easypay-api/api/LAST_RECEIPT_ENDPOINT.md

Last Payment Receipt API - Implementation Summary

🎯 Overview

A new API endpoint has been added to the EasyPay system that returns the receipt image (PNG format) of the last payment made by a student.

✅ What Was Implemented

1. New API Endpoint

File: api/students/last_receipt.php

Endpoint: GET /api/students/last_receipt

Description: Returns the receipt image of the most recent payment made by a student.

Parameters:

• student_id (required): The student's unique ID

Response:

• Success: PNG image (binary data)
• Error: JSON with error message

2. Key Features

✅ Automatic Last Payment Detection

• Queries the database to find the most recent payment for the student
• Orders by payment date (DESC) and ID (DESC) to get the latest

✅ Complete Receipt Generation

• Uses the existing ReceiptGenerator class
• Shows all fee items (not just those in the last payment)
• Displays proper totals and balances
• Includes school branding and formatting

✅ Validation & Security

• Validates student ID is provided
• Checks student exists and is active
• Verifies payment records exist
• Optional API key authentication support
• Proper error handling with JSON responses

✅ Error Handling

• Student ID missing (HTTP 400)
• Student not found (HTTP 404)
• No payment records (HTTP 404)
• Receipt generation errors (HTTP 500)

3. Documentation Updates

Updated Files:

• api/README.md - Added student endpoints section with last_receipt documentation
• api/API_DOCUMENTATION.md - Added comprehensive documentation with examples in:
  • cURL
  • PHP
  • JavaScript (Fetch API)
  • Python

4. Testing Tool

File: api/test_receipt.html

An interactive web-based testing tool that allows you to:

• Enter a student ID
• Optionally use API key authentication
• View the receipt image in the browser
• Download the receipt as a PNG file

📁 Files Created/Modified

Created:

1. api/students/last_receipt.php - Main endpoint
2. api/test_receipt.html - Testing tool

Modified:

1. api/README.md - Added student endpoints documentation
2. api/API_DOCUMENTATION.md - Added detailed endpoint documentation

🚀 How to Use

1. Basic Usage (cURL)

# Get receipt and save to file
curl -X GET "http://localhost/easypay/api/students/last_receipt?student_id=000001234567890123" \
  --output receipt.png

2. With API Authentication

curl -X GET "http://localhost/easypay/api/students/last_receipt?student_id=000001234567890123" \
  -H "Authorization: Bearer your-api-key-here" \
  --output receipt.png

3. Using the Test Tool

Open in your browser:

http://localhost/easypay/api/test_receipt.html

Enter a student ID and click "Get Receipt" to view and download.

4. PHP Example

<?php
$studentId = '000001234567890123';
$url = "http://localhost/easypay/api/students/last_receipt?student_id={$studentId}";

$imageData = file_get_contents($url);

if ($imageData !== false) {
    // Save to file
    file_put_contents('receipt.png', $imageData);
    
    // Or display in browser
    header('Content-Type: image/png');
    echo $imageData;
}
?>

5. JavaScript Example

const studentId = '000001234567890123';
const url = `http://localhost/easypay/api/students/last_receipt?student_id=${studentId}`;

fetch(url)
  .then(response => response.blob())
  .then(blob => {
    // Create download link
    const url = window.URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = 'receipt.png';
    a.click();
  });

🔍 How It Works

1. Validates Request: Checks HTTP method and student ID parameter
2. Validates Student: Ensures student exists and is active
3. Finds Last Payment: Queries tb_account_payment_registers for most recent payment
4. Fetches Receipt Data: Gets all fee information for the student
5. Generates Image: Uses ReceiptGenerator to create PNG receipt
6. Returns Image: Sends PNG image with proper headers

📊 Database Tables Used

• tb_account_payment_registers - Payment records and receipts
• tb_student_registrations - Student information
• tb_academic_levels - Student class/level
• tb_account_receivables - Fee billing information
• tb_account_school_fees - Fee descriptions

✨ Key Benefits

1. Easy Integration: Simple GET request with student ID
2. Consistent Format: Uses same receipt generator as web application
3. Automatic Detection: No need to specify receipt number or date
4. Flexible Output: Can be displayed, downloaded, or embedded
5. Secure: Validates student and supports API authentication
6. Well Documented: Comprehensive examples in multiple languages

🧪 Testing

Test Cases to Verify:

1. ✅ Valid Student with Payments

   • Send request with valid student ID
   • Expect: PNG image of last receipt

2. ✅ Valid Student without Payments

   • Send request for student with no payments
   • Expect: HTTP 404 "No payment records found"

3. ✅ Invalid Student

   • Send request with non-existent student ID
   • Expect: HTTP 404 "Student not found"

4. ✅ Missing Student ID

   • Send request without student_id parameter
   • Expect: HTTP 400 "Student ID is required"

5. ✅ With API Authentication

   • Send request with valid API key
   • Expect: PNG image

📝 Notes

• The endpoint returns the last payment made by the student (most recent by date)
• The receipt shows all fees for the student, not just those in the last payment
• The receipt format matches the web-generated receipts exactly
• Images are generated on-the-fly (not cached)
• The endpoint supports both authenticated and unauthenticated requests (based on config)

🔐 Security Considerations

• Input validation on student ID
• SQL injection protection (prepared statements)
• Optional API key authentication
• Proper error messages (no sensitive data leakage)
• Active student verification

📞 Support

For issues or questions:

1. Check the API documentation in api/API_DOCUMENTATION.md
2. Use the test tool at api/test_receipt.html
3. Review the endpoint code in api/students/last_receipt.php

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Version: 1.0
Date: 2026-01-16
Author: AI Assistant