/*
 * 86Box	A hypervisor and IBM PC system emulator that specializes in
 *		running old operating systems and software designed for IBM
 *		PC systems and compatibles from 1981 through fairly recent
 *		system designs based on the PCI bus.
 *
 *		This file is part of the 86Box distribution.
 *
 *		Emulation of the Compaq CGA graphics cards.
 *
 *
 *
 * Authors:	John Elliott, <jce@seasip.info>
 *		Sarah Walker, <http://pcem-emulator.co.uk/>
 *		Miran Grca, <mgrca8@gmail.com>
 *
 *		Copyright 2016-2019 John Elliott.
 *		Copyright 2008-2019 Sarah Walker.
 *		Copyright 2016-2019 Miran Grca.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <wchar.h>
#include <math.h>
#include <86box/86box.h>
#include "cpu.h"
#include <86box/io.h>
#include <86box/timer.h>
#include <86box/pit.h>
#include <86box/mem.h>
#include <86box/rom.h>
#include <86box/device.h>
#include <86box/video.h>
#include <86box/vid_cga.h>
#include <86box/vid_cga_comp.h>


#define CGA_RGB 0
#define CGA_COMPOSITE 1


static uint32_t		vflags;
static uint8_t		mdaattr[256][2][2];


typedef struct compaq_cga_t 
{
    cga_t cga;
} compaq_cga_t;


#ifdef ENABLE_COMPAQ_CGA_LOG
int compaq_cga_do_log = ENABLE_COMPAQ_CGA_LOG;


static void
compaq_cga_log(const char *fmt, ...)
{
    va_list ap;

    if (compaq_cga_do_log) {
	va_start(ap, fmt);
	pclog_ex(fmt, ap);
	va_end(ap);
    }
}
#else
#define compaq_cga_log(fmt, ...)
#endif


void
compaq_cga_recalctimings(compaq_cga_t *self)
{
    double _dispontime, _dispofftime, disptime;
    disptime = self->cga.crtc[0] + 1;

    _dispontime = self->cga.crtc[1];
    _dispofftime = disptime - _dispontime;
    _dispontime *= MDACONST;
    _dispofftime *= MDACONST;
    self->cga.dispontime = (uint64_t)(_dispontime);
    self->cga.dispofftime = (uint64_t)(_dispofftime);
}


void
compaq_cga_poll(void *p)
{
    compaq_cga_t *self = (compaq_cga_t *)p;
    uint16_t ca = (self->cga.crtc[15] | (self->cga.crtc[14] << 8)) & 0x3fff;
    int drawcursor;
    int x, c, xs_temp, ys_temp;
    int oldvc;
    uint8_t chr, attr;
    uint8_t border;
    uint8_t cols[4];
    int oldsc;
    int underline = 0;
    int blink = 0;

    /* If in graphics mode or character height is not 13, behave as CGA */
    if ((self->cga.cgamode & 0x12) || (self->cga.crtc[9] != 13)) {
	overscan_x = overscan_y = 16;
	cga_poll(&self->cga);
	return;
    } else
	overscan_x = overscan_y = 0;

    /* We are in Compaq 350-line CGA territory */
    if (!self->cga.linepos) {
	timer_advance_u64(&self->cga.timer, self->cga.dispofftime);
	self->cga.cgastat |= 1;
	self->cga.linepos = 1;
	oldsc = self->cga.sc;
	if ((self->cga.crtc[8] & 3) == 3) 
		self->cga.sc = ((self->cga.sc << 1) + self->cga.oddeven) & 7;
	if (self->cga.cgadispon) {
		if (self->cga.displine < self->cga.firstline) {
			self->cga.firstline = self->cga.displine;
			video_wait_for_buffer();
			compaq_cga_log("Firstline %i\n", firstline);
		}
		self->cga.lastline = self->cga.displine;

		cols[0] = (self->cga.cgacol & 15) + 16;

		for (c = 0; c < 8; c++) {
			buffer32->line[self->cga.displine][c] = cols[0];
			if (self->cga.cgamode & 1)
				buffer32->line[self->cga.displine][c + (self->cga.crtc[1] << 3) + 8] = cols[0];
			else
				buffer32->line[self->cga.displine][c + (self->cga.crtc[1] << 4) + 8] = cols[0];
		}

		if (self->cga.cgamode & 1) {
			for (x = 0; x < self->cga.crtc[1]; x++) {
				chr = self->cga.charbuffer[x << 1];
				attr = self->cga.charbuffer[(x << 1) + 1];
				drawcursor = ((self->cga.ma == ca) && self->cga.con && self->cga.cursoron);

				if (vflags) {
					underline = 0;
					blink = ((self->cga.cgablink & 8) && (self->cga.cgamode & 0x20) && (attr & 0x80) && !drawcursor);
				}

				if (vflags && (self->cga.cgamode & 0x80)) {
					cols[0] = mdaattr[attr][blink][0];
					cols[1] = mdaattr[attr][blink][1];

					if ((self->cga.sc == 12) && ((attr & 7) == 1))
						underline = 1;
				} else if (self->cga.cgamode & 0x20) {
					cols[1] = (attr & 15) + 16;
					cols[0] = ((attr >> 4) & 7) + 16;

					if (vflags) {
						if (blink)
							cols[1] = cols[0];
					} else {
						if ((self->cga.cgablink & 8) && (attr & 0x80) && !self->cga.drawcursor) 
							cols[1] = cols[0];
					}
				} else {
					cols[1] = (attr & 15) + 16;
					cols[0] = (attr >> 4) + 16;
				}

				if (vflags && underline) {
					for (c = 0; c < 8; c++)
						buffer32->line[self->cga.displine][(x << 3) + c + 8] = mdaattr[attr][blink][1];
				} else if (drawcursor) {
					for (c = 0; c < 8; c++)
						buffer32->line[self->cga.displine][(x << 3) + c + 8] = cols[(fontdatm[chr + self->cga.fontbase][self->cga.sc & 15] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;
				} else {
					for (c = 0; c < 8; c++)
						buffer32->line[self->cga.displine][(x << 3) + c + 8] = cols[(fontdatm[chr + self->cga.fontbase][self->cga.sc & 15] & (1 << (c ^ 7))) ? 1 : 0];
				}
				self->cga.ma++;
			}
		} else {
			for (x = 0; x < self->cga.crtc[1]; x++) {
				chr  = self->cga.vram[((self->cga.ma << 1) & 0x3fff)];
				attr = self->cga.vram[(((self->cga.ma << 1) + 1) & 0x3fff)];
				drawcursor = ((self->cga.ma == ca) && self->cga.con && self->cga.cursoron);

				if (vflags) {
					underline = 0;
					blink = ((self->cga.cgablink & 8) && (self->cga.cgamode & 0x20) && (attr & 0x80) && !drawcursor);
				}

				if (vflags && (self->cga.cgamode & 0x80)) {
					cols[0] = mdaattr[attr][blink][0];
					cols[1] = mdaattr[attr][blink][1];
					if (self->cga.sc == 12 && (attr & 7) == 1) underline = 1;
				} else if (self->cga.cgamode & 0x20) {
					cols[1] = (attr & 15) + 16;
					cols[0] = ((attr >> 4) & 7) + 16;

					if (vflags) {
						if (blink)
							cols[1] = cols[0];
					} else {
						if ((self->cga.cgablink & 8) && (attr & 0x80) && !self->cga.drawcursor) 
						cols[1] = cols[0];
					}
				} else {
					cols[1] = (attr & 15) + 16;
					cols[0] = (attr >> 4) + 16;
				}
				self->cga.ma++;

				if (vflags && underline) {
					for (c = 0; c < 8; c++)
						buffer32->line[self->cga.displine][(x << 4)+(c << 1) + 8] =
						buffer32->line[self->cga.displine][(x << 4)+(c << 1) + 9] = mdaattr[attr][blink][1];
				} else if (drawcursor) {
					for (c = 0; c < 8; c++)
						buffer32->line[self->cga.displine][(x << 4)+(c << 1) + 8] =
						buffer32->line[self->cga.displine][(x << 4) + (c << 1) + 1 + 8] =
							cols[(fontdatm[chr + self->cga.fontbase][self->cga.sc & 15] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;
				} else {
					for (c = 0; c < 8; c++)
						buffer32->line[self->cga.displine][(x << 4) + (c << 1) + 8] =
						buffer32->line[self->cga.displine][(x << 4) + (c << 1) + 1 + 8] =
							cols[(fontdatm[chr + self->cga.fontbase][self->cga.sc & 15] & (1 << (c ^ 7))) ? 1 : 0];
				}
			}
		}
	} else {
		cols[0] = (self->cga.cgacol & 15) + 16;

		if (self->cga.cgamode & 1)	hline(buffer32, 0, self->cga.displine, (self->cga.crtc[1] << 3) + 16, cols[0]);
		else				hline(buffer32, 0, self->cga.displine, (self->cga.crtc[1] << 4) + 16, cols[0]);
	}

	if (self->cga.cgamode & 1) x = (self->cga.crtc[1] << 3) + 16;
	else                  x = (self->cga.crtc[1] << 4) + 16;

	if (self->cga.composite) {
		if (self->cga.cgamode & 0x10)
			border = 0x00;
		else
			border = self->cga.cgacol & 0x0f;

		if (vflags)
			Composite_Process(self->cga.cgamode & 0x7f, border, x >> 2, buffer32->line[self->cga.displine]);
		else
			Composite_Process(self->cga.cgamode, border, x >> 2, buffer32->line[self->cga.displine]);
	}

	self->cga.sc = oldsc;
	if (self->cga.vc == self->cga.crtc[7] && !self->cga.sc)
		self->cga.cgastat |= 8;
	self->cga.displine++;
	if (self->cga.displine >= 500) 
		self->cga.displine = 0;
    } else {
	timer_advance_u64(&self->cga.timer, self->cga.dispontime);
	self->cga.linepos = 0;
	if (self->cga.vsynctime) {
		self->cga.vsynctime--;
		if (!self->cga.vsynctime)
			self->cga.cgastat &= ~8;
	}

	if (self->cga.sc == (self->cga.crtc[11] & 31) || ((self->cga.crtc[8] & 3) == 3 && self->cga.sc == ((self->cga.crtc[11] & 31) >> 1))) { 
		self->cga.con = 0; 
		self->cga.coff = 1; 
	}
	if ((self->cga.crtc[8] & 3) == 3 && self->cga.sc == (self->cga.crtc[9] >> 1))
		self->cga.maback = self->cga.ma;
	if (self->cga.vadj) {
		self->cga.sc++;
		self->cga.sc &= 31;
		self->cga.ma = self->cga.maback;
		self->cga.vadj--;
		if (!self->cga.vadj) {
			self->cga.cgadispon = 1;
			self->cga.ma = self->cga.maback = (self->cga.crtc[13] | (self->cga.crtc[12] << 8)) & 0x3fff;
			self->cga.sc = 0;
		}
	} else if (self->cga.sc == self->cga.crtc[9]) {
		self->cga.maback = self->cga.ma;
		self->cga.sc = 0;
		oldvc = self->cga.vc;
		self->cga.vc++;
		self->cga.vc &= 127;

		if (self->cga.vc == self->cga.crtc[6]) 
			self->cga.cgadispon = 0;

		if (oldvc == self->cga.crtc[4]) {
			self->cga.vc = 0;
			self->cga.vadj = self->cga.crtc[5];

			if (!self->cga.vadj) self->cga.cgadispon = 1;

			if (!self->cga.vadj) self->cga.ma = self->cga.maback = (self->cga.crtc[13] | (self->cga.crtc[12] << 8)) & 0x3fff;

			if ((self->cga.crtc[10] & 0x60) == 0x20)
				self->cga.cursoron = 0;
			else
				self->cga.cursoron = self->cga.cgablink & 8;
		}

		if (self->cga.vc == self->cga.crtc[7]) {
			self->cga.cgadispon = 0;
			self->cga.displine = 0;
			self->cga.vsynctime = 16;

			if (self->cga.crtc[7]) {
				compaq_cga_log("Lastline %i Firstline %i  %i\n", self->cga.lastline,
					       self->cga.firstline ,self->cga.lastline - self->cga.firstline);

				if (self->cga.cgamode & 1)	x = (self->cga.crtc[1] << 3);
				else				x = (self->cga.crtc[1] << 4);

				self->cga.lastline++;

				xs_temp = x;
				ys_temp = (self->cga.lastline - self->cga.firstline);

				if ((xs_temp > 0) && (ys_temp > 0)) {
					if (xs_temp < 64) xs_temp = 656;
					if (ys_temp < 32) ys_temp = 400;
					if (!enable_overscan)
						xs_temp -= 16;

					if ((self->cga.cgamode & 8) && ((xs_temp != xsize) || (ys_temp != ysize) || video_force_resize_get())) {
						xsize = xs_temp;
						ysize = ys_temp;
						set_screen_size(xsize, ysize + (enable_overscan ? 16 : 0));

						if (video_force_resize_get())
							video_force_resize_set(0);
					}

					if (enable_overscan) {
	                                        if (self->cga.composite) 
       		                                   video_blit_memtoscreen(0, self->cga.firstline - 8, xsize, (self->cga.lastline - self->cga.firstline) + 16);
               		                        else          
                       		                   video_blit_memtoscreen_8(0, self->cga.firstline - 8, xsize, (self->cga.lastline - self->cga.firstline) + 16);
					} else {
	                                        if (self->cga.composite) 
       		                                   video_blit_memtoscreen(8, self->cga.firstline, xsize, self->cga.lastline - self->cga.firstline);
               		                        else          
                       		                   video_blit_memtoscreen_8(8, self->cga.firstline, xsize, self->cga.lastline - self->cga.firstline);
					}
				}

				frames++;

				video_res_x = xsize;
				if (enable_overscan)
					xsize -= 16;
				video_res_y = ysize;
				if (self->cga.cgamode & 1) {
					video_res_x /= 8;
					video_res_y /= self->cga.crtc[9] + 1;
					video_bpp = 0;
				} else if (!(self->cga.cgamode & 2)) {
					video_res_x /= 16;
					video_res_y /= self->cga.crtc[9] + 1;
					video_bpp = 0;
				} else if (!(self->cga.cgamode & 16)) {
					video_res_x /= 2;
					video_bpp = 2;
				} else
					video_bpp = 1;
			}

			self->cga.firstline = 1000;
			self->cga.lastline = 0;
			self->cga.cgablink++;
			self->cga.oddeven ^= 1;
		}
	} else {
		self->cga.sc++;
		self->cga.sc &= 31;
		self->cga.ma = self->cga.maback;
	}

	if (self->cga.cgadispon)
		self->cga.cgastat &= ~1;

	if ((self->cga.sc == (self->cga.crtc[10] & 31) || ((self->cga.crtc[8] & 3) == 3 && self->cga.sc == ((self->cga.crtc[10] & 31) >> 1)))) 
		self->cga.con = 1;

	if (self->cga.cgadispon && (self->cga.cgamode & 1)) {
		for (x = 0; x < (self->cga.crtc[1] << 1); x++)
			self->cga.charbuffer[x] = self->cga.vram[(((self->cga.ma << 1) + x) & 0x3fff)];
	}
    }
}


void *
compaq_cga_init(const device_t *info)
{
    int display_type;
    int c;
    compaq_cga_t *self = malloc(sizeof(compaq_cga_t));
    memset(self, 0, sizeof(compaq_cga_t));

    display_type = device_get_config_int("display_type");
    self->cga.composite = (display_type != CGA_RGB);
    self->cga.revision = device_get_config_int("composite_type");
    self->cga.snow_enabled = device_get_config_int("snow_enabled");

    self->cga.vram = malloc(0x4000);

    cga_comp_init(self->cga.revision);
    timer_add(&self->cga.timer, compaq_cga_poll, self, 1);
    mem_mapping_add(&self->cga.mapping, 0xb8000, 0x08000, cga_read, NULL, NULL, cga_write, NULL, NULL, NULL /*self->cga.vram*/, MEM_MAPPING_EXTERNAL, self);
    io_sethandler(0x03d0, 0x0010, cga_in, NULL, NULL, cga_out, NULL, NULL, self);

    if (info->local) {
	for (c = 0; c < 256; c++) {
		mdaattr[c][0][0] = mdaattr[c][1][0] = mdaattr[c][1][1] = 16;
		if (c & 8)	mdaattr[c][0][1] = 15 + 16;
		else		mdaattr[c][0][1] =  7 + 16;
	}

	mdaattr[0x70][0][1] = 16;
	mdaattr[0x70][0][0] = mdaattr[0x70][1][0] = mdaattr[0x70][1][1] = 16 + 15;
	mdaattr[0xF0][0][1] = 16;
	mdaattr[0xF0][0][0] = mdaattr[0xF0][1][0] = mdaattr[0xF0][1][1] = 16 + 15;
	mdaattr[0x78][0][1] = 16 + 7;
	mdaattr[0x78][0][0] = mdaattr[0x78][1][0] = mdaattr[0x78][1][1] = 16 + 15;
	mdaattr[0xF8][0][1] = 16 + 7;
	mdaattr[0xF8][0][0] = mdaattr[0xF8][1][0] = mdaattr[0xF8][1][1] = 16 + 15;
	mdaattr[0x00][0][1] = mdaattr[0x00][1][1] = 16;
	mdaattr[0x08][0][1] = mdaattr[0x08][1][1] = 16;
	mdaattr[0x80][0][1] = mdaattr[0x80][1][1] = 16;
	mdaattr[0x88][0][1] = mdaattr[0x88][1][1] = 16;
    }

    vflags = info->local;

    overscan_x = overscan_y = 16;

    self->cga.rgb_type = device_get_config_int("rgb_type");
    cga_palette = (self->cga.rgb_type << 1);
    cgapal_rebuild();

    self->cga.crtc[9] = 13;

    return self;
}


void
compaq_cga_close(void *p)
{
    compaq_cga_t *self = (compaq_cga_t *)p;

    free(self->cga.vram);
    free(self);
}


void
compaq_cga_speed_changed(void *p)
{
    compaq_cga_t *self = (compaq_cga_t *)p;

    if (self->cga.crtc[9] == 13)	/* Character height */
	compaq_cga_recalctimings(self);
    else
	cga_recalctimings(&self->cga);
}


extern const device_config_t cga_config[];

const device_t compaq_cga_device =
{
        "Compaq CGA",
        DEVICE_ISA, 0,
        compaq_cga_init,
        compaq_cga_close,
        NULL,
	{ NULL },
        compaq_cga_speed_changed,
        NULL,
        cga_config
};

const device_t compaq_cga_2_device =
{
        "Compaq CGA 2",
        DEVICE_ISA, 1,
        compaq_cga_init,
        compaq_cga_close,
        NULL,
	{ NULL },
        compaq_cga_speed_changed,
        NULL,
        cga_config
};
