<?php
/**
 * API Endpoint: Get Available Source Blocks
 * Returns available source blocks for a specific date, channel, and template
 */

require_once __DIR__ . '/../vendor/autoload.php';
require_once __DIR__ . '/../helpers.php';
require_once __DIR__ . '/../auth/auth_functions.php';

use Dotenv\Dotenv;

$dotenv = Dotenv::createImmutable(__DIR__ . '/..');
$dotenv->load();

header('Content-Type: application/json');

if (!isLoggedIn()) {
    http_response_code(401);
    echo json_encode(['success' => false, 'error' => 'Niet geautoriseerd.']);
    exit;
}

try {
    $db = getDbConnection();
    
    // Validate input
    $date = $_GET['date'] ?? null;
    $channel = $_GET['channel'] ?? null;
    $templateId = $_GET['template_id'] ?? null;
    
    if (!$date || !$channel || !$templateId) {
        jsonResponse(['success' => false, 'error' => 'Missing parameters'], 400);
    }
    
    if (!isValidDate($date)) {
        jsonResponse(['success' => false, 'error' => 'Invalid date format'], 400);
    }
    
    // Ensure blocks exist for this date
    ensureDailyBlocks($db, $date, $date);
    
    // Get the template name from the target template
    $stmt = $db->prepare("SELECT name FROM block_templates WHERE id = ?");
    $stmt->execute([$templateId]);
    $targetTemplateName = $stmt->fetchColumn();
    
    if (!$targetTemplateName) {
        jsonResponse(['success' => false, 'error' => 'Target template not found'], 404);
    }
    
    // Get blocks for this date and channel with matching template NAME (not ID)
    // This allows copying between different template IDs that have the same name
    $stmt = $db->prepare("
        SELECT
            db.*,
            bt.name as template_name,
            COUNT(t.id) as transmission_count
        FROM daily_blocks db
        LEFT JOIN block_templates bt ON db.template_id = bt.id
        LEFT JOIN transmissions t ON t.start_date = db.block_date
            AND t.channel = db.channel
            AND t.start_time >= db.actual_start_time
            AND t.start_time < COALESCE(db.actual_end_time, '23:59:59')
        WHERE db.block_date = ?
        AND db.channel = ?
        AND bt.name = ?
        GROUP BY db.id
        ORDER BY db.actual_start_time
    ");
    $stmt->execute([$date, $channel, $targetTemplateName]);
    $blocks = $stmt->fetchAll();
    
    jsonResponse([
        'success' => true,
        'blocks' => $blocks
    ]);
    
} catch (Exception $e) {
    jsonResponse(['success' => false, 'error' => $e->getMessage()], 500);
}