import { RequestHandler } from 'express';

export type BillingType = 'stripe' | 'purchase_order';

export interface Customer {
  id: string;
  name: string;
  tierId: string;
  apiKey: string;
  stripeCustomerId?: string;
  multiplierOverride?: number;
  /** How this customer is billed. Absent means 'stripe' (the default). */
  billingType?: BillingType;
  email?: string;
  /** scrypt hash for portal login. Absent = no portal password set yet. */
  passwordHash?: string;
  /** Base32 TOTP secret. Present once 2FA setup begins. */
  totpSecret?: string;
  /** True once the customer has confirmed a TOTP code. */
  totpEnabled?: boolean;
  /** Prepaid balance in cents, drawn down when invoices are issued. */
  balanceCents?: number;
  /** Email a copy of each issued invoice to the customer's address. */
  emailInvoicing?: boolean;
}

export interface CustomerRepo {
  findByApiKey(apiKey: string): Customer | undefined;
  findByEmail(email: string): Customer | undefined;
  list(): Customer[];
  save(customer: Customer): void;
}

export class InMemoryCustomerRepo implements CustomerRepo {
  private customers: Customer[];

  constructor(customers: Customer[] = []) {
    // Defensive copy: save() replaces elements, and callers often pass shared
    // seed arrays (DEFAULT_CUSTOMERS) that must not be mutated across tests.
    this.customers = customers.map((c) => ({ ...c }));
  }

  findByApiKey(apiKey: string): Customer | undefined {
    return this.customers.find((c) => c.apiKey === apiKey);
  }

  findByEmail(email: string): Customer | undefined {
    const needle = email.toLowerCase();
    return this.customers.find((c) => c.email?.toLowerCase() === needle);
  }

  list(): Customer[] {
    return [...this.customers];
  }

  save(customer: Customer): void {
    const i = this.customers.findIndex((c) => c.id === customer.id);
    if (i >= 0) this.customers[i] = customer;
    else this.customers.push(customer);
  }
}

declare global {
  // eslint-disable-next-line @typescript-eslint/no-namespace
  namespace Express {
    interface Request {
      customer?: Customer;
    }
  }
}

export function apiKeyAuth(repo: CustomerRepo): RequestHandler {
  return (req, res, next) => {
    const key = req.header('x-api-key');
    const customer = key ? repo.findByApiKey(key) : undefined;
    if (!customer) {
      res.status(401).json({ error: 'invalid or missing API key' });
      return;
    }
    req.customer = customer;
    next();
  };
}