sourceController.ts

import knex, {
  sourceTable,
  sourceKeys,
  SourceAttributes,
  SourceInstance,
} from '../models'

/**
 * Creates a new source from the specified parameters given. Returns that source instance.
 *
 * @param {SourceAttributes} attributes An object of attributes for the source.
 */
export async function createSource(
  source: SourceAttributes
): Promise<SourceInstance> {
  const newSource: SourceInstance[] = await knex
    .table(sourceTable)
    .returning(sourceKeys)
    .insert(source)

  return newSource[0]
}

/**
 * Returns a source instance by it's id. If no source with the specified id exists, return null.
 *
 * @param {number} id The id of the desired source.
 */
export async function getSource(id: number): Promise<SourceInstance | null> {
  const source: SourceInstance[] = await knex
    .table(sourceTable)
    .returning(sourceKeys)
    .where('id', id)

  return source.length === 1 ? source[0] : null
}

/**
 * Returns an array of all source instances in the database.
 */
export async function getAllSources(): Promise<SourceInstance[]> {
  const sources: SourceInstance[] = await knex
    .table(sourceTable)
    .returning(sourceKeys)
  return sources
}

/**
 * Updates a source with the given id to the attributes specified. Returns the instance of the updated source. If no source with the given id is found, return null.
 *
 * @param id
 * @param attributes
 */
export async function updateSource(
  id: number,
  attributes: SourceAttributes
): Promise<SourceInstance | null> {
  const updatedSources = await knex
    .table(sourceTable)
    .where('id', '=', id)
    .update(attributes)
    .returning(sourceKeys)

  if (updatedSources.length === 1) {
    return updatedSources[0]
  } else if (updatedSources.length !== 0) {
    throw new Error(
      'More than 1 rows updated from single id in `updateSource`! This is bad!'
    )
  }
  return null
}

/**
 * Deletes a source with the given id. Returns true if the source was deleted, returns false if there was an error.
 *
 * @param id
 */
export async function deleteSource(id: number): Promise<boolean> {
  const numberOfDeletedSources = await knex
    .table(sourceTable)
    .where('id', '=', id)
    .del()

  if (numberOfDeletedSources === 1) {
    return true
  } else if (numberOfDeletedSources !== 0) {
    throw new Error('More than 1 rows deleted from single id! This is bad!')
  }
  return false
}