import { DEFAULT_SETTINGS, OPEN_IN_VALUES } from "./defaults.js";

// Pure. Layers stored values over the defaults, dropping unknown keys and
// falling back on wrong types or out-of-range values. A fresh or signed-out
// profile returns {} from storage, which yields the defaults.
export function mergeSettings(stored) {
  const merged = { ...DEFAULT_SETTINGS };
  if (stored === null || typeof stored !== "object") {
    return merged;
  }
  if (typeof stored.model === "string") {
    merged.model = stored.model;
  }
  if (typeof stored.temporaryChat === "boolean") {
    merged.temporaryChat = stored.temporaryChat;
  }
  if (typeof stored.webSearch === "boolean") {
    merged.webSearch = stored.webSearch;
  }
  if (OPEN_IN_VALUES.includes(stored.openIn)) {
    merged.openIn = stored.openIn;
  }
  if (typeof stored.promptTemplate === "string") {
    merged.promptTemplate = stored.promptTemplate;
  }
  return merged;
}

// storage.sync works with no Mozilla account (it behaves as local storage and
// syncs later if the user signs in), so no capability probe is needed. Any
// rejection falls back to defaults rather than blocking the user's action.
// Firefox sanitises all non-quota backend errors to a single generic string, so
// there is nothing useful to branch on.
export async function load() {
  try {
    const stored = await browser.storage.sync.get(Object.keys(DEFAULT_SETTINGS));
    return mergeSettings(stored);
  } catch {
    return mergeSettings(null);
  }
}

export async function save(partial) {
  await browser.storage.sync.set(partial);
}