<?php

namespace App\Services;

use App\Enums\OrderStatus;
use App\Enums\PriceType;
use App\Enums\RawMaterialUnit;
use App\Models\Attendance;
use App\Models\CashAccount;
use App\Models\Employee;
use App\Models\EmployeeAdvance;
use App\Models\Expense;
use App\Models\LeaveRequest;
use App\Models\Order;
use App\Models\ProductVariant;
use App\Models\Purchase;
use App\Models\RawMaterialPrice;
use App\Models\User;
use Carbon\Carbon;
use Illuminate\Support\Facades\DB;

class AnalysisService
{
    public function getAttendanceStats(?string $startDate, ?string $endDate): array
    {
        $start = $startDate ? Carbon::parse($startDate) : Carbon::now()->startOfMonth();
        $end = $endDate ? Carbon::parse($endDate) : Carbon::now();

        $workingDays = 0;
        $current = $start->copy();

        while ($current->lte($end)) {
            if (! in_array($current->dayOfWeek, [Carbon::SATURDAY, Carbon::SUNDAY])) {
                $workingDays++;
            }
            $current->addDay();
        }

        $totalEmployees = Employee::whereHas('user', fn($q) => $q->where('is_active', true))->count();

        $present = Attendance::whereBetween('attendance_date', [$start, $end])->count();

        $leaveDays = LeaveRequest::approved()
            ->where('start_date', '<=', $end)
            ->where('end_date', '>=', $start)
            ->get()
            ->reduce(function ($carry, $leave) use ($start, $end) {
                $leaveStart = max($leave->start_date->timestamp, $start->timestamp);
                $leaveEnd = min($leave->end_date->timestamp, $end->timestamp);
                $days = Carbon::createFromTimestamp($leaveStart)->diffInDays(Carbon::createFromTimestamp($leaveEnd)) + 1;

                return $carry + max(0, $days);
            }, 0);

        $absent = max(0, $workingDays - $present - $leaveDays);

        return [
            'total_employees' => $totalEmployees,
            'present' => $present,
            'absent' => $absent,
            'on_leave' => $leaveDays,
            'percentage' => $workingDays > 0 ? round(($present / $workingDays) * 100) : 0,
        ];
    }

    public function getMyAttendance(User $user, ?string $startDate, ?string $endDate): ?array
    {
        $employee = $user->employee;

        if (! $employee) {
            return null;
        }

        $start = $startDate ? Carbon::parse($startDate) : Carbon::now()->startOfMonth();
        $end = $endDate ? Carbon::parse($endDate) : Carbon::now();

        $workingDays = 0;
        $current = $start->copy();

        while ($current->lte($end)) {
            if (! in_array($current->dayOfWeek, [Carbon::SATURDAY, Carbon::SUNDAY])) {
                $workingDays++;
            }
            $current->addDay();
        }

        $present = Attendance::where('employee_id', $employee->id)
            ->whereBetween('attendance_date', [$start, $end])
            ->count();

        $leaveDays = LeaveRequest::approved()
            ->where('employee_id', $employee->id)
            ->where('start_date', '<=', $end)
            ->where('end_date', '>=', $start)
            ->get()
            ->reduce(function ($carry, $leave) use ($start, $end) {
                $leaveStart = max($leave->start_date->timestamp, $start->timestamp);
                $leaveEnd = min($leave->end_date->timestamp, $end->timestamp);
                $days = Carbon::createFromTimestamp($leaveStart)->diffInDays(Carbon::createFromTimestamp($leaveEnd)) + 1;

                return $carry + max(0, $days);
            }, 0);

        $absent = max(0, $workingDays - $present - $leaveDays);

        return [
            'total_days' => $workingDays,
            'present_days' => $present,
            'absent_days' => $absent,
            'leave_days' => $leaveDays,
            'percentage' => $workingDays > 0 ? round(($present / $workingDays) * 100) : 0,
        ];
    }

    public function getCashOverview(): array
    {
        $cashAccount = CashAccount::first();

        if (! $cashAccount) {
            return [
                'total_balance' => 0,
                'total_transactions' => 0,
                'total_deposit' => 0,
                'total_withdrawal' => 0,
            ];
        }

        $transactions = $cashAccount->cashTransactions();

        return [
            'total_balance' => $cashAccount->balance,
            'total_transactions' => (clone $transactions)->count(),
            'total_deposit' => (int) (clone $transactions)->where('type', 'deposit')->sum('amount'),
            'total_withdrawal' => (int) (clone $transactions)->where('type', 'withdrawal')->sum('amount'),
        ];
    }

    public function getRawMaterialStock(): array
    {
        $prices = RawMaterialPrice::select('stock', 'price', 'raw_material_id')
            ->with('rawMaterial:id,unit')
            ->get();

        $totalStock = $prices->sum('stock');
        $totalValue = $prices->sum(fn($p) => $p->stock * $p->price);

        $byUnit = [
            'yard' => $prices->filter(fn($p) => $p->rawMaterial?->unit === RawMaterialUnit::YARD)->sum('stock'),
            'meter' => $prices->filter(fn($p) => $p->rawMaterial?->unit === RawMaterialUnit::METER)->sum('stock'),
            'kilogram' => $prices->filter(fn($p) => $p->rawMaterial?->unit === RawMaterialUnit::KG)->sum('stock'),
        ];

        return [
            'total_stock' => $totalStock,
            'total_value' => $totalValue,
            'by_unit' => $byUnit,
        ];
    }

    public function getProductStock(): array
    {
        $variants = ProductVariant::select('id', 'product_id', 'stock', 'reject_stock', 'retail_stock')
            ->with(['product:id,name', 'productPrices' => fn ($q) => $q->where('type', PriceType::CAPITAL)])
            ->get();

        $totalStock = $variants->sum('stock');
        $totalReject = $variants->sum('reject_stock');
        $totalRetail = $variants->sum('retail_stock');

        $totalValue = $variants->sum(function ($v) {
            $capitalPrice = $v->productPrices->first()?->price ?? 0;

            return $v->stock * $capitalPrice;
        });

        return [
            'total_stock' => $totalStock,
            'total_reject' => $totalReject,
            'total_retail' => $totalRetail,
            'total_value' => $totalValue,
            'total_products' => ProductVariant::distinct('product_id')->count('product_id'),
            'total_variants' => ProductVariant::count(),
            'total_categories' => DB::table('product_categories')->distinct('category_id')->count('category_id'),
        ];
    }

    public function getRevenueSummary(?string $startDate, ?string $endDate): array
    {
        $query = Order::where('orders.status', OrderStatus::COMPLETED);
        $this->applyDateFilter($query, $startDate, $endDate);

        $stats = (clone $query)
            ->selectRaw('COUNT(*) as total_orders')
            ->selectRaw('COALESCE(SUM(total_amount), 0) as total_revenue')
            ->selectRaw('COALESCE(SUM(discount), 0) as total_discount')
            ->selectRaw('COALESCE(SUM(discount), 0) as total_deduction')
            ->selectRaw('COALESCE(SUM(total_amount) - SUM(discount), 0) as net')
            ->selectRaw("COALESCE(SUM(CASE WHEN price_type != 'retail' THEN total_amount ELSE 0 END), 0) as net_warehouse")
            ->selectRaw("COALESCE(SUM(CASE WHEN price_type = 'retail' THEN total_amount ELSE 0 END), 0) as net_retail")
            ->first();

        return [
            'total_revenue' => (int) $stats->total_revenue,
            'total_discount' => (int) $stats->total_discount,
            'total_deduction' => (int) $stats->total_deduction,
            'net' => (int) $stats->net,
            'net_warehouse' => (int) $stats->net_warehouse,
            'net_retail' => (int) $stats->net_retail,
            'total_orders' => (int) $stats->total_orders,
            'avg_order' => $stats->total_orders > 0 ? (int) ($stats->total_revenue / $stats->total_orders) : 0,
        ];
    }

    public function getMonthlyRevenue(?string $startDate, ?string $endDate): array
    {
        $query = Order::where('orders.status', OrderStatus::COMPLETED);
        $this->applyDateFilter($query, $startDate, $endDate);

        $monthly = (clone $query)
            ->selectRaw("DATE_FORMAT(created_at, '%b %Y') as month")
            ->selectRaw('COALESCE(SUM(total_amount), 0) as total')
            ->selectRaw('COALESCE(SUM(total_amount) - SUM(discount), 0) as net')
            ->selectRaw("COALESCE(SUM(CASE WHEN price_type != 'retail' THEN total_amount ELSE 0 END), 0) as net_warehouse")
            ->selectRaw("COALESCE(SUM(CASE WHEN price_type = 'retail' THEN total_amount ELSE 0 END), 0) as net_retail")
            ->selectRaw('COALESCE(SUM(discount), 0) as deduction')
            ->groupBy(DB::raw("DATE_FORMAT(created_at, '%Y-%m')"), DB::raw("DATE_FORMAT(created_at, '%b %Y')"))
            ->orderBy(DB::raw("DATE_FORMAT(created_at, '%Y-%m')"))
            ->get()
            ->map(fn($item) => $item->only(['month', 'total', 'net', 'net_warehouse', 'net_retail', 'deduction']));

        return $monthly->values()->toArray();
    }

    public function getMonthlyRevenueByChannel(?string $startDate, ?string $endDate): array
    {
        $query = Order::where('orders.status', OrderStatus::COMPLETED);
        $this->applyDateFilter($query, $startDate, $endDate);

        $monthly = (clone $query)
            ->selectRaw("DATE_FORMAT(created_at, '%b %Y') as month")
            ->selectRaw("SUM(CASE WHEN channel = 'store' THEN total_amount ELSE 0 END) as store")
            ->selectRaw("SUM(CASE WHEN channel = 'shopee' THEN total_amount ELSE 0 END) as shopee")
            ->selectRaw("SUM(CASE WHEN channel = 'tiktok' THEN total_amount ELSE 0 END) as tiktok")
            ->groupBy(DB::raw("DATE_FORMAT(created_at, '%Y-%m')"), DB::raw("DATE_FORMAT(created_at, '%b %Y')"))
            ->orderBy(DB::raw("DATE_FORMAT(created_at, '%Y-%m')"))
            ->get()
            ->map(fn($item) => $item->only(['month', 'store', 'shopee', 'tiktok']));

        return $monthly->values()->toArray();
    }

    public function getRevenueByPaymentType(?string $startDate, ?string $endDate): array
    {
        $query = Order::where('orders.status', OrderStatus::COMPLETED);
        $this->applyDateFilter($query, $startDate, $endDate);

        $data = (clone $query)
            ->select('payment_type')
            ->selectRaw('COALESCE(SUM(total_amount), 0) as total')
            ->groupBy('payment_type')
            ->get()
            ->map(fn($item) => [
                'payment_type' => $item->payment_type,
                'label' => $item->payment_type->label(),
                'total' => (int) $item->total,
            ]);

        return $data->toArray();
    }

    public function getExpenseSummary(?string $startDate, ?string $endDate): array
    {
        $expenseQuery = Expense::query();
        $this->applyDateFilter($expenseQuery, $startDate, $endDate);

        $advanceQuery = EmployeeAdvance::where('status', 'paid');
        $this->applyDateFilter($advanceQuery, $startDate, $endDate);

        $purchaseQuery = Purchase::query();
        $this->applyDateFilter($purchaseQuery, $startDate, $endDate);

        $expenseTotal = (clone $expenseQuery)->sum('amount');
        $advanceTotal = (clone $advanceQuery)->sum('amount');
        $purchaseTotal = (clone $purchaseQuery)->sum('total');

        return [
            'total' => $expenseTotal + $advanceTotal + $purchaseTotal,
            'purchase_total' => $purchaseTotal,
            'expense_total' => $expenseTotal,
            'advance_total' => $advanceTotal,
        ];
    }

    public function getMonthlyExpense(?string $startDate, ?string $endDate): array
    {
        $expenseMonthly = Expense::query();
        $this->applyDateFilter($expenseMonthly, $startDate, $endDate);

        $expenseByMonth = (clone $expenseMonthly)->toBase()
            ->selectRaw("DATE_FORMAT(created_at, '%b %Y') as month")
            ->selectRaw('COALESCE(SUM(amount), 0) as expense')
            ->groupBy(DB::raw("DATE_FORMAT(created_at, '%Y-%m')"), DB::raw("DATE_FORMAT(created_at, '%b %Y')"))
            ->get()
            ->keyBy('month');

        $purchaseMonthly = Purchase::query();
        $this->applyDateFilter($purchaseMonthly, $startDate, $endDate);

        $purchaseByMonth = (clone $purchaseMonthly)->toBase()
            ->selectRaw("DATE_FORMAT(created_at, '%b %Y') as month")
            ->selectRaw('COALESCE(SUM(total), 0) as purchase')
            ->groupBy(DB::raw("DATE_FORMAT(created_at, '%Y-%m')"), DB::raw("DATE_FORMAT(created_at, '%b %Y')"))
            ->get()
            ->keyBy('month');

        $advanceMonthly = EmployeeAdvance::where('status', 'paid');
        $this->applyDateFilter($advanceMonthly, $startDate, $endDate);

        $advanceByMonth = (clone $advanceMonthly)->toBase()
            ->selectRaw("DATE_FORMAT(created_at, '%b %Y') as month")
            ->selectRaw('COALESCE(SUM(amount), 0) as advance')
            ->groupBy(DB::raw("DATE_FORMAT(created_at, '%Y-%m')"), DB::raw("DATE_FORMAT(created_at, '%b %Y')"))
            ->get()
            ->keyBy('month');

        $allMonths = [];
        foreach ([$expenseByMonth, $purchaseByMonth, $advanceByMonth] as $data) {
            foreach ($data as $month => $row) {
                if (! array_key_exists($month, $allMonths)) {
                    $allMonths[$month] = ['month' => $month, 'total' => 0, 'purchase' => 0, 'expense' => 0, 'advance' => 0];
                }
            }
        }

        foreach ($allMonths as $month => &$row) {
            $row['purchase'] = (int) ($purchaseByMonth[$month]->purchase ?? 0);
            $row['expense'] = (int) ($expenseByMonth[$month]->expense ?? 0);
            $row['advance'] = (int) ($advanceByMonth[$month]->advance ?? 0);
            $row['total'] = $row['purchase'] + $row['expense'] + $row['advance'];
        }

        return array_values($allMonths);
    }

    public function getBusyHours(?string $startDate, ?string $endDate): array
    {
        $query = Order::where('orders.status', OrderStatus::COMPLETED);
        $this->applyDateFilter($query, $startDate, $endDate);

        $hours = range(0, 23);
        $hourCounts = (clone $query)
            ->selectRaw('HOUR(created_at) as hour')
            ->selectRaw('COUNT(*) as orders')
            ->groupBy(DB::raw('HOUR(created_at)'))
            ->pluck('orders', 'hour')
            ->toArray();

        return array_map(function ($h) use ($hourCounts) {
            return [
                'hour' => sprintf('%02d:00', $h),
                'orders' => (int) ($hourCounts[$h] ?? 0),
            ];
        }, $hours);
    }

    public function getProfitMetrics(?string $startDate, ?string $endDate): array
    {
        $query = Order::where('orders.status', OrderStatus::COMPLETED);
        $this->applyDateFilter($query, $startDate, $endDate);

        $stats = (clone $query)
            ->selectRaw('COUNT(*) as total_orders')
            ->selectRaw('COALESCE(SUM(total_amount), 0) as total_revenue')
            ->selectRaw('COALESCE(SUM(cogs), 0) as hpp')
            ->first();

        $totalProductsSold = (clone $query)
            ->join('order_items', 'orders.id', '=', 'order_items.order_id')
            ->sum('order_items.quantity');

        $grossProfit = $stats->total_revenue - $stats->hpp;
        $netProfit = $grossProfit;
        $profitMargin = $stats->total_revenue > 0 ? round(($netProfit / $stats->total_revenue) * 100, 1) : 0;
        $aov = $stats->total_orders > 0 ? (int) ($stats->total_revenue / $stats->total_orders) : 0;
        $itemsPerTransaction = $stats->total_orders > 0 ? round($totalProductsSold / $stats->total_orders, 1) : 0;

        return [
            'total_orders' => (int) $stats->total_orders,
            'total_products_sold' => (int) $totalProductsSold,
            'hpp' => (int) $stats->hpp,
            'gross_profit' => (int) $grossProfit,
            'net_profit' => (int) $netProfit,
            'profit_margin' => $profitMargin,
            'aov' => $aov,
            'items_per_transaction' => $itemsPerTransaction,
        ];
    }

    public function getTopSuppliers(?string $startDate, ?string $endDate): array
    {
        $query = Purchase::query();
        $this->applyDateFilter($query, $startDate, $endDate);

        return (clone $query)->toBase()
            ->join('suppliers', 'purchases.supplier_id', '=', 'suppliers.id')
            ->select('suppliers.name')
            ->selectRaw('COALESCE(SUM(purchases.total), 0) as total_amount')
            ->selectRaw('COUNT(*) as purchase_count')
            ->groupBy('suppliers.name')
            ->orderByDesc('total_amount')
            ->limit(5)
            ->get()
            ->toArray();
    }

    public function getTopCustomers(?string $startDate, ?string $endDate): array
    {
        $query = Order::where('orders.status', OrderStatus::COMPLETED)->whereNotNull('orders.customer_id');
        $this->applyDateFilter($query, $startDate, $endDate);

        return (clone $query)->toBase()
            ->join('customers', 'orders.customer_id', '=', 'customers.id')
            ->select('customers.name')
            ->selectRaw('COALESCE(SUM(orders.total_amount), 0) as total_amount')
            ->selectRaw('COUNT(*) as order_count')
            ->groupBy('customers.name')
            ->orderByDesc('total_amount')
            ->limit(5)
            ->get()
            ->toArray();
    }

    public function getTopProducts(?string $startDate, ?string $endDate): array
    {
        $query = Order::where('orders.status', OrderStatus::COMPLETED);
        $this->applyDateFilter($query, $startDate, $endDate);

        return (clone $query)->toBase()
            ->join('order_items', 'orders.id', '=', 'order_items.order_id')
            ->join('product_variants', 'order_items.product_variant_id', '=', 'product_variants.id')
            ->join('products', 'product_variants.product_id', '=', 'products.id')
            ->select('products.name')
            ->selectRaw('SUM(order_items.quantity) as total_qty')
            ->selectRaw('COALESCE(SUM(order_items.subtotal), 0) as total_revenue')
            ->groupBy('products.name')
            ->orderByDesc('total_qty')
            ->limit(5)
            ->get()
            ->toArray();
    }

    public function getMarketingSales(?string $startDate, ?string $endDate): array
    {
        $query = Order::where('orders.status', OrderStatus::COMPLETED)
            ->whereNotNull('orders.marketing_id');
        $this->applyDateFilter($query, $startDate, $endDate);

        return (clone $query)->toBase()
            ->join('users', 'orders.marketing_id', '=', 'users.id')
            ->leftJoin('user_profiles', 'users.id', '=', 'user_profiles.user_id')
            ->leftJoin('order_items', 'orders.id', '=', 'order_items.order_id')
            ->select('user_profiles.full_name as marketing_name')
            ->selectRaw('COUNT(DISTINCT orders.id) as total_orders')
            ->selectRaw('COALESCE(SUM(order_items.quantity), 0) as total_products_sold')
            ->selectRaw('COALESCE(SUM(orders.total_amount), 0) as total_revenue')
            ->selectRaw('COALESCE(SUM(orders.subtotal), 0) as total_subtotal')
            ->selectRaw('COALESCE(SUM(orders.discount), 0) as total_discount')
            ->selectRaw('ROUND(COALESCE(SUM(orders.total_amount), 0) / COUNT(DISTINCT orders.id)) as avg_order')
            ->groupBy('user_profiles.full_name')
            ->orderByDesc('total_revenue')
            ->get()
            ->toArray();
    }

    private function applyDateFilter($query, ?string $startDate, ?string $endDate, string $dateColumn = 'created_at'): void
    {
        if ($startDate) {
            $query->whereDate($dateColumn, '>=', $startDate);
        }
        if ($endDate) {
            $query->whereDate($dateColumn, '<=', $endDate);
        }
    }
}