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

#include "export_transactions_dialog.h"
#include "../../app.h"
#include "../../util/i18n.h"
#include "../../util/platform.h"
#include "../../data/transaction_csv.h"
#include "transactions_tab.h"
#include "../notifications.h"
#include "../schema/ui_schema.h"
#include "../material/draw_helpers.h"
#include "../material/type.h"
#include "../widgets/copy_field.h"
#include "../theme.h"
#include "../../embedded/IconsMaterialDesign.h"
#include "imgui.h"

#include <string>
#include <ctime>
#include <algorithm>
#include <cctype>

namespace dragonx {
namespace ui {

// Static state
static bool s_open = false;
static char s_filename[256] = "";
static std::string s_saved_path;   // full path on success (shown as a copy field); empty otherwise
static std::string s_error;        // error message on failure; empty otherwise
static int  s_scope = 0;           // 0 = all, 1 = current History filter, 2 = date range
static char s_from[16] = "";       // YYYY-MM-DD (date-range scope)
static char s_to[16]   = "";

// Parse a YYYY-MM-DD string to the local-time start-of-day unix seconds. Returns false on empty/invalid.
static bool parseYmd(const char* s, std::int64_t& outStartOfDay) {
    if (!s || !*s) return false;
    int y = 0, mo = 0, d = 0;
    if (std::sscanf(s, "%d-%d-%d", &y, &mo, &d) != 3) return false;
    if (y < 1970 || y > 9999 || mo < 1 || mo > 12 || d < 1 || d > 31) return false;
    std::tm tm{}; tm.tm_year = y - 1900; tm.tm_mon = mo - 1; tm.tm_mday = d; tm.tm_isdst = -1;
    std::time_t t = std::mktime(&tm);
    if (t == (std::time_t)-1) return false;
    // Reject rollover (e.g. Feb 31 → Mar) by requiring the normalized fields to round-trip.
    if (tm.tm_year != y - 1900 || tm.tm_mon != mo - 1 || tm.tm_mday != d) return false;
    outStartOfDay = (std::int64_t)t;
    return true;
}

// Make a user-typed filename safe to write into the config dir: basename only, illegal chars → '_',
// no leading dots / trailing dots-or-spaces, length-capped, always ending in .csv.
static std::string sanitizeExportFilename(std::string name) {
    const size_t slash = name.find_last_of("/\\");
    if (slash != std::string::npos) name = name.substr(slash + 1);
    auto notspace = [](unsigned char c) { return !std::isspace(c); };
    name.erase(name.begin(), std::find_if(name.begin(), name.end(), notspace));
    name.erase(std::find_if(name.rbegin(), name.rend(), notspace).base(), name.end());
    for (char& c : name) {
        const unsigned char u = static_cast<unsigned char>(c);
        if (u < 0x20 || c == '<' || c == '>' || c == ':' || c == '"' || c == '|' || c == '?' || c == '*')
            c = '_';
    }
    const size_t firstGood = name.find_first_not_of('.');
    if (firstGood == std::string::npos) name.clear(); else name.erase(0, firstGood);
    while (!name.empty() && (name.back() == '.' || name.back() == ' ')) name.pop_back();
    if (name.size() > 120) name.resize(120);
    std::string lower = name;
    std::transform(lower.begin(), lower.end(), lower.begin(),
                   [](unsigned char c) { return static_cast<char>(std::tolower(c)); });
    if (lower.size() < 4 || lower.compare(lower.size() - 4, 4, ".csv") != 0) name += ".csv";
    if (name.empty() || name == ".csv") name = "dragonx_transactions.csv";
    return name;
}

void ExportTransactionsDialog::show()
{
    s_open = true;
    s_saved_path.clear();
    s_error.clear();
    // Pre-select the current History filter only when one is actually applied.
    s_scope = GetTransactionsFilterSnapshot().active ? 1 : 0;
    s_from[0] = '\0';
    s_to[0] = '\0';

    // Generate default filename with timestamp
    std::time_t now = std::time(nullptr);
    char timebuf[32];
    std::tm nowTm{};
#ifdef _WIN32
    const bool nowOk = localtime_s(&nowTm, &now) == 0;
#else
    const bool nowOk = localtime_r(&now, &nowTm) != nullptr;
#endif
    timebuf[0] = '\0';
    if (nowOk) std::strftime(timebuf, sizeof(timebuf), "%Y%m%d_%H%M%S", &nowTm);
    snprintf(s_filename, sizeof(s_filename), "dragonx_transactions_%s.csv", timebuf);
}

bool ExportTransactionsDialog::isOpen()
{
    return s_open;
}

void ExportTransactionsDialog::hide()
{
    s_open = false;
    s_saved_path.clear();
    s_error.clear();
}

void ExportTransactionsDialog::render(App* app)
{
    if (!s_open) return;
    namespace m = material;

    m::OverlayDialogSpec ov;
    ov.title     = TR("export_tx_title");
    ov.p_open    = &s_open;
    ov.style     = m::OverlayStyle::BlurFloat;
    ov.cardWidth = 520.0f;
    ov.idSuffix  = "exporttx";
    if (!m::BeginOverlayDialog(ov)) return;

    const auto& state = app->getWalletState();
    const TxFilterSnapshot& snap = GetTransactionsFilterSnapshot();
    const bool filterUsable = snap.valid && snap.active && snap.txRevision == state.tx_revision;

    // ---- Export scope ----
    ImGui::TextColored(ImGui::ColorConvertU32ToFloat4(m::OnSurfaceMedium()), "%s", TR("export_tx_scope"));
    ImGui::RadioButton(TR("export_tx_scope_all"), &s_scope, 0);
    if (!filterUsable) ImGui::BeginDisabled();
    ImGui::RadioButton(TR("export_tx_scope_filter"), &s_scope, 1);
    if (!filterUsable) ImGui::EndDisabled();
    if (ImGui::IsItemHovered(ImGuiHoveredFlags_AllowWhenDisabled) && !filterUsable)
        m::Tooltip("%s", TR("export_tx_scope_filter_none"));
    if (s_scope == 1 && filterUsable && !snap.description.empty()) {
        ImGui::SameLine();
        ImGui::TextColored(ImGui::ColorConvertU32ToFloat4(m::OnSurfaceDisabled()), "(%s)", snap.description.c_str());
    }
    ImGui::RadioButton(TR("export_tx_scope_range"), &s_scope, 2);

    std::int64_t fromT = 0, toT = 0; bool fromOk = false, toOk = false, rangeBad = false;
    if (s_scope == 2) {
        ImGui::Indent();
        const float dw = 130.0f * Layout::dpiScale();
        ImGui::SetNextItemWidth(dw);
        ImGui::InputTextWithHint("##exfrom", TR("export_tx_range_from"), s_from, sizeof(s_from));
        ImGui::SameLine();
        ImGui::SetNextItemWidth(dw);
        ImGui::InputTextWithHint("##exto", TR("export_tx_range_to"), s_to, sizeof(s_to));
        fromOk = parseYmd(s_from, fromT);
        toOk   = parseYmd(s_to, toT);
        if (toOk) toT += 24 * 3600 - 1;   // inclusive end-of-day
        if ((s_from[0] && !fromOk) || (s_to[0] && !toOk)) rangeBad = true;
        if (fromOk && toOk && fromT > toT) rangeBad = true;
        if (rangeBad)
            ImGui::TextColored(m::ErrorVec4(), "%s", TR("export_tx_range_invalid"));
        else
            ImGui::TextColored(ImGui::ColorConvertU32ToFloat4(m::OnSurfaceDisabled()), "%s", TR("export_tx_range_pending_note"));
        ImGui::Unindent();
    }

    // Resolve the subset for the chosen scope (scopeOk=false ⇒ can't export: stale snapshot / bad range).
    std::vector<size_t> subsetIdx; bool scopeOk = true;
    if (s_scope == 1) {
        if (!filterUsable) scopeOk = false;
        else for (size_t i : snap.indices) if (i < state.transactions.size()) subsetIdx.push_back(i);
    } else if (s_scope == 2) {
        if (rangeBad) scopeOk = false;
        else for (size_t i = 0; i < state.transactions.size(); ++i) {
            const auto& tx = state.transactions[i];
            if (tx.timestamp <= 0) continue;                 // pending rows have no date
            if (fromOk && tx.timestamp < fromT) continue;
            if (toOk && tx.timestamp > toT) continue;
            subsetIdx.push_back(i);
        }
    } else {
        for (size_t i = 0; i < state.transactions.size(); ++i) subsetIdx.push_back(i);
    }

    ImGui::Spacing();
    ImGui::Text(TR("export_tx_count"), scopeOk ? subsetIdx.size() : (size_t)0);
    ImGui::Spacing();

    // Filename + save-location hint.
    m::LabeledInput(TR("output_filename"), "##Filename", s_filename, sizeof(s_filename));
    ImGui::Spacing();
    // Show the real, resolved config directory (the old hardcoded ~/.config path was wrong on Windows/macOS).
    ImGui::TextColored(ImGui::ColorConvertU32ToFloat4(m::OnSurfaceDisabled()), "%s %s",
                       TR("file_save_location"), util::Platform::getConfigDir().c_str());

    // Result — success shows the saved path as a copy field; failure shows a red line.
    if (!s_saved_path.empty()) {
        ImGui::Spacing();
        ImGui::PushFont(m::Type().iconSmall());
        ImGui::TextColored(m::SuccessVec4(), ICON_MD_CHECK_CIRCLE);
        ImGui::PopFont();
        ImGui::SameLine(0, 4.0f * Layout::dpiScale());
        ImGui::TextColored(m::SuccessVec4(), "%s", TR("export_tx_success"));
        widgets::AddressCopyField("##exportedpath", s_saved_path);
        if (m::TactileButton(TR("export_tx_open_folder"), ImVec2(0, 0)))
            util::Platform::openFolder(util::Platform::getConfigDir());
    } else if (!s_error.empty()) {
        ImGui::Spacing();
        ImGui::PushTextWrapPos(0.0f);
        ImGui::TextColored(ImVec4(0.8f, 0.3f, 0.3f, 1.0f), "%s", s_error.c_str());
        ImGui::PopTextWrapPos();
    }

    ImGui::Spacing();

    bool doExport = false, doClose = false;
    m::DialogActionFooter(TR("export"), true, TR("close"), doExport, doClose);
    if (doClose) s_open = false;
    if (doExport) {
        s_saved_path.clear();
        s_error.clear();
        if (!scopeOk) {
            // Stale filter snapshot (tx list changed) or an invalid date range — never silently export all.
            Notifications::instance().warning(s_scope == 1 ? TR("export_tx_scope_stale") : TR("export_tx_range_invalid"));
        } else if (subsetIdx.empty()) {
            Notifications::instance().warning(TR("export_tx_none"));
        } else {
            std::string configDir = util::Platform::getConfigDir();
            // Sanitize in-buffer so the user sees exactly what was written (and we can't be pointed outside
            // the config dir by a pasted path).
            std::string safeName = sanitizeExportFilename(s_filename);
            snprintf(s_filename, sizeof(s_filename), "%s", safeName.c_str());
            std::string filepath = configDir + "/" + safeName;
            // Build the chosen subset (scope 0 exports the whole list with no copy), then write atomically
            // (temp + fsync + rename) so a disk-full failure is reported instead of a truncated CSV.
            std::string csv;
            if (s_scope == 0) {
                csv = data::formatTransactionsCsv(state.transactions);
            } else {
                std::vector<TransactionInfo> subset;
                subset.reserve(subsetIdx.size());
                for (size_t i : subsetIdx) subset.push_back(state.transactions[i]);
                csv = data::formatTransactionsCsv(subset);
            }
            if (!util::Platform::writeFileAtomically(filepath, csv)) {
                s_error = TR("export_tx_file_fail");
                Notifications::instance().error(TR("export_tx_file_fail"));
            } else {
                s_saved_path = filepath;
                Notifications::instance().success(TR("export_tx_success"), 5.0f);
            }
        }
    }

    m::EndOverlayDialog();
}

} // namespace ui
} // namespace dragonx