// Ways a real collection goes wrong. The page lets you apply them; the tests apply the same functions.
import type { Snapshot, SourceKey, SourceStatus } from "./types";

export type ScenarioId = "no_email_channel" | "cursor_expired" | "no_calendar_permission" | "stale_run";

export const scenarios: { id: ScenarioId; label: string; what: string }[] = [
  {
    id: "no_email_channel",
    label: "Export messages without channel=Email",
    what: "Without that parameter the export returns every channel except email.",
  },
  {
    id: "cursor_expired",
    label: "Export cursor expires halfway",
    what: "A cursor is valid for two minutes after the last request. A slow run loses the rest of the pages.",
  },
  {
    id: "no_calendar_permission",
    label: "Token without calendar read access",
    what: "The token owner chose not to grant calendar scopes.",
  },
  {
    id: "stale_run",
    label: "Report built from a three-day-old run",
    what: "The scheduled collection stopped and nobody noticed.",
  },
];

function setStatus(s: Snapshot, key: SourceKey, status: SourceStatus, note: string): Snapshot {
  return { ...s, sources: s.sources.map((x) => (x.source === key ? { ...x, status, note } : x)) };
}

export function applyScenario(s: Snapshot, id: ScenarioId): Snapshot {
  switch (id) {
    case "no_email_channel":
      return setStatus(
        { ...s, messages: s.messages.filter((m) => m.messageType !== "TYPE_EMAIL") },
        "messages.email", "not_read", "Export called without channel=Email: email messages were not returned.",
      );
    case "cursor_expired": {
      const sorted = [...s.messages].filter((m) => m.messageType !== "TYPE_EMAIL")
        .sort((a, b) => a.dateAdded.localeCompare(b.dateAdded));
      const kept = new Set(sorted.slice(0, Math.floor(sorted.length / 2)).map((m) => m.id));
      return setStatus(
        { ...s, messages: s.messages.filter((m) => m.messageType === "TYPE_EMAIL" || kept.has(m.id)) },
        "messages.nonEmail", "partial", "Cursor expired after page 1; the remaining pages were not read.",
      );
    }
    case "no_calendar_permission":
      return setStatus(
        setStatus({ ...s, events: [], notifications: {} }, "calendars.events", "forbidden", "401: token lacks calendar read scope."),
        "calendars.notifications", "forbidden", "401: token lacks calendar read scope.",
      );
    case "stale_run": {
      // The last successful run was three days ago: it could not contain anything newer.
      const at = new Date(new Date(s.collectedAt).getTime() - 72 * 3600_000).toISOString();
      const before = (d: string) => new Date(d).getTime() <= new Date(at).getTime();
      return {
        ...s,
        collectedAt: at,
        contacts: s.contacts.filter((c) => before(c.dateAdded)),
        submissions: s.submissions.filter((x) => before(x.createdAt)),
        messages: s.messages.filter((m) => before(m.dateAdded)),
        events: s.events.filter((e) => before(e.dateAdded)),
        opportunities: s.opportunities.filter((o) => before(o.createdAt)),
      };
    }
  }
}

export function applyScenarios(s: Snapshot, ids: ScenarioId[]): Snapshot {
  return ids.reduce(applyScenario, s);
}