import type { OnboardingEmojiConfig } from "../components/onboarding/OnboardingOoDesigner";
import type { UiLocale } from "./ui-locale";

export const ONBOARDING_DRAFT_STORAGE_KEY = "rakazo.onboardingDraft";

export type OnboardingStepDraft =
  | "emoji"
  | "name"
  | "language"
  | "voice"
  | "integrations"
  | "scan"
  | "bot";

export type OnboardingDraft = {
  step: OnboardingStepDraft;
  emojiConfig: OnboardingEmojiConfig;
  ooName: string;
  languageChoice: UiLocale | null;
  currentLocale: UiLocale;
  selectedVoiceId: string;
  voiceSkipped: boolean;
};

function readStorage(
  storage: Pick<Storage, "getItem"> | null | undefined,
): Pick<Storage, "getItem"> | null {
  if (storage !== undefined) return storage;
  return typeof sessionStorage !== "undefined" ? sessionStorage : null;
}

function writeStorage(
  storage: Pick<Storage, "setItem" | "removeItem"> | null | undefined,
): Pick<Storage, "setItem" | "removeItem"> | null {
  if (storage !== undefined) return storage;
  return typeof sessionStorage !== "undefined" ? sessionStorage : null;
}

/** Restore in-progress onboarding after reload or deep link within the same tab. */
export function readOnboardingDraft(
  storage: Pick<Storage, "getItem"> | null = readStorage(undefined),
): OnboardingDraft | null {
  if (!storage) return null;
  try {
    const raw = storage.getItem(ONBOARDING_DRAFT_STORAGE_KEY);
    if (!raw) return null;
    const parsed = JSON.parse(raw) as Partial<OnboardingDraft>;
    if (
      !parsed ||
      typeof parsed.step !== "string" ||
      !parsed.emojiConfig ||
      typeof parsed.emojiConfig.avatarValue !== "string" ||
      typeof parsed.emojiConfig.pose !== "string" ||
      typeof parsed.ooName !== "string"
    ) {
      return null;
    }
    return {
      step: parsed.step as OnboardingStepDraft,
      emojiConfig: parsed.emojiConfig,
      ooName: parsed.ooName,
      languageChoice: parsed.languageChoice ?? null,
      currentLocale: parsed.currentLocale ?? "en",
      selectedVoiceId: parsed.selectedVoiceId ?? "",
      voiceSkipped: parsed.voiceSkipped ?? false,
    };
  } catch {
    return null;
  }
}

export function persistOnboardingDraft(
  draft: OnboardingDraft,
  storage: Pick<Storage, "setItem"> | null = writeStorage(undefined),
): void {
  if (!storage) return;
  try {
    storage.setItem(ONBOARDING_DRAFT_STORAGE_KEY, JSON.stringify(draft));
  } catch {
    // Quota / private mode — onboarding still works without persistence.
  }
}

export function clearOnboardingDraft(
  storage: Pick<Storage, "removeItem"> | null = writeStorage(undefined),
): void {
  if (!storage) return;
  try {
    storage.removeItem(ONBOARDING_DRAFT_STORAGE_KEY);
  } catch {
    // Ignore storage failures on completion.
  }
}