Kordant/packages/shared-billing/src/config/billing.config.ts

import { z } from 'zod';

export const SubscriptionTier = {
  FREE: 'free',
  BASIC: 'basic',
  PLUS: 'plus',
  PREMIUM: 'premium',
} as const;

export type SubscriptionTier = typeof SubscriptionTier[keyof typeof SubscriptionTier];

export const BillingConfigSchema = z.object({
  stripe: z.object({
    apiKey: z.string().min(1, 'STRIPE_API_KEY required'),
    webhookSecret: z.string().min(1, 'STRIPE_WEBHOOK_SECRET required'),
    pricingTableId: z.string().optional(),
  }),
  tiers: z.object({
    free: z.object({
      priceId: z.string(),
      monthlyPriceCents: z.number().default(0),
      callMinutesLimit: z.number().default(100),
      smsCountLimit: z.number().default(500),
      darkWebScans: z.number().default(1),
    }),
    basic: z.object({
      priceId: z.string(),
      monthlyPriceCents: z.number().default(999),
      callMinutesLimit: z.number().default(500),
      smsCountLimit: z.number().default(2000),
      darkWebScans: z.number().default(12),
    }),
    plus: z.object({
      priceId: z.string(),
      monthlyPriceCents: z.number().default(1999),
      callMinutesLimit: z.number().default(2000),
      smsCountLimit: z.number().default(10000),
      darkWebScans: z.number().default(12),
      voiceCloning: z.boolean().default(true),
    }),
    premium: z.object({
      priceId: z.string(),
      monthlyPriceCents: z.number().default(4999),
      callMinutesLimit: z.number().default(10000),
      smsCountLimit: z.number().default(50000),
      darkWebScans: z.number().default(12),
      voiceCloning: z.boolean().default(true),
      homeTitleMonitor: z.boolean().default(true),
    }),
  }),
});

export type BillingConfig = z.infer<typeof BillingConfigSchema>;

// Allowed return URL origins for Stripe customer portal (open redirect prevention)
const allowedReturnUrlOrigins: string[] = (process.env.ALLOWED_RETURN_URL_ORIGINS || 'https://app.shieldai.com,shieldai://').split(',').map(s => s.trim()).filter(Boolean);

export function isValidReturnUrl(url: string): boolean {
  try {
    const parsed = new URL(url);
    // Custom app schemes (e.g., shieldai://) have origin === 'null'
    // Use prefix matching for these since they don't have a standard origin
    if (parsed.origin === 'null') {
      return allowedReturnUrlOrigins.some(origin => url.startsWith(origin));
    }
    // Standard web protocols: compare origins to prevent substring attacks
    return allowedReturnUrlOrigins.some(origin => {
      try {
        const originUrl = new URL(origin);
        return parsed.origin === originUrl.origin;
      } catch {
        // If the allowed origin can't be parsed as a URL, it's a custom scheme
        return false;
      }
    });
  } catch {
    return false;
  }
}

export const loadBillingConfig = (): BillingConfig => {
  const rawConfig = {
    stripe: {
      apiKey: process.env.STRIPE_API_KEY!,
      webhookSecret: process.env.STRIPE_WEBHOOK_SECRET!,
      pricingTableId: process.env.STRIPE_PRICING_TABLE_ID,
    },
    tiers: {
      free: {
        priceId: process.env.STRIPE_FREE_TIER_PRICE_ID || 'price_free',
        monthlyPriceCents: 0,
        callMinutesLimit: 100,
        smsCountLimit: 500,
        darkWebScans: 1,
      },
      basic: {
        priceId: process.env.STRIPE_BASIC_TIER_PRICE_ID || 'price_basic',
        monthlyPriceCents: 999,
        callMinutesLimit: 500,
        smsCountLimit: 2000,
        darkWebScans: 12,
      },
      plus: {
        priceId: process.env.STRIPE_PLUS_TIER_PRICE_ID || 'price_plus',
        monthlyPriceCents: 1999,
        callMinutesLimit: 2000,
        smsCountLimit: 10000,
        darkWebScans: 12,
        voiceCloning: true,
      },
      premium: {
        priceId: process.env.STRIPE_PREMIUM_TIER_PRICE_ID || 'price_premium',
        monthlyPriceCents: 4999,
        callMinutesLimit: 10000,
        smsCountLimit: 50000,
        darkWebScans: 12,
        voiceCloning: true,
        homeTitleMonitor: true,
      },
    },
  };

  return BillingConfigSchema.parse(rawConfig);
};