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

/**
 * A group's history in leasable pieces (REBUILD.md, coordinator):
 * planned → (spooled by the prefetcher) → leased → done. `next_id` is the
 * resume point: everything before it has been stored.
 */
export default class extends BaseSchema {
  async up() {
    this.schema.createTable('ranges', (table) => {
      table.bigIncrements('id')
      table.integer('group_id').notNullable().references('id').inTable('groups').onDelete('CASCADE')
      table.bigInteger('start_id').notNullable()
      table.bigInteger('end_id').notNullable()
      table.bigInteger('next_id').notNullable()
      table.string('status', 8).notNullable().defaultTo('planned')
      // Lower first; the coordinator plans the oldest era first.
      table.integer('priority').notNullable().defaultTo(0)
      table.integer('rule_version').nullable()
      table.integer('node_id').nullable()
      table.integer('attempts').notNullable().defaultTo(0)
      // Chunks of this range in the spool (prefetch); all of them when spooled_at is set.
      table.integer('spooled_chunks').notNullable().defaultTo(0)
      table.timestamp('spooled_at', { useTz: true }).nullable()
      table.timestamp('leased_at', { useTz: true }).nullable()
      table.timestamp('heartbeat_at', { useTz: true }).nullable()
      table.timestamp('done_at', { useTz: true }).nullable()
      table.bigInteger('headers').notNullable().defaultTo(0)
      table.text('error').nullable()
      table.unique(['group_id', 'start_id'])
    })
    this.schema.raw(`CREATE INDEX ranges_todo_idx ON ranges (priority, id) WHERE status IN ('planned', 'leased')`)
  }

  async down() {
    this.schema.dropTable('ranges')
  }
}