// An app with two surfaces, run in snapshot mode: checks surface set-up
// (overlay keys, names, sizes, shared engine, backends), the lifecycle hooks,
// the app's own command-line options and that every surface renders its own
// scene. No SteamVR involved.
// VRDASH_TEST_PREPARE_FAIL=1: prepare() fails, so exec() must return 1
// without calling the other hooks.
// VRDASH_TEST_DESKTOP_NOVR=1: --desktop-novr instead of --snapshot; prepare()
// checks the mode and then fails (no window, no event loop).
// Exit codes: 0 pass, 1 fail, 77 skipped (no GPU context).

#include <QCommandLineOption>
#include <QDir>
#include <QImage>
#include <QTemporaryDir>
#include <cstdio>
#include <string>
#include <vector>

#include "app/DashboardApplication.h"

namespace {

bool check(bool condition, const char* what) {
  if (!condition) fprintf(stderr, "FAIL: %s\n", what);
  return condition;
}

class TwoSurfaceApp : public DashboardApplication {
 public:
  TwoSurfaceApp(int& argc, char** argv)
      : DashboardApplication(
            argc, argv,
            {QCommandLineOption(QStringLiteral("test-value"),
                                QStringLiteral("An app option."),
                                QStringLiteral("value")),
             QCommandLineOption(QStringLiteral("test-flag"),
                                QStringLiteral("An app flag, never set."))}) {
    setQmlModule(QStringLiteral("SurfacesTest"));
    setDisplayName(QStringLiteral("Test App"));
    setAppKey(QStringLiteral("config.key"));
    addSurface({.id = QStringLiteral("red"),
                .qmlRootType = QStringLiteral("Red"),
                .textureSize = QSize(64, 32)});
    addSurface({.id = QStringLiteral("blue"),
                .qmlRootType = QStringLiteral("Blue"),
                .displayName = QStringLiteral("Blue tab"),
                .textureSize = QSize(32, 32)});
  }

  QString expectedKey;  // --app-key overrides setAppKey()
  DashboardMode expectedMode = DashboardMode::Snapshot;
  bool failPrepare = false;
  int prepareCalls = 0;
  int loadingCalls = 0;
  int startedCalls = 0;
  bool ok = true;

 protected:
  bool prepare(QString* error) override {
    ++prepareCalls;
    ok &= check(loadingCalls == 0 && startedCalls == 0, "prepare() first");
    ok &= check(engine() == nullptr && surfaces().isEmpty(),
                "prepare() before engine and surfaces");
    ok &= check(mode() == expectedMode, "mode in prepare()");
    ok &= check(appKey() == expectedKey, "app key in prepare()");
    ok &= check(
        isOptionSet(QStringLiteral("test-value")) &&
            optionValue(QStringLiteral("test-value")) == QLatin1String("42"),
        "app option value");
    ok &= check(!isOptionSet(QStringLiteral("test-flag")), "app option unset");
    if (failPrepare) *error = QStringLiteral("prepare() failed on purpose");
    return !failPrepare;
  }
  void loading() override {
    ++loadingCalls;
    Surface* red = surface(QStringLiteral("red"));
    Surface* blue = surface(QStringLiteral("blue"));
    ok &= check(surfaces().size() == 2 && red && blue, "two surfaces by id");
    ok &= check(surface() == red, "primary is the first");
    ok &= check(surface(QStringLiteral("none")) == nullptr, "unknown id");
    ok &= check(engine() != nullptr, "shared engine");
    ok &= check(mode() == DashboardMode::Snapshot, "mode");
    ok &= check(red && blue && red->backend() && blue->backend() &&
                    red->backend() != blue->backend(),
                "a backend per surface");
    ok &= check(appKey() == expectedKey, "app key (setAppKey / --app-key)");
    ok &= check(red && red->overlayKey() == expectedKey + QLatin1String(".red"),
                "overlay key = <app key>.<id>");
    ok &= check(red && red->displayName() == QLatin1String("Test App"),
                "tab name defaults to the app name");
    ok &= check(blue && blue->displayName() == QLatin1String("Blue tab"),
                "tab name from config");
    ok &= check(blue && blue->textureSize() == QSize(32, 32),
                "texture size from config");
    ok &= check(vrRuntime() == nullptr, "no VR outside overlay mode");
  }
  void started() override {
    ++startedCalls;
    const QList<Surface*> all = surfaces();
    ok &= check(all.size() == 2 && all[0]->window() && all[1]->window() &&
                    all[0]->window() != all[1]->window(),
                "a window per surface");
  }
};

}  // namespace

int main(int argc, char* argv[]) {
  QTemporaryDir dir;
  const std::string snapshot =
      QDir(dir.path()).filePath(QStringLiteral("shot.png")).toStdString();
  // VRDASH_TEST_CLI_KEY=1: also pass --app-key (must win over setAppKey()).
  const bool cliKey = qEnvironmentVariableIntValue("VRDASH_TEST_CLI_KEY");
  const bool desktopNoVr =
      qEnvironmentVariableIntValue("VRDASH_TEST_DESKTOP_NOVR");
  const bool failPrepare =
      qEnvironmentVariableIntValue("VRDASH_TEST_PREPARE_FAIL") || desktopNoVr;
  std::vector<std::string> args = {argv[0], "--test-value", "42"};
  if (desktopNoVr) {
    args.emplace_back("--desktop-novr");
  } else {
    args.emplace_back("--snapshot");
    args.emplace_back(snapshot);
  }
  if (cliKey) {
    args.emplace_back("--app-key");
    args.emplace_back("cli.key");
  }
  for (int i = 1; i < argc; ++i) args.emplace_back(argv[i]);
  std::vector<char*> cargs;
  for (std::string& arg : args) cargs.push_back(arg.data());
  int cargc = int(cargs.size());

  TwoSurfaceApp app(cargc, cargs.data());
  app.expectedKey =
      cliKey ? QStringLiteral("cli.key") : QStringLiteral("config.key");
  app.failPrepare = failPrepare;
  if (desktopNoVr) app.expectedMode = DashboardMode::DesktopNoVr;
  const int result = app.exec();
  if (failPrepare) {
    bool ok = app.ok;
    ok &= check(result == 1, "exec() returns 1 when prepare() fails");
    ok &= check(
        app.prepareCalls == 1 && app.loadingCalls == 0 && app.startedCalls == 0,
        "no hooks after a failed prepare()");
    fprintf(stderr, ok ? "PASS\n" : "FAILED\n");
    return ok ? 0 : 1;
  }
  if (app.loadingCalls == 0) {
    fprintf(stderr, "SKIP: no render backend (no GPU context?)\n");
    return 77;
  }
  bool ok = app.ok;
  ok &= check(result == 0, "exec() succeeded");
  ok &= check(
      app.prepareCalls == 1 && app.loadingCalls == 1 && app.startedCalls == 1,
      "each hook called once");

  const QImage red(QDir(dir.path()).filePath(QStringLiteral("shot-red.png")));
  const QImage blue(QDir(dir.path()).filePath(QStringLiteral("shot-blue.png")));
  ok &= check(red.size() == QSize(64, 32) &&
                  red.pixelColor(10, 10) == QColor(255, 0, 0),
              "red surface rendered");
  ok &= check(blue.size() == QSize(32, 32) &&
                  blue.pixelColor(10, 10) == QColor(0, 0, 255),
              "blue surface rendered");
  fprintf(stderr, ok ? "PASS\n" : "FAILED\n");
  return ok ? 0 : 1;
}