import prisma from '@/lib/prisma'
import { MARKETING_CONSENT_VERSION, marketingConsentText } from '@/lib/marketing/consent-copy'
import { normalizeMarketingEmail } from '@/lib/marketing/normalize-email'

export const MARKETING_BLOCKING_REASONS = ['COMPLAINT', 'HARD_BOUNCE', 'INVALID'] as const

export type MarketingSource =
  | 'settings'
  | 'register'
  | 'unsubscribe'
  | 'unsubscribe-one-click'
  | 'complaint'
  | 'bounce'

export type MarketingPreferenceView = {
  optedIn: boolean
  emailNormalized: string
  consentVersion: string | null
  updatedAt: Date | null
  blocked: boolean
  blockReason: string | null
}

type RequestMeta = {
  ip?: string | null
  userAgent?: string | null
}

export async function getMarketingPreferenceView(userId: string): Promise<MarketingPreferenceView> {
  const user = await prisma.user.findUnique({
    where: { id: userId },
    select: {
      email: true,
      marketingPreference: true,
    },
  })
  const emailNormalized = normalizeMarketingEmail(user?.email || '')
  const suppression = emailNormalized
    ? await prisma.emailSuppression.findUnique({ where: { emailNormalized } })
    : null
  const blocked = Boolean(
    suppression && MARKETING_BLOCKING_REASONS.includes(suppression.reason as (typeof MARKETING_BLOCKING_REASONS)[number]),
  )
  return {
    optedIn: user?.marketingPreference?.optedIn === true && !suppression,
    emailNormalized,
    consentVersion: user?.marketingPreference?.consentVersion ?? null,
    updatedAt: user?.marketingPreference?.updatedAt ?? null,
    blocked,
    blockReason: blocked ? suppression?.reason ?? null : null,
  }
}

export async function canReceiveMarketing(opts: {
  userId?: string | null
  email: string
  requireVerified?: boolean
}): Promise<{ allowed: boolean; reason: string }> {
  const emailNormalized = normalizeMarketingEmail(opts.email)
  if (!emailNormalized) return { allowed: false, reason: 'invalid_email' }

  const suppression = await prisma.emailSuppression.findUnique({ where: { emailNormalized } })
  if (suppression) return { allowed: false, reason: `suppressed:${suppression.reason}` }

  const user = opts.userId
    ? await prisma.user.findUnique({
        where: { id: opts.userId },
        select: {
          emailVerified: true,
          marketingPreference: { select: { optedIn: true, emailNormalized: true } },
        },
      })
    : await prisma.user.findUnique({
        where: { email: emailNormalized },
        select: {
          emailVerified: true,
          marketingPreference: { select: { optedIn: true, emailNormalized: true } },
        },
      })

  if (!user) return { allowed: false, reason: 'no_account' }
  if (opts.requireVerified !== false && !user.emailVerified) {
    return { allowed: false, reason: 'unverified' }
  }
  if (!user.marketingPreference?.optedIn) return { allowed: false, reason: 'not_opted_in' }
  return { allowed: true, reason: 'ok' }
}

export async function setMarketingOptIn(opts: {
  userId: string
  optedIn: boolean
  source: MarketingSource
  language?: string | null
  meta?: RequestMeta
}): Promise<{ ok: true } | { ok: false; error: 'blocked' | 'missing_user' }> {
  const user = await prisma.user.findUnique({
    where: { id: opts.userId },
    select: { id: true, email: true },
  })
  if (!user) return { ok: false, error: 'missing_user' }

  const emailNormalized = normalizeMarketingEmail(user.email)
  const existingSuppression = await prisma.emailSuppression.findUnique({
    where: { emailNormalized },
  })
  if (
    opts.optedIn &&
    existingSuppression &&
    MARKETING_BLOCKING_REASONS.includes(existingSuppression.reason as (typeof MARKETING_BLOCKING_REASONS)[number])
  ) {
    return { ok: false, error: 'blocked' }
  }

  const consentText = opts.optedIn ? marketingConsentText(opts.language) : null
  const consentVersion = opts.optedIn ? MARKETING_CONSENT_VERSION : null

  const preference = await prisma.marketingPreference.upsert({
    where: { userId: user.id },
    create: {
      userId: user.id,
      emailNormalized,
      optedIn: opts.optedIn,
      preferredLanguage: opts.language || null,
      consentVersion,
      consentText,
      source: opts.source,
    },
    update: {
      emailNormalized,
      optedIn: opts.optedIn,
      preferredLanguage: opts.language || undefined,
      consentVersion: opts.optedIn ? consentVersion : undefined,
      consentText: opts.optedIn ? consentText : undefined,
      source: opts.source,
    },
  })

  await prisma.marketingPreferenceEvent.create({
    data: {
      preferenceId: preference.id,
      userId: user.id,
      emailNormalized,
      optedIn: opts.optedIn,
      source: opts.source,
      consentVersion,
      consentText,
      ip: opts.meta?.ip || null,
      userAgent: opts.meta?.userAgent || null,
    },
  })

  if (opts.optedIn) {
    if (existingSuppression?.reason === 'UNSUBSCRIBE') {
      await prisma.emailSuppression.delete({ where: { emailNormalized } })
    }
  } else {
    await prisma.emailSuppression.upsert({
      where: { emailNormalized },
      create: {
        emailNormalized,
        reason: 'UNSUBSCRIBE',
        source: opts.source,
        userId: user.id,
      },
      update: {
        reason: existingSuppression && MARKETING_BLOCKING_REASONS.includes(existingSuppression.reason as (typeof MARKETING_BLOCKING_REASONS)[number])
          ? existingSuppression.reason
          : 'UNSUBSCRIBE',
        source: opts.source,
        userId: user.id,
      },
    })
  }

  await prisma.auditLog.create({
    data: {
      userId: user.id,
      action: opts.optedIn ? 'marketing.opt_in' : 'marketing.opt_out',
      resource: 'MarketingPreference',
      metadata: { source: opts.source, consentVersion },
      ip: opts.meta?.ip || null,
      userAgent: opts.meta?.userAgent || null,
    },
  }).catch(() => {})

  return { ok: true }
}

export async function unsubscribeByUserId(opts: {
  userId: string
  source: MarketingSource
  meta?: RequestMeta
}): Promise<{ ok: true; already: boolean } | { ok: false }> {
  const view = await getMarketingPreferenceView(opts.userId)
  if (!view.emailNormalized) return { ok: false }
  const already = !view.optedIn
  const result = await setMarketingOptIn({
    userId: opts.userId,
    optedIn: false,
    source: opts.source,
    meta: opts.meta,
  })
  if (!result.ok) return { ok: false }
  return { ok: true, already }
}