module game_core.job_updater;

import bubel.ecs.std;
import bubel.ecs.vector;
import bubel.ecs.atomic;

import ecs_utils.utils;

//import core.time;
import bubel.ecs.manager;
import mmutils.thread_pool;

version(LDC)
{
    import ldc.attributes;
}
else 
{
    struct optStrategy {
        string strategy;
    }
}

//import supre.core.call_graph_generator;

struct ECSJobUpdater
{

    this(uint threads)
    {
        onCreate(threads);
    }

    ~this()
    {
        pool.waitThreads();
        //pool.unregistExternalThread(thread_data);
        if(jobs)Mallocator.dispose(jobs);
        version(WebAssembly)pthread_key_delete(tls_key);
    }

    version(WebAssembly)
    {
        __gshared pthread_key_t tls_key;
    }
    else static uint thread_id = 0;

    ThreadPool pool;
    ThreadData* thread_data;
    
    int job_id = 0;
    int no_dep_count = 0;
    //static uint thread_id = 0;

    struct Group
    {
        ~this() nothrow
        {

        }

        JobsGroup group;
        JobData[1024] jobs;
        JobCaller[1024] callers;
        uint count = 0;
        string name;

        void dependantOn(Group* dependency)
        {
            group.dependantOn(&dependency.group);
        }

        void start()
        {
            group.thPool.addGroupAsynchronous(&group);
        }

        void build(ThreadPool* pool)
        {
            group.thPool = pool;
            group.jobs = jobs[0..count];
        }

        void clear()
        {
            group = JobsGroup("name",null);
            count = 0;
        }

        void add(JobCaller caller)
        {
            callers[count] = caller;
            jobs[count] = JobData(&callers[count].callJob,name);
            count++;
        }
    }

    Group[] jobs;
    Vector!(Group*) call_jobs;
    Group last_job;
    JobData[1] groupEndJobs;

    //TrackData[32] trackers;

    void onCreate(uint threads_count)
    {
        version(WebAssembly)pthread_key_create(&tls_key, null);

        pool.initialize();
        thread_data = pool.registerExternalThread();
        pool.setThreadsNum(threads_count);

        jobs = Mallocator.makeArray!Group(256);
    }

    uint getThreadID() @nogc nothrow
    {
        version(WebAssembly)return cast(int)pthread_getspecific(tls_key);
        else return thread_id;
    }

    void begin()
    {
        job_id = 0;
        call_jobs.clear();

        foreach(ref job;jobs)
        {
            job.clear();
        }

        last_job.clear();
    }

    void clearTracker()
    {
        //foreach(ref tracker;trackers)tracker.clear();
    }

    @optStrategy("none")
    void nop()
    {
        int i;
        i++;
    }

    //@optStrategy("none")
    void call()
    {
        if(last_job.group.getDependenciesWaitCount() == 0)return;
        if(call_jobs.length == 0)return;
        
        //JobData[1] groupEndJobs;
		groupEndJobs[0] = JobData(&releaseMainThread, "Stop Threads", null, null);
        
        last_job.group.jobs = groupEndJobs;
        last_job.group.thPool = &pool;
        last_job.group.executeOnThreadNum = 0;

        foreach(job;call_jobs)
        {
            job.start();
        }
        
        /*while(atomicLoad(ret) == 1)//!cas(&ret,0,1))
        {
            nop();
            version(WebAssembly)//emscripten_main_thread_process_queued_calls();
        }//*/

        thread_data.threadStartFunc();
    }
    
    void releaseMainThread(ThreadData* th_data, JobData* data)
    {
        //atomicStore(ret,0);
        pool.releaseExternalThreads();
    }
    
    static struct JobCaller
    {
        EntityManager.Job* job;
        ECSJobUpdater* updater;
        uint id;

        void callJob(ThreadData* th_data, JobData* data)
        {
            
            //uint job_id = updater.getThreadID();
            //updater.trackers[job_id].begin(id);
            version(WebAssembly)
            {
                //updater.thread_id = th_data.threadId;
                pthread_setspecific(tls_key, cast(void*)th_data.threadId);
                if(th_data.threadId == 0)
                {
                    emscripten_main_thread_process_queued_calls();
                    job.execute();
                    emscripten_main_thread_process_queued_calls();
                }
                else job.execute();
            }
            else 
            {
                updater.thread_id = th_data.threadId;
                job.execute();
            }
            //atomicOp!"-="(updater.jobs_count,1);
            //updater.trackers[job_id].end();
        }
    }

    void dispatch(EntityManager.JobGroup group)
    {
        if(group.jobs.length == 0)
        {
            return;
        }

        jobs[group.id].name = cast(string)group.caller.system.name;

        foreach(ref job;group.jobs)
        {
            uint index = 0;
            if(job.callers.length)index = job.callers[0].system_id;
            JobCaller caller;
            caller.updater = &this;
            caller.job = &job;
            caller.id = index;
            jobs[group.id].add(caller);
        }
        
        jobs[group.id].build(&pool);

        uint deps = cast(uint)group.dependencies.length;

        foreach(dep;group.dependencies)
        {
            if(jobs[dep.id].count && dep.caller.system.willExecute && dep.caller.system.enabled)jobs[group.id].dependantOn(&jobs[dep.id]);
            else deps--;
        }

        if(deps == 0)
        {
            call_jobs.add(&jobs[group.id]);
        }

        last_job.dependantOn(&jobs[group.id]);
    }
}