send_message.php

<?php
require_once 'includes/session_config.php';
include 'conn.php';

// Check if user is logged in
if (!isset($_SESSION['logged_in']) || !isset($_SESSION['user_id'])) {
    echo json_encode(['success' => false, 'message' => 'User not logged in']);
    exit();
}

// Get user information from session
$user_id = $_SESSION['user_id'];
$user_type = $_SESSION['user_type'] ?? "";

// Check if required parameters are provided
if (!isset($_POST['project_id']) || !isset($_POST['message'])) {
    echo json_encode(['success' => false, 'message' => 'Missing required parameters']);
    exit();
}

$project_id = intval($_POST['project_id']);
$message = trim($_POST['message']);

// Validate message
if (empty($message)) {
    echo json_encode(['success' => false, 'message' => 'Message cannot be empty']);
    exit();
}

// Check if user has access to this project
$has_access = false;
if ($user_type === 'client') {
    // Check if this client owns the project
    $access_sql = "SELECT * FROM projects WHERE id = ? AND user_id = ?";
    $access_stmt = $conn->prepare($access_sql);
    $access_stmt->bind_param("ii", $project_id, $user_id);
    $access_stmt->execute();
    $access_result = $access_stmt->get_result();
    if ($access_result->num_rows > 0) {
        $has_access = true;
    }
} else if ($user_type === 'freelancer') {
    // Check if this freelancer is assigned to this project
    $access_sql = "SELECT * FROM project_assignments 
                  WHERE project_id = ? AND freelancer_id = ? AND is_accepted = 1";
    $access_stmt = $conn->prepare($access_sql);
    $access_stmt->bind_param("ii", $project_id, $user_id);
    $access_stmt->execute();
    $access_result = $access_stmt->get_result();
    if ($access_result->num_rows > 0) {
        $has_access = true;
    }
}

if (!$has_access) {
    echo json_encode(['success' => false, 'message' => 'You do not have access to this project']);
    exit();
}

// Insert message into database
$sql = "INSERT INTO project_messages (project_id, user_id, message, timestamp) VALUES (?, ?, ?, NOW())";
$stmt = $conn->prepare($sql);
$stmt->bind_param("iis", $project_id, $user_id, $message);

if ($stmt->execute()) {
    echo json_encode(['success' => true]);
} else {
    echo json_encode(['success' => false, 'message' => 'Failed to save message: ' . $conn->error]);
}
?>