<?php

namespace Modules\Accounting\Services;

use App\HoldingEntity;
use App\Services\Holding\AssignmentQueryScopeService;
use Illuminate\Support\Facades\DB;
use Modules\Accounting\Entities\AccountingConsolidationRun;

class ConsolidationService
{
    public function __construct(
        protected HoldingEntityResolutionService $entityResolution,
        protected AssignmentQueryScopeService $assignmentScope
    ) {}

    public function run(
        int $businessId,
        string $periodStart,
        string $periodEnd,
        int $userId,
        ?int $parentEntityId = null,
        string $targetCurrencyCode = 'IRR',
        array $entityExchangeRates = [],
        string $rateMode = 'market',
        array $officialExchangeRates = []
    ): AccountingConsolidationRun {
        $entityQuery = HoldingEntity::where('business_id', $businessId)->where('is_active', true);
        $allowedEntityIds = $this->assignmentScope->allowedEntityIds();
        if ($allowedEntityIds !== null) {
            $entityQuery->whereIn('id', $allowedEntityIds);
        }
        $entities = $entityQuery->get();
        $entityBalances = [];
        $rateComparison = [];

        foreach ($entities as $entity) {
            $balance = $this->entityNetBalance($businessId, $entity, $periodStart, $periodEnd);
            $entityCurrency = (string) data_get($entity->meta, 'currency_code', $targetCurrencyCode);
            $exchangeRate = (float) ($entityExchangeRates[$entity->id] ?? 1);
            $officialRate = (float) ($officialExchangeRates[$entity->id] ?? $exchangeRate);
            if ($exchangeRate <= 0) {
                $exchangeRate = 1;
            }
            if ($officialRate <= 0) {
                $officialRate = $exchangeRate;
            }

            $convertedMarket = round($balance * $exchangeRate, 4);
            $convertedOfficial = round($balance * $officialRate, 4);
            $activeRate = $rateMode === 'official' ? $officialRate : $exchangeRate;

            $entityBalances[] = [
                'entity_id' => $entity->id,
                'entity_name' => $entity->name,
                'entity_currency' => $entityCurrency,
                'exchange_rate' => $activeRate,
                'market_rate' => $exchangeRate,
                'official_rate' => $officialRate,
                'net_balance' => $balance,
                'converted_net_balance' => round($balance * $activeRate, 4),
                'converted_market_balance' => $convertedMarket,
                'converted_official_balance' => $convertedOfficial,
                'rate_variance' => round($convertedMarket - $convertedOfficial, 4),
            ];

            if ($entityCurrency !== strtoupper($targetCurrencyCode)) {
                $rateComparison[] = [
                    'entity' => $entity->name,
                    'currency' => $entityCurrency,
                    'market_rate' => $exchangeRate,
                    'official_rate' => $officialRate,
                    'variance_pct' => $officialRate > 0 ? round((($exchangeRate - $officialRate) / $officialRate) * 100, 2) : null,
                    'balance_variance' => round($convertedMarket - $convertedOfficial, 4),
                ];
            }
        }

        $elimination = $this->estimateIntercompanyElimination($businessId, $periodStart, $periodEnd);

        return AccountingConsolidationRun::create([
            'business_id' => $businessId,
            'parent_entity_id' => $parentEntityId,
            'period_start' => $periodStart,
            'period_end' => $periodEnd,
            'currency_code' => strtoupper($targetCurrencyCode),
            'rate_mode' => $rateMode,
            'elimination_amount' => $elimination,
            'entity_balances' => $entityBalances,
            'rate_comparison' => $rateComparison,
            'status' => 'draft',
            'created_by' => $userId,
        ]);
    }

    public function readiness(int $businessId): array
    {
        $entities = HoldingEntity::where('business_id', $businessId)->where('is_active', true)->count();
        $tagging = $this->entityResolution->assessTagging($businessId);
        $fx = app(ExchangeRateService::class)->staleRateSummary($businessId);

        $issues = [];
        if ($entities === 0) {
            $issues[] = 'no_entities';
        }
        if (! $tagging['ready']) {
            $issues[] = 'untagged_gl_lines';
        }
        if (($fx['total_issues'] ?? 0) > 0) {
            $issues[] = 'stale_fx_rates';
        }

        return [
            'entities' => $entities,
            'tagging' => $tagging,
            'fx' => $fx,
            'ready' => empty($issues),
            'issues' => $issues,
        ];
    }

    public function finalize(AccountingConsolidationRun $run): AccountingConsolidationRun
    {
        $run->status = 'finalized';
        $run->save();

        return $run;
    }

    protected function entityNetBalance(int $businessId, HoldingEntity $entity, string $periodStart, string $periodEnd): float
    {
        $query = DB::table('accounting_accounts_transactions as aat')
            ->join('accounting_accounts as aa', 'aa.id', '=', 'aat.accounting_account_id')
            ->where('aa.business_id', $businessId)
            ->whereDate('aat.operation_date', '>=', $periodStart)
            ->whereDate('aat.operation_date', '<=', $periodEnd);

        $this->entityResolution->applyEntityScope($query, $businessId, $entity);

        return (float) ($query->select(DB::raw("SUM(IF(aat.type='debit', aat.amount, -1*aat.amount)) as net"))->value('net') ?? 0);
    }

    protected function estimateIntercompanyElimination(int $businessId, string $start, string $end): float
    {
        return (float) DB::table('accounting_accounts_transactions as aat')
            ->join('accounting_accounts as aa', 'aa.id', '=', 'aat.accounting_account_id')
            ->where('aa.business_id', $businessId)
            ->where('aat.source_type', 'intercompany')
            ->whereDate('aat.operation_date', '>=', $start)
            ->whereDate('aat.operation_date', '<=', $end)
            ->sum('aat.amount');
    }
}