'use client'

import { useCallback, useEffect, useState } from 'react'

import { texts, format } from '@/texts'
import type { DiscountBearer, DiscountCode, DiscountRedemption, DiscountReport, DiscountType } from '@/services/discountCodes'
import { Chip } from '@/components/heroui/Chip'
import { addToast } from '@/lib/toast'
import Button from '@/components/formElements/Button'
import Input from '@/components/formElements/Input'
import StatusChip from '@/components/ui/StatusChip'
import { getActiveStatus } from '@/constants/status'
import { convertPersianToEnglish, formatCurrency, formatNumber, coerceToString } from '@/helpers'
import { formatPersianDate } from '@/lib/formatters'
import {
  BULK_CREATE_DISCOUNT_CODES,
  DELETE_DISCOUNT_CODE,
  GET_DISCOUNT_MANAGEMENT_BOOTSTRAP,
  SET_DISCOUNT_CODE_ACTIVE,
} from '@/services/discountCodes'

interface EventDiscountsPanelProps {
  eventId: string
  isFree: boolean
  isEnded?: boolean
  /** Admins can shift the discount cost onto the platform. Hosts always absorb it. */
  isAdmin?: boolean
}

const number = formatNumber

const toInt = (value: string): number | undefined => {
  const parsed = Number(convertPersianToEnglish(value).replace(/[^\d]/g, ''))

  return Number.isFinite(parsed) && parsed > 0 ? parsed : undefined
}

const describeCode = (code: DiscountCode): string =>
  code.type === 'percent'
    ? format(texts.events.percentOff, { value: number(code.value) })
    : format(texts.events.amountOff, { value: formatCurrency(code.value) })

const DISCOUNT_TYPE_OPTIONS = [
  { code: 'percent', name: texts.events.discountTypePercent },
  { code: 'fixed', name: texts.events.discountTypeFixed },
] as const

const DISCOUNT_BEARER_OPTIONS = [
  { code: 'organizer', name: texts.events.host },
  { code: 'platform', name: texts.events.bearerPlatform },
] as const

const EventDiscountsPanel = ({ eventId, isFree, isEnded = false, isAdmin = false }: EventDiscountsPanelProps) => {
  const [codes, setCodes] = useState<DiscountCode[]>([])
  const [redemptions, setRedemptions] = useState<DiscountRedemption[]>([])
  const [report, setReport] = useState<DiscountReport | null>(null)
  const [isLoading, setIsLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)

  // Create form
  const [type, setType] = useState<DiscountType>('percent')
  const [value, setValue] = useState('')
  const [quantity, setQuantity] = useState('1')
  const [maxUses, setMaxUses] = useState('')
  const [maxUsesPerUser, setMaxUsesPerUser] = useState('')
  const [bearer, setBearer] = useState<DiscountBearer>('organizer')
  const [showAdvanced, setShowAdvanced] = useState(false)
  const [isCreating, setIsCreating] = useState(false)
  const [pendingCodeId, setPendingCodeId] = useState<string | null>(null)
  const [lastBatch, setLastBatch] = useState<string[] | null>(null)

  const load = useCallback(async () => {
    setIsLoading(true)
    setError(null)

    const result = await GET_DISCOUNT_MANAGEMENT_BOOTSTRAP(eventId)

    if (!result.ok) {
      setError(texts.events.discountsLoadFailed)
      setIsLoading(false)

      return
    }

    setCodes(result.data.codes.items)
    setReport(result.data.report)
    setRedemptions(result.data.redemptions.items)
    setIsLoading(false)
  }, [eventId])

  useEffect(() => {
    if (!isFree) void load()
    else setIsLoading(false)
  }, [isFree, load])

  const canCreate = !isFree && !isEnded
  const canMutateCodes = !isEnded

  const handleCreate = async () => {
    const numericValue = toInt(value)
    const numericQuantity = toInt(quantity)

    if (!numericValue) {
      addToast({ title: texts.events.discountValueRequired, color: 'warning' })

      return
    }
    if (type === 'percent' && (numericValue < 1 || numericValue > 99)) {
      addToast({ title: texts.events.discountPercentRange, color: 'warning' })

      return
    }
    if (!numericQuantity) {
      addToast({ title: texts.events.discountCountRequired, color: 'warning' })

      return
    }

    setIsCreating(true)
    const result = await BULK_CREATE_DISCOUNT_CODES(eventId, {
      type,
      value: numericValue,
      quantity: numericQuantity,
      maxUses: toInt(maxUses),
      maxUsesPerUser: toInt(maxUsesPerUser),
      bearer: isAdmin ? bearer : undefined,
    })

    setIsCreating(false)

    if (!result.ok) {
      addToast({ title: texts.events.discountCreateFailed, description: result.error.message, color: 'danger' })

      return
    }

    addToast({ title: format(texts.events.discountCreatedCount, { count: number(result.data.count) }), color: 'success' })
    setLastBatch(result.data.codes)
    setValue('')
    setQuantity('1')
    setMaxUses('')
    setMaxUsesPerUser('')
    await load()
  }

  const handleToggleActive = async (code: DiscountCode, nextActive: boolean) => {
    if (!canMutateCodes) {
      addToast({ title: texts.events.discountToggleAfterEnd, color: 'warning' })

      return
    }

    setPendingCodeId(code.id)
    const result = await SET_DISCOUNT_CODE_ACTIVE(code.id, nextActive)

    setPendingCodeId(null)

    if (!result.ok) {
      addToast({ title: texts.events.discountToggleFailed, color: 'danger' })

      return
    }

    setCodes((current) => current.map((item) => (item.id === code.id ? { ...item, isActive: nextActive } : item)))
  }

  const handleDelete = async (code: DiscountCode) => {
    if (!canMutateCodes) {
      addToast({ title: texts.events.discountDeleteAfterEnd, color: 'warning' })

      return
    }

    if (code.redeemedCount > 0) {
      addToast({ title: texts.events.discountDeleteUsed, color: 'warning' })

      return
    }

    setPendingCodeId(code.id)
    const result = await DELETE_DISCOUNT_CODE(code.id)

    setPendingCodeId(null)

    if (!result.ok) {
      addToast({ title: texts.events.discountDeleteFailed, description: result.error.message, color: 'danger' })

      return
    }

    addToast({ title: texts.events.discountDeleted, color: 'success' })
    setCodes((current) => current.filter((item) => item.id !== code.id))
  }

  const copyCodes = async (list: string[]) => {
    try {
      await navigator.clipboard.writeText(list.join('\n'))
      addToast({ title: texts.events.codesCopied, color: 'success' })
    } catch {
      addToast({ title: texts.events.copyFailed, color: 'danger' })
    }
  }

  if (isFree) {
    return (
      <div className="consumer-surface p-6 text-center">
        <h2 className="font-extrabold text-secondary-10">{texts.events.eventIsFreeTitle}</h2>
        <p className="mt-2 text-sm text-secondary-30">{texts.events.freeEventNoDiscounts}</p>
      </div>
    )
  }

  return (
    <section className="space-y-4">
      {report ? (
        <div className="space-y-1">
          <div className="consumer-surface flex items-center justify-between p-3">
            <span className="text-xs text-secondary-20">{texts.events.activeCodes}</span>
            <strong className="mt-2 block text-lg font-semibold text-consumer-text">{number(report.totalCodes)}</strong>
          </div>
          <div className="consumer-surface flex items-center justify-between p-3">
            <span className="text-xs text-secondary-20">{texts.events.redemptionCount}</span>
            <strong className="mt-2 block text-lg font-semibold text-consumer-text">{number(report.totalRedemptions)}</strong>
          </div>
          <div className="consumer-surface flex items-center justify-between p-3">
            <span className="text-xs text-secondary-20">{texts.events.totalDiscount}</span>
            <strong className="mt-2 block font-extrabold text-consumer-text">{formatCurrency(report.totalDiscountAmount)}</strong>
          </div>
          <div className="consumer-surface flex items-center justify-between p-3">
            <span className="text-xs text-secondary-20">{texts.events.platformDiscountShare}</span>
            <strong className="mt-2 block font-extrabold text-consumer-text">{formatCurrency(report.totalPlatformAbsorbed)}</strong>
          </div>
        </div>
      ) : null}

      <section className="consumer-surface space-y-4 p-5">
        <div>
          <h2 className="font-semibold text-secondary-10">{texts.events.createDiscountTitle}</h2>
          <p className="mt-1 text-xs leading-6 text-secondary-30">{texts.events.createDiscountIntro}</p>
        </div>

        {!canCreate ? (
          <div className="rounded-2xl bg-fourth-100 p-4 text-sm text-fourth-700">{texts.events.createDiscountEnded}</div>
        ) : (
          <>
            <div className="space-y-3">
              <Input
                generalType="select"
                label={texts.events.discountTypeLabel}
                name="discountType"
                selectKey="code"
                selectOptions={[...DISCOUNT_TYPE_OPTIONS]}
                selectValue="name"
                value={type}
                variant="flat"
                onValueChange={(next) => {
                  setType(coerceToString(next) as DiscountType)
                }}
              />
              <Input
                englishDigitsOnly
                direction="ltr"
                generalType="input"
                label={type === 'percent' ? texts.events.discountPercentValueLabel : texts.events.discountFixedValueLabel}
                name="discountValue"
                placeholder={type === 'percent' ? '20' : '50000'}
                value={value}
                variant="bordered"
                onValueChange={(next) => {
                  setValue(coerceToString(next))
                }}
              />
              <Input
                englishDigitsOnly
                direction="ltr"
                generalType="input"
                label={texts.events.uniqueCodeCountLabel}
                name="discountQuantity"
                placeholder="1"
                value={quantity}
                variant="bordered"
                onValueChange={(next) => {
                  setQuantity(coerceToString(next))
                }}
              />
              {isAdmin ? (
                <Input
                  description={texts.events.bearerPlatformHint}
                  generalType="select"
                  label={texts.events.bearerLabel}
                  name="discountBearer"
                  selectKey="code"
                  selectOptions={[...DISCOUNT_BEARER_OPTIONS]}
                  selectValue="name"
                  value={bearer}
                  variant="bordered"
                  onValueChange={(next) => {
                    setBearer(coerceToString(next) as DiscountBearer)
                  }}
                />
              ) : null}
            </div>

            <Button
              className="text-xs text-primary"
              size="sm"
              variant="light"
              onClick={() => {
                setShowAdvanced((prev) => !prev)
              }}
            >
              {showAdvanced ? texts.events.advancedSettingsClose : texts.events.advancedSettingsOpen}
            </Button>

            {showAdvanced ? (
              <div className="space-y-3">
                <Input
                  englishDigitsOnly
                  direction="ltr"
                  generalType="input"
                  label={texts.events.maxUsesLabel}
                  name="maxUses"
                  placeholder={texts.events.unlimitedPlaceholder}
                  value={maxUses}
                  variant="bordered"
                  onValueChange={(next) => {
                    setMaxUses(coerceToString(next))
                  }}
                />
                <Input
                  englishDigitsOnly
                  direction="ltr"
                  generalType="input"
                  label={texts.events.maxUsesPerUserLabel}
                  name="maxUsesPerUser"
                  placeholder={texts.events.unlimitedPlaceholder}
                  value={maxUsesPerUser}
                  variant="bordered"
                  onValueChange={(next) => {
                    setMaxUsesPerUser(coerceToString(next))
                  }}
                />
              </div>
            ) : null}

            <Button
              fullWidth
              isLoading={isCreating}
              size="lg"
              onClick={handleCreate}
            >
              {texts.events.createDiscountTitle}
            </Button>
          </>
        )}

        {lastBatch?.length ? (
          <div className="rounded-2xl border border-fifth-200 bg-fifth-50 p-4">
            <div className="flex items-center justify-between gap-2">
              <p className="text-sm font-bold text-fifth-700">
                {format(texts.events.codesCreatedCount, { count: number(lastBatch.length) })}
              </p>
              <Button
                size="sm"
                variant="flat"
                onClick={() => void copyCodes(lastBatch)}
              >
                {texts.events.copyAll}
              </Button>
            </div>
            <div className="mt-3 flex flex-wrap gap-2">
              {lastBatch.map((code) => (
                <span
                  key={code}
                  className="rounded-lg bg-white px-3 py-1 font-mono text-sm font-bold text-secondary-20"
                  dir="ltr"
                >
                  {code}
                </span>
              ))}
            </div>
          </div>
        ) : null}
      </section>

      <section className="space-y-3">
        <h2 className="font-extrabold text-secondary-10">{texts.events.definedCodesTitle}</h2>

        {isLoading ? (
          <div className="space-y-3">
            {[0, 1, 2].map((item) => (
              <div
                key={item}
                className="h-24 animate-pulse rounded-3xl border border-secondary-40 bg-white"
              />
            ))}
          </div>
        ) : error ? (
          <div className="rounded-2xl bg-fourth-100 p-4 text-sm text-fourth-700">{error}</div>
        ) : codes.length === 0 ? (
          <div className="rounded-3xl border border-dashed border-secondary-40 bg-white p-6 text-center text-sm text-secondary-30">
            {texts.events.noDiscountCodes}
          </div>
        ) : (
          <div className="space-y-3">
            {codes.map((code) => (
              <article
                key={code.id}
                className="consumer-surface space-y-3 p-4"
              >
                <div className="flex items-start justify-between gap-3">
                  <div className="min-w-0">
                    <div className="flex items-center gap-2">
                      <h3
                        className="truncate font-mono text-base font-extrabold text-secondary-10"
                        dir="ltr"
                      >
                        {code.code}
                      </h3>
                      {code.bearer === 'platform' ? (
                        <Chip
                          color="secondary"
                          size="sm"
                          variant="flat"
                        >
                          {texts.events.platformCostChip}
                        </Chip>
                      ) : null}
                    </div>
                    <p className="mt-1 text-sm font-semibold text-primary-700">{describeCode(code)}</p>
                  </div>
                  <StatusChip {...getActiveStatus(code.isActive)} />
                </div>

                <div className="grid grid-cols-3 gap-2 rounded-2xl bg-secondary-50 p-3 text-xs">
                  <div>
                    <span className="block text-secondary-30">{texts.events.redemptionCount}</span>
                    <span className="mt-1 block font-bold text-secondary-20">
                      {number(code.redeemedCount)}
                      {code.maxUses ? ` / ${number(code.maxUses)}` : ''}
                    </span>
                  </div>
                  <div>
                    <span className="block text-secondary-30">{texts.events.totalDiscount}</span>
                    <span className="mt-1 block font-bold text-secondary-20">{formatCurrency(code.totalDiscountAmount)}</span>
                  </div>
                  <div>
                    <span className="block text-secondary-30">{texts.events.createdLabel}</span>
                    <span className="mt-1 block font-bold text-secondary-20">{formatPersianDate(code.createdAt)}</span>
                  </div>
                </div>

                <div className="flex items-center justify-between gap-3">
                  <div className="flex items-center gap-2">
                    <Input
                      disabled={!canMutateCodes || pendingCodeId === code.id}
                      generalType="switch"
                      label=""
                      name={`code-active-${code.id}`}
                      value={code.isActive}
                      onValueChange={(next) => void handleToggleActive(code, Boolean(next))}
                    />
                    <span className="text-xs text-secondary-30">
                      {isEnded ? texts.events.eventEndedShort : code.isActive ? texts.events.availableToGuests : texts.events.deactivated}
                    </span>
                  </div>
                  <Button
                    color="danger"
                    disabled={!canMutateCodes || code.redeemedCount > 0 || pendingCodeId === code.id}
                    size="sm"
                    variant="flat"
                    onClick={() => void handleDelete(code)}
                  >
                    {texts.common.delete}
                  </Button>
                </div>
              </article>
            ))}
          </div>
        )}
      </section>

      {!isLoading && !error && redemptions.length ? (
        <section className="space-y-3">
          <h2 className="font-extrabold text-secondary-10">
            {format(texts.events.redeemedCodesTitle, { count: number(redemptions.length) })}
          </h2>
          <div className="space-y-2">
            {redemptions.map((r) => (
              <article
                key={r.id}
                className="consumer-surface flex items-center justify-between gap-3 p-4"
              >
                <div className="min-w-0">
                  <div className="flex items-center gap-2">
                    <span
                      className="font-mono text-sm font-bold text-secondary-10"
                      dir="ltr"
                    >
                      {r.code}
                    </span>
                    {r.bearer === 'platform' ? (
                      <Chip
                        color="secondary"
                        size="sm"
                        variant="flat"
                      >
                        {texts.events.bearerPlatform}
                      </Chip>
                    ) : null}
                  </div>
                  <p className="mt-1 text-xs text-secondary-30">{formatPersianDate(r.createdAt)}</p>
                </div>
                <div className="text-left">
                  <p className="text-sm font-bold text-fifth-700">-{formatCurrency(r.discountAmount)}</p>
                  <p className="mt-1 text-xs text-secondary-30">
                    {format(texts.events.payableAmount, { amount: formatCurrency(r.payableAmount) })}
                  </p>
                </div>
              </article>
            ))}
          </div>
        </section>
      ) : null}
    </section>
  )
}

export default EventDiscountsPanel