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

/**
 * Article ranges handed to worker:fetch, so a range only counts as indexed
 * once it was fetched successfully (CONCEPT.md D18).
 */
export default class extends BaseSchema {
  async up() {
    this.schema.alterTable('groups', (table) => {
      // How far the scheduler has queued; last_indexed_id becomes the
      // watermark below which every article was fetched.
      table.bigInteger('last_queued_id').notNullable().defaultTo(0)
    })
    this.defer(async (db) => {
      await db.rawQuery('UPDATE groups SET last_queued_id = last_indexed_id')
    })

    this.schema.createTable('fetch_ranges', (table) => {
      table.bigIncrements('id')
      table.integer('group_id').notNullable().references('groups.id').onDelete('CASCADE')
      table.bigInteger('start_id').notNullable()
      table.bigInteger('end_id').notNullable()
      // queued | done | failed
      table.string('status', 8).notNullable().defaultTo('queued')
      table.integer('requeues').notNullable().defaultTo(0)
      table.text('error')
      table.timestamp('created_at', { useTz: true }).notNullable()
      table.timestamp('updated_at', { useTz: true }).notNullable()
      table.index(['group_id', 'status'])
    })
  }

  async down() {
    this.schema.dropTable('fetch_ranges')
    this.schema.alterTable('groups', (table) => table.dropColumn('last_queued_id'))
  }
}