chore: Remove unused billing-related collections, types, and utility modules

- Drop `customers` collection and associated types (`types/index.ts`, `payload.ts`)
- Remove generated `payload-types.ts` file
- Clean up unused exports and dependencies across modules
- Streamline codebase by eliminating redundant billing logic

src/plugin/config.ts

@@ -0,0 +1,76 @@
+
+export const defaults = {
+  paymentsCollection: 'payments'
+}
+
+// Provider configurations
+export interface StripeConfig {
+  apiVersion?: string
+  publishableKey: string
+  secretKey: string
+  webhookEndpointSecret: string
+}
+
+export interface MollieConfig {
+  apiKey: string
+  testMode?: boolean
+  webhookUrl: string
+}
+
+export interface TestProviderConfig {
+  autoComplete?: boolean
+  defaultDelay?: number
+  enabled: boolean
+  failureRate?: number
+  simulateFailures?: boolean
+}
+
+// Customer info extractor callback type
+export interface CustomerInfoExtractor {
+  (customer: any): {
+    name: string
+    email: string
+    phone?: string
+    company?: string
+    taxId?: string
+    billingAddress?: {
+      line1: string
+      line2?: string
+      city: string
+      state?: string
+      postalCode: string
+      country: string
+    }
+  }
+}
+
+// Plugin configuration
+export interface BillingPluginConfig {
+  admin?: {
+    customComponents?: boolean
+    dashboard?: boolean
+  }
+  collections?: {
+    customerRelation?: boolean | string // false to disable, string for custom collection slug
+    customers?: string
+    invoices?: string
+    payments?: string
+    refunds?: string
+  }
+  customerInfoExtractor?: CustomerInfoExtractor // Callback to extract customer info from relationship
+  disabled?: boolean
+  providers?: {
+    mollie?: MollieConfig
+    stripe?: StripeConfig
+    test?: TestProviderConfig
+  }
+  webhooks?: {
+    basePath?: string
+    cors?: boolean
+  }
+}
+
+// Plugin type
+export interface BillingPluginOptions extends BillingPluginConfig {
+  disabled?: boolean
+}

src/plugin/index.ts

@@ -0,0 +1,70 @@
+import type { Config } from 'payload'
+import { createInvoicesCollection, createPaymentsCollection, createRefundsCollection } from '@/collections'
+import { BillingPluginConfig } from '@/plugin/config'
+
+export const billingPlugin = (pluginConfig: BillingPluginConfig = {}) => (config: Config): Config => {
+  if (pluginConfig.disabled) {
+    return config
+  }
+
+  // Initialize collections
+  if (!config.collections) {
+    config.collections = []
+  }
+
+  const customerSlug = pluginConfig.collections?.customers || 'customers'
+
+  config.collections.push(
+    createPaymentsCollection(pluginConfig.collections?.payments || 'payments'),
+    createInvoicesCollection(
+      pluginConfig.collections?.invoices || 'invoices',
+      pluginConfig.collections?.customerRelation !== false ? customerSlug : undefined,
+      pluginConfig.customerInfoExtractor
+    ),
+    createRefundsCollection(pluginConfig.collections?.refunds || 'refunds'),
+  )
+
+  // Initialize endpoints
+  if (!config.endpoints) {
+    config.endpoints = []
+  }
+
+  config.endpoints?.push(
+    // Webhook endpoints
+    {
+      handler: (_req) => {
+        try {
+          const provider = null
+          if (!provider) {
+            return Response.json({ error: 'Provider not found' }, { status: 404 })
+          }
+
+          // TODO: Process webhook event and update database
+
+          return Response.json({ received: true })
+        } catch (error) {
+          // TODO: Use proper logger instead of console
+          // eslint-disable-next-line no-console
+          console.error('[BILLING] Webhook error:', error)
+          return Response.json({ error: 'Webhook processing failed' }, { status: 400 })
+        }
+      },
+      method: 'post',
+      path: '/billing/webhooks/:provider'
+    },
+  )
+
+  // Initialize providers and onInit hook
+  const incomingOnInit = config.onInit
+
+  config.onInit = async (payload) => {
+    // Execute any existing onInit functions first
+    if (incomingOnInit) {
+      await incomingOnInit(payload)
+    }
+
+  }
+
+  return config
+}
+export default billingPlugin

src/plugin/types.ts

@@ -0,0 +1,168 @@
+import { Customer, Refund } from '../../dev/payload-types'
+
+export type Id = string | number
+
+export interface Payment {
+  id: Id;
+  provider: 'stripe' | 'mollie' | 'test';
+  /**
+   * The payment ID from the payment provider
+   */
+  providerId: Id;
+  status: 'pending' | 'processing' | 'succeeded' | 'failed' | 'canceled' | 'refunded' | 'partially_refunded';
+  /**
+   * Amount in cents (e.g., 2000 = $20.00)
+   */
+  amount: number;
+  /**
+   * ISO 4217 currency code (e.g., USD, EUR)
+   */
+  currency: string;
+  /**
+   * Payment description
+   */
+  description?: string | null;
+  customer?: (Id | null) | Customer;
+  invoice?: (Id | null) | Invoice;
+  /**
+   * Additional metadata for the payment
+   */
+  metadata?:
+    | {
+    [k: string]: unknown;
+  }
+    | unknown[]
+    | string
+    | number
+    | boolean
+    | null;
+  /**
+   * Raw data from the payment provider
+   */
+  providerData?:
+    | {
+    [k: string]: unknown;
+  }
+    | unknown[]
+    | string
+    | number
+    | boolean
+    | null;
+  refunds?: (number | Refund)[] | null;
+  updatedAt: string;
+  createdAt: string;
+}
+
+export interface Invoice {
+  id: Id;
+  /**
+   * Invoice number (e.g., INV-001)
+   */
+  number: string;
+  /**
+   * Link to customer record (optional)
+   */
+  customer?: (Id | null) | Customer;
+  /**
+   * Customer billing information (auto-populated from customer relationship)
+   */
+  customerInfo?: {
+    /**
+     * Customer name
+     */
+    name?: string | null;
+    /**
+     * Customer email address
+     */
+    email?: string | null;
+    /**
+     * Customer phone number
+     */
+    phone?: string | null;
+    /**
+     * Company name (optional)
+     */
+    company?: string | null;
+    /**
+     * Tax ID or VAT number
+     */
+    taxId?: string | null;
+  };
+  /**
+   * Billing address (auto-populated from customer relationship)
+   */
+  billingAddress?: {
+    /**
+     * Address line 1
+     */
+    line1?: string | null;
+    /**
+     * Address line 2
+     */
+    line2?: string | null;
+    city?: string | null;
+    /**
+     * State or province
+     */
+    state?: string | null;
+    /**
+     * Postal or ZIP code
+     */
+    postalCode?: string | null;
+    /**
+     * Country code (e.g., US, GB)
+     */
+    country?: string | null;
+  };
+  status: 'draft' | 'open' | 'paid' | 'void' | 'uncollectible';
+  /**
+   * ISO 4217 currency code (e.g., USD, EUR)
+   */
+  currency: string;
+  items: {
+    description: string;
+    quantity: number;
+    /**
+     * Amount in cents
+     */
+    unitAmount: number;
+    /**
+     * Calculated: quantity × unitAmount
+     */
+    totalAmount?: number | null;
+    id?: Id | null;
+  }[];
+  /**
+   * Sum of all line items
+   */
+  subtotal?: number | null;
+  /**
+   * Tax amount in cents
+   */
+  taxAmount?: number | null;
+  /**
+   * Total amount (subtotal + tax)
+   */
+  amount?: number | null;
+  dueDate?: string | null;
+  paidAt?: string | null;
+  payment?: (number | null) | Payment;
+  /**
+   * Internal notes
+   */
+  notes?: string | null;
+  /**
+   * Additional invoice metadata
+   */
+  metadata?:
+    | {
+    [k: string]: unknown;
+  }
+    | unknown[]
+    | string
+    | number
+    | boolean
+    | null;
+  updatedAt: string;
+  createdAt: string;
+}