How to Retrieve a List of Tasks from Deals

require_once('crest.php');
        
        $result = CRest::call(
            'user.current',
            []
        );
        

require_once('crest.php');
        
        $result = CRest::call(
            'crm.item.list',
            [
                'entityTypeId' => 2,
                'select' => ['id','title'],
                'filter' => [
                    'assignedById' => 29
                ]
            ]
        );
        

require_once('crest.php');
        
        $result = CRest::call(
            'crm.activity.list',
            [
                'filter' => [
                    'BINDINGS' => [
                        ['OWNER_TYPE_ID' => 2, 'OWNER_ID' => 5111],
                        ['OWNER_TYPE_ID' => 2, 'OWNER_ID' => 5199],
                        ['OWNER_TYPE_ID' => 2, 'OWNER_ID' => 5257]
                    ],
                    'COMPLETED' => 'N'
                ],
                'select' => ['ID', 'OWNER_ID', 'SUBJECT', 'DEADLINE', 'RESPONSIBLE_ID']
            ]
        );
        

require_once('crest.php');
        
        $result = CRest::call(
            'user.get',
            [
                'filter' => [
                    'ID' => [29, 47, ...]
                ]
            }
        );
        

<?php
        
        require_once('crest.php');
        
        // Function to build an array of bindings to deals
        // OWNER_TYPE_ID: 2 — CRM object type — deal
        function buildBindingsFromDealIds($dealIds) {
            $bindings = [];
            foreach ($dealIds as $id) {
                $bindings[] = [
                    'OWNER_TYPE_ID' => 2,
                    'OWNER_ID' => (int)$id,
                ];
            }
            return $bindings;
        }
        
        // Function to retrieve all items using pagination
        // Necessary for list methods, as one request retrieves a maximum of 50 records
        function fetchAllItems($method, $params) {
            $allResults = [];
            
            $start = 0;
            $batchSize = 50;
            
            do {
                $params['start'] = $start;
                $result = CRest::call($method, $params);
                
                if (!empty($result['error'])) {
                    return ['error' => $result['error'], 'error_description' => $result['error_description']];
                }
                
                $data = $result['result'] ?? [];
                
                // Process results based on the method
                if ($method === 'crm.item.list') {
                    if (!empty($data['items']) && is_array($data['items'])) {
                        $allResults = array_merge($allResults, $data['items']);
                    }
                } elseif ($method === 'crm.activity.list') {
                    if (is_array($data)) {
                        $allResults = array_merge($allResults, $data);
                    }
                } else {
                    if (is_array($data)) {
                        $allResults = array_merge($allResults, $data);
                    }
                }
                
                // Check if there are more data
                if (count($data) >= $batchSize) {
                    $start += $batchSize;
                } else {
                    break;
                }
                
            } while (true);
            
            return ['result' => $allResults];
        }
        
        // Step 1: Retrieve information about the current user
        $userResult = CRest::call('user.current', []);
        
        if (!empty($userResult['error'])) {
            echo 'Error retrieving user: ' . $userResult['error_description'] . "\n";
            exit;
        }
        
        $current = $userResult['result'] ?? null;
        if (!$current || empty($current['ID'])) {
            echo "Failed to retrieve the current user\n";
            exit;
        }
        
        $userId = (int)$current['ID'];
        echo "Current user ID: $userId\n";
        
        // Step 2: Retrieve the list of all deals
        $itemsResult = fetchAllItems('crm.item.list', [
            'entityTypeId' => 2,
            'select' => ['id', 'title'],
            'filter' => ['assignedById' => $userId]
        ]);
        
        if (isset($itemsResult['error'])) {
            echo 'Error retrieving all deals: ' . $itemsResult['error_description'] . "\n";
            exit;
        }
        
        $allItems = $itemsResult['result'];
        
        $dealMap = [];
        $dealIds = [];
        foreach ($allItems as $item) {
            $id = (int)$item['id'];
            $dealIds[] = $id;
            $dealMap[$id] = $item['title'];
        }
        
        echo "Deals found: " . count($dealIds) . "\n";
        
        if (empty($dealIds)) {
            echo "The employee has no deals\n";
            exit;
        }
        
        // Build bindings to search for tasks by deals
        $bindings = buildBindingsFromDealIds($dealIds);
        
        // Step 3: Retrieve all tasks linked to these deals
        $activitiesResult = fetchAllItems('crm.activity.list', [
            'filter' => [
                'BINDINGS' => $bindings,
                'COMPLETED' => 'N',
            ],
            'select' => ['ID', 'OWNER_ID', 'SUBJECT', 'DEADLINE', 'RESPONSIBLE_ID']
        ]);
        
        if (isset($activitiesResult['error'])) {
            echo 'Error retrieving all tasks: ' . $activitiesResult['error_description'] . "\n";
            exit;
        }
        
        $allActivities = $activitiesResult['result'];
        
        if (empty($allActivities)) {
            echo "No incomplete tasks for the deals.\n";
            echo implode("\t", ['Task ID', 'Deal', 'Subject', 'Deadline', 'Responsible']) . "\n";
            exit;
        }
        
        // Collect unique responsible IDs
        $responsibleIds = array_unique(array_column($allActivities, 'RESPONSIBLE_ID'));
        $userMap = [];
        
        if (!empty($responsibleIds)) {
            // Step 4: Retrieve user data
            $usersResult = fetchAllItems('user.get', [
                'filter' => ['ID' => array_values($responsibleIds)]
            ]);
        
            if (isset($usersResult['error'])) {
                echo 'Error retrieving users: ' . $usersResult['error_description'] . "\n";
                $userMap = [];
            } else {
                foreach ($usersResult['result'] as $user) {
                    $fullName = trim(($user['NAME'] ?? '') . ' ' . ($user['LAST_NAME'] ?? ''));
                    $userMap[$user['ID']] = $fullName ?: ($user['LOGIN'] ?? "User {$user['ID']}");
                }
            }
        }
        
        // Build and display the table
        $header = ['Task ID', 'Deal', 'Subject', 'Deadline', 'Responsible'];
        echo implode("\t", $header) . "\n";
        
        foreach ($allActivities as $a) {
            $activityId = $a['ID'] ?? '';
            $ownerId = (int)($a['OWNER_ID'] ?? 0);
            $dealTitle = $dealMap[$ownerId] ?? "Deal #{$ownerId}";
            $subject = $a['SUBJECT'] ?? '';
            $deadline = $a['DEADLINE'] ?? '';
            $responsibleId = $a['RESPONSIBLE_ID'] ?? '';
            $responsibleName = $userMap[$responsibleId] ?? "User {$responsibleId} (not found)";
        
            echo implode("\t", [
                $activityId,
                $dealTitle,
                $subject,
                $deadline,
                $responsibleName
            ]) . "\n";
        }