#include "vdi_input_priority.h"
#undef NDEBUG
#include <cassert>
#include <cstdio>

constexpr Sint32 frameCode = 123;
static SDL_Event frame() {
    SDL_Event e{}; e.type = SDL_USEREVENT; e.user.code = frameCode; return e;
}
static SDL_Event input(Uint32 type, Uint32 window = 1) {
    SDL_Event e{}; e.type = type; e.key.windowID = window; return e;
}
static void push(SDL_Event e) { assert(SDL_PushEvent(&e) == 1); }
static SDL_Event pop() {
    SDL_Event e{};
    assert(SDL_PeepEvents(&e,1,SDL_GETEVENT,SDL_FIRSTEVENT,SDL_LASTEVENT)==1);
    return e;
}
int main() {
    assert(SDL_Init(SDL_INIT_EVENTS)==0);
    SDL_Event out{};
    VdiInputPriority disabled(false, frameCode);
    push(input(SDL_MOUSEMOTION));
    assert(!disabled.deferFrame(frame()) && !disabled.takeDeferred(out,1));
    assert(pop().type == SDL_MOUSEMOTION);

    // Only a contiguous input prefix can pass a frame. No focus/quit/decoder
    // barrier may be skipped, even if input is waiting further down the queue.
    for (Uint32 barrier : {Uint32(SDL_WINDOWEVENT),Uint32(SDL_QUIT),
                          Uint32(SDL_USEREVENT),Uint32(SDL_RENDER_DEVICE_RESET),
                          Uint32(SDL_CONTROLLERDEVICEADDED)}) {
        VdiInputPriority scheduler(true, frameCode);
        push(input(SDL_MOUSEBUTTONDOWN)); push(input(SDL_MOUSEBUTTONUP));
        push(input(barrier)); push(input(SDL_KEYDOWN));
        assert(scheduler.deferFrame(frame()));
        assert(scheduler.takeDeferred(out,1) && out.type==SDL_MOUSEBUTTONDOWN);
        assert(scheduler.takeDeferred(out,1) && out.type==SDL_MOUSEBUTTONUP);
        assert(scheduler.takeDeferred(out,1) && out.type==SDL_USEREVENT && out.user.code==frameCode);
        assert(!scheduler.takeDeferred(out,1));
        assert(pop().type==barrier && pop().type==SDL_KEYDOWN);
        assert(scheduler.prioritized()==2);
    }
    // Preserve all input order, including keyboard releases and drag edges.
    {
        VdiInputPriority scheduler(true,frameCode);
        for (Uint32 t : {Uint32(SDL_KEYDOWN),Uint32(SDL_MOUSEMOTION),Uint32(SDL_MOUSEBUTTONDOWN),
                         Uint32(SDL_MOUSEMOTION),Uint32(SDL_MOUSEBUTTONUP),Uint32(SDL_KEYUP)}) push(input(t));
        assert(scheduler.deferFrame(frame()));
        for (Uint32 t : {Uint32(SDL_KEYDOWN),Uint32(SDL_MOUSEMOTION),Uint32(SDL_MOUSEBUTTONDOWN),
                         Uint32(SDL_MOUSEMOTION),Uint32(SDL_MOUSEBUTTONUP),Uint32(SDL_KEYUP)})
            assert(scheduler.takeDeferred(out,1) && out.type==t);
        assert(scheduler.takeDeferred(out,1) && out.type==SDL_USEREVENT);
    }
    for (bool synthetic : {false,true}) {
        VdiInputPriority scheduler(true,frameCode);
        auto e=input(SDL_MOUSEMOTION,synthetic?1:2);
        if(synthetic) e.motion.which=SDL_TOUCH_MOUSEID;
        push(e); assert(scheduler.deferFrame(frame()));
        assert(scheduler.takeDeferred(out,1) && out.type==SDL_USEREVENT);
        assert(pop().type==SDL_MOUSEMOTION);
    }
    // A high-rate input device cannot starve video.
    {
        VdiInputPriority scheduler(true,frameCode);
        for(int i=0;i<1000;++i) push(input(SDL_MOUSEWHEEL));
        assert(scheduler.deferFrame(frame()));
        unsigned n=0;
        while(scheduler.takeDeferred(out,1) && out.type!=SDL_USEREVENT) ++n;
        assert(n<=32 && n>0 && out.type==SDL_USEREVENT);
        SDL_FlushEvents(SDL_FIRSTEVENT,SDL_LASTEVENT);
    }
    {
        VdiInputPriority scheduler(true,frameCode);
        push(input(SDL_MOUSEBUTTONUP));
        assert(scheduler.deferFrame(frame())); SDL_Delay(4);
        assert(scheduler.takeDeferred(out,1) && out.type==SDL_USEREVENT);
        assert(pop().type==SDL_MOUSEBUTTONUP);
    }
    // Instrumentation never consumes events or changes cursor visibility.
    VdiInputTiming timing(true);
    auto e=input(SDL_MOUSEMOTION); e.common.timestamp=SDL_GetTicks();
    timing.observe(e,1); auto start=timing.startRender(); timing.endRender(start);
    timing.report(0);
    SDL_Quit();
    std::puts("PASS: input FIFO, focus/quit/reset/window barriers, disabled mode, device/window isolation, count/time bounds");
}