<?php

namespace Modules\IndustrialEngineering\Services;

use App\Business;
use App\BusinessLocation;
use App\Product;
use App\Unit;
use App\Variation;
use App\Utils\ProductUtil;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Modules\IndustrialEngineering\Models\Bom;
use Modules\IndustrialEngineering\Models\ItemMaster;
use Modules\IndustrialEngineering\Models\LineTemplate;
use Modules\IndustrialEngineering\Support\ActorResolver;
use Modules\IndustrialEngineering\Support\CmmsAvailability;

/**
 * Resolves ERP/CMMS gaps: match existing products or create them in inventory.
 */
class ConnectionResolutionService
{
    public function __construct(
        protected ErpItemLinkService $erpItemLink,
        protected ConnectionGateService $connectionGate,
        protected IntegrationBridgeService $integrationBridge,
        protected ProductUtil $productUtil
    ) {
    }

    public function resolveLine(LineTemplate $line, Bom $mbom, bool $syncCmms = true): array
    {
        $result = $this->resolveBom($mbom, true);
        $result['cmms_synced'] = false;
        $result['cmms_parts_count'] = 0;

        $line->refresh();

        if ($syncCmms && CmmsAvailability::isReady()) {
            try {
                $sync = $this->integrationBridge->syncLineBomToMaintenance($line, $mbom->fresh());
                $line = $sync['line'];
                $result['cmms_synced'] = true;
                $result['cmms_parts_count'] = $sync['parts_count'] ?? 0;
                $result['messages'][] = ['type' => 'success', 'text' => __('industrialengineering::lang.cmms_synced_parts', [
                    'code' => $line->effectiveCode(),
                    'count' => $result['cmms_parts_count'],
                ])];
            } catch (\Throwable $e) {
                Log::warning('IE resolve CMMS: '.$e->getMessage());
                $result['messages'][] = ['type' => 'warning', 'text' => __('industrialengineering::lang.cmms_sync_failed', ['error' => $e->getMessage()])];
            }
        }

        $mbom->unsetRelation('lines');
        $result['gate'] = $this->connectionGate->assessBom($mbom->fresh(), 1);
        $result['fully_resolved'] = ($result['gate']['can_run_mrp'] ?? false)
            && (! CmmsAvailability::isReady() || (bool) $line->fresh()->maintenance_equipment_id);
        $result['summary'] = $this->buildSummary($result);

        return $result;
    }

    public function resolveBom(Bom $bom, bool $createMissing = true): array
    {
        $gate = $this->connectionGate->assessBom($bom, 1);
        $itemIds = collect($gate['analysis']['leaf_lines'] ?? [])
            ->filter(fn ($row) => empty($row['variation_id']) && ! empty($row['item_master_id']))
            ->pluck('item_master_id')
            ->unique()
            ->values();

        $stats = ['matched' => 0, 'created' => 0, 'failed' => 0];
        $messages = [];
        $failures = [];

        foreach ($itemIds as $itemId) {
            $item = ItemMaster::forBusiness($bom->business_id)->find($itemId);
            if (! $item) {
                continue;
            }

            $outcome = $this->resolveItem($item, $createMissing);
            if ($outcome['action'] === 'failed') {
                $stats['failed']++;
            } elseif ($outcome['action'] === 'created') {
                $stats['created']++;
            } else {
                $stats['matched']++;
            }

            if ($outcome['action'] === 'failed') {
                $failures[] = $outcome['message'];
                $messages[] = ['type' => 'warning', 'text' => $outcome['message']];
            } elseif ($outcome['action'] === 'created') {
                $messages[] = ['type' => 'success', 'text' => __('industrialengineering::lang.erp_product_created', [
                    'code' => $item->item_code,
                    'name' => $item->name,
                ])];
            } else {
                $messages[] = ['type' => 'info', 'text' => $outcome['message']];
            }
        }

        return [
            'stats' => $stats,
            'messages' => $messages,
            'failures' => $failures,
            'gate_before' => $gate,
            'gate' => $this->connectionGate->assessBom($bom->fresh(), 1),
        ];
    }

    protected function resolveActorId(int $businessId): int
    {
        return ActorResolver::id($businessId) ?? 1;
    }

    public function resolveItem(ItemMaster $item, bool $createMissing = true): array
    {
        if ($item->variation_id) {
            return ['action' => 'matched', 'message' => __('industrialengineering::lang.auto_erp_already_linked')];
        }

        $match = $this->erpItemLink->autoMatchProduct($item->fresh());
        if ($match['linked']) {
            return ['action' => 'matched', 'message' => $match['message']];
        }

        if (! $createMissing) {
            return ['action' => 'failed', 'message' => $match['message']];
        }

        return $this->provisionErpProduct($item);
    }

    public function provisionErpProduct(ItemMaster $item): array
    {
        try {
            return DB::transaction(function () use ($item) {
                $unitId = Unit::where('business_id', $item->business_id)
                    ->whereNull('base_unit_id')
                    ->value('id')
                    ?? Unit::where('business_id', $item->business_id)->value('id');

                if (! $unitId) {
                    throw new \RuntimeException(__('industrialengineering::lang.erp_no_unit'));
                }

                $sku = trim((string) $item->item_code) ?: ('IE-'.$item->id);

                $existingVariation = Variation::query()
                    ->whereHas('product', fn ($q) => $q->where('business_id', $item->business_id))
                    ->where('sub_sku', $sku)
                    ->first();
                if ($existingVariation) {
                    $this->erpItemLink->linkItem($item, ['variation_id' => $existingVariation->id]);

                    return [
                        'action' => 'matched',
                        'message' => __('industrialengineering::lang.auto_erp_matched', [
                            'name' => $this->erpItemLink->variationLabel($existingVariation),
                        ]),
                        'variation_id' => $existingVariation->id,
                    ];
                }

                $cost = max(0, (float) ($item->standard_cost ?? 0));

                $product = Product::create([
                    'business_id' => $item->business_id,
                    'name' => $item->name,
                    'type' => 'single',
                    'unit_id' => $unitId,
                    'sku' => $sku,
                    'enable_stock' => 1,
                    'not_for_selling' => 0,
                    'created_by' => $this->resolveActorId($item->business_id),
                    'tax_type' => 'exclusive',
                    'barcode_type' => 'C128',
                ]);

                $locationIds = BusinessLocation::where('business_id', $item->business_id)->pluck('id');
                if ($locationIds->isNotEmpty()) {
                    $product->product_locations()->sync($locationIds);
                }

                $this->productUtil->createSingleProductVariation(
                    $product->id,
                    $sku,
                    $cost,
                    $cost,
                    0,
                    $cost,
                    $cost
                );

                $variation = $product->fresh()->variations()->first();
                if (! $variation) {
                    throw new \RuntimeException(__('industrialengineering::lang.erp_provision_failed', ['code' => $item->item_code]));
                }

                $this->erpItemLink->linkItem($item, ['variation_id' => $variation->id]);

                return [
                    'action' => 'created',
                    'message' => __('industrialengineering::lang.erp_product_created', [
                        'code' => $item->item_code,
                        'name' => $item->name,
                    ]),
                    'product_id' => $product->id,
                    'variation_id' => $variation->id,
                ];
            });
        } catch (\Throwable $e) {
            Log::error('IE ERP provision '.$item->item_code.': '.$e->getMessage());

            return [
                'action' => 'failed',
                'message' => __('industrialengineering::lang.erp_provision_failed', ['code' => $item->item_code]).' — '.$e->getMessage(),
            ];
        }
    }

    protected function buildSummary(array $result): string
    {
        $s = $result['stats'];
        $gate = $result['gate'] ?? [];
        $parts = [
            __('industrialengineering::lang.resolve_summary_matched', ['n' => $s['matched'] ?? 0]),
            __('industrialengineering::lang.resolve_summary_created', ['n' => $s['created'] ?? 0]),
        ];
        if (($s['failed'] ?? 0) > 0) {
            $parts[] = __('industrialengineering::lang.resolve_summary_failed', ['n' => $s['failed']]);
        }
        if (! empty($gate['can_run_mrp'])) {
            $parts[] = __('industrialengineering::lang.resolve_mrp_ready');
        } elseif (($s['failed'] ?? 0) === 0 && ($s['matched'] ?? 0) === 0 && ($s['created'] ?? 0) === 0) {
            $parts[] = __('industrialengineering::lang.resolve_nothing_todo');
        }

        return implode(' — ', $parts);
    }
}