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//////////////////////////////////////////////////////////////////////////////

#pragma once

#include <musikcore/config.h>
#include <musikcore/library/IQuery.h>
#include <musikcore/db/Connection.h>

#include <sigslot/sigslot.h>

#include <mutex>
#include <atomic>

namespace musik { namespace core { namespace library { namespace query {

    class QueryBase:
        public musik::core::db::ISerializableQuery,
        public sigslot::has_slots<>
    {
        public:
            enum class MatchType : int {
                Substring = 1,
                Regex = 2
            };

            QueryBase() noexcept
            : status(IQuery::Idle)
            , options(0)
            , queryId(nextId())
            , cancel(false) {
            }

            bool Run(musik::core::db::Connection &db) {
                this->SetStatus(Running);
                try {
                    if (this->IsCanceled()) {
                        this->SetStatus(Canceled);
                        return true;
                    }
                    else if (OnRun(db)) {
                        this->SetStatus(Finished);
                        return true;
                    }
                }
                catch (...) {
                }

                this->SetStatus(Failed);
                return false;
            }

            virtual void Cancel() noexcept {
                this->cancel = true;
            }

            virtual bool IsCanceled() noexcept {
                return cancel;
            }

            /* IQuery */

            int GetStatus() override {
                std::unique_lock<std::mutex> lock(this->stateMutex);
                return this->status;
            }

            int GetId() noexcept override {
                return this->queryId;
            }

            int GetOptions() override {
                std::unique_lock<std::mutex> lock(this->stateMutex);
                return this->options;
            }

            /* ISerializableQuery */

            std::string SerializeQuery() override {
                throw std::runtime_error("not implemented");
            }

            std::string SerializeResult() override {
                throw std::runtime_error("not implemented");
            }

            void DeserializeResult(const std::string& data) override {
                throw std::runtime_error("not implemented");
            }

            void Invalidate() override {
                this->SetStatus(IQuery::Failed);
            }

        protected:
            void SetStatus(int status) {
                std::unique_lock<std::mutex> lock(this->stateMutex);
                this->status = status;
            }

            void SetOptions(int options) {
                std::unique_lock<std::mutex> lock(this->stateMutex);
                this->options = options;
            }

            virtual bool OnRun(musik::core::db::Connection& db) = 0;

        private:
            static int nextId() noexcept {
                static std::atomic<int> next(0);
                return ++next;
            }

            unsigned int status;
            unsigned int queryId;
            unsigned int options;
            volatile bool cancel;
            std::mutex stateMutex;
    };

} } } }
