#include <cstdio>
#include <algorithm>

#include <xf86drm.h>
#include <xf86drmMode.h>
#include <drm_fourcc.h>

#include "kms++.h"

#include "test.h"

using namespace std;
using namespace kms;

static void main_loop(Card& card);

class OutputFlipHandler
{
public:
	OutputFlipHandler(Connector* conn, Crtc* crtc, DumbFramebuffer* fb1, DumbFramebuffer* fb2)
		: m_connector(conn), m_crtc(crtc), m_fbs { fb1, fb2 }, m_front_buf(1), m_bar_xpos(0)
	{
	}

	~OutputFlipHandler()
	{
		delete m_fbs[0];
		delete m_fbs[1];
	}

	OutputFlipHandler(const OutputFlipHandler& other) = delete;
	OutputFlipHandler& operator=(const OutputFlipHandler& other) = delete;

	void set_mode()
	{
		auto mode = m_connector->get_default_mode();
		int r = m_crtc->set_mode(m_connector, *m_fbs[0], mode);
		ASSERT(r == 0);
	}

	void handle_event()
	{
		m_front_buf = (m_front_buf + 1) % 2;

		const int bar_width = 20;
		const int bar_speed = 8;

		auto crtc = m_crtc;
		auto fb = m_fbs[(m_front_buf + 1) % 2];

		ASSERT(crtc);
		ASSERT(fb);

		int current_xpos = m_bar_xpos;
		int old_xpos = (current_xpos + (fb->width() - bar_width - bar_speed)) % (fb->width() - bar_width);
		int new_xpos = (current_xpos + bar_speed) % (fb->width() - bar_width);

		draw_color_bar(*fb, old_xpos, new_xpos, bar_width);

		m_bar_xpos = new_xpos;

		auto& card = crtc->card();

		if (card.has_atomic()) {
			int r;

			AtomicReq ctx(card);

			ctx.add(m_crtc, card.get_prop("FB_ID"), fb->id());

			r = ctx.test();
			ASSERT(r == 0);

			r = ctx.commit(this);
			ASSERT(r == 0);
		} else {
			int r = crtc->page_flip(*fb, this);
			ASSERT(r == 0);
		}
	}

private:
	Connector* m_connector;
	Crtc* m_crtc;
	DumbFramebuffer* m_fbs[2];

	int m_front_buf;
	int m_bar_xpos;
};

int main()
{
	Card card;

	if (card.master() == false)
		printf("Not DRM master, modeset may fail\n");

	//card.print_short();

	vector<OutputFlipHandler*> outputs;

	for (auto pipe : card.get_connected_pipelines())
	{
		auto conn = pipe.connector;
		auto crtc = pipe.crtc;

		auto mode = conn->get_default_mode();

		auto fb1 = new DumbFramebuffer(card, mode.hdisplay, mode.vdisplay, "XR24");
		auto fb2 = new DumbFramebuffer(card, mode.hdisplay, mode.vdisplay, "XR24");

		printf("conn %u, crtc %u, fb1 %u, fb2 %u\n", conn->id(), crtc->id(), fb1->id(), fb2->id());

		auto output = new OutputFlipHandler(conn, crtc, fb1, fb2);
		outputs.push_back(output);
	}

	for(auto out : outputs)
		out->set_mode();

	for(auto out : outputs)
		out->handle_event();

	main_loop(card);

	for(auto out : outputs)
		delete out;
}

static void page_flip_handler(int fd, unsigned int frame,
			      unsigned int sec, unsigned int usec,
			      void *data)
{
	//printf("flip event %d, %d, %u, %u, %p\n", fd, frame, sec, usec, data);

	auto out = (OutputFlipHandler*)data;

	out->handle_event();
}


static void main_loop(Card& card)
{
	drmEventContext ev = {
		.version = DRM_EVENT_CONTEXT_VERSION,
		.vblank_handler = 0,
		.page_flip_handler = page_flip_handler,
	};

	fd_set fds;

	FD_ZERO(&fds);

	int fd = card.fd();

	printf("press enter to exit\n");

	while (true) {
		int r;

		FD_SET(0, &fds);
		FD_SET(fd, &fds);

		r = select(fd + 1, &fds, NULL, NULL, NULL);
		if (r < 0) {
			fprintf(stderr, "select() failed with %d: %m\n", errno);
			break;
		} else if (FD_ISSET(0, &fds)) {
			fprintf(stderr, "exit due to user-input\n");
			break;
		} else if (FD_ISSET(fd, &fds)) {
			drmHandleEvent(fd, &ev);
		}
	}
}