// Copyright © 2021-present 650 Industries, Inc. (aka Expo)

#pragma once

#include <jsi/jsi.h>
#include <fbjni/fbjni.h>
#include <ReactCommon/CallInvoker.h>

namespace jsi = facebook::jsi;
namespace jni = facebook::jni;
namespace react = facebook::react;

namespace expo {
class JavaScriptValue;

class JavaScriptObject;

/**
 * Dummy CallInvoker that invokes everything immediately.
 * Used in the test environment to check the async flow.
 */
class SyncCallInvoker : public react::CallInvoker {
public:
  void invokeAsync(std::function<void()> &&func) override;

  void invokeSync(std::function<void()> &&func) override;

  ~SyncCallInvoker() override = default;
};

/**
 * A wrapper for the jsi::Runtime.
 * This class is used as a bridge between CPP and Kotlin and to encapsulate common runtime helper functions.
 *
 * Instances of this class should be managed using a shared smart pointer.
 * To pass runtime information to all of `JavaScriptValue` and `JavaScriptObject` we use `weak_from_this()`
 * that requires that the object is held via a smart pointer. Otherwise, `weak_from_this()` returns `nullptr`.
 */
class JavaScriptRuntime : public std::enable_shared_from_this<JavaScriptRuntime> {
public:
  /**
   * Initializes a runtime that is independent from React Native and its runtime initialization.
   * This flow is mostly intended for tests. The JS call invoker is set to `SyncCallInvoker`.
   */
  JavaScriptRuntime();

  JavaScriptRuntime(
    jsi::Runtime *runtime,
    std::shared_ptr<react::CallInvoker> jsInvoker,
    std::shared_ptr<react::CallInvoker> nativeInvoker
  );

  /**
   * Returns the underlying runtime object.
   */
  jsi::Runtime &get() const;

  /**
   * Evaluates given JavaScript source code.
   * @throws if the input format is unknown, or evaluation causes an error,
   * a jni::JniException<JavaScriptEvaluateException> will be thrown.
   */
  jni::local_ref<jni::HybridClass<JavaScriptValue>::javaobject> evaluateScript(
    const std::string &script
  );

  /**
   * Returns the runtime global object for use in Kotlin.
   */
  jni::local_ref<jni::HybridClass<JavaScriptObject>::javaobject> global();

  /**
   * Creates a new object for use in Kotlin.
   */
  jni::local_ref<jni::HybridClass<JavaScriptObject>::javaobject> createObject();

  /**
   * Drains the JavaScript VM internal Microtask (a.k.a. event loop) queue.
   */
  void drainJSEventLoop();

  std::shared_ptr<react::CallInvoker> jsInvoker;
  std::shared_ptr<react::CallInvoker> nativeInvoker;
private:
  std::shared_ptr<jsi::Runtime> runtime;
};
} // namespace expo