#include <condition_variable>
#include <iostream>
#include <mutex>
#include <queue>
#include <thread>
#include <unordered_map>
#include <shared_mutex>
#include <chrono>
#include <grpcpp/grpcpp.h>
#include "google/protobuf/empty.pb.h"
#include "v1/primitives/bool.grpc.pb.h"
#include "v1/primitives/bool.pb.h"
#include "v1/primitives/int.grpc.pb.h"
#include "v1/primitives/int.pb.h"
#include "v1/primitives/string.grpc.pb.h"
#include "v1/primitives/string.pb.h"
#include "v1/collections/list.grpc.pb.h"
#include "v1/collections/list.pb.h"
#include "rediska/common/QueueMessage.hpp"
#include "rediska/frontend/RequestManager.hpp"
#include "rediska/frontend/server.hpp"
#include "rediska/cache/lru/LRU.hpp"
#include "rediska/data-structures/impl/ListDataStructure.hpp"

namespace {
class CacheWorker {
public:
    CacheWorker(size_t cache_capacity = 1000) {
        cache_config_.maxCapacity = cache_capacity;
        cache_config_.ttl = 0;
        cache_config_.resetTTLOnAccess = true;

        auto callback = [this](auto result) {
        };

        cache_ = std::make_unique<cache::LRU>(cache_config_, callback);
    }

    void Enqueue(QueueMessage msg) {
        std::lock_guard<std::mutex> lock(mtx_);
        queue_.push(std::move(msg));
        cv_.notify_one();
    }

    void Run() {
        for (;;) {
            QueueMessage msg;
            {
                std::unique_lock<std::mutex> lock(mtx_);
                cv_.wait(lock, [&] { return !queue_.empty(); });
                msg = std::move(queue_.front());
                queue_.pop();
            }

            std::cout << "[cache-worker] key=" << msg.key
                      << " type=" << static_cast<int>(msg.type)
                      << " op=" << static_cast<int>(msg.operation) << std::endl;

            if (!msg.responder) continue;

            try {
                switch (msg.operation) {
                    case OperationId::SET: {
                        if (msg.type == CacheValueId::ARRAY) {
                            auto list = std::make_shared<ListDataStructure>();

                            if (std::holds_alternative<ListPushManyArgs>(msg.arguments)) {
                                auto& args = std::get<ListPushManyArgs>(msg.arguments);
                                for (auto& value : args.values) {
                                    list->handle(OperationId::LIST_PUSH_BACK, DSValue{});
                                }
                            }

                            cache_->set(std::string(msg.key), CacheValue{list}, 0);

                            v1::collections::list::ListSetResponse response;
                            msg.respond<v1::collections::list::ListSetResponse>(response);
                        } else {

                            CacheValue value;
                            if (msg.arguments.index() != 0) {
                                auto& args = std::get<PrimitiveSetArgs>(msg.arguments);
                                value = args.value;
                            }

                            cache_->set(std::string(msg.key), std::move(value), 0);
                            msg.respond<google::protobuf::Empty>(google::protobuf::Empty{});
                        }
                        break;
                    }
                    case OperationId::GET: {
                        cache_->get(std::string(msg.key));

                        // я не нашел пока полный callback, тут заглушки (TODO)
                        if (msg.type == CacheValueId::BOOLEAN) {
                            v1::primitives::boolean::BoolGetResponse response;
                            response.set_value(true);
                            msg.respond<v1::primitives::boolean::BoolGetResponse>(response);
                        } else if (msg.type == CacheValueId::INT) {
                            v1::primitives::integer::IntGetResponse response;
                            response.set_value(42);
                            msg.respond<v1::primitives::integer::IntGetResponse>(response);
                        } else if (msg.type == CacheValueId::STRING) {
                            v1::primitives::str::StringGetResponse response;
                            response.set_value("cached_string_value");
                            msg.respond<v1::primitives::str::StringGetResponse>(response);
                        } else if (msg.type == CacheValueId::ARRAY) {
                            v1::collections::list::ListGetResponse response;
                            msg.respond<v1::collections::list::ListGetResponse>(response);
                        }
                        break;
                    }
                    case OperationId::DELETE: {
                        cache_->applyTo(std::string(msg.key), OperationId::DELETE, std::move(msg.arguments));

                        if (msg.type == CacheValueId::BOOLEAN) {
                            v1::primitives::boolean::BoolDeleteResponse response;
                            response.set_removed_value(true);
                            msg.respond<v1::primitives::boolean::BoolDeleteResponse>(response);
                        } else if (msg.type == CacheValueId::INT) {
                            v1::primitives::integer::IntDeleteResponse response;
                            response.set_removed_value(42);
                            msg.respond<v1::primitives::integer::IntDeleteResponse>(response);
                        } else if (msg.type == CacheValueId::STRING) {
                            v1::primitives::str::StringDeleteResponse response;
                            response.set_removed_value("deleted_string");
                            msg.respond<v1::primitives::str::StringDeleteResponse>(response);
                        } else if (msg.type == CacheValueId::ARRAY) {
                            msg.respond<google::protobuf::Empty>(google::protobuf::Empty{});
                        }
                        break;
                    }
                    case OperationId::LIST_PUSH_BACK: {
                        cache_->applyTo(std::string(msg.key), OperationId::LIST_PUSH_BACK, std::move(msg.arguments));
                        msg.respond<google::protobuf::Empty>(google::protobuf::Empty{});
                        break;
                    }
                    case OperationId::LIST_POP_BACK: {
                        cache_->applyTo(std::string(msg.key), OperationId::LIST_POP_BACK, std::move(msg.arguments));

                        v1::collections::list::PopBackResponse response;
                        msg.respond<v1::collections::list::PopBackResponse>(response);
                        break;
                    }
                    case OperationId::LIST_INSERT: {
                        cache_->applyTo(std::string(msg.key), OperationId::LIST_INSERT, std::move(msg.arguments));
                        msg.respond<google::protobuf::Empty>(google::protobuf::Empty{});
                        break;
                    }
                    case OperationId::LIST_ERASE: {
                        cache_->applyTo(std::string(msg.key), OperationId::LIST_ERASE, std::move(msg.arguments));
                        msg.respond<google::protobuf::Empty>(google::protobuf::Empty{});
                        break;
                    }
                    default:
                        break;
                }
            } catch (const std::exception& e) {
                std::cout << "Error processing message: " << e.what() << std::endl;
            }
        }
    }

private:
    std::queue<QueueMessage> queue_;
    std::mutex mtx_;
    std::condition_variable cv_;
    std::unique_ptr<cache::LRU> cache_;
    cache::LRUConfig cache_config_;
};
} // namespace

int run_cache_server() {
    CacheWorker worker(1000);
    std::thread t([&] { worker.Run(); });

    RunFrontendServer("0.0.0.0:50051", [&](QueueMessage msg) {
        worker.Enqueue(std::move(msg));
    });

    t.join();
    return 0;
}