/*IBM VGA emulation*/
#include <stdlib.h>
#include "ibm.h"
#include "device.h"
#include "io.h"
#include "mem.h"
#include "rom.h"
#include "video.h"
#include "vid_svga.h"
#include "vid_vga.h"

svga_t *mb_vga = NULL;

typedef struct vga_t {
	svga_t svga;

	rom_t bios_rom;
} vga_t;

void vga_out(uint16_t addr, uint8_t val, void *p) {
	vga_t *vga = (vga_t *)p;
	svga_t *svga = &vga->svga;
	uint8_t old;

//        pclog("vga_out : %04X %02X  %04X:%04X  %02X  %i\n", addr, val, CS,pc, ram[0x489], ins);

	if (((addr & 0xfff0) == 0x3d0 || (addr & 0xfff0) == 0x3b0) && !(svga->miscout & 1))
		addr ^= 0x60;

	switch (addr) {
	case 0x3D4:svga->crtcreg = val & 0x3f;
		return;
	case 0x3D5:
		if (svga->crtcreg & 0x20)
			return;
		if ((svga->crtcreg < 7) && (svga->crtc[0x11] & 0x80))
			return;
		if ((svga->crtcreg == 7) && (svga->crtc[0x11] & 0x80))
			val = (svga->crtc[7] & ~0x10) | (val & 0x10);
		old = svga->crtc[svga->crtcreg];
		svga->crtc[svga->crtcreg] = val;
		if (old != val) {
			if (svga->crtcreg < 0xe || svga->crtcreg > 0x10) {
				svga->fullchange = changeframecount;
				svga_recalctimings(svga);
			}
		}
		break;
	}
	svga_out(addr, val, svga);
}

uint8_t vga_in(uint16_t addr, void *p) {
	vga_t *vga = (vga_t *)p;
	svga_t *svga = &vga->svga;
	uint8_t temp;

//        if (addr != 0x3da) pclog("vga_in : %04X ", addr);

	if (((addr & 0xfff0) == 0x3d0 || (addr & 0xfff0) == 0x3b0) && !(svga->miscout & 1))
		addr ^= 0x60;

	switch (addr) {
	case 0x3D4:temp = svga->crtcreg;
		break;
	case 0x3D5:
		if (svga->crtcreg & 0x20)
			temp = 0xff;
		else
			temp = svga->crtc[svga->crtcreg];
		break;
	default:temp = svga_in(addr, svga);
		break;
	}
//        if (addr != 0x3da) pclog("%02X  %04X:%04X\n", temp, CS,pc);
	return temp;
}

void vga_disable(void *p) {
	vga_t *vga = (vga_t *)p;
	svga_t *svga = &vga->svga;

//        pclog("vga_disable\n");
	io_removehandler(0x03a0, 0x0040, vga_in, NULL, NULL, vga_out, NULL, NULL, vga);
	mem_mapping_disable(&svga->mapping);
}

void vga_enable(void *p) {
	vga_t *vga = (vga_t *)p;
	svga_t *svga = &vga->svga;

//        pclog("vga_enable\n");
	io_sethandler(0x03c0, 0x0020, vga_in, NULL, NULL, vga_out, NULL, NULL, vga);
	if (!(svga->miscout & 1))
		io_sethandler(0x03a0, 0x0020, vga_in, NULL, NULL, vga_out, NULL, NULL, vga);

	mem_mapping_enable(&svga->mapping);
}

void *vga_init() {
	vga_t *vga = malloc(sizeof(vga_t));
	memset(vga, 0, sizeof(vga_t));

	rom_init(&vga->bios_rom, "ibm_vga.bin", 0xc0000, 0x8000, 0x7fff, 0x2000, MEM_MAPPING_EXTERNAL);

	svga_init(&vga->svga, vga, 1 << 18, /*256kb*/
		  NULL,
		  vga_in, vga_out,
		  NULL,
		  NULL);

	io_sethandler(0x03c0, 0x0020, vga_in, NULL, NULL, vga_out, NULL, NULL, vga);

	vga->svga.bpp = 8;
	vga->svga.miscout = 1;

	return vga;
}

/*PS/1 uses a standard VGA controller, but with no option ROM*/
void *ps1vga_init() {
	vga_t *vga = malloc(sizeof(vga_t));
	memset(vga, 0, sizeof(vga_t));

	svga_init(&vga->svga, vga, 1 << 18, /*256kb*/
		  NULL,
		  vga_in, vga_out,
		  NULL,
		  NULL);

	io_sethandler(0x03c0, 0x0020, vga_in, NULL, NULL, vga_out, NULL, NULL, vga);

	vga->svga.bpp = 8;
	vga->svga.miscout = 1;

	mb_vga = &vga->svga;

	return vga;
}

static int vga_available() {
	return rom_present("ibm_vga.bin");
}

void vga_close(void *p) {
	vga_t *vga = (vga_t *)p;

	mb_vga = NULL;

	svga_close(&vga->svga);

	free(vga);
}

void vga_speed_changed(void *p) {
	vga_t *vga = (vga_t *)p;

	svga_recalctimings(&vga->svga);
}

void vga_force_redraw(void *p) {
	vga_t *vga = (vga_t *)p;

	vga->svga.fullchange = changeframecount;
}

void vga_add_status_info(char *s, int max_len, void *p) {
	vga_t *vga = (vga_t *)p;

	svga_add_status_info(s, max_len, &vga->svga);
}

device_t vga_device =
	{
		"VGA",
		0,
		vga_init,
		vga_close,
		vga_available,
		vga_speed_changed,
		vga_force_redraw,
		vga_add_status_info
	};
device_t ps1vga_device =
	{
		"PS/1 VGA",
		0,
		ps1vga_init,
		vga_close,
		vga_available,
		vga_speed_changed,
		vga_force_redraw,
		vga_add_status_info
	};
