import { z } from 'zod';
import { baseListQuerySchema } from '@/lib/api/route-helpers';

export const INVOICE_KINDS = ['general', 'deposit'] as const;
export type InvoiceKind = (typeof INVOICE_KINDS)[number];

export const createInvoiceSchema = z
  .object({
    billingEntity: z.object({
      type: z.enum(['client', 'company']),
      id: z.string().min(1),
    }),
    billingEmail: z.string().email().optional(),
    billingAddress: z.string().max(500).optional(),
    dueDate: z.string().min(1),
    paymentTerms: z
      .enum(['immediate', 'net10', 'net15', 'net30', 'net45', 'net60'])
      .default('net30'),
    currency: z.string().length(3).default('USD'),
    notes: z.string().max(2000).optional(),
    /** Optional link to a sales interest. Required when kind === 'deposit'. */
    interestId: z.string().min(1).optional(),
    kind: z.enum(INVOICE_KINDS).default('general'),
    lineItems: z
      .array(
        z.object({
          description: z.string().min(1),
          quantity: z.coerce.number().positive().default(1),
          unitPrice: z.coerce.number().min(0),
        }),
      )
      .optional(),
    expenseIds: z.array(z.string()).optional(),
  })
  .refine((data) => data.kind !== 'deposit' || !!data.interestId, {
    message: 'Deposit invoices must be linked to an interest',
    path: ['interestId'],
  })
  .refine(
    (data) =>
      (data.lineItems && data.lineItems.length > 0) ||
      (data.expenseIds && data.expenseIds.length > 0),
    { message: 'Invoice must have at least one line item or linked expense' },
  );

export const updateInvoiceSchema = z.object({
  clientName: z.string().min(1).max(200).optional(),
  billingEmail: z.string().email().optional(),
  billingAddress: z.string().max(500).optional(),
  dueDate: z.string().min(1).optional(),
  paymentTerms: z.enum(['immediate', 'net10', 'net15', 'net30', 'net45', 'net60']).optional(),
  currency: z.string().length(3).optional(),
  notes: z.string().max(2000).optional(),
  interestId: z.string().min(1).nullable().optional(),
  kind: z.enum(INVOICE_KINDS).optional(),
  lineItems: z
    .array(
      z.object({
        description: z.string().min(1),
        quantity: z.coerce.number().positive().default(1),
        unitPrice: z.coerce.number().min(0),
      }),
    )
    .optional(),
  expenseIds: z.array(z.string()).optional(),
});

export const recordPaymentSchema = z.object({
  paymentDate: z.string().min(1),
  paymentMethod: z.string().optional(),
  paymentReference: z.string().optional(),
});

export const listInvoicesSchema = baseListQuerySchema.extend({
  status: z.string().optional(),
  clientName: z.string().optional(),
  dateFrom: z.string().optional(),
  dateTo: z.string().optional(),
  billingEntityType: z.enum(['client', 'company']).optional(),
  billingEntityId: z.string().optional(),
});

// `z.input` keeps fields with `.default()` (paymentTerms, currency, kind)
// optional from the caller's perspective. The schema parser still fills in
// the defaults, so the service body can rely on them being present at runtime.
export type CreateInvoiceInput = z.input<typeof createInvoiceSchema>;
export type UpdateInvoiceInput = z.input<typeof updateInvoiceSchema>;
export type RecordPaymentInput = z.infer<typeof recordPaymentSchema>;
export type ListInvoicesInput = z.infer<typeof listInvoicesSchema>;