import type { Rules } from '../rules/index.js'

/** What a worker gets with a range (the coordinator's lease). */
export interface Lease {
  range: { id: number; group: string; start: number; end: number; next: number }
  rules: Rules
}

/**
 * A group's two cursors (REBUILD.md, "Voyager 3: window indexing", 1): `history` works the ranges the lease bounds
 * hand out (the windows, the history), `tail` the tail planner's ranges. Each lane has its own holder, window and
 * snapshot; the group routes take `?lane=` (history by default).
 */
export type Lane = 'history' | 'tail'

/**
 * A group lease (REBUILD.md, "Voyager 3: window indexing", 1): the group a worker thread holds, the lane, the rules,
 * and the snapshot of the lane's window when there is one (its next article; the body comes from GET
 * groups/:id/snapshot).
 */
export interface GroupLease {
  group: { id: number; name: string; priority: number }
  lane: Lane
  rules: Rules
  snapshot: { next: number } | null
}

/** The group's next range in article order, leased to the holder (POST groups/:id/next; 204 when caught up). */
export interface NextRange {
  range: { id: number; start: number; end: number; next: number }
}