// The activity page's view in the address bar (`?page=activity&at=runs&aw=24h&rjob=backfill`), so a
// filtered view is a link: which tab, the filters every tab shares (time range, account, text), and
// each tab's own (the run list's job and status, the audit list's action). The server log's own
// filters keep their `l…` keys (./logsUrlState). setPage clears all of them (ACTIVITY_KEYS); the page
// re-mirrors them while it is open.
import type { RunStatus } from "./api";
import { LOGS_KEYS } from "./logsUrlState";

export type ActivityTab = "runs" | "admin" | "logs" | "quota";
export type ActivityWindow = "1h" | "24h" | "7d" | "30d" | "90d" | "all";
/** The run statuses the list can narrow to: the API's `RunStatus` (held by backendIds.contract.test). */
export type RunStatusFilter = RunStatus;

export interface ActivityUrlState {
  tab: ActivityTab;
  window: ActivityWindow;
  /** An account id, or `none` for what no account did (the background). */
  user: string | null;
  q: string;
  /** Runs: one job's runs. */
  job: string | null;
  status: RunStatusFilter | null;
  /** Admin actions: one action. */
  action: string | null;
}

export const ACTIVITY_TABS: readonly ActivityTab[] = ["runs", "admin", "logs", "quota"];
// `all` = everything still kept: runs and admin actions are kept 180 days by default (0 = for ever),
// longer than any fixed range.
export const ACTIVITY_WINDOWS: readonly ActivityWindow[] = ["1h", "24h", "7d", "30d", "90d", "all"];
export const RUN_STATUSES: readonly RunStatusFilter[] = [
  "error",
  "interrupted",
  "skipped",
  "running",
  "ok",
];

const WINDOW_HOURS: Record<ActivityWindow, number | null> = {
  "1h": 1,
  "24h": 24,
  "7d": 24 * 7,
  "30d": 24 * 30,
  "90d": 24 * 90,
  all: null,
};

export const DEFAULT_ACTIVITY_STATE: ActivityUrlState = {
  tab: "runs",
  window: "7d",
  user: null,
  q: "",
  job: null,
  status: null,
  action: null,
};

const OWN_KEYS = ["at", "aw", "au", "aq", "rjob", "rst", "aact"] as const;
export const ACTIVITY_KEYS = [...OWN_KEYS, ...LOGS_KEYS] as const;

// The same shapes the API validates: a hand-edited link degrades to "no filter" here instead of to
// a 422 on every request the page makes.
const USER_RE = /^(none|\d{1,10})$/;
const ID_RE = /^[a-z][a-z0-9_]*$/;
const Q_MAX = 200;

const pick = (value: string | null, re: RegExp, max: number) =>
  value && value.length <= max && re.test(value) ? value : null;
const oneOf = <T extends string>(value: string | null, list: readonly T[]): T | null =>
  list.includes(value as T) ? (value as T) : null;

export function activityParamsToState(params: URLSearchParams): ActivityUrlState {
  return {
    // A link to a page this one replaced arrives with its tab already set (urlState's RETIRED).
    tab: oneOf(params.get("at"), ACTIVITY_TABS) ?? DEFAULT_ACTIVITY_STATE.tab,
    window: oneOf(params.get("aw"), ACTIVITY_WINDOWS) ?? DEFAULT_ACTIVITY_STATE.window,
    user: pick(params.get("au"), USER_RE, 10),
    q: (params.get("aq") ?? "").slice(0, Q_MAX),
    job: pick(params.get("rjob"), ID_RE, 40),
    status: oneOf(params.get("rst"), RUN_STATUSES),
    action: pick(params.get("aact"), ID_RE, 48),
  };
}

/** The URL updates for a state: a filter at its default clears its key. */
export function activityParamUpdates(state: ActivityUrlState): Record<string, string | null> {
  const d = DEFAULT_ACTIVITY_STATE;
  return {
    at: state.tab === d.tab ? null : state.tab,
    aw: state.window === d.window ? null : state.window,
    au: state.user,
    aq: state.q.trim() ? state.q : null,
    rjob: state.job,
    rst: state.status,
    aact: state.action,
  };
}

/** Where the window starts, as the API takes it: `all` from the epoch (the quota read would default
 *  to its last 30 days without one). */
export function sinceOf(window: ActivityWindow, now = Date.now()): string {
  const hours = WINDOW_HOURS[window];
  return new Date(hours === null ? 0 : now - hours * 3_600_000).toISOString();
}