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

/**
 * Get Menu Items for Customer Apps
 *
 * POST body:
 * {
 *   "BusinessID": 37,
 *   "OrderTypeID": 0,   // optional: 1=Dine-In, 2=Takeaway, 3=Delivery
 *   "MenuID": 0          // optional: filter to specific menu
 * }
 */

$data = readJsonBody();
$businessID      = (int) ($data['BusinessID'] ?? 0);
$orderTypeID     = (int) ($data['OrderTypeID'] ?? 0);
$requestedMenuID = (int) ($data['MenuID'] ?? 0);

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

// Get business timezone for schedule filtering
$businessTimezone = 'America/Los_Angeles';
try {
    $qTz = queryOne("SELECT Timezone FROM Businesses WHERE ID = ?", [$businessID]);
    if ($qTz && !empty($qTz['Timezone'])) {
        $businessTimezone = $qTz['Timezone'];
    }
} catch (Exception $e) {
    // Column might not exist yet, use default
}

$currentTime = getTimeInZone($businessTimezone);
$currentDayID = getDayInZone($businessTimezone);

$menuList = [];

try {
    // Check if new schema is active (BusinessID column exists and has data)
    $newSchemaActive = false;
    try {
        $qCheck = queryOne("SELECT COUNT(*) as cnt FROM Items WHERE BusinessID = ? AND BusinessID > 0", [$businessID]);
        $newSchemaActive = $qCheck && (int) $qCheck['cnt'] > 0;
    } catch (Exception $e) {
        $newSchemaActive = false;
    }

    $rows = [];
    $qCategories = null;

    if ($newSchemaActive) {
        // Check if Categories table has data for this business
        $hasCategoriesData = false;
        try {
            $qCatCheck = queryOne("SELECT COUNT(*) as cnt FROM Categories WHERE BusinessID = ?", [$businessID]);
            $hasCategoriesData = $qCatCheck && (int) $qCatCheck['cnt'] > 0;
        } catch (Exception $e) {
            $hasCategoriesData = false;
        }

        if ($hasCategoriesData) {
            // Get active menus
            $activeMenuIds = '';
            try {
                $qAllMenus = queryTimed("
                    SELECT ID, Name FROM Menus
                    WHERE BusinessID = ? AND IsActive = 1
                    ORDER BY SortOrder, Name
                ", [$businessID]);

                if ($requestedMenuID > 0) {
                    $activeMenuIds = (string) $requestedMenuID;
                } else {
                    $ids = array_column($qAllMenus, 'ID');
                    $activeMenuIds = implode(',', $ids);
                }

                foreach ($qAllMenus as $m) {
                    $menuList[] = ['MenuID' => (int) $m['ID'], 'Name' => $m['Name']];
                }
            } catch (Exception $e) {
                // Menus table might not exist yet
            }

            // Build category query with schedule/channel/menu filtering
            $catParams = [$businessID, $orderTypeID, $orderTypeID, $currentTime, $currentTime, $currentDayID];
            $menuClause = '';
            if (strlen($activeMenuIds) > 0) {
                // Build safe IN clause for menu IDs
                $menuIdArr = array_map('intval', explode(',', $activeMenuIds));
                $menuPlaceholders = implode(',', $menuIdArr);
                $menuClause = "OR MenuID IN ($menuPlaceholders)";
            }

            $qCategories = queryTimed("
                SELECT
                    ID, Name, SortOrder, OrderTypes, ParentCategoryID,
                    ScheduleStart, ScheduleEnd, ScheduleDays, MenuID
                FROM Categories
                WHERE BusinessID = ?
                  AND (? = 0 OR FIND_IN_SET(?, OrderTypes) > 0)
                  AND (
                    ScheduleStart IS NULL
                    OR ScheduleEnd IS NULL
                    OR (TIME(?) >= ScheduleStart AND TIME(?) <= ScheduleEnd)
                  )
                  AND (
                    ScheduleDays IS NULL
                    OR ScheduleDays = ''
                    OR FIND_IN_SET(?, ScheduleDays) > 0
                  )
                  AND (
                    MenuID IS NULL
                    OR MenuID = 0
                    $menuClause
                  )
                ORDER BY SortOrder
            ", $catParams);

            // Get visible category IDs
            $visibleCategoryIds = array_column($qCategories, 'ID');
            $visibleStr = count($visibleCategoryIds) > 0
                ? implode(',', array_map('intval', $visibleCategoryIds))
                : '0';

            // Get menu items for visible categories
            $q = queryTimed("
                SELECT
                    i.ID,
                    i.CategoryID,
                    c.Name AS CategoryName,
                    i.Name AS ItemName,
                    i.Description,
                    i.ParentItemID,
                    i.Price,
                    i.IsActive,
                    i.IsCheckedByDefault,
                    i.RequiresChildSelection,
                    i.MaxNumSelectionReq,
                    i.IsCollapsible,
                    i.SortOrder,
                    i.StationID,
                    s.Name AS StationName,
                    s.Color,
                    c.MenuID
                FROM Items i
                LEFT JOIN Categories c ON c.ID = i.CategoryID
                LEFT JOIN Stations s ON s.ID = i.StationID
                WHERE i.BusinessID = ?
                  AND i.IsActive = 1
                  AND (i.CategoryID IN ($visibleStr) OR (i.CategoryID = 0 AND i.ParentItemID > 0))
                  AND NOT EXISTS (SELECT 1 FROM lt_ItemID_TemplateItemID tl WHERE tl.TemplateItemID = i.ID)
                  AND NOT EXISTS (SELECT 1 FROM lt_ItemID_TemplateItemID tl2 WHERE tl2.TemplateItemID = i.ParentItemID)
                  AND NOT (i.ParentItemID = 0 AND i.CategoryID = 0 AND i.Price = 0)
                ORDER BY COALESCE(c.SortOrder, 999), i.SortOrder, i.ID
            ", [$businessID]);

        } else {
            // Fallback: Derive categories from parent Items
            $q = queryTimed("
                SELECT
                    i.ID,
                    CASE
                      WHEN i.ParentItemID = 0 AND i.IsCollapsible = 0 THEN i.ID
                      ELSE COALESCE(
                        (SELECT cat.ID FROM Items cat
                         WHERE cat.ID = i.ParentItemID
                           AND cat.ParentItemID = 0
                           AND cat.IsCollapsible = 0),
                        0
                      )
                    END as CategoryID,
                    CASE
                      WHEN i.ParentItemID = 0 AND i.IsCollapsible = 0 THEN i.Name
                      ELSE COALESCE(
                        (SELECT cat.Name FROM Items cat
                         WHERE cat.ID = i.ParentItemID
                           AND cat.ParentItemID = 0
                           AND cat.IsCollapsible = 0),
                        ''
                      )
                    END as CategoryName,
                    i.Name AS ItemName,
                    i.Description,
                    i.ParentItemID,
                    i.Price,
                    i.IsActive,
                    i.IsCheckedByDefault,
                    i.RequiresChildSelection,
                    i.MaxNumSelectionReq,
                    i.IsCollapsible,
                    i.SortOrder,
                    i.StationID,
                    s.Name AS StationName,
                    s.Color
                FROM Items i
                LEFT JOIN Stations s ON s.ID = i.StationID
                WHERE i.BusinessID = ?
                  AND i.IsActive = 1
                  AND NOT EXISTS (SELECT 1 FROM lt_ItemID_TemplateItemID tl WHERE tl.TemplateItemID = i.ID)
                  AND NOT EXISTS (SELECT 1 FROM lt_ItemID_TemplateItemID tl2 WHERE tl2.TemplateItemID = i.ParentItemID)
                  AND (
                    i.ParentItemID > 0
                    OR (i.ParentItemID = 0 AND i.IsCollapsible = 0)
                  )
                ORDER BY i.ParentItemID, i.SortOrder, i.ID
            ", [$businessID]);
        }
    } else {
        // OLD SCHEMA: Use Categories table
        $q = queryTimed("
            SELECT
                i.ID,
                i.CategoryID,
                c.Name AS CategoryName,
                i.Name AS ItemName,
                i.Description,
                i.ParentItemID,
                i.Price,
                i.IsActive,
                i.IsCheckedByDefault,
                i.RequiresChildSelection,
                i.MaxNumSelectionReq,
                i.IsCollapsible,
                i.SortOrder,
                i.StationID,
                s.Name AS StationName,
                s.Color
            FROM Items i
            INNER JOIN Categories c ON c.ID = i.CategoryID
            LEFT JOIN Stations s ON s.ID = i.StationID
            WHERE c.BusinessID = ?
            ORDER BY i.ParentItemID, i.SortOrder, i.ID
        ", [$businessID]);
    }

    // Build set of category IDs that have items
    $categoriesWithItems = [];
    foreach ($q as $row) {
        if ((int) $row['CategoryID'] > 0) {
            $categoriesWithItems[(int) $row['CategoryID']] = true;
        }
    }

    // Build category ID set for parent remapping
    $categoryIdSet = [];
    if ($qCategories !== null) {
        // Mark parent categories of subcategories that have items
        foreach ($qCategories as $cat) {
            if ((int) ($cat['ParentCategoryID'] ?? 0) > 0 && isset($categoriesWithItems[(int) $cat['ID']])) {
                $categoriesWithItems[(int) $cat['ParentCategoryID']] = true;
            }
        }
        foreach ($qCategories as $cat) {
            $categoryIdSet[(int) $cat['ID']] = true;
        }

        // Add category headers as virtual parent items
        foreach ($qCategories as $cat) {
            if (isset($categoriesWithItems[(int) $cat['ID']])) {
                $rows[] = [
                    'ItemID'               => (int) $cat['ID'],
                    'CategoryID'           => (int) $cat['ID'],
                    'Name'                 => $cat['Name'],
                    'Description'          => '',
                    'ParentItemID'         => 0,
                    'ParentCategoryID'     => (int) ($cat['ParentCategoryID'] ?? 0),
                    'Price'                => 0,
                    'IsActive'             => 1,
                    'IsCheckedByDefault'   => 0,
                    'RequiresChildSelection' => 0,
                    'MaxNumSelectionReq'   => 0,
                    'IsCollapsible'        => 0,
                    'SortOrder'            => (int) $cat['SortOrder'],
                    'MenuID'               => (int) ($cat['MenuID'] ?? 0),
                    'StationID'            => '',
                    'ItemName'             => '',
                    'ItemColor'            => '',
                ];
            }
        }
    }

    // Process items
    foreach ($q as $row) {
        $effectiveParentID = (int) $row['ParentItemID'];

        if ($newSchemaActive && $qCategories !== null && (int) $row['CategoryID'] > 0) {
            if ($effectiveParentID === 0) {
                $effectiveParentID = (int) $row['CategoryID'];
            } elseif (isset($categoryIdSet[$effectiveParentID])) {
                // Parent IS a category ID — correct
            } elseif (!isset($categoryIdSet[$effectiveParentID])) {
                $effectiveParentID = (int) $row['CategoryID'];
            }
        }

        $itemMenuID = (int) ($row['MenuID'] ?? 0);
        $itemName = $row['ItemName'] ?? $row['Name'] ?? '';
        $catName  = $row['CategoryName'] ?? $row['Name'] ?? '';

        $rows[] = [
            'ItemID'               => (int) $row['ID'],
            'CategoryID'           => (int) $row['CategoryID'],
            'Name'                 => strlen(trim($itemName)) > 0 ? $itemName : $catName,
            'Description'          => $row['Description'] ?? '',
            'ParentItemID'         => $effectiveParentID,
            'Price'                => $row['Price'],
            'IsActive'             => (int) $row['IsActive'],
            'IsCheckedByDefault'   => (int) $row['IsCheckedByDefault'],
            'RequiresChildSelection' => (int) $row['RequiresChildSelection'],
            'MaxNumSelectionReq'   => (int) $row['MaxNumSelectionReq'],
            'IsCollapsible'        => (int) $row['IsCollapsible'],
            'SortOrder'            => (int) $row['SortOrder'],
            'MenuID'               => $itemMenuID,
            'StationID'            => !empty($row['StationID']) ? $row['StationID'] : '',
            'ItemName'             => strlen(trim($catName)) > 0 ? $catName : '',
            'ItemColor'            => !empty($row['Color']) ? $row['Color'] : '',
        ];
    }

    // Add template-linked modifiers as virtual children (unified schema only)
    if ($newSchemaActive) {
        $qTemplateLinks = queryTimed("
            SELECT
                tl.ItemID as MenuItemID,
                tmpl.ID as TemplateItemID,
                tmpl.Name as TemplateName,
                tmpl.Description as TemplateDescription,
                tmpl.RequiresChildSelection as TemplateRequired,
                tmpl.MaxNumSelectionReq as TemplateMaxSelections,
                tmpl.IsCollapsible as TemplateIsCollapsible,
                tl.SortOrder as TemplateSortOrder
            FROM lt_ItemID_TemplateItemID tl
            INNER JOIN Items tmpl ON tmpl.ID = tl.TemplateItemID AND tmpl.IsActive = 1
            INNER JOIN Items menuItem ON menuItem.ID = tl.ItemID
            WHERE menuItem.BusinessID = ?
              AND menuItem.IsActive = 1
            ORDER BY tl.ItemID, tl.SortOrder
        ", [$businessID]);

        $qTemplateOptions = queryTimed("
            SELECT DISTINCT
                opt.ID as OptionItemID,
                opt.ParentItemID as TemplateItemID,
                opt.Name as OptionName,
                opt.Description as OptionDescription,
                opt.Price as OptionPrice,
                opt.IsCheckedByDefault as OptionIsDefault,
                opt.SortOrder as OptionSortOrder
            FROM Items opt
            INNER JOIN lt_ItemID_TemplateItemID tl ON tl.TemplateItemID = opt.ParentItemID
            INNER JOIN Items menuItem ON menuItem.ID = tl.ItemID
            WHERE menuItem.BusinessID = ?
              AND menuItem.IsActive = 1
              AND opt.IsActive = 1
            ORDER BY opt.ParentItemID, opt.SortOrder
        ", [$businessID]);

        // Build template options map: templateID -> [options]
        $templateOptionsMap = [];
        foreach ($qTemplateOptions as $opt) {
            $tid = (int) $opt['TemplateItemID'];
            $templateOptionsMap[$tid][] = [
                'ItemID'             => (int) $opt['OptionItemID'],
                'Name'               => $opt['OptionName'],
                'Description'        => $opt['OptionDescription'] ?? '',
                'Price'              => $opt['OptionPrice'],
                'IsCheckedByDefault' => (int) $opt['OptionIsDefault'],
                'SortOrder'          => (int) $opt['OptionSortOrder'],
            ];
        }

        // Add templates and options as virtual children
        $addedTemplates = [];
        foreach ($qTemplateLinks as $link) {
            $menuItemID = (int) $link['MenuItemID'];
            $templateID = (int) $link['TemplateItemID'];
            $linkKey = "{$menuItemID}_{$templateID}";

            if (isset($addedTemplates[$linkKey])) continue;
            $addedTemplates[$linkKey] = true;

            $virtualTemplateID = $menuItemID * 100000 + $templateID;

            // Template as modifier group
            $rows[] = [
                'ItemID'               => $virtualTemplateID,
                'CategoryID'           => 0,
                'Name'                 => $link['TemplateName'],
                'Description'          => $link['TemplateDescription'] ?? '',
                'ParentItemID'         => $menuItemID,
                'Price'                => 0,
                'IsActive'             => 1,
                'IsCheckedByDefault'   => 0,
                'RequiresChildSelection' => (int) $link['TemplateRequired'],
                'MaxNumSelectionReq'   => (int) $link['TemplateMaxSelections'],
                'IsCollapsible'        => (int) $link['TemplateIsCollapsible'],
                'SortOrder'            => (int) $link['TemplateSortOrder'],
                'StationID'            => '',
                'ItemName'             => '',
                'ItemColor'            => '',
            ];

            // Template options
            if (isset($templateOptionsMap[$templateID])) {
                foreach ($templateOptionsMap[$templateID] as $opt) {
                    $virtualOptionID = $menuItemID * 100000 + $opt['ItemID'];
                    $rows[] = [
                        'ItemID'               => $virtualOptionID,
                        'CategoryID'           => 0,
                        'Name'                 => $opt['Name'],
                        'Description'          => $opt['Description'],
                        'ParentItemID'         => $virtualTemplateID,
                        'Price'                => $opt['Price'],
                        'IsActive'             => 1,
                        'IsCheckedByDefault'   => $opt['IsCheckedByDefault'],
                        'RequiresChildSelection' => 0,
                        'MaxNumSelectionReq'   => 0,
                        'IsCollapsible'        => 0,
                        'SortOrder'            => $opt['SortOrder'],
                        'StationID'            => '',
                        'ItemName'             => '',
                        'ItemColor'            => '',
                    ];
                }
            }
        }
    }

    // Get brand color, tax rate, payfrit fee, header image
    $qBrand = queryOne("
        SELECT BrandColor, BrandColorLight, TaxRate, PayfritFee,
               HeaderImageExtension, SessionEnabled, OrderTypes
        FROM Businesses WHERE ID = ?
    ", [$businessID]);

    if (!$qBrand) {
        apiAbort(['OK' => false, 'ERROR' => 'business_not_found']);
    }

    if (!is_numeric($qBrand['TaxRate'])) {
        apiAbort(['OK' => false, 'ERROR' => 'business_tax_rate_not_configured']);
    }
    if (!is_numeric($qBrand['PayfritFee']) || (float) $qBrand['PayfritFee'] <= 0) {
        apiAbort(['OK' => false, 'ERROR' => 'business_payfrit_fee_not_configured']);
    }

    $brandColor = '';
    if (!empty($qBrand['BrandColor'])) {
        $brandColor = $qBrand['BrandColor'][0] === '#' ? $qBrand['BrandColor'] : '#' . $qBrand['BrandColor'];
    }
    $brandColorLight = '';
    if (!empty($qBrand['BrandColorLight'])) {
        $brandColorLight = $qBrand['BrandColorLight'][0] === '#' ? $qBrand['BrandColorLight'] : '#' . $qBrand['BrandColorLight'];
    }
    $headerImageUrl = '';
    if (!empty($qBrand['HeaderImageExtension'])) {
        $headerImageUrl = "/uploads/headers/{$businessID}.{$qBrand['HeaderImageExtension']}";
    }

    jsonResponse([
        'OK'              => true,
        'ERROR'           => '',
        'Items'           => $rows,
        'COUNT'           => count($rows),
        'SCHEMA'          => $newSchemaActive ? 'unified' : 'legacy',
        'BRANDCOLOR'      => $brandColor,
        'BRANDCOLORLIGHT' => $brandColorLight,
        'HEADERIMAGEURL'  => $headerImageUrl,
        'TAXRATE'         => (float) $qBrand['TaxRate'],
        'PAYFRITFEE'      => (float) $qBrand['PayfritFee'],
        'SESSIONENABLED'  => (int) ($qBrand['SessionEnabled'] ?? 0),
        'Menus'           => $menuList,
        'SelectedMenuID'  => $requestedMenuID,
        'ORDERTYPES'      => !empty($qBrand['OrderTypes']) ? $qBrand['OrderTypes'] : '1',
    ]);

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