import { z } from "zod";
import type { InvoiceTemplateConfig } from "./schema";

// ── Validation ─────────────────────────────────────────────

// Logo data URI: must be image/* MIME with base64 payload, capped at
// 500KB encoded (≈ 375KB raw image data). The cropper rasterizes to a
// 400x133 PNG which is typically well under 50KB, so this gives plenty
// of headroom while preventing JSON blob abuse.
const MAX_LOGO_BYTES = 500 * 1024;

const dataUriLogoSchema = z
  .string()
  .max(MAX_LOGO_BYTES, "Logo data URI exceeds 500KB limit")
  .refine(
    (value) => /^data:image\/[a-z+.-]+;base64,/i.test(value),
    "Logo must be a base64-encoded image data URI",
  );

// Hex color: #rgb / #rrggbb / #rrggbbaa with optional case
const hexColorSchema = z
  .string()
  .regex(
    /^#([0-9a-fA-F]{3}|[0-9a-fA-F]{6}|[0-9a-fA-F]{8})$/,
    "Invalid hex color",
  );

export const invoiceTemplateConfigSchema: z.ZodType<InvoiceTemplateConfig> = z
  .object({
    logo: dataUriLogoSchema.optional(),
    companyName: z.string().min(1).max(200),
    companyAddress: z.string().max(500).optional(),
    companyEmail: z.email().max(254).optional().or(z.literal("")),
    companyPhone: z.string().max(50).optional(),
    primaryColor: hexColorSchema,
    accentColor: hexColorSchema,
    textColor: hexColorSchema,
    headerStyle: z.enum(["classic", "modern", "minimal"]),
    showLogo: z.boolean(),
    showCompanyDetails: z.boolean(),
    showHours: z.boolean(),
    showRate: z.boolean(),
    showProjectBreakdown: z.boolean(),
    footerText: z.string().max(500).optional(),
    paymentInstructions: z.string().max(2000).optional(),
    paymentMethods: z
      .array(
        z.object({
          type: z.string().min(1).max(50),
          label: z.string().min(1).max(100),
          details: z.record(z.string(), z.string().max(500)),
        }),
      )
      .max(20)
      .optional(),
  })
  // Reject unknown keys so the JSON blob can't be smuggled to
  // arbitrary size via fields the renderer ignores anyway. If we add
  // new template fields we add them here first.
  .strict();

/**
 * Validate an unknown invoice template config payload from an API
 * request. Throws a zod error with details on the first invalid field.
 */
export function parseInvoiceTemplateConfig(
  input: unknown,
): InvoiceTemplateConfig {
  return invoiceTemplateConfigSchema.parse(input);
}

// Default invoice template configurations

export const DEFAULT_TEMPLATES: Record<string, InvoiceTemplateConfig> = {
  classic: {
    companyName: "Your Company",
    primaryColor: "#000000",
    accentColor: "#22d3ee",
    textColor: "#374151",
    headerStyle: "classic",
    showLogo: true,
    showCompanyDetails: true,
    showHours: true,
    showRate: true,
    showProjectBreakdown: true,
    footerText: "Thank you for your business!",
    paymentInstructions: "Payment due within 30 days.",
  },
  modern: {
    companyName: "Your Company",
    primaryColor: "#22d3ee",
    accentColor: "#000000",
    textColor: "#1f2937",
    headerStyle: "modern",
    showLogo: true,
    showCompanyDetails: true,
    showHours: true,
    showRate: true,
    showProjectBreakdown: true,
    footerText: "Thank you!",
  },
  minimal: {
    companyName: "Your Company",
    primaryColor: "#6b7280",
    accentColor: "#000000",
    textColor: "#374151",
    headerStyle: "minimal",
    showLogo: false,
    showCompanyDetails: false,
    showHours: false,
    showRate: false,
    showProjectBreakdown: false,
  },
};

export function getDefaultTemplate(): InvoiceTemplateConfig {
  return DEFAULT_TEMPLATES.classic;
}