#pragma once

#include "../../conversion/constant.hpp"
#include "../../conversion/conversion.hpp"
#include "geometry.hpp"
#include "../../gson/json_object.hpp"

#include <mbgl/util/feature.hpp>
#include <mapbox/variant.hpp>
#include <mapbox/geometry.hpp>

#include <jni/jni.hpp>
#include "../../jni/local_object.hpp"
#include "../feature.hpp"

#include <string>
#include <array>
#include <vector>
#include <sstream>

#include <mbgl/util/logging.hpp>

namespace mbgl {
namespace android {
namespace conversion {

/**
 * Turn feature identifier into std::string
 */
class FeatureIdVisitor {
public:

    template<class T>
    std::string operator()(const T& i) const {
        return std::to_string(i);
    }

    std::string operator()(const std::string& i) const {
        return i;
    }

    std::string operator()(const std::nullptr_t&) const {
        return "";
    }

};

/**
 * Turn properties into Java GSON JsonObject's
 */
class PropertyValueEvaluator {
public:
    jni::JNIEnv& env;

    /**
     * null
     */
    jni::jobject* operator()(const mapbox::geometry::null_value_t &) const {
        return (jni::jobject*) nullptr;
    }

    /**
     * Boolean primitive
     */
    jni::jobject* operator()(const bool& value) const {
        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonPrimitive")).release();
        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "(Ljava/lang/Boolean;)V");

        // Create JsonPrimitive
        jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, *convert<jni::jobject*, bool>(env, value));
        jni::jobject* object = &jni::NewObject(env, *javaClass, *constructor, *converted);

        return object;
    }

    /**
     * String primitive
     */
    jni::jobject* operator()(const std::string& value) const {
        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonPrimitive")).release();
        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "(Ljava/lang/String;)V");

        // Create JsonPrimitive
        jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, *convert<jni::jobject*, std::string>(env, value));
        jni::jobject* object = &jni::NewObject(env, *javaClass, *constructor, converted.get());

        return object;
    }

    /**
     * Number primitives
     */
    template <class Number>
    jni::jobject* operator()(const Number& value) const {
        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonPrimitive")).release();
        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "(Ljava/lang/Number;)V");

        // Create JsonPrimitive
        jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, *convert<jni::jobject*, Number>(env, value));
        jni::jobject* object = &jni::NewObject(env, *javaClass, *constructor, converted.get());

        return object;
    }


    /**
     * Json Array
     */
    jni::jobject* operator()(const std::vector<mbgl::Value> &values) const {
        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonArray")).release();
        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "()V");;
        static jni::jmethodID* add = &jni::GetMethodID(env, *javaClass, "add", "(Lcom/google/gson/JsonElement;)V");

        // Create json array
        jni::jobject* jarray = &jni::NewObject(env, *javaClass, *constructor);

        // Add values
        for (const auto &v : values) {
            jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, mbgl::Value::visit(v, *this));
            jni::CallMethod<void>(env, jarray, *add, converted.get());
        }

        return jarray;
    }

    /**
     * Json Object
     */
    jni::jobject* operator()(const std::unordered_map<std::string, mbgl::Value> &value) const {
        // TODO: clean up duplication here
        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonObject")).release();
        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "()V");;
        static jni::jmethodID* add = &jni::GetMethodID(env, *javaClass, "add", "(Ljava/lang/String;Lcom/google/gson/JsonElement;)V");

        // Create json object
        jni::jobject* jsonObject = &jni::NewObject(env, *javaClass, *constructor);

        // Add items
        for (auto &item : value) {
            jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, mbgl::Value::visit(item.second, *this));
            jni::LocalObject<jni::jobject> key = jni::NewLocalObject(env, *convert<jni::jobject*, std::string>(env, item.first));
            jni::CallMethod<void>(env, jsonObject, *add, key.get(), converted.get());
        }

        return jsonObject;
    }
};

template <>
struct Converter<jni::jobject*, std::unordered_map<std::string, mbgl::Value>> {
    Result<jni::jobject*> operator()(jni::JNIEnv& env, const std::unordered_map<std::string, mbgl::Value>& value) const {
        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonObject")).release();
        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "()V");;
        static jni::jmethodID* add = &jni::GetMethodID(env, *javaClass, "add", "(Ljava/lang/String;Lcom/google/gson/JsonElement;)V");

        // Create json object
        jni::jobject* jsonObject = &jni::NewObject(env, *javaClass, *constructor);

        // Add items
        PropertyValueEvaluator evaluator {env};
        for (auto &item : value) {
            jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, mbgl::Value::visit(item.second, evaluator));
            jni::LocalObject<jni::jobject> key = jni::NewLocalObject(env, *convert<jni::jobject*, std::string>(env, item.first));
            jni::CallMethod<void>(env, jsonObject, *add, key.get(), converted.get());
        }

        return {jsonObject};
    }
};


template <>
struct Converter<jni::Object<android::geojson::Feature>, mbgl::Feature> {
    Result<jni::Object<android::geojson::Feature>> operator()(jni::JNIEnv& env, const mbgl::Feature& value) const {

        // Convert Id
        FeatureIdVisitor idEvaluator;
        std::string id = (value.id) ? mapbox::geometry::identifier::visit(value.id.value(), idEvaluator) : "";
        auto jid = jni::Make<jni::String>(env, id);

        // Convert properties
        auto properties = jni::Object<gson::JsonObject>(*convert<jni::jobject*>(env, value.properties));

        // Convert geometry
        auto geometry = *convert<jni::Object<android::geojson::Geometry>>(env, value.geometry);

        // Create feature
        auto feature = android::geojson::Feature::fromGeometry(env, geometry, properties, jid);

        //Cleanup
        jni::DeleteLocalRef(env, jid);
        jni::DeleteLocalRef(env, geometry);
        jni::DeleteLocalRef(env, properties);

        return feature;
    }
};

template <>
struct Converter<jni::Array<jni::Object<android::geojson::Feature>>, std::vector<mbgl::Feature>> {
    Result<jni::Array<jni::Object<android::geojson::Feature>>> operator()(jni::JNIEnv& env, const std::vector<mbgl::Feature>& value) const {
        using namespace mbgl::android::geojson;
        auto features = jni::Array<jni::Object<Feature>>::New(env, value.size(), Feature::javaClass);

        for(size_t i = 0; i < value.size(); i = i + 1) {
            auto converted = *convert<jni::Object<android::geojson::Feature>, mbgl::Feature>(env, value.at(i));
            features.Set(env, i, converted);
            jni::DeleteLocalRef(env, converted);
        }

        return {features};
    }
};

} // namespace conversion
} // namespace android
} // namespace mbgl