import { BaseSchema } from '@adonisjs/lucid/schema'

/**
 * Group leases (REBUILD.md, "Voyager 3: window indexing", 1 and 5; 2026-10-26): a worker thread holds a group, not
 * a range, and indexes its ranges in article order through one carried window. One row a group: the holder and
 * its heartbeat, the range it works, and the snapshot of its window (the article it stands at: the next one to
 * index) that the coordinator keeps on bulk. Ranges stay what is planned, fetched and finished.
 */
export default class extends BaseSchema {
  async up() {
    this.schema.raw(`
      CREATE TABLE group_leases (
        group_id integer PRIMARY KEY REFERENCES groups (id) ON DELETE CASCADE,
        -- The holder; null between holders. A holder quiet for LEASE_TTL_SECONDS is taken over.
        node_id integer,
        leased_at timestamptz,
        heartbeat_at timestamptz,
        -- The range the holder works (null between ranges).
        range_id bigint,
        -- The window's snapshot: the article it stands at (a resume point), and when it was taken; null: none.
        snapshot_next bigint,
        snapshot_at timestamptz,
        ranges_done integer NOT NULL DEFAULT 0,
        headers bigint NOT NULL DEFAULT 0,
        created_at timestamptz NOT NULL DEFAULT now()
      )`)
    this.schema.raw(`CREATE INDEX group_leases_held_idx ON group_leases (heartbeat_at) WHERE node_id IS NOT NULL`)
  }

  async down() {
    this.schema.raw(`DROP TABLE IF EXISTS group_leases`)
  }
}