#pragma once

#include <stddef.h>
#include <stdint.h>

#define OWB_CONFIG_MAGIC 0x4f574243u /* OWBC */
#define OWB_COMMAND_MAGIC 0x4f574245u /* OWBE */
#define OWB_PROTOCOL_VERSION 3u
#define OWB_MAX_STRING (16u * 1024u * 1024u)
#define OWB_SHARED_MAGIC 0x4f574246u /* OWBF */
#define OWB_SHARED_FRAME_FD 198
#define OWB_SHARED_FRAME_SLOTS 2u

struct owb_config_header {
	uint32_t magic;
	uint32_t version;
	uint32_t width;
	uint32_t height;
	uint32_t fps;
	uint32_t zoom_percent;
	uint32_t transparent;
	uint32_t hardware_acceleration;
	uint32_t url_length;
	uint32_t css_length;
};

struct owb_shared_frames {
	uint32_t magic;
	uint32_t version;
	uint32_t width;
	uint32_t height;
	uint32_t stride;
	uint32_t slot_count;
	uint64_t sequence[OWB_SHARED_FRAME_SLOTS];
	uint8_t pixels[1];
};

static inline size_t owb_frame_size(uint32_t width, uint32_t height)
{
	return (size_t)width * (size_t)height * 4u;
}

static inline size_t owb_shared_size(uint32_t width, uint32_t height)
{
	return offsetof(struct owb_shared_frames, pixels) +
	       owb_frame_size(width, height) * OWB_SHARED_FRAME_SLOTS;
}

static inline uint8_t *owb_shared_slot(struct owb_shared_frames *shared, uint32_t slot)
{
	return shared->pixels + owb_frame_size(shared->width, shared->height) * slot;
}

enum owb_command_type {
	OWB_MOUSE_MOVE = 1,
	OWB_MOUSE_CLICK = 2,
	OWB_MOUSE_WHEEL = 3,
	OWB_FOCUS = 4,
	OWB_KEY = 5,
	OWB_RELOAD = 6,
};

/* Fixed-size control messages keep the renderer's nonblocking parser simple. */
struct owb_command {
	uint32_t magic;
	uint32_t type;
	int32_t x;
	int32_t y;
	int32_t value1;
	int32_t value2;
	uint32_t modifiers;
	uint32_t text_length;
	char text[64];
};