#include "CloudViewSettings.h"

#include <QColor>
#include <QDir>
#include <QSettings>
#include <QStandardPaths>
#include <cmath>

namespace
{
QString settingsFilePath()
{
    QString settingsDir = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
    if (settingsDir.isEmpty()) {
        settingsDir = QDir::homePath() + "/CloudView";
    }
    QDir().mkpath(settingsDir);
    return QDir(settingsDir).filePath("CloudView.ini");
}
}

CloudViewSettingsData CloudViewSettings::load()
{
    CloudViewSettingsData result;
    QSettings settings(settingsFilePath(), QSettings::IniFormat);

    // 模式独立于启用状态保存；缺失或非法配置默认采用“替换为全 0”。
    const QVariant savedModeValue = settings.contains("PointCloudRange/filterMode")
        ? settings.value("PointCloudRange/filterMode")
        : settings.value("PointCloudRange/mode",
                         static_cast<int>(PointCloudXYZRangeFilterMode::ReplaceWithZero));
    const int savedFilterMode = savedModeValue.toInt();
    const PointCloudXYZRangeFilterMode filterMode =
        savedFilterMode == static_cast<int>(PointCloudXYZRangeFilterMode::Remove)
            ? PointCloudXYZRangeFilterMode::Remove
            : PointCloudXYZRangeFilterMode::ReplaceWithZero;

    const float poseAxisLength = settings.value("Display/poseAxisLength", result.poseAxisLength).toFloat();
    if (std::isfinite(poseAxisLength) && poseAxisLength > 0.0f) {
        result.poseAxisLength = poseAxisLength;
    }

    result.pseudoColorEnabled = settings.value("PseudoColor/enabled", result.pseudoColorEnabled).toBool();
    const bool hasPaletteSetting = settings.contains("PseudoColor/defaultPalette");
    result.pseudoColorDefaultPalette = hasPaletteSetting
        ? settings.value("PseudoColor/defaultPalette").toBool()
        : result.pseudoColorDefaultPalette;
    const float period = settings.value("PseudoColor/period", result.pseudoColorPeriod).toFloat();
    if (std::isfinite(period) && period > 0.0f) {
        result.pseudoColorPeriod = period;
    }
    const QColor startColor(settings.value("PseudoColor/startColor", "#0000ff").toString());
    const QColor endColor(settings.value("PseudoColor/endColor", "#ff0000").toString());
    if (startColor.isValid()) {
        result.pseudoColorStartColor = QVector3D(startColor.redF(), startColor.greenF(), startColor.blueF());
    }
    if (endColor.isValid()) {
        result.pseudoColorEndColor = QVector3D(endColor.redF(), endColor.greenF(), endColor.blueF());
    }

    if (!hasPaletteSetting && settings.contains("PseudoColor/period")) {
        const QColor legacyStartColor(settings.value("PseudoColor/startColor", "#0000ff").toString());
        const QColor legacyEndColor(settings.value("PseudoColor/endColor", "#ff0000").toString());
        const bool legacyDefaults = qFuzzyCompare(result.pseudoColorPeriod, 100.0f) &&
                                    legacyStartColor == QColor("#0000ff") &&
                                    legacyEndColor == QColor("#ff0000");
        if (legacyDefaults) {
            // 旧版周期色环配置迁移为 Z 范围蓝→红梯度。
            result.pseudoColorPeriod = 500.0f;
            result.pseudoColorStartColor = QVector3D(0.0f, 0.0f, 1.0f);
            result.pseudoColorEndColor = QVector3D(1.0f, 0.0f, 0.0f);
            result.pseudoColorDefaultPalette = true;
        } else {
            // 非默认旧配置继续使用原有的自定义起止色渐变。
            result.pseudoColorDefaultPalette = false;
        }
    }

    const bool rangeEnabled = settings.value("PointCloudRange/enabled", false).toBool();
    PointCloudXYZRange range;
    range.enabled = rangeEnabled;
    range.filterMode = filterMode;
    if (rangeEnabled) {
        const auto readBound = [&settings](const char* key, double fallback) {
            bool ok = false;
            const double value = settings.value(key).toDouble(&ok);
            return ok && std::isfinite(value) ? value : fallback;
        };
        // Missing bounds retain the range object's implicit unbounded side.
        range.minX = readBound("PointCloudRange/minX", range.minX);
        range.maxX = readBound("PointCloudRange/maxX", range.maxX);
        range.minY = readBound("PointCloudRange/minY", range.minY);
        range.maxY = readBound("PointCloudRange/maxY", range.maxY);
        range.minZ = readBound("PointCloudRange/minZ", range.minZ);
        range.maxZ = readBound("PointCloudRange/maxZ", range.maxZ);
        if (range.isValid()) {
            result.pointCloudRange = range;
        }
    } else {
        result.pointCloudRange = range;
    }
    // Keep the mode even when a persisted enabled range is invalid and is
    // therefore reset to the disabled default range.
    result.pointCloudRange.filterMode = filterMode;

    return result;
}

bool CloudViewSettings::save(const CloudViewSettingsData& value)
{
    QSettings settings(settingsFilePath(), QSettings::IniFormat);
    if (std::isfinite(value.poseAxisLength) && value.poseAxisLength > 0.0f) {
        settings.setValue("Display/poseAxisLength", value.poseAxisLength);
    }

    settings.setValue("PseudoColor/enabled", value.pseudoColorEnabled);
    settings.setValue("PseudoColor/defaultPalette", value.pseudoColorDefaultPalette);
    settings.setValue("PseudoColor/period", qMax(1.0f, value.pseudoColorPeriod));
    settings.setValue("PseudoColor/startColor",
                      QColor::fromRgbF(value.pseudoColorStartColor.x(),
                                       value.pseudoColorStartColor.y(),
                                       value.pseudoColorStartColor.z()).name(QColor::HexRgb));
    settings.setValue("PseudoColor/endColor",
                      QColor::fromRgbF(value.pseudoColorEndColor.x(),
                                       value.pseudoColorEndColor.y(),
                                       value.pseudoColorEndColor.z()).name(QColor::HexRgb));

    const PointCloudXYZRange& range = value.pointCloudRange;
    const bool saveRange = range.enabled && range.isValid();
    settings.setValue("PointCloudRange/enabled", saveRange);
    const int filterModeValue = range.filterMode == PointCloudXYZRangeFilterMode::Remove
        ? static_cast<int>(PointCloudXYZRangeFilterMode::Remove)
        : static_cast<int>(PointCloudXYZRangeFilterMode::ReplaceWithZero);
    settings.setValue("PointCloudRange/filterMode", filterModeValue);
    settings.setValue("PointCloudRange/mode", filterModeValue);
    if (saveRange) {
        const auto saveBound = [&settings](const char* key, double bound) {
            if (std::isfinite(bound)) {
                settings.setValue(key, bound);
            } else {
                settings.remove(key);
            }
        };
        saveBound("PointCloudRange/minX", range.minX);
        saveBound("PointCloudRange/maxX", range.maxX);
        saveBound("PointCloudRange/minY", range.minY);
        saveBound("PointCloudRange/maxY", range.maxY);
        saveBound("PointCloudRange/minZ", range.minZ);
        saveBound("PointCloudRange/maxZ", range.maxZ);
    } else {
        // Disabled ranges use implicit infinite bounds; do not persist infinities.
        settings.remove("PointCloudRange/minX");
        settings.remove("PointCloudRange/maxX");
        settings.remove("PointCloudRange/minY");
        settings.remove("PointCloudRange/maxY");
        settings.remove("PointCloudRange/minZ");
        settings.remove("PointCloudRange/maxZ");
    }

    // Remove keys from the former min/max/stop based implementation so old
    // values cannot reappear in the user configuration file.
    settings.remove("PseudoColor/autoRange");
    settings.remove("PseudoColor/minZ");
    settings.remove("PseudoColor/maxZ");
    settings.remove("PseudoColor/divisionCount");
    settings.remove("PseudoColor/gradient");
    settings.remove("PseudoColor/stops");

    settings.sync();
    return settings.status() == QSettings::NoError;
}