export const PATTERN_BACKGROUND_OPACITY = 0.05;
export const PATTERN_VECTOR_OPACITY = 0.1;
export const PRIMARY_LIGHT_OPACITY = 0.15;

export type BgType = "pattern" | "custom" | "color";

export type RestaurantBackgroundSettings = {
  bgType?: BgType | string | null;
  bgUrl?: string | null;
  bgBlur?: number | string | null;
  bgOpacity?: number | string | null;
  bgOverlay?: string | null;
  menuColor?: string | null;
  isPattern?: boolean;
};

export const normalizeBgNumber = (value: unknown): number | null => {
  if (value == null || value === "") return null;
  const parsed = typeof value === "string" ? Number(value) : value;
  if (typeof parsed !== "number" || Number.isNaN(parsed)) return null;
  return parsed;
};

export const hexToRgba = (hex: string, alpha: number): string => {
  const normalized = hex.replace("#", "");
  if (normalized.length !== 6) {
    return `rgba(0, 0, 0, ${alpha})`;
  }

  const r = parseInt(normalized.slice(0, 2), 16);
  const g = parseInt(normalized.slice(2, 4), 16);
  const b = parseInt(normalized.slice(4, 6), 16);
  return `rgba(${r}, ${g}, ${b}, ${alpha})`;
};

const isUnsetBgValue = (value: unknown): boolean =>
  value == null || value === "" || value === 0;

const isCustomImageBackgroundLegacy = (
  settings: RestaurantBackgroundSettings,
): boolean => {
  if (!settings.bgUrl) return false;

  return (
    !isUnsetBgValue(settings.bgBlur) ||
    !isUnsetBgValue(settings.bgOpacity) ||
    !isUnsetBgValue(settings.bgOverlay)
  );
};

export const resolveBgType = (
  settings: RestaurantBackgroundSettings,
): BgType => {
  if (settings.bgType === null) return "color";

  const normalized = settings.bgType?.toLowerCase();
  if (
    normalized === "pattern" ||
    normalized === "custom" ||
    normalized === "color"
  ) {
    return normalized;
  }

  if (settings.isPattern === true) return "pattern";
  if (settings.isPattern === false && settings.bgUrl && isCustomImageBackgroundLegacy(settings)) {
    return "custom";
  }
  if (settings.isPattern === false) return "color";
  if (isCustomImageBackgroundLegacy(settings)) return "custom";
  if (settings.bgUrl) return "pattern";

  return "color";
};

export const isCustomImageBackground = (
  settings: RestaurantBackgroundSettings,
): boolean => resolveBgType(settings) === "custom";

export const isPatternBackground = (
  settings: RestaurantBackgroundSettings,
): boolean => resolveBgType(settings) === "pattern";

export const isColorBackground = (
  settings: RestaurantBackgroundSettings,
): boolean => resolveBgType(settings) === "color";

export const colorizeSvg = (
  svg: string,
  color: string,
  vectorOpacity: number = PATTERN_VECTOR_OPACITY,
): string => {
  let result = svg.replace(/fill="(?!black|none)[^"]+"/g, `fill="${color}"`);
  result = result.replace(
    /fill-opacity="[^"]+"/g,
    `fill-opacity="${vectorOpacity}"`,
  );
  result = result.replace(
    /(<(?:path|circle|rect|ellipse|polygon)[^>]*fill="(?!black|none)[^"]+")(?![^>]*fill-opacity)/g,
    `$1 fill-opacity="${vectorOpacity}"`,
  );
  return result;
};

export const applyColorBackgroundCssVariables = (menuColor: string) => {
  const root = document.documentElement;
  root.removeAttribute("data-pattern-bg");
  root.removeAttribute("data-image-bg");
  root.style.removeProperty("--bg-pattern-base");
  root.style.removeProperty("--bg-pattern-vector");
  root.style.setProperty(
    "--background",
    hexToRgba(menuColor, PATTERN_BACKGROUND_OPACITY),
  );
  root.style.setProperty(
    "--primary-light",
    hexToRgba(menuColor, PRIMARY_LIGHT_OPACITY),
  );
};

export const applyPatternCssVariables = (menuColor: string) => {
  const root = document.documentElement;
  const baseTint = hexToRgba(menuColor, PATTERN_BACKGROUND_OPACITY);

  root.setAttribute("data-pattern-bg", "true");
  root.style.setProperty("--bg-pattern-base", baseTint);
  root.style.setProperty(
    "--bg-pattern-vector",
    hexToRgba(menuColor, PATTERN_VECTOR_OPACITY),
  );
  root.style.setProperty(
    "--primary-light",
    hexToRgba(menuColor, PRIMARY_LIGHT_OPACITY),
  );
  root.style.setProperty("--background", baseTint);
};

export const clearPatternCssVariables = () => {
  const root = document.documentElement;
  root.removeAttribute("data-pattern-bg");
  root.style.removeProperty("--bg-pattern-base");
  root.style.removeProperty("--bg-pattern-vector");
  root.style.removeProperty("--primary-light");
  root.style.removeProperty("--background");
};

export const applyCustomImageCssVariables = () => {
  const root = document.documentElement;
  root.setAttribute("data-image-bg", "true");
  root.removeAttribute("data-pattern-bg");
};

export const clearCustomImageCssVariables = () => {
  document.documentElement.removeAttribute("data-image-bg");
};