<?php
/**
 * API Endpoint: Create Transmission
 * Creates a new transmission (planning entry)
 */

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 for write operations
if (!canCreate()) {
    http_response_code(403);
    echo json_encode(['success' => false, 'error' => 'Geen toegang. Alleen admins kunnen uitzendingen aanmaken.']);
    exit;
}

try {
    $db = getDbConnection();
    
    // Get POST data
    $input = json_decode(file_get_contents('php://input'), true);
    
    if (!$input) {
        $input = $_POST;
    }
    
    // Validate required fields
    $required = ['infomercial_id', 'channel', 'start_date', 'start_time'];
    foreach ($required as $field) {
        if (empty($input[$field])) {
            jsonResponse([
                'success' => false,
                'error' => "Missing required field: $field"
            ], 400);
        }
    }
    
    // Validate date and time formats
    if (!isValidDate($input['start_date'])) {
        jsonResponse([
            'success' => false,
            'error' => 'Invalid date format'
        ], 400);
    }
    
    if (!isValidTime($input['start_time'])) {
        jsonResponse([
            'success' => false,
            'error' => 'Invalid time format'
        ], 400);
    }
    
    // Get infomercial details (duration)
    $stmt = $db->prepare("SELECT duration, title FROM infomercials WHERE id = ?");
    $stmt->execute([$input['infomercial_id']]);
    $infomercial = $stmt->fetch();
    
    if (!$infomercial) {
        jsonResponse([
            'success' => false,
            'error' => 'Infomercial not found'
        ], 404);
    }
    
    // Get template from input or use default
    $template = $input['template'] ?? 'HOME030';
    
    // Calculate end time
    $endTime = addTimeToTime($input['start_time'], $infomercial['duration']);
    
    // Validate that transmission falls within a block (inline to avoid curl issues)
    ensureDailyBlocks($db, $input['start_date'], $input['start_date']);
    
    $stmt = $db->prepare("
        SELECT * FROM daily_blocks
        WHERE block_date = ? AND channel = ?
        ORDER BY actual_start_time
    ");
    $stmt->execute([$input['start_date'], $input['channel']]);
    $blocks = $stmt->fetchAll();
    
    $withinBlock = false;
    foreach ($blocks as $block) {
        $blockStart = $block['actual_start_time'];
        $blockEnd = $block['actual_end_time'] ?? '23:59:59';
        
        // Handle overnight blocks
        $isOvernight = $blockEnd < $blockStart;
        
        if ($isOvernight) {
            if ($input['start_time'] >= $blockStart || $input['start_time'] < $blockEnd) {
                if ($endTime <= $blockEnd || $endTime >= $blockStart) {
                    $withinBlock = true;
                    break;
                }
            }
        } else {
            if ($input['start_time'] >= $blockStart && $endTime <= $blockEnd) {
                $withinBlock = true;
                break;
            }
        }
    }
    
    if (!$withinBlock) {
        $errorMessage = "Uitzending valt buiten blok tijden. ";
        if (!empty($blocks)) {
            $errorMessage .= "Beschikbare blokken: ";
            foreach ($blocks as $block) {
                $blockStart = substr($block['actual_start_time'], 0, 5);
                $blockEnd = $block['actual_end_time'] ? substr($block['actual_end_time'], 0, 5) : '∞';
                $errorMessage .= "{$blockStart}-{$blockEnd}, ";
            }
            $errorMessage = rtrim($errorMessage, ', ');
        }
        
        jsonResponse([
            'success' => false,
            'error' => $errorMessage,
            'attempted_time' => $input['start_time'] . ' - ' . $endTime
        ], 400);
    }
    
    // Check for overlapping transmissions
    
    $stmt = $db->prepare("
        SELECT t.id, t.start_time, t.duration, c.title
        FROM transmissions t
        JOIN infomercials c ON t.infomercial_id = c.id
        WHERE t.start_date = ? 
        AND t.channel = ?
        AND t.id != ?
    ");
    $stmt->execute([
        $input['start_date'],
        $input['channel'],
        $input['id'] ?? 0
    ]);
    $existing = $stmt->fetchAll();
    
    foreach ($existing as $tx) {
        $txEnd = addTimeToTime($tx['start_time'], $tx['duration']);
        if (timeRangesOverlap($input['start_time'], $endTime, $tx['start_time'], $txEnd)) {
            jsonResponse([
                'success' => false,
                'error' => "Overlap detected with: {$tx['title']} ({$tx['start_time']} - {$txEnd})",
                'overlap' => true
            ], 409);
        }
    }
    
    // Insert transmission
    $stmt = $db->prepare("
        INSERT INTO transmissions 
        (infomercial_id, channel, template, start_date, start_time, duration, api_status) 
        VALUES (?, ?, ?, ?, ?, ?, 'pending')
    ");
    
    $stmt->execute([
        $input['infomercial_id'],
        $input['channel'],
        $template,
        $input['start_date'],
        $input['start_time'],
        $infomercial['duration']
    ]);
    
    $transmissionId = $db->lastInsertId();
    
    // Get the created transmission with all details
    $stmt = $db->prepare("
        SELECT 
            t.*,
            c.title,
            c.color_code,
            c.series_code
        FROM transmissions t
        JOIN infomercials c ON t.infomercial_id = c.id
        WHERE t.id = ?
    ");
    $stmt->execute([$transmissionId]);
    $transmission = $stmt->fetch();
    
    jsonResponse([
        'success' => true,
        'message' => 'Transmission created successfully',
        'transmission' => $transmission
    ]);
    
} catch (Exception $e) {
    jsonResponse([
        'success' => false,
        'error' => $e->getMessage()
    ], 500);
}