chore: import upstream snapshot with attribution

apps/sim/lib/billing/plans.ts

@@ -0,0 +1,143 @@
+import type Stripe from 'stripe'
+import { CREDIT_TIERS } from '@/lib/billing/constants'
+import { CREDIT_MULTIPLIER } from '@/lib/billing/credits/conversion'
+import { isTeam } from '@/lib/billing/plan-helpers'
+import { getFreeTierLimit } from '@/lib/billing/subscriptions/utils'
+import { env } from '@/lib/core/config/env'
+
+export interface BillingPlan {
+  name: string
+  priceId: string
+  annualDiscountPriceId?: string
+  limits: {
+    cost: number
+  }
+}
+
+/**
+ * Build the billing plans for the Better Auth Stripe plugin.
+ *
+ * Plans:
+ *   - free
+ *   - pro_6000  (Pro, $25/mo)   + team_6000
+ *   - pro_25000 (Max, $100/mo)  + team_25000
+ *   - enterprise (dynamic pricing)
+ *
+ * Legacy subscriptions with plan='pro' or plan='team' are handled by
+ * plan-helpers.ts which maps them to their original dollar amounts.
+ */
+export function getPlans(): BillingPlan[] {
+  const plans: BillingPlan[] = [
+    {
+      name: 'free',
+      priceId: env.STRIPE_FREE_PRICE_ID || '',
+      limits: { cost: getFreeTierLimit() },
+    },
+  ]
+
+  const proPriceMap: Record<number, { monthly: string; annual: string }> = {
+    25: {
+      monthly: env.STRIPE_PRICE_TIER_25_MO || '',
+      annual: env.STRIPE_PRICE_TIER_25_YR || '',
+    },
+    100: {
+      monthly: env.STRIPE_PRICE_TIER_100_MO || '',
+      annual: env.STRIPE_PRICE_TIER_100_YR || '',
+    },
+  }
+
+  const teamPriceMap: Record<number, { monthly: string; annual: string }> = {
+    25: {
+      monthly: env.STRIPE_PRICE_TEAM_25_MO || '',
+      annual: env.STRIPE_PRICE_TEAM_25_YR || '',
+    },
+    100: {
+      monthly: env.STRIPE_PRICE_TEAM_100_MO || '',
+      annual: env.STRIPE_PRICE_TEAM_100_YR || '',
+    },
+  }
+
+  for (const tier of CREDIT_TIERS) {
+    const proPrices = proPriceMap[tier.dollars]
+    const teamPrices = teamPriceMap[tier.dollars]
+
+    const creditValueDollars = tier.credits / CREDIT_MULTIPLIER
+
+    if (proPrices?.monthly) {
+      plans.push({
+        name: `pro_${tier.credits}`,
+        priceId: proPrices.monthly,
+        annualDiscountPriceId: proPrices.annual || undefined,
+        limits: { cost: creditValueDollars },
+      })
+    }
+
+    if (teamPrices?.monthly) {
+      plans.push({
+        name: `team_${tier.credits}`,
+        priceId: teamPrices.monthly,
+        annualDiscountPriceId: teamPrices.annual || undefined,
+        limits: { cost: creditValueDollars },
+      })
+    }
+  }
+
+  plans.push({
+    name: 'enterprise',
+    priceId: 'price_dynamic',
+    limits: { cost: 200 },
+  })
+
+  return plans
+}
+
+/**
+ * Get a specific plan by name
+ */
+export function getPlanByName(planName: string): BillingPlan | undefined {
+  return getPlans().find((plan) => plan.name === planName)
+}
+
+/**
+ * Get a specific plan by Stripe price ID.
+ * Matches against both monthly (`priceId`) and annual (`annualDiscountPriceId`) prices.
+ */
+export function getPlanByPriceId(priceId: string): BillingPlan | undefined {
+  if (!priceId) return undefined
+  return getPlans().find(
+    (plan) => plan.priceId === priceId || plan.annualDiscountPriceId === priceId
+  )
+}
+
+/**
+ * Get plan limits for a given plan name
+ */
+export function getPlanLimits(planName: string): number {
+  const plan = getPlanByName(planName)
+  return plan?.limits.cost ?? getFreeTierLimit()
+}
+
+export interface StripePlanResolution {
+  priceId: string | undefined
+  planFromStripe: string | null
+  isTeamPlan: boolean
+  isAnnual: boolean
+}
+
+/**
+ * Resolve plan information from a Stripe subscription object.
+ */
+export function resolvePlanFromStripeSubscription(
+  stripeSubscription: Stripe.Subscription
+): StripePlanResolution {
+  const priceId = stripeSubscription?.items?.data?.[0]?.price?.id
+  const interval = stripeSubscription?.items?.data?.[0]?.price?.recurring?.interval
+  const plan = priceId ? getPlanByPriceId(priceId) : undefined
+
+  return {
+    priceId,
+    planFromStripe: plan?.name ?? null,
+    isTeamPlan: plan ? isTeam(plan.name) : false,
+    isAnnual: interval === 'year',
+  }
+}