#include "main_window/RecentProjectHistory.h"

#include <QDir>
#include <QFile>
#include <QFileInfo>
#include <QJsonArray>
#include <QJsonDocument>
#include <QJsonValue>
#include <QDebug>
#include <QStandardPaths>

QString RecentProjectHistory::cacheFilePath() {
    const QString base = QStandardPaths::writableLocation(QStandardPaths::GenericCacheLocation);
    return QDir(base).filePath(QStringLiteral("landscape_tool/recent_projects.cache"));
}

QString RecentProjectHistory::normalizePath(const QString& path) {
    if (path.isEmpty()) {
        return QString();
    }
    const QFileInfo fi(path);
    const QString c = fi.canonicalFilePath();
    return c.isEmpty() ? QDir::cleanPath(fi.absoluteFilePath()) : c;
}

QStringList RecentProjectHistory::dedupeNewestFirst(const QStringList& paths) {
    QStringList out;
    out.reserve(paths.size());
    for (const QString& p : paths) {
        const QString n = normalizePath(p);
        if (n.isEmpty()) {
            continue;
        }
        if (out.contains(n)) {
            continue;
        }
        out.append(n);
        if (out.size() >= kMaxEntries) {
            break;
        }
    }
    return out;
}

QStringList RecentProjectHistory::load() const {
    const QString filePath = cacheFilePath();
    QFile f(filePath);
    if (!f.open(QIODevice::ReadOnly)) {
        return {};
    }
    const QJsonDocument doc = QJsonDocument::fromJson(f.readAll());
    if (!doc.isArray()) {
        return {};
    }
    QStringList paths;
    for (const QJsonValue& v : doc.array()) {
        if (v.isString()) {
            paths.append(v.toString());
        }
    }
    return dedupeNewestFirst(paths);
}

bool RecentProjectHistory::save(const QStringList& paths) const {
    const QString filePath = cacheFilePath();
    const QFileInfo fi(filePath);
    QDir().mkpath(fi.absolutePath());

    QJsonArray arr;
    for (const QString& p : dedupeNewestFirst(paths)) {
        arr.append(p);
    }
    const QJsonDocument doc(arr);

    QFile f(filePath);
    if (!f.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
        qWarning() << "RecentProjectHistory: cannot write" << filePath;
        return false;
    }
    f.write(doc.toJson(QJsonDocument::Compact));
    return true;
}

void RecentProjectHistory::addAndSave(const QString& projectDir) {
    const QString n = normalizePath(projectDir);
    if (n.isEmpty()) {
        return;
    }
    QStringList paths = load();
    paths.removeAll(n);
    paths.prepend(n);
    save(paths);
}

void RecentProjectHistory::removeAndSave(const QString& projectDir) {
    const QString n = normalizePath(projectDir);
    QStringList paths = load();
    paths.removeAll(n);
    save(paths);
}