<?php

namespace Modules\Tms\Services;

use App\Transaction;
use Modules\Tms\Models\CustomsClearance;
use Modules\Tms\Models\CustomsItem;
use Modules\Tms\Models\CustomsStatusLog;
use Modules\Tms\Models\Shipment;
use Modules\Tms\Utils\TmsUtil;

class TmsCustomsService
{
    public function __construct(
        protected TmsUtil $tmsUtil,
        protected TmsAccountingService $accountingService,
        protected TmsCustomsShipmentSyncService $customsSyncService
    ) {}

    public function createFromTransaction(Transaction $transaction, array $extra = []): ?CustomsClearance
    {
        $typeMap = [
            'purchase' => 'import',
            'sell' => 'export',
        ];

        if (! isset($typeMap[$transaction->type])) {
            return null;
        }

        $business_id = (int) $transaction->business_id;

        $existing = CustomsClearance::where('business_id', $business_id)
            ->where('transaction_id', $transaction->id)
            ->first();

        if ($existing) {
            return $existing;
        }

        $clearance = CustomsClearance::create([
            'business_id' => $business_id,
            'ref_no' => $this->tmsUtil->generateCustomsRefNo($business_id),
            'clearance_type' => $typeMap[$transaction->type],
            'transaction_id' => $transaction->id,
            'contact_id' => $transaction->contact_id,
            'customs_value' => (float) ($transaction->final_total ?? 0),
            'status' => 'draft',
            'created_by' => auth()->id(),
            ...$extra,
        ]);

        $this->importItemsFromTransaction($clearance, $transaction);
        $this->recalculateTotals($clearance);
        $this->logStatus($clearance, 'draft', __('tms::lang.auto_created_from_transaction'));

        return $this->customsSyncService->linkByTransaction($clearance->fresh(['items']));
    }

    public function createFromShipment(Shipment $shipment, array $extra = []): CustomsClearance
    {
        $business_id = (int) $shipment->business_id;

        $existing = CustomsClearance::where('business_id', $business_id)
            ->where('shipment_id', $shipment->id)
            ->first();

        if ($existing) {
            return $existing;
        }

        $clearance = CustomsClearance::create([
            'business_id' => $business_id,
            'ref_no' => $this->tmsUtil->generateCustomsRefNo($business_id),
            'clearance_type' => $extra['clearance_type'] ?? 'import',
            'shipment_id' => $shipment->id,
            'transaction_id' => $shipment->transaction_id,
            'contact_id' => $shipment->contact_id,
            'customs_value' => (float) ($shipment->freight_cost ?? 0),
            'status' => 'draft',
            'created_by' => auth()->id(),
            ...$extra,
        ]);

        if ($shipment->transaction_id) {
            $transaction = Transaction::find($shipment->transaction_id);
            if ($transaction) {
                $this->importItemsFromTransaction($clearance, $transaction);
            }
        }

        $this->recalculateTotals($clearance);
        $this->logStatus($clearance, 'draft', __('tms::lang.created_from_shipment', ['ref' => $shipment->ref_no]));

        $this->customsSyncService->linkMutually($clearance, $shipment);
        $this->customsSyncService->syncShipmentFromCustoms($clearance->fresh());

        return $clearance->fresh(['items', 'shipment']);
    }

    public function syncItems(CustomsClearance $clearance, array $items): void
    {
        $clearance->items()->delete();

        foreach ($items as $row) {
            if (empty($row['description'])) {
                continue;
            }

            $qty = (float) ($row['quantity'] ?? 1);
            $value = (float) ($row['customs_value'] ?? 0);
            $dutyRate = (float) ($row['duty_rate'] ?? 0);
            $vatRate = (float) ($row['vat_rate'] ?? 0);
            $dutyAmount = round($value * $dutyRate / 100, 4);
            $vatAmount = round(($value + $dutyAmount) * $vatRate / 100, 4);

            CustomsItem::create([
                'customs_clearance_id' => $clearance->id,
                'description' => $row['description'],
                'hs_code' => $row['hs_code'] ?? null,
                'quantity' => $qty,
                'unit' => $row['unit'] ?? null,
                'customs_value' => $value,
                'duty_rate' => $dutyRate,
                'duty_amount' => $dutyAmount,
                'vat_rate' => $vatRate,
                'vat_amount' => $vatAmount,
            ]);
        }

        $this->recalculateTotals($clearance->fresh());
    }

    public function recalculateTotals(CustomsClearance $clearance): void
    {
        $clearance->load('items');

        $customsValue = $clearance->items->sum('customs_value');
        $dutyAmount = $clearance->items->sum('duty_amount');
        $vatAmount = $clearance->items->sum('vat_amount');
        $other = (float) $clearance->other_charges;

        $clearance->update([
            'customs_value' => $customsValue > 0 ? $customsValue : $clearance->customs_value,
            'duty_amount' => $dutyAmount,
            'vat_amount' => $vatAmount,
            'total_duties' => $dutyAmount + $vatAmount + $other,
        ]);
    }

    public function updateStatus(CustomsClearance $clearance, string $status, ?string $note = null): CustomsClearance
    {
        $updates = ['status' => $status];

        if ($status === 'declared' && ! $clearance->declared_at) {
            $updates['declared_at'] = now();
        }

        if ($status === 'cleared' && ! $clearance->cleared_at) {
            $updates['cleared_at'] = now();
        }

        if ($status === 'released' && ! $clearance->released_at) {
            $updates['released_at'] = now();
        }

        $clearance->update($updates);
        $this->logStatus($clearance, $status, $note);

        if (in_array($status, ['cleared', 'released'], true)) {
            $this->accountingService->postCustomsDutiesOnClearance(
                $clearance->fresh(),
                (int) (auth()->id() ?? $clearance->created_by ?? 0)
            );
        }

        $this->customsSyncService->syncShipmentFromCustoms($clearance->fresh());

        return $clearance->fresh();
    }

    public function logStatus(CustomsClearance $clearance, string $status, ?string $note = null): CustomsStatusLog
    {
        return CustomsStatusLog::create([
            'customs_clearance_id' => $clearance->id,
            'status' => $status,
            'note' => $note,
            'created_by' => auth()->id(),
            'logged_at' => now(),
        ]);
    }

    protected function importItemsFromTransaction(CustomsClearance $clearance, Transaction $transaction): void
    {
        $lines = $transaction->type === 'purchase'
            ? $transaction->purchase_lines
            : ($transaction->sell_lines ?? collect());

        if (! $lines || $lines->isEmpty()) {
            return;
        }

        $items = [];
        foreach ($lines as $line) {
            $product = $line->product ?? null;
            $items[] = [
                'description' => $product?->name ?? ($line->product?->name ?? __('tms::lang.item')),
                'hs_code' => $product?->sku ?? null,
                'quantity' => (float) ($line->quantity ?? 1),
                'unit' => $line->sub_unit?->short_name ?? $product?->unit?->short_name ?? null,
                'customs_value' => (float) ($line->purchase_price_inc_tax ?? $line->unit_price_inc_tax ?? $line->unit_price ?? 0) * (float) ($line->quantity ?? 1),
                'duty_rate' => 0,
                'vat_rate' => 0,
            ];
        }

        $this->syncItems($clearance, $items);
    }
}