<?php
/**
 * API Endpoint: Update Block Time
 * Updates the start time for a daily block
 */

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');

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

// Authorization check - admin only
if (!canEdit()) {
    http_response_code(403);
    echo json_encode(['success' => false, 'error' => 'Geen toegang. Alleen admins kunnen bloktijden bijwerken.']);
    exit;
}

try {
    $db = getDbConnection();
    
    // Get POST data
    $input = json_decode(file_get_contents('php://input'), true);
    
    if (!$input) {
        $input = $_POST;
    }
    
    // Validate required fields
    $required = ['date', 'channel', 'start_time'];
    foreach ($required as $field) {
        if (empty($input[$field])) {
            jsonResponse([
                'success' => false,
                'error' => "Missing required field: $field"
            ], 400);
        }
    }
    
    // Validate formats
    if (!isValidDate($input['date'])) {
        jsonResponse([
            'success' => false,
            'error' => 'Invalid date format'
        ], 400);
    }
    
    if (!isValidTime($input['start_time'])) {
        jsonResponse([
            'success' => false,
            'error' => 'Invalid time format'
        ], 400);
    }
    
    // Get template_id if provided, or find matching template
    $templateId = $input['template_id'] ?? null;
    
    if (!$templateId) {
        // Try to find matching template
        $dayOfWeek = ['zo', 'ma', 'di', 'wo', 'do', 'vr', 'za'][date('w', strtotime($input['date']))];
        $stmt = $db->prepare("
            SELECT id FROM block_templates
            WHERE channel = ?
            AND (day_of_week = ? OR day_of_week = 'all')
            AND is_active = 1
            ORDER BY day_of_week DESC
            LIMIT 1
        ");
        $stmt->execute([$input['channel'], $dayOfWeek]);
        $templateId = $stmt->fetchColumn();
    }
    
    // Check if daily block exists for this template
    $stmt = $db->prepare("
        SELECT id FROM daily_blocks
        WHERE block_date = ? AND channel = ? AND template_id = ?
    ");
    $stmt->execute([$input['date'], $input['channel'], $templateId]);
    $block = $stmt->fetch();
    
    if ($block) {
        // Update existing block
        $stmt = $db->prepare("
            UPDATE daily_blocks
            SET actual_start_time = ?, updated_at = NOW()
            WHERE id = ?
        ");
        $stmt->execute([$input['start_time'], $block['id']]);
    } else {
        // Update or insert - use ON DUPLICATE KEY UPDATE
        $stmt = $db->prepare("
            INSERT INTO daily_blocks
            (template_id, channel, block_date, actual_start_time)
            VALUES (?, ?, ?, ?)
            ON DUPLICATE KEY UPDATE
            actual_start_time = VALUES(actual_start_time),
            updated_at = NOW()
        ");
        $stmt->execute([
            $templateId,
            $input['channel'],
            $input['date'],
            $input['start_time']
        ]);
    }
    
    // Optionally recalculate all transmission times in this block
    if (!empty($input['recalculate'])) {
        $stmt = $db->prepare("
            SELECT t.id, t.start_time, c.duration
            FROM transmissions t
            JOIN infomercials c ON t.infomercial_id = c.id
            WHERE t.start_date = ? AND t.channel = ?
            ORDER BY t.start_time ASC
        ");
        $stmt->execute([$input['date'], $input['channel']]);
        $transmissions = $stmt->fetchAll();
        
        $currentTime = $input['start_time'];
        
        foreach ($transmissions as $tx) {
            // Update transmission start time
            $stmt = $db->prepare("
                UPDATE transmissions 
                SET start_time = ?, api_status = 'pending'
                WHERE id = ?
            ");
            $stmt->execute([$currentTime, $tx['id']]);
            
            // Calculate next start time
            $currentTime = addTimeToTime($currentTime, $tx['duration']);
        }
    }
    
    jsonResponse([
        'success' => true,
        'message' => 'Block time updated successfully'
    ]);
    
} catch (Exception $e) {
    jsonResponse([
        'success' => false,
        'error' => $e->getMessage()
    ], 500);
}