<?php
require_once __DIR__ . '/../helpers.php';
runAuth();

/**
 * Customer initiates a chat with staff
 * POST: { BusinessID, ServicePointID?, OrderID?, UserID?, Message?, ForceNew? }
 */

$data = readJsonBody();
$businessID = (int) ($data['BusinessID'] ?? 0);
$servicePointID = (int) ($data['ServicePointID'] ?? 0);
$orderID = (int) ($data['OrderID'] ?? 0);
$initialMessage = trim($data['Message'] ?? '');
$userID = (int) ($data['UserID'] ?? 0);

if ($businessID <= 0) {
    apiAbort(['OK' => false, 'ERROR' => 'missing_params', 'MESSAGE' => 'BusinessID is required']);
}

try {
    // If servicePointID not provided but orderID is, look it up
    if ($servicePointID <= 0 && $orderID > 0) {
        $qOrderSP = queryOne("SELECT ServicePointID FROM Orders WHERE ID = ?", [$orderID]);
        if ($qOrderSP && (int) $qOrderSP['ServicePointID'] > 0) {
            $servicePointID = (int) $qOrderSP['ServicePointID'];
        }
    }

    // Look up "Chat" task type for this business
    $ttQuery = queryOne("
        SELECT ID FROM tt_TaskTypes
        WHERE BusinessID = ? AND Name LIKE '%Chat%'
        LIMIT 1
    ", [$businessID]);
    $chatTaskTypeID = $ttQuery ? (int) $ttQuery['ID'] : 0;

    // Check for existing open chat
    $forceNew = !empty($data['ForceNew']) && $data['ForceNew'] === true;

    if (!$forceNew) {
        $existingChat = queryOne("
            SELECT t.ID, t.CreatedOn,
                   (SELECT MAX(cm.CreatedOn) FROM ChatMessages cm WHERE cm.TaskID = t.ID) as LastMessageTime
            FROM Tasks t
            LEFT JOIN ChatMessages cm2 ON cm2.TaskID = t.ID AND cm2.SenderUserID = ?
            WHERE t.BusinessID = ?
              AND (t.TaskTypeID = ? OR t.Title LIKE 'Chat%')
              AND t.CompletedOn IS NULL
              AND (
                  (t.OrderID = ? AND ? > 0)
                  OR (t.SourceType = 'servicepoint' AND t.SourceID = ? AND ? > 0)
                  OR (t.SourceType = 'user' AND t.SourceID = ? AND ? > 0)
                  OR (cm2.SenderUserID = ? AND ? > 0)
              )
            ORDER BY t.CreatedOn DESC
            LIMIT 1
        ", [
            $userID, $businessID, $chatTaskTypeID,
            $orderID, $orderID,
            $servicePointID, $servicePointID,
            $userID, $userID,
            $userID, $userID,
        ]);

        if ($existingChat) {
            $lastActivity = $existingChat['LastMessageTime'];
            if (empty($lastActivity)) {
                $lastActivity = $existingChat['CreatedOn'];
            }
            $chatAge = (int) ((time() - strtotime($lastActivity)) / 60);

            if ($chatAge > 30) {
                // Auto-close stale chat
                queryTimed("UPDATE Tasks SET CompletedOn = NOW() WHERE ID = ?", [$existingChat['ID']]);
            } else {
                jsonResponse([
                    'OK' => true,
                    'TaskID' => (int) $existingChat['ID'],
                    'MESSAGE' => 'Rejoined existing chat',
                    'EXISTING' => true,
                ]);
            }
        }
    }

    // Get service point info
    $tableName = '';
    if ($servicePointID > 0) {
        $spQuery = queryOne("SELECT Name FROM ServicePoints WHERE ID = ?", [$servicePointID]);
        $tableName = $spQuery ? $spQuery['Name'] : "Table #$servicePointID";
    }

    // Get user name
    $userName = '';
    if ($userID > 0) {
        $userQuery = queryOne("SELECT FirstName FROM Users WHERE ID = ?", [$userID]);
        if ($userQuery && !empty(trim($userQuery['FirstName']))) {
            $userName = $userQuery['FirstName'];
        }
    }

    // Create task title
    if ($servicePointID > 0) {
        $taskTitle = !empty($userName)
            ? "Chat - $userName ($tableName)"
            : "Chat - $tableName";
    } else {
        $taskTitle = !empty($userName)
            ? "Chat - $userName (Remote)"
            : "Remote Chat";
    }

    $taskDetails = !empty($initialMessage) ? $initialMessage : 'Customer initiated chat';

    // Look up or create a "Chat" category
    $catQuery = queryOne("
        SELECT ID FROM TaskCategories
        WHERE BusinessID = ? AND Name = 'Chat'
        LIMIT 1
    ", [$businessID]);

    if (!$catQuery) {
        queryTimed("
            INSERT INTO TaskCategories (BusinessID, Name, Color)
            VALUES (?, 'Chat', '#2196F3')
        ", [$businessID]);
        $categoryID = (int) lastInsertId();
    } else {
        $categoryID = (int) $catQuery['ID'];
    }

    // Determine source type and ID
    $sourceType = $servicePointID > 0 ? 'servicepoint' : 'user';
    $sourceID = $servicePointID > 0 ? $servicePointID : $userID;

    // Insert task
    queryTimed("
        INSERT INTO Tasks (
            BusinessID, CategoryID, OrderID, TaskTypeID,
            Title, Details, ClaimedByUserID, SourceType, SourceID, CreatedOn
        ) VALUES (?, ?, ?, ?, ?, ?, 0, ?, ?, NOW())
    ", [
        $businessID,
        $categoryID,
        $orderID > 0 ? $orderID : null,
        $chatTaskTypeID > 0 ? $chatTaskTypeID : null,
        $taskTitle,
        $taskDetails,
        $sourceType,
        $sourceID,
    ]);

    $taskID = (int) lastInsertId();

    // If there's an initial message, save it
    if (!empty($initialMessage) && $userID > 0) {
        queryTimed("
            INSERT INTO ChatMessages (TaskID, SenderUserID, SenderType, MessageBody)
            VALUES (?, ?, 'customer', ?)
        ", [$taskID, $userID, $initialMessage]);
    }

    jsonResponse([
        'OK' => true,
        'TaskID' => $taskID,
        'MESSAGE' => 'Chat started',
    ]);

} catch (Exception $e) {
    jsonResponse(['OK' => false, 'ERROR' => 'server_error', 'MESSAGE' => $e->getMessage()]);
}