/**
 * Persistent config (sync/local) vs session token.
 */

const SYNC_KEYS = [
  "baseUrl",
  "rootUri",
  "rootPath",
  "userId",
  "email",
  "connectedAt",
  /** 上次保存选用的分组路径，扩展确认层默认选中 */
  "lastFolderPath",
  /**
   * 去重记忆（不跨浏览器配置同步，仅 local）：
   * - savedSites: { [origin]: { [usernameKey]: { credentialId, passwordFp, savedAt, hasSession? } } }
   * - dismissedSites: { [origin]: { [usernameKey]: dismissedAt }
   * - neverAskOrigins: { [origin]: true }
   */
  "savedSites",
  "dismissedSites",
  "neverAskOrigins",
];
const SESSION_KEYS = ["token", "tokenExpiresAt", "jti"];

/** Normalize username for dedupe keys. */
export function normalizeUsernameKey(username) {
  return String(username || "")
    .trim()
    .toLowerCase();
}

/**
 * Lightweight non-cryptographic fingerprint for password equality checks.
 * Not a security hash — only used to avoid re-prompting the same login.
 * @param {string} password
 */
export function passwordFingerprint(password) {
  const s = String(password || "");
  // FNV-1a 32-bit + length, enough for local dedupe.
  let h = 0x811c9dc5;
  for (let i = 0; i < s.length; i++) {
    h ^= s.charCodeAt(i);
    h = Math.imul(h, 0x01000193);
  }
  return `fp_${(h >>> 0).toString(16)}_${s.length}`;
}

/**
 * @param {string} pageUrl
 * @returns {string} origin or ""
 */
export function originFromUrl(pageUrl) {
  try {
    return new URL(String(pageUrl || "")).origin;
  } catch {
    return "";
  }
}

/**
 * @returns {Promise<{savedSites:object, dismissedSites:object, neverAskOrigins:object}>}
 */
export async function loadDedupeState() {
  const data = await chrome.storage.local.get([
    "savedSites",
    "dismissedSites",
    "neverAskOrigins",
  ]);
  return {
    savedSites:
      data.savedSites && typeof data.savedSites === "object"
        ? data.savedSites
        : {},
    dismissedSites:
      data.dismissedSites && typeof data.dismissedSites === "object"
        ? data.dismissedSites
        : {},
    neverAskOrigins:
      data.neverAskOrigins && typeof data.neverAskOrigins === "object"
        ? data.neverAskOrigins
        : {},
  };
}

/**
 * Remember a successful save so the same site+user+password does not re-prompt.
 * @param {{ pageUrl: string, username?: string, password?: string, credentialId?: string, hasSession?: boolean }} info
 */
export async function rememberSavedSite(info) {
  const origin = originFromUrl(info.pageUrl);
  if (!origin) return;
  const userKey = normalizeUsernameKey(info.username) || "_";
  const state = await loadDedupeState();
  const byOrigin = { ...(state.savedSites[origin] || {}) };
  byOrigin[userKey] = {
    credentialId: info.credentialId || byOrigin[userKey]?.credentialId || "",
    passwordFp: passwordFingerprint(info.password || ""),
    savedAt: new Date().toISOString(),
    hasSession: Boolean(info.hasSession),
  };
  const savedSites = { ...state.savedSites, [origin]: byOrigin };
  // Clear dismiss for this user after explicit save.
  const dismissed = { ...(state.dismissedSites[origin] || {}) };
  delete dismissed[userKey];
  const dismissedSites = { ...state.dismissedSites };
  if (Object.keys(dismissed).length) dismissedSites[origin] = dismissed;
  else delete dismissedSites[origin];
  await chrome.storage.local.set({ savedSites, dismissedSites });
}

/**
 * User cancelled save prompt for this site+username (suppress for a while).
 * @param {{ pageUrl: string, username?: string, forever?: boolean }} info
 */
export async function rememberDismissedSite(info) {
  const origin = originFromUrl(info.pageUrl);
  if (!origin) return;
  if (info.forever) {
    const state = await loadDedupeState();
    await chrome.storage.local.set({
      neverAskOrigins: { ...state.neverAskOrigins, [origin]: true },
    });
    return;
  }
  const userKey = normalizeUsernameKey(info.username) || "_";
  const state = await loadDedupeState();
  const byOrigin = { ...(state.dismissedSites[origin] || {}) };
  byOrigin[userKey] = Date.now();
  await chrome.storage.local.set({
    dismissedSites: { ...state.dismissedSites, [origin]: byOrigin },
  });
}

/**
 * Decide whether auto-prompt should be suppressed for this login draft.
 * @param {{ pageUrl: string, username?: string, password?: string }} draft
 * @param {{ dismissTtlMs?: number }} [opts]
 * @returns {Promise<{ suppress: boolean, reason?: string, credentialId?: string, needSessionOnly?: boolean }>}
 */
export async function shouldSuppressPrompt(draft, opts = {}) {
  const origin = originFromUrl(draft.pageUrl);
  if (!origin) return { suppress: false };
  const userKey = normalizeUsernameKey(draft.username) || "_";
  const state = await loadDedupeState();
  if (state.neverAskOrigins[origin]) {
    return { suppress: true, reason: "never_ask_origin" };
  }
  const dismissTtlMs = opts.dismissTtlMs ?? 14 * 24 * 60 * 60 * 1000;
  const dismissedAt = state.dismissedSites?.[origin]?.[userKey];
  if (typeof dismissedAt === "number" && Date.now() - dismissedAt < dismissTtlMs) {
    return { suppress: true, reason: "recently_dismissed" };
  }
  const saved = state.savedSites?.[origin]?.[userKey];
  if (saved && draft.password) {
    const fp = passwordFingerprint(draft.password);
    if (saved.passwordFp === fp) {
      // Same account+password already saved: do not re-ask for credential.
      // If session was never captured, allow a silent session-only update path.
      return {
        suppress: true,
        reason: "already_saved_same_password",
        credentialId: saved.credentialId || "",
        needSessionOnly: !saved.hasSession,
      };
    }
  }
  return { suppress: false };
}

/**
 * @returns {Promise<{baseUrl?:string, rootUri?:string, userId?:string, email?:string, connectedAt?:string, lastFolderPath?:string}>}
 */
export async function loadPersistent() {
  return chrome.storage.local.get(SYNC_KEYS);
}

/**
 * @param {object} data
 */
export async function savePersistent(data) {
  /** @type {Record<string, unknown>} */
  const patch = {};
  for (const k of SYNC_KEYS) {
    if (data[k] !== undefined) patch[k] = data[k];
  }
  await chrome.storage.local.set(patch);
}

/**
 * @returns {Promise<{token?:string, tokenExpiresAt?:string, jti?:string}>}
 */
export async function loadSession() {
  // Prefer session storage (cleared on browser restart) when available.
  if (chrome.storage.session) {
    return chrome.storage.session.get(SESSION_KEYS);
  }
  return chrome.storage.local.get(SESSION_KEYS);
}

/**
 * @param {object} data
 */
export async function saveSession(data) {
  /** @type {Record<string, unknown>} */
  const patch = {};
  for (const k of SESSION_KEYS) {
    if (data[k] !== undefined) patch[k] = data[k];
  }
  if (chrome.storage.session) {
    await chrome.storage.session.set(patch);
  } else {
    await chrome.storage.local.set(patch);
  }
}

export async function clearSession() {
  if (chrome.storage.session) {
    await chrome.storage.session.remove(SESSION_KEYS);
  }
  await chrome.storage.local.remove(SESSION_KEYS);
}

/**
 * Full runtime config for API calls.
 * @returns {Promise<{baseUrl:string, rootUri:string, token?:string, userId?:string, email?:string, connected:boolean}>}
 */
export async function loadConfig() {
  const [p, s] = await Promise.all([loadPersistent(), loadSession()]);
  const baseUrl = (p.baseUrl || "").trim();
  const rootUri = (p.rootUri || "").trim();
  const token = (s.token || "").trim();
  const connected = Boolean(baseUrl && rootUri && token);
  return {
    baseUrl,
    rootUri,
    token: token || undefined,
    userId: p.userId,
    email: p.email,
    connected,
    tokenExpiresAt: s.tokenExpiresAt,
    jti: s.jti,
    lastFolderPath: p.lastFolderPath || "",
  };
}

/**
 * 规范化逻辑分组路径（与 vault store normalize_folder_path 对齐）。
 * @param {string} [raw]
 * @returns {string}
 */
export function normalizeFolderPath(raw) {
  const s = String(raw || "").trim();
  if (!s) return "";
  const parts = s
    .split(/[/\\]+/)
    .map((p) => p.trim())
    .filter((p) => p && p !== "." && p !== "..");
  return parts.join("/");
}

/**
 * 记住用户上次选用的分组。
 * @param {string} folderPath
 */
export async function saveLastFolderPath(folderPath) {
  const fp = normalizeFolderPath(folderPath);
  await savePersistent({ lastFolderPath: fp });
}

/**
 * @param {boolean} connected
 * @param {string} [label]
 */
export async function setBadge(connected, label) {
  try {
    if (connected) {
      await chrome.action.setBadgeText({ text: "ON" });
      await chrome.action.setBadgeBackgroundColor({ color: "#0a7" });
      if (label) {
        await chrome.action.setTitle({ title: `MNote Vault · ${label}` });
      }
    } else {
      await chrome.action.setBadgeText({ text: "—" });
      await chrome.action.setBadgeBackgroundColor({ color: "#888" });
      await chrome.action.setTitle({ title: "MNote Vault · 未连接" });
    }
  } catch {
    // ignore in non-extension env
  }
}