<?php
/**
 * API Endpoint: Copy Block
 * Copies a block (block times + transmissions) from source block to target 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 blokken kopiëren.']);
    exit;
}

try {
    $db = getDbConnection();
    
    // Get POST data
    $input = json_decode(file_get_contents('php://input'), true);
    
    $sourceBlockId = $input['source_block_id'] ?? null;
    $targetBlockId = $input['target_block_id'] ?? null;
    $targetDate = $input['target_date'] ?? null;
    
    // Validate input
    if (!$sourceBlockId || !$targetBlockId || !$targetDate) {
        jsonResponse(['success' => false, 'error' => 'Missing required parameters'], 400);
    }
    
    if (!isValidDate($targetDate)) {
        jsonResponse(['success' => false, 'error' => 'Invalid target date format'], 400);
    }
    
    // Start transaction
    $db->beginTransaction();
    
    try {
        // Get source block info
        $stmt = $db->prepare("
            SELECT * FROM daily_blocks WHERE id = ?
        ");
        $stmt->execute([$sourceBlockId]);
        $sourceBlock = $stmt->fetch();
        
        if (!$sourceBlock) {
            throw new Exception('Source block not found');
        }
        
        // Get target block info
        $stmt = $db->prepare("
            SELECT * FROM daily_blocks WHERE id = ?
        ");
        $stmt->execute([$targetBlockId]);
        $targetBlock = $stmt->fetch();
        
        if (!$targetBlock) {
            throw new Exception('Target block not found');
        }
        
        // Validate that blocks are compatible (same channel)
        if ($sourceBlock['channel'] !== $targetBlock['channel']) {
            throw new Exception('Source and target blocks must be on the same channel');
        }
        
        // Get template names to compare (allows copying between different template IDs with same name)
        $stmt = $db->prepare("SELECT name FROM block_templates WHERE id = ?");
        $stmt->execute([$sourceBlock['template_id']]);
        $sourceTemplateName = $stmt->fetchColumn();
        
        $stmt = $db->prepare("SELECT name FROM block_templates WHERE id = ?");
        $stmt->execute([$targetBlock['template_id']]);
        $targetTemplateName = $stmt->fetchColumn();
        
        if ($sourceTemplateName !== $targetTemplateName) {
            throw new Exception('Source and target blocks must have the same template name');
        }
        
        // Step 1: Update target block times
        $stmt = $db->prepare("
            UPDATE daily_blocks
            SET actual_start_time = ?,
                actual_end_time = ?
            WHERE id = ?
        ");
        $stmt->execute([
            $sourceBlock['actual_start_time'],
            $sourceBlock['actual_end_time'],
            $targetBlockId
        ]);
        
        // Step 2: Delete existing transmissions in target block
        // Use the OLD target block times to find transmissions to delete
        $stmt = $db->prepare("
            DELETE FROM transmissions
            WHERE start_date = ?
            AND channel = ?
            AND start_time >= ?
            AND start_time < ?
        ");
        $stmt->execute([
            $targetDate,
            $targetBlock['channel'],
            $targetBlock['actual_start_time'],
            $targetBlock['actual_end_time'] ?? '23:59:59'
        ]);
        $deletedCount = $stmt->rowCount();
        
        // Step 3: Get source transmissions
        $stmt = $db->prepare("
            SELECT t.*, 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([
            $sourceBlock['block_date'],
            $sourceBlock['channel'],
            $sourceBlock['actual_start_time'],
            $sourceBlock['actual_end_time'] ?? '23:59:59'
        ]);
        $sourceTransmissions = $stmt->fetchAll();
        
        // Step 4: Copy transmissions to target block
        $copiedCount = 0;
        $insertStmt = $db->prepare("
            INSERT INTO transmissions
            (infomercial_id, channel, template, start_date, start_time, duration, api_status)
            VALUES (?, ?, ?, ?, ?, ?, 'pending')
        ");
        
        foreach ($sourceTransmissions as $tx) {
            $insertStmt->execute([
                $tx['infomercial_id'],
                $tx['channel'],
                $tx['template'],
                $targetDate,  // Use target date
                $tx['start_time'],
                $tx['duration'],
            ]);
            $copiedCount++;
        }
        
        // Commit transaction
        $db->commit();
        
        jsonResponse([
            'success' => true,
            'message' => 'Block copied successfully',
            'copied_count' => $copiedCount,
            'deleted_count' => $deletedCount,
            'block_times_updated' => true
        ]);
        
    } catch (Exception $e) {
        $db->rollBack();
        throw $e;
    }
    
} catch (Exception $e) {
    jsonResponse([
        'success' => false,
        'error' => $e->getMessage()
    ], 500);
}