#include <stdio.h>
#include <string.h>
#include <gb.h>
#include <r_io.h>
#include <r_util.h>

RIOPlugin r_io_plugin_gb_ppu;

static ut64 __lseek(RIO* io, RIODesc *desc, ut64 offset, int whence) {
	GBPPU *ppu = desc->data;
	ut64 seek = ppu->seek & 0xffff;
	switch (whence) {
	case R_IO_SEEK_SET:
		seek = R_MIN (GB_PPU_N_REGS, offset);
		break;
	case R_IO_SEEK_CUR:
		seek = R_MIN (GB_PPU_N_REGS, seek + offset);
		break;
	case R_IO_SEEK_END:
		seek = GB_PPU_N_REGS;
		break;
	}
	ppu->seek = (ppu->seek & (~0xffff)) | seek;
	return seek;
}

static bool __check(RIO *io, const char *pathname, bool many) {
	return r_str_startswith (pathname, "gb_ppu://");
}

static int __read(RIO *io, RIODesc *desc, ut8 *buf, int len) {
	GBPPU *ppu = desc->data;
	ut64 seek = ppu->seek & 0xffff;
	if (ppu->seek >= GB_PPU_N_REGS || len < 1) {
		return 0;
	}
	len = R_MIN (len, GB_PPU_N_REGS - seek);
	memcpy (buf, &ppu->buf[ppu->seek], len);
	seek += len;
	ppu->seek = (ppu->seek & (~0xffff)) | seek;
	return len;
}

static int __write(RIO *io, RIODesc *desc, const ut8 *buf, int len) {
	GBPPU *ppu = desc->data;
	ut64 seek = ppu->seek & 0xffff;
	if (ppu->seek >= GB_PPU_N_REGS || len < 1) {
		return 0;
	}
	len = R_MIN (len, GB_PPU_N_REGS - seek);
	ut32 i;
	for (i = 0; i < len; i++) {
		switch (seek) {
		case GB_PPU_STAT:
			ppu->buf[GB_PPU_STAT] = (buf[i] & 0xf8) | (ppu->buf[GB_PPU_STAT] & 0x7);
		case GB_PPU_LY:
			break;
		default:
			ppu->buf[seek] = buf[i];
			break;
		}
		seek++;
	}
	return len;
}

static bool __close(RIODesc *desc) {
	return true;
}

static RIODesc *__open(RIO *io, const char *pathname, int rw, int mode) {
	if (!r_str_startswith (pathname, "gb_ppu://")) {
		return NULL;
	}
	GBPPU *ppu = NULL;
	sscanf (pathname, "gb_ppu://%p", &ppu);
	RIODesc *desc = r_io_desc_new (io, &r_io_plugin_gb_ppu, pathname,
		R_PERM_RWX, mode, ppu);
	return desc;
}

RIOPlugin r_io_plugin_gb_ppu = {
	.meta = {
		.name = "gb_ppu",
		.desc = "gb_ppu",
		.license = "LGPL",
	},
	.uris = "gb_ppu://",
	.open = __open,
	.close = __close,
	.read = __read,
	.check = __check,
	.seek = __lseek,
	.write = __write,
};