Solar Flare Monitor Script

Content is user-generated and unverified.
<?php
/**
 * Solar Flare Monitor Script
 * Reads GOES-18 satellite data and generates HTML report
 */

// Configuration
define('JSON_URL', 'https://services.swpc.noaa.gov/json/goes/primary/xray-flares-latest.json');
define('OUTPUT_FILE', '/var/www/html/current_flare.html');
define('STATE_FILE', '/tmp/solar_flare_state.json');

// Function to fetch JSON data
function fetchFlareData() {
    $context = stream_context_create([
        'http' => [
            'timeout' => 10,
            'user_agent' => 'Mozilla/5.0 (Ubuntu; PHP Solar Flare Monitor)'
        ]
    ]);
    
    $jsonData = @file_get_contents(JSON_URL, false, $context);
    
    if ($jsonData === false) {
        error_log("Failed to fetch solar flare data from " . JSON_URL);
        return null;
    }
    
    $data = json_decode($jsonData, true);
    
    if (json_last_error() !== JSON_ERROR_NONE) {
        error_log("Failed to parse JSON: " . json_last_error_msg());
        return null;
    }
    
    return $data;
}

// Function to load previous state
function loadState() {
    if (!file_exists(STATE_FILE)) {
        return ['last_time_tag' => null, 'history' => []];
    }
    
    $stateData = @file_get_contents(STATE_FILE);
    if ($stateData === false) {
        return ['last_time_tag' => null, 'history' => []];
    }
    
    $state = json_decode($stateData, true);
    if (json_last_error() !== JSON_ERROR_NONE) {
        return ['last_time_tag' => null, 'history' => []];
    }
    
    return $state;
}

// Function to save state
function saveState($state) {
    $jsonState = json_encode($state, JSON_PRETTY_PRINT);
    @file_put_contents(STATE_FILE, $jsonState);
}

// Function to generate HTML
function generateHTML($currentClass, $currentTime, $history) {
    $html = <<<HTML
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>GOES-18 Satellite Current Solar Flare Level</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            max-width: 800px;
            margin: 40px auto;
            padding: 20px;
            background-color: #f5f5f5;
        }
        h1 {
            color: #333;
            border-bottom: 3px solid #0066cc;
            padding-bottom: 10px;
        }
        .current-reading {
            background-color: #e6f2ff;
            padding: 20px;
            border-radius: 8px;
            margin: 30px 0;
            font-size: 18px;
            border-left: 5px solid #0066cc;
        }
        .current-value {
            font-weight: bold;
            color: #0066cc;
            font-size: 24px;
        }
        .history {
            background-color: white;
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
        }
        .history h2 {
            color: #333;
            margin-top: 0;
        }
        ul {
            list-style-type: none;
            padding-left: 0;
        }
        li {
            padding: 8px 0;
            border-bottom: 1px solid #eee;
        }
        li:last-child {
            border-bottom: none;
        }
        .timestamp {
            color: #666;
            font-size: 14px;
        }
        .footer {
            margin-top: 30px;
            text-align: center;
            color: #666;
            font-size: 12px;
        }
    </style>
</head>
<body>
    <h1>GOES-18 Satellite Current Solar Flare Level</h1>
    
    <div class="current-reading">
        The latest GOES-18 satellite Xray Flare Class level is <span class="current-value">{$currentClass}</span> at <span class="timestamp">{$currentTime} UTC</span>
    </div>
    
    <div class="history">
        <h2>Historical Readings</h2>
        <ul>

HTML;
    
    foreach ($history as $entry) {
        $html .= "            <li><strong>{$entry['class']}</strong> - <span class=\"timestamp\">{$entry['time']} UTC</span></li>\n";
    }
    
    $html .= <<<HTML
        </ul>
    </div>
    
    <div class="footer">
        Last updated: {$currentTime} UTC | Data source: NOAA SWPC
    </div>
</body>
</html>
HTML;
    
    return $html;
}

// Main execution
try {
    // Fetch current data
    $data = fetchFlareData();
    
    if ($data === null || empty($data)) {
        error_log("No data retrieved from solar flare service");
        exit(1);
    }
    
    // Get the first entry (most recent)
    $latestEntry = $data[0];
    $currentTimeTag = $latestEntry['time_tag'] ?? null;
    $currentClass = $latestEntry['current_class'] ?? 'Unknown';
    
    if ($currentTimeTag === null) {
        error_log("Missing time_tag in JSON data");
        exit(1);
    }
    
    // Load previous state
    $state = loadState();
    
    // Check if data has changed
    if ($state['last_time_tag'] === $currentTimeTag) {
        // No change, exit without updating
        exit(0);
    }
    
    // Data has changed, update history
    $newEntry = [
        'class' => $currentClass,
        'time' => $currentTimeTag
    ];
    
    // Add new entry to beginning of history
    array_unshift($state['history'], $newEntry);
    
    // Keep only last 50 entries
    $state['history'] = array_slice($state['history'], 0, 50);
    
    // Update last time tag
    $state['last_time_tag'] = $currentTimeTag;
    
    // Generate and save HTML
    $html = generateHTML($currentClass, $currentTimeTag, $state['history']);
    
    if (@file_put_contents(OUTPUT_FILE, $html) === false) {
        error_log("Failed to write HTML file to " . OUTPUT_FILE);
        exit(1);
    }
    
    // Save state
    saveState($state);
    
    error_log("Successfully updated solar flare data. Current class: {$currentClass}");
    
} catch (Exception $e) {
    error_log("Error in solar flare monitor: " . $e->getMessage());
    exit(1);
}

exit(0);
Content is user-generated and unverified.