<?php

namespace Modules\AssetExchange\Services;

use App\Business;
use App\User;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
use Modules\AssetExchange\Models\CatalogMatch;
use Modules\AssetExchange\Models\Listing;

class CatalogMatchService
{
    public const CATALOG_TYPES = [
        'ie_line_template',
        'ie_item_master',
        'ie_installed_asset',
        'maintenance_equipment',
        'ie_product_platform',
    ];

    public function discoverMatches(Business $business, Listing $listing, bool $replaceSuggested = false): Collection
    {
        if (! Schema::hasTable('aex_catalog_matches')) {
            return collect();
        }

        $candidates = collect();

        $candidates = $candidates->merge($this->searchIeLineTemplates($business, $listing));
        $candidates = $candidates->merge($this->searchIeItemMasters($business, $listing));
        $candidates = $candidates->merge($this->searchInstalledAssets($business, $listing));
        $candidates = $candidates->merge($this->searchCmmsEquipment($business, $listing));

        return DB::transaction(function () use ($business, $listing, $replaceSuggested, $candidates) {
            if ($replaceSuggested) {
                CatalogMatch::where('listing_id', $listing->id)
                    ->where('status', 'suggested')
                    ->delete();
            }

            $saved = collect();
            foreach ($candidates->sortByDesc('score')->take(15) as $row) {
                $match = CatalogMatch::updateOrCreate(
                    [
                        'listing_id' => $listing->id,
                        'catalog_type' => $row['catalog_type'],
                        'catalog_id' => $row['catalog_id'],
                    ],
                    [
                        'business_id' => $business->id,
                        'catalog_label' => $row['label'],
                        'match_score' => $row['score'],
                        'match_reason' => $row['reason'],
                        'status' => 'suggested',
                    ]
                );
                $saved->push($match);
            }

            return $saved;
        });
    }

    public function confirmMatch(Business $business, CatalogMatch $match, ?User $user = null): Listing
    {
        $match->loadMissing('listing');
        $listing = $match->listing;

        if (! $listing || $listing->business_id !== $business->id) {
            throw new \RuntimeException('عرضه نامعتبر است.');
        }

        return DB::transaction(function () use ($business, $match, $listing, $user) {
            $match->update([
                'status' => 'confirmed',
                'confirmed_by' => $user?->id,
                'confirmed_at' => now(),
            ]);

            $updates = match ($match->catalog_type) {
                'ie_line_template' => ['ie_line_template_id' => $match->catalog_id],
                'ie_item_master' => [],
                'ie_installed_asset' => ['ie_installed_asset_id' => $match->catalog_id],
                'maintenance_equipment' => ['maintenance_equipment_id' => $match->catalog_id],
                default => [],
            };

            if ($match->catalog_type === 'ie_line_template' && Schema::hasTable('ie_line_revisions')) {
                $revision = DB::table('ie_line_revisions')
                    ->where('business_id', $business->id)
                    ->where('line_template_id', $match->catalog_id)
                    ->orderByDesc('id')
                    ->first();
                if ($revision) {
                    $updates['ie_line_revision_id'] = $revision->id;
                    if (Schema::hasTable('ie_boms')) {
                        $bom = DB::table('ie_boms')
                            ->where('business_id', $business->id)
                            ->where('line_revision_id', $revision->id)
                            ->orderByDesc('id')
                            ->first();
                        if ($bom) {
                            $updates['ie_bom_id'] = $bom->id;
                        }
                    }
                }
            }

            if (! empty($updates)) {
                $listing->update($updates);
            }

            CatalogMatch::where('listing_id', $listing->id)
                ->where('id', '!=', $match->id)
                ->where('catalog_type', $match->catalog_type)
                ->where('status', 'suggested')
                ->update(['status' => 'rejected']);

            return $listing->fresh(['catalogMatches']);
        });
    }

    public function searchCatalog(Business $business, string $term, ?string $type = null): array
    {
        $listing = new Listing([
            'business_id' => $business->id,
            'title' => $term,
            'manufacturer' => $term,
            'model' => $term,
        ]);

        $all = collect();
        if (! $type || $type === 'ie_line_template') {
            $all = $all->merge($this->searchIeLineTemplates($business, $listing, 30));
        }
        if (! $type || $type === 'ie_item_master') {
            $all = $all->merge($this->searchIeItemMasters($business, $listing, 30));
        }
        if (! $type || $type === 'maintenance_equipment') {
            $all = $all->merge($this->searchCmmsEquipment($business, $listing, 30));
        }
        if (! $type || $type === 'ie_installed_asset') {
            $all = $all->merge($this->searchInstalledAssets($business, $listing, 30));
        }

        return $all->sortByDesc('score')->take(25)->values()->all();
    }

    protected function searchIeLineTemplates(Business $business, Listing $listing, int $limit = 10): Collection
    {
        if (! Schema::hasTable('ie_line_templates')) {
            return collect();
        }

        $terms = $this->searchTerms($listing);
        $query = DB::table('ie_line_templates')->where('business_id', $business->id);

        $query->where(function ($q) use ($terms) {
            foreach ($terms as $term) {
                $q->orWhere('name', 'like', '%'.$term.'%')
                    ->orWhere('code', 'like', '%'.$term.'%');
            }
        });

        return $query->limit($limit)->get()->map(function ($row) use ($terms) {
            return [
                'catalog_type' => 'ie_line_template',
                'catalog_id' => $row->id,
                'label' => $row->name.' ('.$row->code.')',
                'score' => $this->scoreMatch($row->name.' '.$row->code, $terms),
                'reason' => 'تطبیق نام/کد خط تولید در IE',
            ];
        });
    }

    protected function searchIeItemMasters(Business $business, Listing $listing, int $limit = 10): Collection
    {
        if (! Schema::hasTable('ie_item_masters')) {
            return collect();
        }

        $terms = $this->searchTerms($listing);
        $query = DB::table('ie_item_masters')->where('business_id', $business->id);

        $query->where(function ($q) use ($terms, $listing) {
            foreach ($terms as $term) {
                $q->orWhere('name', 'like', '%'.$term.'%')
                    ->orWhere('item_code', 'like', '%'.$term.'%');
            }
            if ($listing->manufacturer) {
                $q->orWhere('manufacturer', 'like', '%'.$listing->manufacturer.'%');
            }
        });

        return $query->limit($limit)->get()->map(function ($row) use ($terms) {
            $label = $row->name;
            if (! empty($row->item_code)) {
                $label .= ' ['.$row->item_code.']';
            }

            return [
                'catalog_type' => 'ie_item_master',
                'catalog_id' => $row->id,
                'label' => $label,
                'score' => $this->scoreMatch($row->name.' '.($row->item_code ?? ''), $terms),
                'reason' => 'تطبیق آیتم/قطعه/ماشین در بانک IE',
            ];
        });
    }

    protected function searchInstalledAssets(Business $business, Listing $listing, int $limit = 10): Collection
    {
        if (! Schema::hasTable('ie_customer_installed_assets')) {
            return collect();
        }

        $terms = $this->searchTerms($listing);
        $query = DB::table('ie_customer_installed_assets')->where('business_id', $business->id);

        $query->where(function ($q) use ($terms) {
            foreach ($terms as $term) {
                $q->orWhere('asset_tag', 'like', '%'.$term.'%')
                    ->orWhere('site_name', 'like', '%'.$term.'%');
            }
        });

        return $query->limit($limit)->get()->map(function ($row) use ($terms) {
            return [
                'catalog_type' => 'ie_installed_asset',
                'catalog_id' => $row->id,
                'label' => ($row->asset_tag ?? 'Asset').' — '.($row->site_name ?? ''),
                'score' => $this->scoreMatch(($row->asset_tag ?? '').' '.($row->site_name ?? ''), $terms),
                'reason' => 'تطبیق دارایی نصب‌شده مشتری در IE',
            ];
        });
    }

    protected function searchCmmsEquipment(Business $business, Listing $listing, int $limit = 10): Collection
    {
        if (! Schema::hasTable('maintenance_equipment')) {
            return collect();
        }

        $terms = $this->searchTerms($listing);
        $query = DB::table('maintenance_equipment')->where('business_id', $business->id);

        $query->where(function ($q) use ($terms, $listing) {
            foreach ($terms as $term) {
                $q->orWhere('name', 'like', '%'.$term.'%')
                    ->orWhere('code', 'like', '%'.$term.'%')
                    ->orWhere('model', 'like', '%'.$term.'%')
                    ->orWhere('serial_number', 'like', '%'.$term.'%');
            }
            if ($listing->serial_number) {
                $q->orWhere('serial_number', $listing->serial_number);
            }
        });

        return $query->limit($limit)->get()->map(function ($row) use ($terms, $listing) {
            $score = $this->scoreMatch($row->name.' '.($row->model ?? '').' '.($row->serial_number ?? ''), $terms);
            if ($listing->serial_number && $row->serial_number === $listing->serial_number) {
                $score = 100;
            }

            return [
                'catalog_type' => 'maintenance_equipment',
                'catalog_id' => $row->id,
                'label' => $row->name.' / '.($row->model ?? '—'),
                'score' => $score,
                'reason' => 'تطبیق تجهیز CMMS',
            ];
        });
    }

    protected function searchTerms(Listing $listing): array
    {
        $parts = array_filter([
            $listing->title,
            $listing->manufacturer,
            $listing->model,
            $listing->serial_number,
        ]);

        $terms = [];
        foreach ($parts as $part) {
            foreach (preg_split('/\s+/', (string) $part) as $word) {
                $word = trim($word);
                if (strlen($word) >= 2) {
                    $terms[] = $word;
                }
            }
        }

        return array_values(array_unique($terms));
    }

    protected function scoreMatch(string $haystack, array $terms): float
    {
        if (empty($terms)) {
            return 0;
        }

        $haystack = mb_strtolower($haystack);
        $hits = 0;
        foreach ($terms as $term) {
            if (str_contains($haystack, mb_strtolower($term))) {
                $hits++;
            }
        }

        return round(min(100, ($hits / count($terms)) * 100), 2);
    }
}