<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;

class AdditionalController extends Controller
{
    protected $magento1Connection = 'magento1';
    protected $magento2Connection = 'magento2';
    protected $magento1Prefix;
    protected $magento2Prefix;

    /** Default attribute code for frontpage tabs (can be overridden in request) */
    protected $frontpageTabsAttributeCode = 'frontpage_tabs';

    public function __construct()
    {
        $this->magento1Prefix = config('database.connections.magento1.prefix', '');
        $this->magento2Prefix = config('database.connections.magento2.prefix', '');
    }

    /**
     * Compare M1 text attributes (potential tab content) against M2 mgs_protabs config.
     * Returns per-scope breakdown of what is configured and what is missing.
     */
    public function compareProtabs(Request $request)
    {
        try {
            // --- M2: gather all Protabs entries and website/store names ---
            $m2Tabs = DB::connection($this->magento2Connection)
                ->table('mgs_protabs')
                ->orderBy('scope')
                ->orderBy('scope_id')
                ->orderBy('position')
                ->get();

            $m2Websites = DB::connection($this->magento2Connection)
                ->table('store_website')
                ->whereNotIn('website_id', [0])
                ->whereRaw("name NOT LIKE '%Admin%'")
                ->pluck('name', 'website_id');

            $m2Stores = DB::connection($this->magento2Connection)
                ->table('store')
                ->where('store_id', '>', 0)
                ->pluck('name', 'store_id');

            // Tabs keyed by "scope:scope_id" for easy lookup
            $tabsByScope = [];
            foreach ($m2Tabs as $tab) {
                $key = $tab->scope . ':' . $tab->scope_id;
                $tabsByScope[$key][] = (array) $tab;
            }

            // --- M1: find all catalog_product text attributes with values ---
            $entityTypeIdM1 = DB::connection($this->magento1Connection)
                ->table($this->magento1Prefix . 'eav_entity_type')
                ->where('entity_type_code', 'catalog_product')
                ->value('entity_type_id');

            // Get all text-backend attributes that actually have product values
            $m1TextAttrs = DB::connection($this->magento1Connection)
                ->table($this->magento1Prefix . 'eav_attribute as a')
                ->join($this->magento1Prefix . 'catalog_product_entity_text as v', 'a.attribute_id', '=', 'v.attribute_id')
                ->where('a.entity_type_id', $entityTypeIdM1)
                ->select('a.attribute_code', 'a.frontend_label', DB::raw('COUNT(v.value_id) as value_count'))
                ->whereNotNull('v.value')
                ->where('v.value', '!=', '')
                ->groupBy('a.attribute_id', 'a.attribute_code', 'a.frontend_label')
                ->having('value_count', '>', 0)
                ->orderBy('a.attribute_code')
                ->get()
                ->keyBy('attribute_code');

            // --- Build per-scope comparison ---
            // Collect all unique scopes from existing tabs
            $scopes = $m2Tabs->map(fn($t) => ['scope' => $t->scope, 'scope_id' => $t->scope_id])
                ->unique(fn($s) => $s['scope'] . ':' . $s['scope_id'])
                ->values();

            $comparison = [];
            foreach ($scopes as $scope) {
                $key = $scope['scope'] . ':' . $scope['scope_id'];
                $existing = $tabsByScope[$key] ?? [];
                $existingAttrCodes = collect($existing)
                    ->where('tab_type', 'attribute')
                    ->pluck('value')
                    ->filter()
                    ->flip(); // use as set

                // Find M1 text attrs with values not in this scope's protabs
                $missing = [];
                foreach ($m1TextAttrs as $attrCode => $attr) {
                    if (!isset($existingAttrCodes[$attrCode])) {
                        $missing[] = [
                            'attribute_code'  => $attrCode,
                            'frontend_label'  => $attr->frontend_label ?? $attrCode,
                            'value_count'     => $attr->value_count,
                            'suggested_title' => ucwords(str_replace('_', ' ', $attrCode)),
                            'suggested_pos'   => count($existing) + count($missing) + 1,
                        ];
                    }
                }

                $scopeLabel = match ($scope['scope']) {
                    'default'  => 'Default (all stores)',
                    'websites' => 'Website: ' . ($m2Websites[$scope['scope_id']] ?? 'ID ' . $scope['scope_id']),
                    'stores'   => 'Store: ' . ($m2Stores[$scope['scope_id']] ?? 'ID ' . $scope['scope_id']),
                    default    => $scope['scope'] . ' ' . $scope['scope_id'],
                };

                $comparison[] = [
                    'scope'       => $scope['scope'],
                    'scope_id'    => $scope['scope_id'],
                    'scope_label' => $scopeLabel,
                    'existing'    => $existing,
                    'missing'     => $missing,
                ];
            }

            return response()->json([
                'success'    => true,
                'comparison' => $comparison,
                'm1_text_attr_count' => $m1TextAttrs->count(),
            ]);
        } catch (\Throwable $e) {
            Log::error('Protabs compare error: ' . $e->getMessage());
            return response()->json(['success' => false, 'message' => $e->getMessage()], 500);
        }
    }

    /**
     * Insert one or more missing tabs into M2 mgs_protabs.
     * Accepts an array of tab objects: [{title, tab_type, value, position, scope, scope_id}, ...]
     */
    public function syncProtabs(Request $request)
    {
        $tabs = $request->input('tabs', []);
        if (empty($tabs)) {
            return response()->json(['success' => false, 'message' => 'No tabs provided.'], 400);
        }

        $inserted = 0;
        $skipped  = 0;
        $errors   = 0;
        $log      = [];

        foreach ($tabs as $tab) {
            $scope   = $tab['scope']    ?? 'default';
            $scopeId = (int)($tab['scope_id'] ?? 0);
            $value   = trim($tab['value']   ?? '');
            $title   = trim($tab['title']   ?? '');
            $tabType = $tab['tab_type'] ?? 'attribute';
            $pos     = (int)($tab['position'] ?? 99);

            if ($value === '' || $title === '') {
                $log[] = "Skipped entry with empty value or title.";
                $skipped++;
                continue;
            }

            // Check if already exists for this scope
            $exists = DB::connection($this->magento2Connection)
                ->table('mgs_protabs')
                ->where('scope', $scope)
                ->where('scope_id', $scopeId)
                ->where('tab_type', $tabType)
                ->where('value', $value)
                ->exists();

            if ($exists) {
                $log[] = "Tab '{$title}' ({$value}) already exists for {$scope}:{$scopeId}, skipped.";
                $skipped++;
                continue;
            }

            try {
                DB::connection($this->magento2Connection)
                    ->table('mgs_protabs')
                    ->insert([
                        'title'    => $title,
                        'tab_type' => $tabType,
                        'value'    => $value,
                        'position' => $pos,
                        'scope'    => $scope,
                        'scope_id' => $scopeId,
                    ]);
                $inserted++;
                $log[] = "Added tab '{$title}' ({$value}) to {$scope}:{$scopeId} at position {$pos}.";
            } catch (\Throwable $e) {
                $errors++;
                $log[] = "Error adding '{$value}': " . $e->getMessage();
                Log::error('Protabs sync error: ' . $e->getMessage());
            }
        }

        return response()->json([
            'success'  => $errors === 0,
            'message'  => "Protabs sync: {$inserted} added, {$skipped} skipped, {$errors} errors.",
            'inserted' => $inserted,
            'skipped'  => $skipped,
            'errors'   => $errors,
            'log'      => $log,
        ]);
    }

    /**
     * Show the Additional tools page
     */
    public function index()
    {
        $frontpageTabsInfo = $this->getFrontpageTabsAttributeInfo();
        return view('additional.index', [
            'frontpageTabsInfo' => $frontpageTabsInfo,
        ]);
    }

    /**
     * Get info about the frontpage tabs attribute in M1 and M2 (for display / discovery)
     */
    protected function getFrontpageTabsAttributeInfo()
    {
        $info = ['m1' => null, 'm2' => null, 'suggested_codes' => []];
        try {
            $entityTypeIdM1 = DB::connection($this->magento1Connection)
                ->table($this->magento1Prefix . 'eav_entity_type')
                ->where('entity_type_code', 'catalog_product')
                ->value('entity_type_id');
            $entityTypeIdM2 = DB::connection($this->magento2Connection)
                ->table($this->magento2Prefix . 'eav_entity_type')
                ->where('entity_type_code', 'catalog_product')
                ->value('entity_type_id');
            if (!$entityTypeIdM1 || !$entityTypeIdM2) {
                return $info;
            }

            foreach (['frontpage_tabs', 'front_tabs', 'product_tabs'] as $code) {
                $m1 = DB::connection($this->magento1Connection)
                    ->table($this->magento1Prefix . 'eav_attribute')
                    ->where('entity_type_id', $entityTypeIdM1)
                    ->where('attribute_code', $code)
                    ->select('attribute_id', 'attribute_code', 'backend_type', 'frontend_label')
                    ->first();
                $m2 = DB::connection($this->magento2Connection)
                    ->table($this->magento2Prefix . 'eav_attribute')
                    ->where('entity_type_id', $entityTypeIdM2)
                    ->where('attribute_code', $code)
                    ->select('attribute_id', 'attribute_code', 'backend_type', 'frontend_label')
                    ->first();
                if ($m1) {
                    $info['m1'] = $m1;
                    $info['m2'] = $m2;
                    break;
                }
                if ($m1 || $m2) {
                    $info['suggested_codes'][] = $code;
                }
            }

            if (!$info['m1']) {
                $suggested = DB::connection($this->magento1Connection)
                    ->table($this->magento1Prefix . 'eav_attribute')
                    ->where('entity_type_id', $entityTypeIdM1)
                    ->where(function ($q) {
                        $q->where('attribute_code', 'like', '%frontpage%')
                            ->orWhere('attribute_code', 'like', '%front%tab%')
                            ->orWhere('attribute_code', 'like', '%tab%');
                    })
                    ->pluck('attribute_code')
                    ->toArray();
                $info['suggested_codes'] = array_unique(array_merge($info['suggested_codes'], $suggested));
            }
        } catch (\Throwable $e) {
            Log::warning('Frontpage tabs attribute info: ' . $e->getMessage());
        }
        return $info;
    }

    /**
     * Return diagnostic info for an attribute code (M1/M2 existence, backend_type, value row counts)
     */
    public function attributeDiagnostic(Request $request)
    {
        $attributeCode = trim((string) $request->input('attribute_code', '')) ?: 'frontpage_tabs';
        try {
            $entityTypeIdM1 = DB::connection($this->magento1Connection)
                ->table($this->magento1Prefix . 'eav_entity_type')
                ->where('entity_type_code', 'catalog_product')
                ->value('entity_type_id');
            $entityTypeIdM2 = DB::connection($this->magento2Connection)
                ->table($this->magento2Prefix . 'eav_entity_type')
                ->where('entity_type_code', 'catalog_product')
                ->value('entity_type_id');
            if (!$entityTypeIdM1 || !$entityTypeIdM2) {
                return response()->json(['success' => false, 'message' => 'Could not resolve entity type.', 'm1' => null, 'm2' => null]);
            }
            $attrM1 = DB::connection($this->magento1Connection)
                ->table($this->magento1Prefix . 'eav_attribute')
                ->where('entity_type_id', $entityTypeIdM1)
                ->where('attribute_code', $attributeCode)
                ->select('attribute_id', 'attribute_code', 'backend_type', 'frontend_input', 'frontend_label')
                ->first();
            $attrM2 = DB::connection($this->magento2Connection)
                ->table($this->magento2Prefix . 'eav_attribute')
                ->where('entity_type_id', $entityTypeIdM2)
                ->where('attribute_code', $attributeCode)
                ->select('attribute_id', 'attribute_code', 'backend_type', 'frontend_input', 'frontend_label')
                ->first();
            $diagnostic = ['attribute_code' => $attributeCode, 'm1' => null, 'm2' => null];
            if ($attrM1) {
                $diagnostic['m1'] = (array) $attrM1;
                $bt = $attrM1->backend_type ?? 'varchar';
                $tables = ['varchar', 'text', 'int', 'decimal', 'datetime'];
                $diagnostic['m1']['value_counts_by_table'] = [];
                foreach ($tables as $t) {
                    try {
                        $c = DB::connection($this->magento1Connection)
                            ->table($this->magento1Prefix . 'catalog_product_entity_' . $t)
                            ->where('attribute_id', $attrM1->attribute_id)
                            ->count();
                        $diagnostic['m1']['value_counts_by_table'][$t] = $c;
                    } catch (\Throwable $e) {
                        $diagnostic['m1']['value_counts_by_table'][$t] = 'error';
                    }
                }
            }
            if ($attrM2) {
                $diagnostic['m2'] = (array) $attrM2;
            }
            return response()->json(['success' => true, 'diagnostic' => $diagnostic]);
        } catch (\Throwable $e) {
            Log::warning('Attribute diagnostic: ' . $e->getMessage());
            return response()->json(['success' => false, 'message' => $e->getMessage(), 'diagnostic' => null], 500);
        }
    }

    /**
     * Sync frontpage tabs from Magento 1 to Magento 2 by SKU
     * Scans all M1 products by SKU and ensures M2 products have the same frontpage tabs value(s)
     */
    public function syncFrontpageTabs(Request $request)
    {
        $attributeCode = $request->input('attribute_code', $this->frontpageTabsAttributeCode);
        $dryRun = $request->boolean('dry_run', false);

        try {
            $entityTypeIdM1 = DB::connection($this->magento1Connection)
                ->table($this->magento1Prefix . 'eav_entity_type')
                ->where('entity_type_code', 'catalog_product')
                ->value('entity_type_id');
            $entityTypeIdM2 = DB::connection($this->magento2Connection)
                ->table($this->magento2Prefix . 'eav_entity_type')
                ->where('entity_type_code', 'catalog_product')
                ->value('entity_type_id');
            if (!$entityTypeIdM1 || !$entityTypeIdM2) {
                return response()->json([
                    'success' => false,
                    'message' => 'Could not resolve catalog_product entity type in M1 or M2.',
                    'updated' => 0,
                    'skipped' => 0,
                    'errors' => 0,
                    'log' => [],
                ], 400);
            }

            $attrM1 = DB::connection($this->magento1Connection)
                ->table($this->magento1Prefix . 'eav_attribute')
                ->where('entity_type_id', $entityTypeIdM1)
                ->where('attribute_code', $attributeCode)
                ->first();
            if (!$attrM1) {
                return response()->json([
                    'success' => false,
                    'message' => "Attribute '{$attributeCode}' not found in Magento 1.",
                    'updated' => 0,
                    'skipped' => 0,
                    'errors' => 0,
                    'log' => [],
                ], 400);
            }

            $attrM2 = DB::connection($this->magento2Connection)
                ->table($this->magento2Prefix . 'eav_attribute')
                ->where('entity_type_id', $entityTypeIdM2)
                ->where('attribute_code', $attributeCode)
                ->first();
            if (!$attrM2) {
                return response()->json([
                    'success' => false,
                    'message' => "Attribute '{$attributeCode}' not found in Magento 2. Create the attribute in M2 first.",
                    'updated' => 0,
                    'skipped' => 0,
                    'errors' => 0,
                    'log' => [],
                ], 400);
            }

            $backendType = $attrM1->backend_type ?? 'varchar';
            if (!in_array($backendType, ['varchar', 'text', 'int', 'decimal', 'datetime'], true)) {
                $backendType = 'varchar';
            }
            $backendTypesToTry = ['varchar', 'text', 'int', 'decimal', 'datetime'];
            $m1ValueTable = null;
            $m2ValueTable = null;
            $resolvedBackendType = null;
            foreach ($backendTypesToTry as $bt) {
                $t1 = $this->magento1Prefix . 'catalog_product_entity_' . $bt;
                $count = 0;
                try {
                    $count = DB::connection($this->magento1Connection)
                        ->table($t1)
                        ->where('attribute_id', $attrM1->attribute_id)
                        ->count();
                } catch (\Throwable $e) {
                    continue;
                }
                if ($count > 0) {
                    $resolvedBackendType = $bt;
                    $m1ValueTable = $t1;
                    $m2ValueTable = $this->magento2Prefix . 'catalog_product_entity_' . $bt;
                    break;
                }
            }
            if ($m1ValueTable === null) {
                $m1ValueTable = $this->magento1Prefix . 'catalog_product_entity_' . $backendType;
                $m2ValueTable = $this->magento2Prefix . 'catalog_product_entity_' . $backendType;
                $resolvedBackendType = $backendType;
            }

            $m1ValueRowCount = 0;
            try {
                $m1ValueRowCount = DB::connection($this->magento1Connection)
                    ->table($m1ValueTable)
                    ->where('attribute_id', $attrM1->attribute_id)
                    ->count();
            } catch (\Throwable $e) {
                return response()->json([
                    'success' => false,
                    'message' => "Magento 1 value table for attribute '{$attributeCode}' (backend_type {$resolvedBackendType}) not found or error: " . $e->getMessage(),
                    'updated' => 0,
                    'skipped' => 0,
                    'errors' => 0,
                    'log' => [],
                    'diagnostic' => ['backend_type' => $resolvedBackendType, 'm1_value_table' => $m1ValueTable],
                ], 400);
            }
            if ($m1ValueRowCount === 0) {
                return response()->json([
                    'success' => false,
                    'message' => "No values found in Magento 1 for attribute '{$attributeCode}'. No products have this attribute set in M1. Check that the attribute is assigned to product attribute sets and that products have values saved.",
                    'updated' => 0,
                    'skipped' => 0,
                    'errors' => 0,
                    'log' => [],
                    'diagnostic' => [
                        'backend_type' => $resolvedBackendType,
                        'm1_value_table' => $m1ValueTable,
                        'm1_value_row_count' => 0,
                    ],
                ], 400);
            }

            $skuAttrIdM1 = DB::connection($this->magento1Connection)
                ->table($this->magento1Prefix . 'eav_attribute')
                ->where('entity_type_id', $entityTypeIdM1)
                ->where('attribute_code', 'sku')
                ->value('attribute_id');
            $skuAttrIdM2 = DB::connection($this->magento2Connection)
                ->table($this->magento2Prefix . 'eav_attribute')
                ->where('entity_type_id', $entityTypeIdM2)
                ->where('attribute_code', 'sku')
                ->value('attribute_id');
            if (!$skuAttrIdM1 || !$skuAttrIdM2) {
                return response()->json([
                    'success' => false,
                    'message' => 'Could not resolve SKU attribute in M1 or M2.',
                    'updated' => 0,
                    'skipped' => 0,
                    'errors' => 0,
                    'log' => [],
                ], 400);
            }

            $m1ProductsWithTabs = DB::connection($this->magento1Connection)
                ->table($this->magento1Prefix . 'catalog_product_entity as e')
                ->leftJoin($this->magento1Prefix . 'catalog_product_entity_varchar as sku_v', function ($join) use ($skuAttrIdM1) {
                    $join->on('e.entity_id', '=', 'sku_v.entity_id')
                        ->where('sku_v.attribute_id', '=', $skuAttrIdM1);
                })
                ->join($m1ValueTable . ' as vt', function ($join) use ($attrM1) {
                    $join->on('e.entity_id', '=', 'vt.entity_id')
                        ->where('vt.attribute_id', '=', $attrM1->attribute_id);
                })
                ->where(function ($q) {
                    $q->whereNotNull('sku_v.value')
                        ->orWhereNotNull('e.sku');
                })
                ->selectRaw('e.entity_id as m1_entity_id, TRIM(COALESCE(sku_v.value, e.sku)) as sku, vt.store_id, vt.value')
                ->get();

            if ($m1ProductsWithTabs->isEmpty()) {
                return response()->json([
                    'success' => false,
                    'message' => "Attribute '{$attributeCode}' has {$m1ValueRowCount} value row(s) in M1, but no rows matched when joining with products (by SKU). Possible causes: SKU is stored in a different store_id in M1, or the value table does not match the attribute's backend_type.",
                    'updated' => 0,
                    'skipped' => 0,
                    'errors' => 0,
                    'log' => [],
                    'diagnostic' => [
                        'backend_type' => $resolvedBackendType,
                        'm1_value_table' => $m1ValueTable,
                        'm1_value_row_count' => $m1ValueRowCount,
                    ],
                ], 400);
            }

            $m2SkuToEntityId = DB::connection($this->magento2Connection)
                ->table($this->magento2Prefix . 'catalog_product_entity as e')
                ->leftJoin($this->magento2Prefix . 'catalog_product_entity_varchar as sku_v', function ($join) use ($skuAttrIdM2) {
                    $join->on('e.entity_id', '=', 'sku_v.entity_id')
                        ->where('sku_v.attribute_id', '=', $skuAttrIdM2);
                })
                ->where(function ($q) {
                    $q->whereNotNull('sku_v.value')
                        ->orWhereNotNull('e.sku');
                })
                ->selectRaw('e.entity_id, TRIM(COALESCE(sku_v.value, e.sku)) as sku')
                ->pluck('e.entity_id', 'sku');

            $log = [];
            $updated = 0;
            $skipped = 0;
            $skippedNoM2 = 0;
            $skippedAlreadyMatch = 0;
            $errors = 0;

            foreach ($m1ProductsWithTabs as $row) {
                $sku = trim((string) $row->sku);
                $m2EntityId = $m2SkuToEntityId->get($sku);
                if ($m2EntityId === null) {
                    $skipped++;
                    $skippedNoM2++;
                    $log[] = "SKU {$sku}: no M2 product, skipped.";
                    continue;
                }
                $existing = DB::connection($this->magento2Connection)
                    ->table($m2ValueTable)
                    ->where('entity_id', $m2EntityId)
                    ->where('attribute_id', $attrM2->attribute_id)
                    ->where('store_id', $row->store_id)
                    ->first();
                if ($existing && (string) $existing->value === (string) $row->value) {
                    $skipped++;
                    $skippedAlreadyMatch++;
                    $log[] = "SKU {$sku} (store {$row->store_id}): M2 value already matches M1, skipped.";
                    continue;
                }
                if ($dryRun) {
                    $updated++;
                    $log[] = "SKU {$sku} (store {$row->store_id}): would set value.";
                    continue;
                }
                try {
                    if ($existing) {
                        DB::connection($this->magento2Connection)
                            ->table($m2ValueTable)
                            ->where('entity_id', $m2EntityId)
                            ->where('attribute_id', $attrM2->attribute_id)
                            ->where('store_id', $row->store_id)
                            ->update(['value' => $row->value]);
                    } else {
                        DB::connection($this->magento2Connection)
                            ->table($m2ValueTable)
                            ->insert([
                                'attribute_id' => $attrM2->attribute_id,
                                'store_id' => $row->store_id,
                                'entity_id' => $m2EntityId,
                                'value' => $row->value,
                            ]);
                    }
                    $updated++;
                    $log[] = "SKU {$sku} (store {$row->store_id}): synced.";
                } catch (\Throwable $e) {
                    $errors++;
                    $log[] = "SKU {$sku}: error - " . $e->getMessage();
                    Log::error("Sync frontpage tabs SKU {$sku}: " . $e->getMessage());
                }
            }

            $m1SampleSkus = $m1ProductsWithTabs->take(5)->pluck('sku')->unique()->values()->toArray();
            $diagnostic = [
                'backend_type' => $resolvedBackendType,
                'm1_value_row_count' => $m1ValueRowCount,
                'm1_products_with_value' => $m1ProductsWithTabs->count(),
                'skipped_no_m2_product' => $skippedNoM2,
                'skipped_already_match' => $skippedAlreadyMatch,
                'm1_sample_skus' => $m1SampleSkus,
            ];
            return response()->json([
                'success' => true,
                'message' => $dryRun
                    ? "Dry run: {$updated} product/store rows would be updated, {$skipped} skipped."
                    : "Synced frontpage tabs: {$updated} updated, {$skipped} skipped, {$errors} errors.",
                'updated' => $updated,
                'skipped' => $skipped,
                'errors' => $errors,
                'log' => array_slice($log, -100),
                'diagnostic' => $diagnostic,
            ]);

        } catch (\Throwable $e) {
            Log::error('Sync frontpage tabs error: ' . $e->getMessage());
            return response()->json([
                'success' => false,
                'message' => 'Sync failed: ' . $e->getMessage(),
                'updated' => 0,
                'skipped' => 0,
                'errors' => 0,
                'log' => [],
            ], 500);
        }
    }
}