<?php

namespace Modules\AssetExchange\Services;

use Carbon\Carbon;
use Modules\AssetExchange\Models\Appraisal;
use Modules\AssetExchange\Models\AppraisalLine;

class ValuationEngine
{
    public function defaultSettings(): array
    {
        return [
            'depreciation_rate_machine' => 0.08,
            'depreciation_rate_line' => 0.10,
            'min_age_factor' => 0.3,
            'target_health_factor' => 0.9,
            'renovation_multipliers' => [
                'none' => 0.0,
                'minor' => 0.05,
                'major' => 0.25,
                'replace' => 1.0,
            ],
            'labor_rate_per_hour' => 0,
            'buy_margin_percent' => 15,
            'sell_margin_percent' => 20,
        ];
    }

    public function resolveSettings(array $businessSettings = []): array
    {
        return array_merge($this->defaultSettings(), $businessSettings);
    }

    /**
     * @return array{health_factor: float, age_factor: float, line_as_is_value: int, renovation_cost: int, line_post_renovation_value: int, age_years: float|null}
     */
    public function calculateLineValue(AppraisalLine $line, array $settings = []): array
    {
        $settings = $this->resolveSettings($settings);

        $replacementCost = max(0, (int) $line->replacement_cost);
        $healthPct = $line->health_percentage !== null ? (float) $line->health_percentage : 100.0;
        $healthFactor = max(0, min(1, $healthPct / 100));

        $ageYears = $this->resolveAgeYears($line);
        $depRate = (float) ($line->depreciation_rate ?: $this->depreciationRateForLine($line, $settings));
        $minAgeFactor = (float) $settings['min_age_factor'];
        $ageFactor = $ageYears !== null
            ? max($minAgeFactor, 1 - ($ageYears * $depRate))
            : 1.0;

        $renovationCost = $this->estimateRenovationCost($line, $replacementCost, $settings);
        $targetHealth = (float) $settings['target_health_factor'];
        $postRenovationValue = (int) round($replacementCost * $targetHealth);

        $asIsValue = (int) round($replacementCost * $healthFactor * $ageFactor);

        if ($line->renovation_need === 'replace') {
            $asIsValue = (int) round($asIsValue * 0.5);
        }

        return [
            'health_factor' => round($healthFactor, 4),
            'age_factor' => round($ageFactor, 4),
            'age_years' => $ageYears,
            'line_as_is_value' => $asIsValue,
            'renovation_cost' => $renovationCost,
            'line_post_renovation_value' => $postRenovationValue,
        ];
    }

    /**
     * @return array{as_is_value: int, renovation_cost_estimate: int, post_renovation_value: int, recommended_buy_price: int, recommended_sell_price: int, line_count: int}
     */
    public function rollupAppraisal(Appraisal $appraisal, array $settings = []): array
    {
        $settings = $this->resolveSettings($settings);
        $appraisal->loadMissing('lines');

        $asIsTotal = 0;
        $renovationTotal = 0;
        $postRenovationTotal = 0;
        $counted = 0;

        foreach ($appraisal->lines as $line) {
            if (! $line->keep_in_line) {
                continue;
            }

            $values = $this->calculateLineValue($line, $settings);
            $line->fill([
                'age_years' => $values['age_years'],
                'line_as_is_value' => $values['line_as_is_value'],
                'renovation_cost' => $values['renovation_cost'],
                'line_post_renovation_value' => $values['line_post_renovation_value'],
            ]);
            $line->save();

            $asIsTotal += $values['line_as_is_value'];
            $renovationTotal += $values['renovation_cost'];
            $postRenovationTotal += $values['line_post_renovation_value'];
            $counted++;
        }

        $buyMargin = (float) ($settings['buy_margin_percent'] ?? 15);
        $sellMargin = (float) ($settings['sell_margin_percent'] ?? 20);

        return [
            'as_is_value' => $asIsTotal,
            'renovation_cost_estimate' => $renovationTotal,
            'post_renovation_value' => $postRenovationTotal,
            'recommended_buy_price' => (int) round($asIsTotal * (1 - ($buyMargin / 100))),
            'recommended_sell_price' => (int) round($postRenovationTotal * (1 + ($sellMargin / 100))),
            'line_count' => $counted,
        ];
    }

    protected function resolveAgeYears(AppraisalLine $line): ?float
    {
        if ($line->age_years !== null) {
            return (float) $line->age_years;
        }

        if ($line->year_manufactured) {
            return max(0, (float) (Carbon::now()->year - (int) $line->year_manufactured));
        }

        return null;
    }

    protected function depreciationRateForLine(AppraisalLine $line, array $settings): float
    {
        return in_array($line->line_kind, ['machine', 'subsystem'], true)
            ? (float) $settings['depreciation_rate_machine']
            : (float) $settings['depreciation_rate_line'];
    }

    protected function estimateRenovationCost(AppraisalLine $line, int $replacementCost, array $settings): int
    {
        $need = $line->renovation_need ?: 'none';
        $multipliers = $settings['renovation_multipliers'] ?? [];
        $multiplier = (float) ($multipliers[$need] ?? 0);

        $base = (int) round($replacementCost * $multiplier);

        if ($need === 'replace') {
            return max($base, $replacementCost);
        }

        $laborHours = match ($need) {
            'minor' => 4,
            'major' => 24,
            default => 0,
        };

        $laborCost = (int) round($laborHours * (float) ($settings['labor_rate_per_hour'] ?? 0));

        return $base + $laborCost;
    }
}