[Issue # 17] Job Posting CRUD API for Backend Service (#19)

* Added mongoDB connection configuration

* Added a post request for job posting

* Added get request to search job postings by email in route.js

* Added delete request that handles deleting a job posting and removed unnecessary comment and console.log codes

* Added Patch request which updates any desired fields in the job posting colletion in route.js

* Removed unused import and removed unnecessary space

* Added get requests for site 1, 2, 3, and 4

* Added pagination feature to the get request in site1,2,3, and 4

* Created siteRequestUtils.js and moved the repeated codes in sites' route codes to it. Also, updated the site names specifically.

* Updated the database connection to handle it in singleton way

* Removed database connection closing code to fix the connection error and added missing import NextResponse in siteRequestUtils

* Removed unnecessary error handling and fixed typo

* Added get request by Id for job posting

* Apply formatting changes

---------

Co-authored-by: ama-cantabile <ama-cantabile@users.noreply.github.com>

src/app/api/job-posting/by-id/route.js

@@ -0,0 +1,69 @@
+import { NextResponse } from 'next/server';
+import { connectMongoDB } from '@/libs/mongodb';
+import posting from '@/app/api/posting';
+import mongoose from 'mongoose';
+
+export async function GET(req) {
+  try {
+    const jobPostingId = req.nextUrl.searchParams.get('job-posting-id');
+
+    if (!jobPostingId) {
+      return NextResponse.json(
+        { message: 'Bad Request - ID parameter is required' },
+        { status: 400 }
+      );
+    }
+
+    await connectMongoDB();
+
+    const Posting =
+      mongoose.models.posting || mongoose.model('posting', posting);
+
+    const jobPostings = await Posting.find({ _id: jobPostingId });
+
+    // Check if job postings were found
+    if (jobPostings.length === 0) {
+      return NextResponse.json(
+        {
+          message:
+            'Not Found - No job postings were found associated with the provided ID',
+        },
+        { status: 404 }
+      );
+    }
+
+    return NextResponse.json({ jobPostings }, { status: 200 });
+  } catch (error) {
+    console.log('Error fetching job postings by ID:', error);
+
+    // Check error status and return appropriate response
+    if (error instanceof SyntaxError || error instanceof TypeError) {
+      // Malformed or invalid request
+      return NextResponse.json(
+        { message: 'Bad Request - The request is malformed or invalid' },
+        { status: 400 }
+      );
+    } else if (error.name === 'UnauthorizedError') {
+      // Unauthorized
+      return NextResponse.json(
+        {
+          message:
+            'Unauthorized - The client is not authorized to perform the operation',
+        },
+        { status: 401 }
+      );
+    } else if (error.name === 'NotFoundError' || error.name === 'CastError') {
+      // Not Found
+      return NextResponse.json(
+        { message: 'Not Found - The specified job ID does not exist' },
+        { status: 404 }
+      );
+    } else {
+      // Other server error
+      return NextResponse.json(
+        { message: 'Internal Server Error:' },
+        { status: 500 }
+      );
+    }
+  }
+}

src/app/api/job-posting/disabled/route.js

@@ -0,0 +1,32 @@
+import { NextResponse } from 'next/server';
+import {
+  getPaginationParams,
+  fetchJobPostings,
+  handleError,
+} from '../siteRequestUtils';
+
+export async function GET(req) {
+  try {
+    //Todo: Update the site3 name to disabled
+    const siteCriteria = { site3: true };
+
+    // Extract pagination parameters
+    const { skip, pageSize } = getPaginationParams(req);
+
+    // Query job postings with pagination
+    const jobPostings = await fetchJobPostings(siteCriteria, skip, pageSize);
+
+    if (jobPostings.length === 0) {
+      return NextResponse.json(
+        { message: 'Not Found - No job postings found on this page' },
+        { status: 404 }
+      );
+    }
+
+    // Return success response with the paginated job postings
+    return NextResponse.json({ jobPostings }, { status: 200 });
+  } catch (error) {
+    // Handle errors
+    return handleError(error);
+  }
+}

src/app/api/job-posting/indigenous/route.js

@@ -0,0 +1,32 @@
+import { NextResponse } from 'next/server';
+import {
+  getPaginationParams,
+  fetchJobPostings,
+  handleError,
+} from '../siteRequestUtils';
+
+export async function GET(req) {
+  try {
+    //Todo: Update the site1 name to indigenous
+    const siteCriteria = { site1: true };
+
+    // Extract pagination parameters
+    const { skip, pageSize } = getPaginationParams(req);
+
+    // Query job postings with pagination
+    const jobPostings = await fetchJobPostings(siteCriteria, skip, pageSize);
+
+    if (jobPostings.length === 0) {
+      return NextResponse.json(
+        { message: 'Not Found - No job postings found on this page' },
+        { status: 404 }
+      );
+    }
+
+    // Return success response with the paginated job postings
+    return NextResponse.json({ jobPostings }, { status: 200 });
+  } catch (error) {
+    // Handle errors
+    return handleError(error);
+  }
+}

src/app/api/job-posting/newcomers/route.js

@@ -0,0 +1,32 @@
+import { NextResponse } from 'next/server';
+import {
+  getPaginationParams,
+  fetchJobPostings,
+  handleError,
+} from '../siteRequestUtils';
+
+export async function GET(req) {
+  try {
+    //Todo: Update the site2 name to newcomers
+    const siteCriteria = { site2: true };
+
+    // Extract pagination parameters
+    const { ski