site/polls/index.php

202 lines
6.9 KiB
PHP

<?php
session_start();
require_once 'db.php'; // Ensures $db is available and the database is set up
// Array to store poll IDs that the user has voted on in this session
if (!isset($_SESSION['voted_polls'])) {
$_SESSION['voted_polls'] = [];
}
// Helper function: Fetch poll details by ID
function getPollById($db, $pollId) {
$stmt = $db->prepare("SELECT * FROM poll_questions WHERE id = :id LIMIT 1");
$stmt->bindValue(':id', $pollId, PDO::PARAM_INT);
$stmt->execute();
return $stmt->fetch(PDO::FETCH_ASSOC);
}
// Helper function: Fetch poll options (and their results) by poll ID
function getPollOptions($db, $pollId) {
$stmt = $db->prepare("
SELECT
po.id AS option_id,
po.option_text,
IFNULL(pr.vote_count, 0) AS vote_count
FROM poll_options po
LEFT JOIN poll_results pr ON po.id = pr.option_id
WHERE po.question_id = :question_id
ORDER BY po.id ASC
");
$stmt->bindValue(':question_id', $pollId, PDO::PARAM_INT);
$stmt->execute();
return $stmt->fetchAll(PDO::FETCH_ASSOC);
}
// If a vote is being cast
if (isset($_POST['vote']) && isset($_POST['option_id']) && isset($_POST['poll_id'])) {
$pollId = (int)$_POST['poll_id'];
$optionId = (int)$_POST['option_id'];
// Ensure this user hasn't already voted on this poll in this session
if (!in_array($pollId, $_SESSION['voted_polls'], true)) {
// Update the vote count
$updateStmt = $db->prepare("
UPDATE poll_results
SET vote_count = vote_count + 1
WHERE question_id = :question_id
AND option_id = :option_id
");
$updateStmt->bindValue(':question_id', $pollId, PDO::PARAM_INT);
$updateStmt->bindValue(':option_id', $optionId, PDO::PARAM_INT);
$updateStmt->execute();
// Mark the user as having voted
$_SESSION['voted_polls'][] = $pollId;
}
// Redirect back to the same poll to show results
header("Location: index.php?poll_id=" . $pollId);
exit;
}
// Check if a specific poll is requested
$pollId = isset($_GET['poll_id']) ? (int)$_GET['poll_id'] : null;
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Poll Application</title>
<style>
body { font-family: Arial, sans-serif; margin: 20px; }
.poll-list, .poll-detail {
max-width: 600px;
margin: 0 auto;
}
h2, h3 { margin-bottom: 10px; }
.poll-item {
margin-bottom: 15px;
padding: 10px;
border: 1px solid #ccc;
}
.poll-options ul { list-style-type: none; padding: 0; }
.poll-options li { margin-bottom: 8px; }
.vote-button { margin-top: 10px; }
.results { margin-top: 10px; }
.results li { margin-bottom: 5px; }
.back-link { margin-top: 20px; display: inline-block; }
</style>
</head>
<body>
<?php
// If no poll_id given, show all polls
if ($pollId === null) {
?>
<div class="poll-list">
<h2>Available Polls</h2>
<?php
// Fetch all polls
$allPollsStmt = $db->query("SELECT id, question_text, created_at FROM poll_questions ORDER BY id DESC");
$allPolls = $allPollsStmt->fetchAll(PDO::FETCH_ASSOC);
if ($allPolls) {
foreach ($allPolls as $poll) {
?>
<div class="poll-item">
<strong>Question:</strong> <?php echo htmlspecialchars($poll['question_text']); ?><br>
<em>Created at: <?php echo htmlspecialchars($poll['created_at']); ?></em><br>
<a href="index.php?poll_id=<?php echo $poll['id']; ?>">View Poll</a>
</div>
<?php
}
} else {
?>
<p>No polls available.</p>
<?php
}
?>
</div>
<?php
} else {
// Display a single poll
$poll = getPollById($db, $pollId);
?>
<div class="poll-detail">
<?php
if (!$poll) {
echo "<p>Poll not found.</p>";
} else {
$options = getPollOptions($db, $pollId);
$hasVoted = in_array($pollId, $_SESSION['voted_polls'], true);
?>
<h2><?php echo htmlspecialchars($poll['question_text']); ?></h2>
<?php
// If not voted yet, show the vote form
if (!$hasVoted) {
if (!empty($options)) {
?>
<form method="post" action="index.php">
<div class="poll-options">
<ul>
<?php foreach ($options as $option) { ?>
<li>
<label>
<input type="radio" name="option_id"
value="<?php echo $option['option_id']; ?>"
required>
<?php echo htmlspecialchars($option['option_text']); ?>
</label>
</li>
<?php } ?>
</ul>
</div>
<input type="hidden" name="poll_id" value="<?php echo $poll['id']; ?>">
<button type="submit" name="vote" class="vote-button">Vote</button>
</form>
<?php
} else {
echo "<p>No options available for this poll.</p>";
}
} else {
// Show the results if user has already voted
?>
<h3>Results</h3>
<div class="results">
<ul>
<?php
$totalVotes = 0;
foreach ($options as $opt) {
$totalVotes += $opt['vote_count'];
}
foreach ($options as $opt) {
$voteCount = (int) $opt['vote_count'];
$percentage = ($totalVotes > 0) ? ($voteCount / $totalVotes) * 100 : 0;
?>
<li>
<?php echo htmlspecialchars($opt['option_text']); ?>:
<?php echo $voteCount; ?> votes
(<?php echo round($percentage, 1); ?>%)
</li>
<?php
}
?>
</ul>
<p>Total votes: <?php echo $totalVotes; ?></p>
</div>
<?php
}
}
?>
<a href="index.php" class="back-link">Back to Poll List</a>
</div>
<?php
}
?>
</body>
</html>