saving')}
                  </>
                ) : (
                  <>
                    {t('continue')}
                    <ArrowRight className="ml-2 h-4 w-4" />
                  </>
                )}
              </Button>
            </div>
          </form>
        </CardContent>
      </Card>
    </div>
  )
}