#include "PgTestEnvironment.h"

#include <QCoreApplication>
#include <QFile>
#include <QUrl>
#include <iostream>
#include <stdexcept>

#include "Pgsql_Connection.h"
#include "Pgsql_Result.h"

namespace pgtest {

namespace {

bool g_available = false;
int g_versionNum = 0;

} // namespace

std::optional<QString> baseUrl()
{
    QByteArray v = qgetenv("TEST_DATABASE_URL");
    if (v.isEmpty())
        return std::nullopt;
    return QString::fromUtf8(v);
}

QString urlForDb(const QString &db)
{
    auto base = baseUrl();
    if (!base)
        throw std::runtime_error("TEST_DATABASE_URL is not set");
    QUrl url(*base);
    url.setPath("/" + db);
    return url.toString();
}

bool available()
{
    return g_available;
}

int serverVersionNum()
{
    return g_versionNum;
}

qint64 processId()
{
    return QCoreApplication::applicationPid();
}

QString templateDbName()
{
    return QString("tmpl_%1").arg(processId());
}

QString quoteIdent(const QString &name)
{
    QString r = name;
    r.replace('"', "\"\"");
    return "\"" + r + "\"";
}

void PgEnv::SetUp()
{
    auto base = baseUrl();
    if (!base) {
        std::cerr << "TEST_DATABASE_URL not set, integration tests will be skipped\n";
        return;
    }

    const QString tmpl = templateDbName();
    try {
        {
            Pgsql::Connection admin;
            admin.connect(*base);
            Pgsql::Result r = admin.query("SHOW server_version_num");
            if (!r || r.rows() != 1)
                throw std::runtime_error("could not query server_version_num");
            g_versionNum = QString::fromUtf8(r.val(0, 0)).toInt();
            admin.query(QString("DROP DATABASE IF EXISTS %1 WITH (FORCE)").arg(quoteIdent(tmpl)));
            admin.query(QString("CREATE DATABASE %1").arg(quoteIdent(tmpl)));
        }
        {
            QFile f(fixtureDir_ + "/schema.sql");
            if (!f.open(QIODevice::ReadOnly))
                throw std::runtime_error("cannot open " + f.fileName().toStdString());
            QByteArray sql = f.readAll();

            Pgsql::Connection c;
            c.connect(urlForDb(tmpl));
            c.query(sql.constData());
        }
        g_available = true;
    }
    catch (const std::exception &e) {
        ADD_FAILURE() << "Setting up template database failed: " << e.what();
        try {
            Pgsql::Connection admin;
            admin.connect(*base);
            admin.query(QString("DROP DATABASE IF EXISTS %1 WITH (FORCE)").arg(quoteIdent(tmpl)));
        }
        catch (const std::exception &) {
        }
    }
}

void PgEnv::TearDown()
{
    if (!g_available)
        return;
    try {
        Pgsql::Connection admin;
        admin.connect(*baseUrl());
        admin.query(QString("DROP DATABASE IF EXISTS %1 WITH (FORCE)").arg(quoteIdent(templateDbName())));
    }
    catch (const std::exception &e) {
        ADD_FAILURE() << "Dropping template database failed: " << e.what();
    }
    g_available = false;
}

} // namespace pgtest