<?php

namespace App\Http\Controllers;

use App\Models\Expense;
use App\Models\Order;
use App\Models\OrderItem;
use App\Models\Purchase;
use Carbon\Carbon;
use Inertia\Inertia;

class DashboardController extends Controller
{
    public function __invoke()
    {
        $today = Carbon::today();
        $yesterday = Carbon::yesterday();

        $stats = [
            'total_sales' => $this->getStats($today, $yesterday, fn ($date) => Order::whereDate('created_at', $date)->count()),
            'total_revenue' => $this->getStats($today, $yesterday, fn ($date) => Order::whereDate('created_at', $date)->sum('total')),
            'total_expenses' => $this->getStats($today, $yesterday, fn ($date) => Expense::whereDate('created_at', $date)->sum('amount')),
            'cogs' => $this->getStats($today, $yesterday, fn ($date) => Order::whereDate('created_at', $date)->sum('hpp')),
            'total_discount' => $this->getStats($today, $yesterday, fn ($date) => Order::whereDate('created_at', $date)->sum('discount')),
            'total_purchases' => $this->getStats($today, $yesterday, fn ($date) => Purchase::whereDate('created_at', $date)->sum('total')),
            'products_sold' => $this->getStats($today, $yesterday, fn ($date) => OrderItem::whereHas('order', fn ($q) => $q->whereDate('created_at', $date))->sum('qty')),
            'total_customers' => $this->getStats($today, $yesterday, fn ($date) => Order::whereDate('created_at', $date)->distinct('customer_name')->count('customer_name')),
        ];

        $stats['aov'] = $this->calculateAov($stats['total_revenue'], $stats['total_sales']);
        $stats['gross_profit'] = $this->calculateDiff($stats['total_revenue'], $stats['cogs']);
        $stats['net_profit'] = $this->calculateDiff($stats['gross_profit'], $stats['total_expenses']);
        $stats['profit_margin'] = $this->calculateMargin($stats['net_profit'], $stats['total_revenue']);

        return Inertia::render('dashboard', [
            'stats' => $stats,
        ]);
    }

    private function getStats($today, $yesterday, $callback): array
    {
        $todayVal = $callback($today);
        $yesterdayVal = $callback($yesterday);

        $diff = $todayVal - $yesterdayVal;
        $change = $this->calculatePercentageChange($todayVal, $yesterdayVal);

        return [
            'value' => $todayVal,
            'yesterday' => $yesterdayVal,
            'diff' => $diff,
            'change' => $change,
        ];
    }

    private function calculatePercentageChange($current, $previous): ?string
    {
        if ($previous == 0) {
            return $current == 0 ? 0 : null;
        }

        return round((($current - $previous) / abs($previous)) * 100, 2);
    }

    private function calculateAov($revenue, $sales)
    {
        $todayVal = $sales['value'] > 0 ? $revenue['value'] / $sales['value'] : 0;
        $yesterdayVal = $sales['yesterday'] > 0 ? $revenue['yesterday'] / $sales['yesterday'] : 0;

        return [
            'value' => $todayVal,
            'yesterday' => $yesterdayVal,
            'change' => $this->calculatePercentageChange($todayVal, $yesterdayVal),
        ];
    }

    private function calculateDiff($a, $b): array
    {
        $todayVal = $a['value'] - $b['value'];
        $yesterdayVal = $a['yesterday'] - $b['yesterday'];

        return [
            'value' => $todayVal,
            'yesterday' => $yesterdayVal,
            'change' => $this->calculatePercentageChange($todayVal, $yesterdayVal),
        ];
    }

    private function calculateMargin($profit, $revenue): array
    {
        $todayVal = $revenue['value'] > 0 ? ($profit['value'] / $revenue['value']) * 100 : 0;
        $yesterdayVal = $revenue['yesterday'] > 0 ? ($profit['yesterday'] / $revenue['yesterday']) * 100 : 0;

        return [
            'value' => round($todayVal, 2),
            'yesterday' => round($yesterdayVal, 2),
            'change' => $this->calculatePercentageChange($todayVal, $yesterdayVal),
        ];
    }
}