export type BrandingFormValues = {
  primary: string;
  accent: string;
  background: string;
  surface: string;
  headingFont: string;
  bodyFont: string;
  logoDataUrl: string;
  mode: 'light' | 'dark' | 'auto';
};

export type BrandingFormDefaults = Pick<BrandingFormValues, 'primary' | 'accent' | 'background' | 'surface' | 'mode'>;

type BrandingRecord = Record<string, unknown>;

const isRecord = (value: unknown): value is BrandingRecord =>
  Boolean(value) && typeof value === 'object' && !Array.isArray(value);

const readHexColor = (value: unknown, fallback: string): string => {
  if (typeof value === 'string' && value.trim().startsWith('#')) {
    return value.trim();
  }
  return fallback;
};

export function extractBrandingForm(settings: unknown, defaults: BrandingFormDefaults): BrandingFormValues {
  const settingsRecord = isRecord(settings) ? settings : {};
  const branding = isRecord(settingsRecord.branding) ? (settingsRecord.branding as BrandingRecord) : settingsRecord;
  const palette = isRecord(branding.palette) ? (branding.palette as BrandingRecord) : {};
  const typography = isRecord(branding.typography) ? (branding.typography as BrandingRecord) : {};

  const primary = readHexColor(palette.primary, readHexColor(branding.primary_color, defaults.primary));
  const accent = readHexColor(
    palette.secondary,
    readHexColor(branding.secondary_color, readHexColor(branding.accent_color, defaults.accent))
  );
  const background = readHexColor(palette.background, readHexColor(branding.background_color, defaults.background));
  const surface = readHexColor(palette.surface, readHexColor(branding.surface_color, background));

  const headingFont = typeof typography.heading === 'string' ? typography.heading : (branding.heading_font as string | undefined);
  const bodyFont = typeof typography.body === 'string' ? typography.body : (branding.body_font as string | undefined);
  const mode = branding.mode === 'light' || branding.mode === 'dark' || branding.mode === 'auto'
    ? branding.mode
    : defaults.mode;

  return {
    primary,
    accent,
    background,
    surface,
    headingFont: headingFont ?? '',
    bodyFont: bodyFont ?? '',
    logoDataUrl: typeof branding.logo_data_url === 'string' ? branding.logo_data_url : '',
    mode,
  };
}