add stripe (#121)

* add some stripe stuff

* more stripe stuff

* more stripe things

* more stripr stuff

* more stripe stuff

* more stripe stuff

* add more stuff

* add more stripe stuff

* more stuff

* fix types

apps/web/src/lib/constants/payments.ts

@@ -0,0 +1,13 @@
+export const PLAN_PERKS = {
+  FREE: [
+    "Send up to 3000 emails per month",
+    "Send up to 100 emails per day",
+    "Can have 1 contact book",
+  ],
+  BASIC: [
+    "Includes $10 of usage monthly",
+    "Send transactional emails at $0.0004 per email",
+    "Send marketing emails at $0.001 per email",
+    "Can have unlimited contact books",
+  ],
+};

apps/web/src/lib/usage.ts

@@ -0,0 +1,66 @@
+import { EmailUsageType, Plan } from "@prisma/client";
+
+/**
+ * Unit price for unsend
+ * 1 marketing email = 1 unit
+ * 4 transaction emails = 1 unit
+ */
+export const UNIT_PRICE = 0.001;
+
+/**
+ * Number of credits per plan
+ * Credits are the units of measurement for email sending capacity.
+ * Each plan comes with a specific number of credits that can be used for sending emails.
+ * Marketing emails consume 1 credit per email, while transactional emails consume 0.25 credits per email.
+ */
+export const PLAN_CREDIT_UNITS = {
+  [Plan.BASIC]: 10_000,
+};
+
+export const USAGE_UNIT_PRICE: Record<EmailUsageType, number> = {
+  [EmailUsageType.MARKETING]: 0.001,
+  [EmailUsageType.TRANSACTIONAL]: 0.0004,
+};
+
+/**
+ * Gets timestamp for usage reporting, set to yesterday's date
+ * Converts to Unix timestamp (seconds since epoch)
+ * @returns Unix timestamp in seconds for yesterday's date
+ */
+export function getUsageTimestamp() {
+  const yesterday = new Date();
+  yesterday.setDate(yesterday.getDate() - 1);
+  return Math.floor(yesterday.getTime() / 1000);
+}
+
+/**
+ * Gets yesterday's date in YYYY-MM-DD format
+ * @returns Yesterday's date string in YYYY-MM-DD format
+ */
+export function getUsageDate(): string {
+  const yesterday = new Date();
+  yesterday.setDate(yesterday.getDate() - 1);
+  const isoString = yesterday.toISOString();
+  return isoString.split("T")[0] as string;
+}
+
+/**
+ * Calculates total usage units based on marketing and transaction emails
+
+ * @param marketingUsage Number of marketing emails sent
+ * @param transactionUsage Number of transaction emails sent
+ * @returns Total usage units rounded down to nearest integer
+ */
+export function getUsageUinits(
+  marketingUsage: number,
+  transactionUsage: number
+) {
+  return marketingUsage + Math.floor(transactionUsage / 4);
+}
+
+export function getCost(usage: number, type: EmailUsageType) {
+  const calculatedUsage =
+    type === EmailUsageType.MARKETING ? usage : Math.floor(usage / 4);
+
+  return calculatedUsage * UNIT_PRICE;
+}