<?php
require_once __DIR__ . '/../db/config.php';

function settleMining($userId) {
    $db = db();
    try {
        $db->beginTransaction();
        
        // Find all running orders for this user
        $stmt = $db->prepare("SELECT * FROM staking_records WHERE user_id = ? AND status = 'running' FOR UPDATE");
        $stmt->execute([$userId]);
        $orders = $stmt->fetchAll();
        
        $now = new DateTime();
        
        foreach ($orders as $order) {
            $lastSettle = new DateTime($order['last_settle_time'] ?: $order['created_at']);
            $diff = $now->getTimestamp() - $lastSettle->getTimestamp();
            
            if ($diff <= 0) continue;
            
            // Daily profit is a percentage (e.g. 0.02 is 2% daily)
            // But looking at the SQL dump: daily_profit was 0.02 for "ETH矿池" which had "8.2%" APY.
            // 8.2 / 365 = 0.02246... so 0.02 seems to be the daily percentage.
            
            $dailyRate = $order['daily_profit'] / 100;
            $profit = $order['amount'] * $dailyRate * ($diff / 86400);
            
            if ($profit > 0.00000001) {
                // Update balance
                $stmt = $db->prepare("UPDATE user_balances SET available = available + ? WHERE user_id = ? AND symbol = ?");
                $stmt->execute([$profit, $userId, $order['symbol']]);
                
                // Add transaction record
                $stmt = $db->prepare("INSERT INTO transactions (user_id, symbol, type, amount, status) VALUES (?, ?, ?, ?, ?)");
                $stmt->execute([$userId, $order['symbol'], 'mining_profit', $profit, 'completed']);
                
                // Update staking record
                $stmt = $db->prepare("UPDATE staking_records SET total_profit = total_profit + ?, last_settle_time = NOW() WHERE id = ?");
                $stmt->execute([$profit, $order['id']]);
                
                // Check if it reached end_date
                $endDate = new DateTime($order['end_date']);
                if ($now >= $endDate) {
                    $stmt = $db->prepare("UPDATE staking_records SET status = 'ended' WHERE id = ?");
                    $stmt->execute([$order['id']]);
                    
                    // Return principal
                    $stmt = $db->prepare("UPDATE user_balances SET frozen = frozen - ?, available = available + ? WHERE user_id = ? AND symbol = ?");
                    $stmt->execute([$order['amount'], $order['amount'], $userId, $order['symbol']]);
                    
                    $stmt = $db->prepare("INSERT INTO transactions (user_id, symbol, type, amount, status) VALUES (?, ?, ?, ?, ?)");
                    $stmt->execute([$userId, $order['symbol'], 'mining_return', $order['amount'], 'completed']);
                }
            }
        }
        
        $db->commit();
    } catch (Exception $e) {
        if ($db->inTransaction()) $db->rollBack();
        error_log("Mining settlement failed for user $userId: " . $e->getMessage());
    }
}