feat(database): implement MembersService and TablesService classes for group management and database setup

- Add `MembersService`:
  - Implement `update` method to update group members while validating input.
  - Implement `add` method to add new members to a group with input validation and error handling.
  - Utilize `DatabaseService` and `GroupService` for modular design and efficient group member updates.

- Add `TablesService`:
  - Implement `initialTables` method to set up initial database tables using an external SQL file.
  - Implement `seedTables` method to seed the database with initial data, including checks to prevent duplicate seeding.
  - Leverage a `ConnectionPool` for database connections.
  - Decorate methods with a `Catch` decorator for error handling and improved debugging.

These enhancements provide comprehensive group management, database setup, and seeding functionalities, ensuring maintainability and scalability of the system.

Author: m-mdy-m

src/database/service/Members.ts

@@ -0,0 +1,67 @@
+import { PoolClient } from 'pg';
+import { Group } from '../../types/database/TablesTypes'; // Adjust this import based on your actual types
+import { GroupService } from '../models/Group';
+import { DatabaseService } from './Databas';
+
+export class MembersService {
+  private group_by_id: Function;
+  private _db: DatabaseService;
+  constructor(private _client: PoolClient) {
+    const groupService = new GroupService(_client);
+    this.group_by_id = groupService.getByGroupId;
+    this._db = new DatabaseService(_client);
+  }
+  async update(groupId: number, newMember: number | string): Promise<Group> {
+    const group = await this.group_by_id(groupId);
+    if (!group) {
+      throw new Error(`Group with ID ${groupId} not found`);
+    }
+
+    // Convert newMember to a number and ensure it's a valid member
+    const memberId = Number(newMember);
+    if (isNaN(memberId)) {
+      throw new Error('Invalid member ID');
+    }
+
+    const members = group.members.map(Number);
+    if (!members.includes(memberId)) {
+      members.push(memberId);
+    }
+    const updatedGroup = await this._db.update<Group>('Group', { members: members }, { group_id: groupId });
+    return updatedGroup;
+  }
+
+  // Add a new member to the group
+  async add(groupId: number, newMember: number | string): Promise<Group> {
+    const group = await this.group_by_id(groupId);
+    if (!group) {
+      throw new Error(`Group with ID ${groupId} not found`);
+    }
+
+    // Ensure the new member ID is valid
+    const memberId = Number(newMember);
+    if (isNaN(memberId)) {
+      throw new Error('Invalid member ID');
+    }
+
+    // Check if the member is already in the group
+    if (group.members.includes(memberId)) {
+      throw new Error('Member already exists in the group');
+    }
+
+    // Add the new member
+    const updatedMembers = [...group.members, memberId];
+
+    const query = `
+      UPDATE "Group"
+      SET members = $1, updated_at = NOW()
+      WHERE group_id = $2
+      RETURNING *;
+    `;
+    const values = [updatedMembers, groupId];
+    const result = await this._client.query(query, values);
+
+    // Return the updated group
+    return result.rows[0];
+  }
+}

src/database/service/Tables.ts

@@ -0,0 +1,37 @@
+import { Catch } from '../../decorators/Catch';
+import { ConnectionPool } from '../ConnectionPool';
+import * as path from 'path';
+import * as fs from 'fs/promises';
+export class TablesService {
+  constructor(private _connectionPool: ConnectionPool) {}
+  @Catch({
+    category: 'Database',
+    message: 'Failed to set up initial tables.',
+    statusCode: 500,
+  })
+  async initialTables() {
+    const client = await this._connectionPool.getClient();
+    const sqlFilePath = path.join(__dirname, '..', './sql/Tables.sql');
+    const sql = await fs.readFile(sqlFilePath, 'utf-8');
+    await client.query(sql);
+    console.log('Initial tables have been set up successfully.');
+  }
+  @Catch({
+    category: 'Database',
+    message: 'Failed to seed tables.',
+    statusCode: 500,
+  })
+  async seedTables() {
+    const client = await this._connectionPool.getClient();
+    const result = await client.query(`SELECT COUNT(*) FROM "User";`);
+    const userCount = parseInt(result.rows[0].count, 10);
+    if (userCount > 0) {
+      console.log('The tables have already been seeded. Skipping seeding process.');
+      return; // Skip seeding if there's already data in the User table
+    }
+    const sqlFilePath = path.join(__dirname, '..', './sql/seed/SeedDataTables.sql');
+    const sql = await fs.readFile(sqlFilePath, 'utf-8');
+    await client.query(sql);
+    console.log('All tables have been seeded successfully.');
+  }
+}