// DragonX Wallet - ImGui Edition
// Copyright 2024-2026 The Hush Developers
// Released under the GPLv3

#include "transaction_csv.h"

#include <cstdio>
#include <ctime>

namespace dragonx {
namespace data {

std::string escapeCsvField(const std::string& field)
{
    // Neutralize spreadsheet formula injection: a field beginning with '=', '+', '-', '@',
    // tab, or CR is interpreted as a formula by Excel/LibreOffice, letting an attacker-supplied
    // memo/address execute on open. Prefix such fields with a single quote so they render as text.
    std::string safe = field;
    if (!safe.empty()) {
        const char c0 = safe.front();
        if (c0 == '=' || c0 == '+' || c0 == '-' || c0 == '@' || c0 == '\t' || c0 == '\r')
            safe.insert(safe.begin(), '\'');
    }
    if (safe.find(',') != std::string::npos ||
        safe.find('"') != std::string::npos ||
        safe.find('\n') != std::string::npos) {
        std::string escaped;
        escaped.reserve(safe.size() + 4);
        escaped += '"';
        for (char c : safe) {
            if (c == '"') escaped += "\"\"";
            else escaped += c;
        }
        escaped += '"';
        return escaped;
    }
    return safe;
}

std::string formatTransactionsCsv(const std::vector<TransactionInfo>& txs)
{
    std::string out;
    out.reserve(64 + txs.size() * 200);
    out += "Date,Type,Amount,Address,TXID,Confirmations,Memo\n";
    for (const auto& tx : txs) {
        std::time_t t = static_cast<std::time_t>(tx.timestamp);
        std::tm tmv{};
#ifdef _WIN32
        const bool okTm = localtime_s(&tmv, &t) == 0;
#else
        const bool okTm = localtime_r(&t, &tmv) != nullptr;
#endif
        char datebuf[32] = "";
        if (okTm) std::strftime(datebuf, sizeof(datebuf), "%Y-%m-%d %H:%M:%S", &tmv);
        char amt[48];
        std::snprintf(amt, sizeof(amt), "%.8f", tx.amount);
        out += datebuf; out += ',';
        out += escapeCsvField(tx.type); out += ',';
        out += amt; out += ',';
        out += escapeCsvField(tx.address); out += ',';
        out += escapeCsvField(tx.txid); out += ',';
        out += std::to_string(tx.confirmations); out += ',';
        out += escapeCsvField(tx.memo); out += '\n';
    }
    return out;
}

} // namespace data
} // namespace dragonx