add server to monorepo.

packages/server/src/services/Tenancy/TenantDBManager.ts

@@ -0,0 +1,153 @@
+import { Container } from 'typedi';
+import Knex from 'knex';
+import { knexSnakeCaseMappers } from 'objection';
+import { tenantKnexConfig, tenantSeedConfig } from '@/config/knexConfig';
+import config from '@/config';
+import { ITenant, ITenantDBManager } from '@/interfaces';
+import SystemService from '@/services/Tenancy/SystemService';
+import { TenantDBAlreadyExists } from '@/exceptions';
+
+export default class TenantDBManager implements ITenantDBManager {
+  static knexCache: { [key: string]: Knex } = {};
+
+  // System database manager.
+  dbManager: any;
+
+  // System knex instance.
+  sysKnex: Knex;
+
+  /**
+   * Constructor method.
+   * @param {ITenant} tenant
+   */
+  constructor() {
+    const systemService = Container.get(SystemService);
+
+    this.dbManager = systemService.dbManager();
+    this.sysKnex = systemService.knex();
+  }
+
+  /**
+   * Retrieve the tenant database name.
+   * @return {string}
+   */
+  private getDatabaseName(tenant: ITenant) {
+    return `${config.tenant.db_name_prefix}${tenant.organizationId}`;
+  }
+
+  /**
+   * Detarmines the tenant database weather exists.
+   * @return {Promise<boolean>}
+   */
+  public async databaseExists(tenant: ITenant) {
+    const databaseName = this.getDatabaseName(tenant);
+
+    const results = await this.sysKnex.raw(
+      'SELECT * FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = "' +
+        databaseName +
+        '"'
+    );
+    return results[0].length > 0;
+  }
+
+  /**
+   * Creates a tenant database.
+   * @throws {TenantAlreadyInitialized}
+   * @return {Promise<void>}
+   */
+  public async createDatabase(tenant: ITenant): Promise<void> {
+    await this.throwErrorIfTenantDBExists(tenant);
+
+    const databaseName = this.getDatabaseName(tenant);
+    await this.dbManager.createDb(databaseName);
+  }
+
+  /**
+   * Dropdowns the tenant database if it was exist.
+   * @param {ITenant} tenant -
+   */
+  public async dropDatabaseIfExists(tenant: ITenant) {
+    const isExists = await this.databaseExists(tenant);
+
+    if (!isExists) {
+      return;
+    }
+
+    await this.dropDatabase(tenant);
+  }
+
+  /**
+   * dropdowns the tenant's database.
+   * @param {ITenant} tenant
+   */
+  public async dropDatabase(tenant: ITenant) {
+    const databaseName = this.getDatabaseName(tenant);
+
+    await this.dbManager.dropDb(databaseName);
+  }
+
+  /**
+   * Migrate tenant database schema to the latest version.
+   * @return {Promise<void>}
+   */
+  public async migrate(tenant: ITenant): Promise<void> {
+    const knex = this.setupKnexInstance(tenant);
+
+    await knex.migrate.latest();
+  }
+
+  /**
+   * Seeds initial data to the tenant database.
+   * @return {Promise<void>}
+   */
+  public async seed(tenant: ITenant): Promise<void> {
+    const knex = this.setupKnexInstance(tenant);
+
+    await knex.migrate.latest({
+      ...tenantSeedConfig(tenant),
+      disableMigrationsListValidation: true,
+    });
+  }
+
+  /**
+   * Retrieve the knex instance of tenant.
+   * @return {Knex}
+   */
+  public setupKnexInstance(tenant: ITenant) {
+    const key: string = `${tenant.id}`;
+    let knexInstance = TenantDBManager.knexCache[key];
+
+    if (!knexInstance) {
+      knexInstance = Knex({
+        ...tenantKnexConfig(tenant),
+        ...knexSnakeCaseMappers({ upperCase: true }),
+      });
+      TenantDBManager.knexCache[key] = knexInstance;
+    }
+    return knexInstance;
+  }
+
+  /**
+   * Retrieve knex instance from the givne tenant.
+   */
+  public getKnexInstance(tenantId: number) {
+    const key: string = `${tenantId}`;
+    let knexInstance = TenantDBManager.knexCache[key];
+
+    if (!knexInstance) {
+      throw new Error('Knex instance is not initialized yut.');
+    }
+    return knexInstance;
+  }
+
+  /**
+   * Throws error if the tenant database already exists.
+   * @return {Promise<void>}
+   */
+  async throwErrorIfTenantDBExists(tenant: ITenant) {
+    const isExists = await this.databaseExists(tenant);
+    if (isExists) {
+      throw new TenantDBAlreadyExists();
+    }
+  }
+}