<?php

namespace Modules\Webstatement\Services;

use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Carbon\Carbon;
use Modules\Webstatement\Models\AccountBalance;
use Modules\Webstatement\Models\StmtEntry;

class AccountBalanceService
{
    /**
     * Get balance summary (opening and closing balance)
     *
     * @param string $accountNumber
     * @param string $startDate
     * @param string $endDate
     * @return array
     */
    public function getBalanceSummary(string $accountNumber, string $startDate, string $endDate): array
    {
        return DB::transaction(function () use ($accountNumber, $startDate, $endDate) {
            Log::info('Calculating balance summary', [
                'account_number' => $accountNumber,
                'start_date'     => $startDate,
                'end_date'       => $endDate
            ]);

              // Convert dates to Carbon instances
            $startDateCarbon = Carbon::parse($startDate);
            $endDateCarbon   = Carbon::parse($endDate);

              // Get opening balance (balance from previous day)
            $openingBalanceDate = $startDateCarbon->copy()->subDay();
            $openingBalance     = $this->getAccountBalance($accountNumber, $openingBalanceDate);

              // Get closing balance date (previous day from end date)
            $closingBalanceDate = $endDateCarbon->copy()->subDay();
            $closingBalanceBase = $this->getAccountBalance($accountNumber, $closingBalanceDate);

              // Get transactions on end date
            $transactionsOnEndDate = $this->getTransactionsOnDate($accountNumber, $endDate);

              // Calculate closing balance
            $closingBalance = $closingBalanceBase + $transactionsOnEndDate;

            $result = [
                'account_number' => $accountNumber,
                'period'         => [
                    'start_date' => $startDate,
                    'end_date'   => $endDate
                ],
                'opening_balance' => [
                    'date'              => $openingBalanceDate->format('Y-m-d'),
                    'balance'           => $openingBalance,
                    'formatted_balance' => number_format($openingBalance, 2)
                ],
                'closing_balance' => [
                    'date'              => $endDate,
                    'balance'           => $closingBalance,
                    'formatted_balance' => number_format($closingBalance, 2),
                    'base_balance'      => [
                        'date'              => $closingBalanceDate->format('Y-m-d'),
                        'balance'           => $closingBalanceBase,
                        'formatted_balance' => number_format($closingBalanceBase, 2)
                    ],
                    'transactions_on_end_date'           => $transactionsOnEndDate,
                    'formatted_transactions_on_end_date' => number_format($transactionsOnEndDate, 2)
                ]
            ];

            Log::info('Balance summary calculated successfully', $result);

            return $result;
        });
    }

    /**
     * Get account balance for specific date
     *
     * @param string $accountNumber
     * @param Carbon $date
     * @return float
     */
    private function getAccountBalance(string $accountNumber, Carbon $date): float
    {
        $balance = AccountBalance::where('account_number', $accountNumber)
            ->where('period', $date->format('Ymd'))
            ->value('actual_balance');

        if ($balance === null) {
            Log::warning('Account balance not found', [
                'account_number' => $accountNumber,
                'date'           => $date->format('Y-m-d'),
                'period'         => $date->format('Ymd')
            ]);
            return 0.00;
        }

        return (float) $balance;
    }

    /**
     * Get transactions on specific date
     *
     * @param string $accountNumber
     * @param string $date
     * @return float
     */
    private function getTransactionsOnDate(string $accountNumber, string $date): float
    {
        $total = StmtEntry::where('account_number', $accountNumber)
            ->whereDate('value_date', $date)
            ->sum(DB::raw('CAST(amount_lcy AS DECIMAL(15,2))'));

        return (float) $total;
    }

    /**
     * Validate if account exists
     *
     * @param string $accountNumber
     * @return bool
     */
    public function validateAccount(string $accountNumber): bool
    {
        return AccountBalance::where('account_number', $accountNumber)->exists();
    }
}