/** Mask shown in the API key field when a key is already stored. The real
 *  token never leaves the server; this is only so the field looks filled. */
export const STORED_API_KEY_MASK = "••••••••";

export type ProviderDraft = {
  modelId: string;
  baseUrl: string;
  apiKey: string;
  keyEdited: boolean;
  clearKey: boolean;
};

export function emptyProviderDraft(modelId = "", baseUrl = ""): ProviderDraft {
  return { modelId, baseUrl, apiKey: "", keyEdited: false, clearKey: false };
}

export function storedApiKeyFieldValue(
  stored: boolean,
  draft: Pick<ProviderDraft, "keyEdited" | "clearKey" | "apiKey">,
): string {
  if (stored && !draft.keyEdited && !draft.clearKey) return STORED_API_KEY_MASK;
  return draft.apiKey;
}

export function applyApiKeyInput(
  showingMask: boolean,
  next: string,
): Pick<ProviderDraft, "apiKey" | "keyEdited" | "clearKey"> {
  if (showingMask) {
    const value = next.split("•").join("");
    return { apiKey: value, keyEdited: value.length > 0, clearKey: false };
  }
  return { apiKey: next, keyEdited: true, clearKey: false };
}

/** What to send on save. `apiKey: null` means keep the stored secret. */
export function apiKeySavePayload(
  draft: Pick<ProviderDraft, "keyEdited" | "clearKey" | "apiKey">,
): { apiKey: string | null; clearApiKey: boolean } {
  if (draft.clearKey) return { apiKey: "", clearApiKey: true };
  if (!draft.keyEdited) return { apiKey: null, clearApiKey: false };
  const value = draft.apiKey.trim();
  if (!value || value === STORED_API_KEY_MASK) return { apiKey: null, clearApiKey: false };
  return { apiKey: value, clearApiKey: false };
}

export function providerHasStoredKey(
  settings: {
    apiKeySet: boolean;
    provider: string;
    providers?: { id: string; apiKeySet?: boolean }[];
  } | null,
  provider: string,
): boolean {
  const listed = settings?.providers?.find((item) => item.id === provider);
  if (listed && typeof listed.apiKeySet === "boolean") return listed.apiKeySet;
  return Boolean(settings?.apiKeySet && settings.provider === provider);
}