import { HttpError } from '../services/HttpService.tsx';

/**
 * Did the server actually answer, or did we never reach it?
 *
 * SPENCER'S RULING, 2026-08-05: "transport failure shouldn't log anyone out."
 *
 * `OrganizationCheck`'s catch (App.tsx) used to treat every failure the same way and call `logout()`,
 * which ends in `window.location.reload()` - so a single dropped connection during app load cleared
 * every token and hard-reloaded the page, for every user. That is
 *, and it is the same distinction spent a review round
 * establishing on `CredentialRevertPage` and `CredentialUnlockPage`: those two pages get it right and
 * the shell above them did not.
 *
 * - `refused` - the server answered and said no. Ending the session may be correct: a 401 means the
 * credentials are bad, and an org that genuinely is not associated with this
 * installation is not one this user can carry on inside.
 * - `unreachable` - the request never arrived. **We learned nothing**, so nothing may be destroyed on
 * the strength of it.
 *
 * FAILS TOWARD KEEPING THE SESSION. Anything we cannot positively identify as a server refusal is
 * `unreachable`, because the cost of the two mistakes is not symmetric: wrongly keeping a session shows
 * a retry screen, wrongly ending one can spend a patient's single-use credential-recovery token (the
 * revert page acts on load and burns its token before doing anything else).
 *
 * `instanceof`, NOT a duck-type. `HttpService.handleErrorResponse` throws a real `HttpError` for
 * every non-2xx response, and `fetch` itself throws a bare `TypeError` when the connection drops - so
 * the constructor genuinely discriminates. The tempting shortcuts do not: `err?.status` is truthy on any
 * hand-rolled reject or mocked fetch that happens to carry one, and `err.name === 'HttpError'` is
 * satisfiable by assignment, since `name` is writable. Both are pinned by their own tests.
 */
export type OrgFetchFailureKind = 'refused' | 'unreachable';

export const classifyOrgFetchFailure = (error: unknown): OrgFetchFailureKind =>
    error instanceof HttpError ? 'refused' : 'unreachable';