<?php
/**
 * API Endpoint: Insert Transmission at Position
 * Inserts a transmission at a specific position in the block
 */

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

use Dotenv\Dotenv;

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

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

try {
    $db = getDbConnection();
    
    // Get POST data
    $input = json_decode(file_get_contents('php://input'), true);
    
    if (!$input) {
        $input = $_POST;
    }
    
    // Validate required fields
    $required = ['infomercial_id', 'channel', 'date', 'block_id', 'position'];
    foreach ($required as $field) {
        if (!isset($input[$field])) {
            jsonResponse([
                'success' => false,
                'error' => "Missing required field: $field"
            ], 400);
        }
    }
    
    // Get infomercial duration
    $stmt = $db->prepare("SELECT duration FROM infomercials WHERE id = ?");
    $stmt->execute([$input['infomercial_id']]);
    $duration = $stmt->fetchColumn();
    
    if (!$duration) {
        jsonResponse([
            'success' => false,
            'error' => 'Infomercial not found'
        ], 404);
    }
    
    // Get block start and end time
    $stmt = $db->prepare("SELECT actual_start_time, actual_end_time FROM daily_blocks WHERE id = ?");
    $stmt->execute([$input['block_id']]);
    $blockInfo = $stmt->fetch();
    $blockStartTime = $blockInfo['actual_start_time'];
    $blockEndTime = $blockInfo['actual_end_time'] ?? '23:59:59';
    
    // Get all transmissions in THIS SPECIFIC block only
    $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 = ?
        AND t.start_time >= ? AND t.start_time < ?
        ORDER BY t.start_time ASC
    ");
    $stmt->execute([$input['date'], $input['channel'], $blockStartTime, $blockEndTime]);
    $transmissions = $stmt->fetchAll();
    
    // Insert new transmission at position
    $position = (int)$input['position'];
    
    // Create temporary transmission entry
    $newTransmission = [
        'infomercial_id' => $input['infomercial_id'],
        'duration' => $duration
    ];
    
    // Insert at position
    array_splice($transmissions, $position, 0, [$newTransmission]);
    
    // Recalculate all start times
    $currentTime = $blockStartTime;
    
    foreach ($transmissions as $index => $tx) {
        if ($index === $position) {
            // Insert new transmission
            $stmt = $db->prepare("
                INSERT INTO transmissions 
                (infomercial_id, channel, template, start_date, start_time, duration, api_status) 
                VALUES (?, ?, 'HOME030', ?, ?, ?, 'pending')
            ");
            $stmt->execute([
                $input['infomercial_id'],
                $input['channel'],
                $input['date'],
                $currentTime,
                $duration
            ]);
        } else {
            // Update existing transmission
            $stmt = $db->prepare("UPDATE transmissions SET start_time = ?, api_status = 'pending' WHERE id = ?");
            $stmt->execute([$currentTime, $tx['id']]);
        }
        
        $currentTime = addTimeToTime($currentTime, $tx['duration']);
    }
    
    jsonResponse([
        'success' => true,
        'message' => 'Transmission inserted successfully'
    ]);
    
} catch (Exception $e) {
    jsonResponse([
        'success' => false,
        'error' => $e->getMessage()
    ], 500);
}