#include "type.h"
#include "stdio.h"
#include "const.h"
#include "protect.h"
#include "string.h"
#include "proc.h"
#include "tty.h"
#include "console.h"
#include "global.h"
#include "keyboard.h"
#include "proto.h"
#include "x86.h"
#include "memman.h"
#include "assert.h"

/*****************************************************************************
 * Low level vga driver
 *****************************************************************************/

/*****************************************************************************
 * Display the cursor by setting CRTC (6845 compatible) registers.
 *
 * @param position  Position of the cursor based on the beginning of the video
 *                  memory. Note that it counts in WORDs, not in BYTEs.
 *****************************************************************************/
static inline void vga_set_cursor(unsigned int position)
{
	disable_int();
	outb(CRTC_ADDR_REG, CURSOR_H);
	outb(CRTC_DATA_REG, (position >> 8) & 0xFF);
	outb(CRTC_ADDR_REG, CURSOR_L);
	outb(CRTC_DATA_REG, position & 0xFF);
	enable_int();
}

static inline void vga_disable_cursor()
{
	outb(CRTC_ADDR_REG, 0x0A);
	outb(CRTC_DATA_REG, 0x20);
}

static inline void vga_enable_cursor(u8 cursor_start, u8 cursor_end)
{
	outb(0x3D4, 0x0A);
	outb(0x3D5, (inb(0x3D5) & 0xC0) | cursor_start);

	outb(0x3D4, 0x0B);
	outb(0x3D5, (inb(0x3D5) & 0xE0) | cursor_end);
}

/*****************************************************************************
 * Routine for hardware screen scrolling.
 *
 * @param addr  Offset in the video memory.
 *****************************************************************************/
static inline void vga_set_video_start_addr(u32 addr)
{
	disable_int();
	outb(CRTC_ADDR_REG, START_ADDR_H);
	outb(CRTC_DATA_REG, (addr >> 8) & 0xFF);
	outb(CRTC_ADDR_REG, START_ADDR_L);
	outb(CRTC_DATA_REG, addr & 0xFF);
	enable_int();
}

/*****************************************************************************
 * Write data directly to Video Memory cell
 *
 * @param pos  text mode position(pos*2 yourself)
 * @param dat  data to be written, with format [ BG | FG |  ASCII  ]
 *****************************************************************************/
static inline void vga_put_raw(u32 pos, u16 dat)
{
	u16 *pch = (u16 *)K_PHY2LIN(V_MEM_BASE + pos);
	*pch = dat;
}

/*****************************************************************************
 * copy a whole screen of text mode data into video memory, assume that screen
 * width is 80 or 40
 *
 * @param src  memory block with the same size as text mode video memory()
 *****************************************************************************/
static inline void vga_flush_screen(void *src)
{
	u32 *_src = src;
	u32 *dst = (u32 *)K_PHY2LIN(V_MEM_BASE);
	for (int i = 0; i < SCR_SIZE * sizeof(u16) / sizeof(u32); ++i)
	{
		*dst++ = *_src++;
	}
}

/*****************************************************************************
 * copy a whole screen of text mode data into video memory, assume that screen
 * width is 80 or 40
 *
 * @param src  memory block with the same size as text mode video memory()
 *****************************************************************************/
static inline void vga_flush_line(void *src, int line_no)
{
	u32 *_src = src;
	u32 *dst = (u32 *)K_PHY2LIN(V_MEM_BASE + line_no * SCR_WIDTH * 2);
	for (int i = 0; i < SCR_WIDTH * sizeof(u16) / sizeof(u32); ++i)
	{
		*dst++ = *_src++;
	}
}

static inline void vga_flush_blankline(int line_no)
{
	u32 *dst = (u32 *)K_PHY2LIN(V_MEM_BASE + line_no * SCR_WIDTH * 2);
	for (int i = 0; i < SCR_WIDTH * sizeof(u16) / sizeof(u32); ++i)
	{
		*dst++ = (BLANK << 16) | BLANK;
	}
}

/*****************************************************************************
 * tty - vga driver
 *****************************************************************************/
static u16 pagebuf[3][SCR_BUFSIZE];

void vga_tty_init(NTTY *tty)
{
	static int _cnt = 0;
	assert(tty->driver_type == 1);
	assert(tty->output_buf);
	vga_buf *vga = tty->output_buf;
	vga->buf = (void *)K_PHY2LIN(do_kmalloc(sizeof(u16) * SCR_BUFSIZE));
	// vga->buf = (void *)pagebuf[_cnt++];
	// kprintf("malloced %p %p %p\n", vga->buf, &vga->buf, &vga->scr_top_line);
	vga->cur_col = vga->cur_row = 0;
	// buf->max_line = SCR_BUFSIZE / SCR_WIDTH;
	vga->scr_top_line = vga->scr_cur_line = vga->scr_bot_line = 0;
	vga->head_line = 0;
	u32 *ptr_buf = (u32 *)vga->buf;
	for (int i = 0; i < SCR_BUFSIZE * sizeof(u16) / sizeof(u32); ++i)
	{
		ptr_buf[i] = (BLANK << 16) | BLANK; // bg-black, fg-white, ascii-space
	}
	// kprintf("%p 0x%x %d\n", vga->buf, ((u32 *)vga->buf)[20], vga->scr_cur_line);
}

#define INDEX(row, col) ((row)*SCR_WIDTH + (col))
#define NEXTLINE(row) NEXT(row, SCR_MAXLINE)
#define LASTLINE(row) LAST(row, SCR_MAXLINE)
#define ADDLINE(row, add_num) (((row) + add_num) % SCR_MAXLINE)

// called by csi
static void csi_scroll(vga_buf *vgabuf, i16 scroll_num)
{
	while (scroll_num > 0) // down
	{
		scroll_num--;
		for (int i = SCR_HEIGHT - 1; i > 0; i--)
		{
			int line_dst = ADDLINE(vgabuf->scr_top_line, i);
			int line_src = ADDLINE(vgabuf->scr_top_line, i - 1);
			u32 *ptr_buf_dst = (u32 *)(vgabuf->buf + sizeof(u16) * line_dst * SCR_WIDTH);
			u32 *ptr_buf_src = (u32 *)(vgabuf->buf + sizeof(u16) * line_src * SCR_WIDTH);
			for (int p = 0; p < SCR_WIDTH * sizeof(u16) / sizeof(u32); ++p)
			{
				*ptr_buf_dst++ = *ptr_buf_src++;
			}
		}
		u32 *ptr_buf_start = (u32 *)(vgabuf->buf + sizeof(u16) * (vgabuf->scr_top_line) * SCR_WIDTH);
		for (int i = 0; i < SCR_WIDTH * sizeof(u16) / sizeof(u32); ++i)
		{
			*ptr_buf_start++ = (BLANK << 16) | BLANK; // bg-black, fg-white, ascii-space
		}
	}
	while (scroll_num < 0) // up
	{
		scroll_num++;

		for (int i = 0; i < SCR_HEIGHT - 1; i++)
		{
			int line_dst = ADDLINE(vgabuf->scr_top_line, i);
			int line_src = ADDLINE(vgabuf->scr_top_line, i + 1);
			u32 *ptr_buf_dst = (u32 *)(vgabuf->buf + sizeof(u16) * line_dst * SCR_WIDTH);
			u32 *ptr_buf_src = (u32 *)(vgabuf->buf + sizeof(u16) * line_src * SCR_WIDTH);
			for (int p = 0; p < SCR_WIDTH * sizeof(u16) / sizeof(u32); ++p)
			{
				*ptr_buf_dst++ = *ptr_buf_src++;
			}
		}
		int line_end = ADDLINE(vgabuf->scr_top_line, SCR_HEIGHT - 1);
		u32 *ptr_buf_end = (u32 *)(vgabuf->buf + sizeof(u16) * line_end * SCR_WIDTH);
		for (int i = 0; i < SCR_WIDTH * sizeof(u16) / sizeof(u32); ++i)
		{
			*ptr_buf_end++ = (BLANK << 16) | BLANK; // bg-black, fg-white, ascii-space
		}
	}
}

static void newline(vga_buf *vga)
{
	u16 *buf = vga->buf;
	vga->cur_col = 0;
	// kprintf("bf %x\n", vgabuf->scr_cur_line);
	vga->scr_cur_line = NEXTLINE(vga->scr_cur_line);
	// kprintf("af %x\n", vgabuf->scr_cur_line);
	vga->cur_row = CYCLE_SUB(vga->scr_top_line, vga->scr_cur_line, SCR_MAXLINE);
	if (vga->cur_row == SCR_HEIGHT)
	{
		// auto scroll
		vga->scr_top_line = NEXTLINE(vga->scr_top_line);
	}
	if (vga->scr_cur_line == vga->head_line)
	{
		vga->head_line = NEXTLINE(vga->head_line);
		// remember to fill blank the old line
		u32 *ptr_buf = (u32 *)(vga->buf + sizeof(u16) * vga->scr_cur_line * SCR_WIDTH);
		for (int i = 0; i < SCR_WIDTH * sizeof(u16) / sizeof(u32); ++i)
		{
			*ptr_buf++ = (BLANK << 16) | BLANK; // bg-black, fg-white, ascii-space
		}
		// for (int i = 0; i < SCR_WIDTH; ++ i) {
		// 	buf[INDEX(vga->scr_cur_line, i)] = BLANK;
		// }
	}
}

static void nextcol(vga_buf *vgabuf)
{
	vgabuf->cur_col++;
	if (vgabuf->cur_col == SCR_WIDTH)
	{
		newline(vgabuf);
	}
}

static void cursor_locate(i16 row, i16 col, vga_buf *vgabuf)
{

	vgabuf->scr_cur_line = vgabuf->scr_top_line;
	while (row > 0 && row < SCR_HEIGHT)
	{
		row--;
		vgabuf->scr_cur_line = NEXTLINE(vgabuf->scr_cur_line);
		if (vgabuf->scr_cur_line == vgabuf->scr_bot_line)
			break;
	}
	if (col >= 0 && col <= SCR_WIDTH - 1)
	{
		vgabuf->cur_col = col;
	}
}
static void cursor_move(i16 move_row, i16 move_col, vga_buf *vgabuf)
{
	// kprintf("%d,%d", move_row, move_col);
	while (move_row > 0) // down
	{
		move_row--;
		if (vgabuf->scr_cur_line == vgabuf->scr_bot_line)
			break;
		vgabuf->scr_cur_line = NEXTLINE(vgabuf->scr_cur_line);
		vgabuf->cur_row = CYCLE_SUB(vgabuf->scr_top_line, vgabuf->scr_cur_line, SCR_MAXLINE);
		if (vgabuf->cur_row == SCR_HEIGHT)
		{
			// auto scroll
			vgabuf->scr_top_line = NEXTLINE(vgabuf->scr_top_line);
		}
	}
	while (move_row < 0) // up
	{
		move_row++;
		vgabuf->scr_cur_line = LASTLINE(vgabuf->scr_cur_line);
		if (vgabuf->scr_cur_line == vgabuf->scr_top_line)
		{
			if (vgabuf->scr_top_line == vgabuf->head_line)
				break;
			// vgabuf->scr_cur_line = LASTLINE(vgabuf->scr_cur_line);
			vgabuf->scr_top_line = LASTLINE(vgabuf->scr_top_line);
			vgabuf->scr_bot_line = LASTLINE(vgabuf->scr_bot_line);
		}
	}
	vgabuf->cur_row = CYCLE_SUB(vgabuf->scr_top_line, vgabuf->scr_cur_line, SCR_MAXLINE);
	vgabuf->cur_col += move_col;
	if (vgabuf->cur_col < 0)
		vgabuf->cur_col = 0;
	else if (vgabuf->cur_col >= SCR_WIDTH)
		vgabuf->cur_col = SCR_WIDTH - 1;
}

inline static void
param12vga_color(i16 *param)
{
	u8 tmp = *param & 1;
	*param &= 0b0110;
	*param |= *param >> 2;
	*param &= 0b0011;
	*param |= tmp << 2;
}

static void clear_screen(vga_buf *vgabuf, i16 src_row, i16 src_col, i16 dst_row, i16 dst_col)
{
	u16 *buf = vgabuf->buf;
	int src_index = INDEX(src_row, src_col);
	int dst_index = INDEX(dst_row, dst_col);
	if (src_index <= dst_index)
		for (int i = src_index; i <= dst_index; i++)
		{
			buf[i] = BLANK;
		}
	else // scr>dst
	{
		for (int i = 0; i <= dst_index; i++)
			buf[i] = BLANK;
		int index_end = INDEX(SCR_MAXLINE - 1, SCR_WIDTH - 1);
		for (int i = 0; i <= index_end; i++)
			buf[i] = BLANK;
	}
}
static void set_color(vga_buf *vgabuf)
{
	if (vgabuf->param1 == 0)
	{
		vgabuf->color = DEFAULT_CHAR_COLOR;
	}
	else if (vgabuf->param1 == 1)
	{
		vgabuf->color |= 0x8800;
	}
	else if (vgabuf->param1 == 2)
	{
		vgabuf->color &= 0x7700;
	}
	else if (30 <= vgabuf->param1 && vgabuf->param1 <= 37)
	{
		vgabuf->param1 -= 30;
		param12vga_color(&(vgabuf->param1));
		vgabuf->color = (vgabuf->color & 0xf8ff) | FOREGROUND(vgabuf->param1);
	}
	else if (40 <= vgabuf->param1 && vgabuf->param1 <= 47)
	{
		vgabuf->param1 -= 40;
		param12vga_color(&(vgabuf->param1));
		vgabuf->color = (vgabuf->color & 0x8fff) | BACKGROUND(vgabuf->param1);
	}
	else if (90 <= vgabuf->param1 && vgabuf->param1 <= 97)
	{
		vgabuf->param1 -= 90;
		param12vga_color(&(vgabuf->param1));
		vgabuf->param1 |= 0x8;
		vgabuf->color = (vgabuf->color & 0xf0ff) | FOREGROUND(vgabuf->param1);
	}
	else if (100 <= vgabuf->param1 && vgabuf->param1 <= 107)
	{
		vgabuf->param1 -= 100;
		param12vga_color(&(vgabuf->param1));
		vgabuf->param1 |= 0x8;
		vgabuf->color = (vgabuf->color & 0x0fff) | BACKGROUND(vgabuf->param1);
	}
	else
	{
		warn("unsupport CSI: color");
	}
	if (vgabuf->Is2param == true)
	{
		if (vgabuf->param2 == 0 && vgabuf->param1 == 0)
		{
			vgabuf->color = DEFAULT_CHAR_COLOR;
		}
		else if (vgabuf->param2 == 1)
		{
			vgabuf->color |= 0x8800;
		}
		else if (vgabuf->param2 == 2)
		{
			vgabuf->color &= 0x7700;
		}
		else if (30 <= vgabuf->param2 && vgabuf->param2 <= 37)
		{
			vgabuf->param2 -= 30;
			param12vga_color(&(vgabuf->param2));
			vgabuf->color = (vgabuf->color & 0xf8ff) | FOREGROUND(vgabuf->param2);
		}
		else if (40 <= vgabuf->param2 && vgabuf->param2 <= 47)
		{
			vgabuf->param2 -= 40;
			param12vga_color(&(vgabuf->param2));
			vgabuf->color = (vgabuf->color & 0x8fff) | BACKGROUND(vgabuf->param2);
		}
		else if (90 <= vgabuf->param2 && vgabuf->param2 <= 97)
		{
			vgabuf->param2 -= 90;
			param12vga_color(&(vgabuf->param2));
			vgabuf->param2 |= 0x8;
			vgabuf->color = (vgabuf->color & 0xf0ff) | FOREGROUND(vgabuf->param2);
		}
		else if (100 <= vgabuf->param2 && vgabuf->param2 <= 107)
		{
			vgabuf->param2 -= 100;
			param12vga_color(&(vgabuf->param2));
			vgabuf->param2 |= 0x8;
			vgabuf->color = (vgabuf->color & 0x0fff) | BACKGROUND(vgabuf->param2);
		}
		else
		{
			warn("unsupport CSI: color");
		}
	}
}

static void CSI_Erase_handler(vga_buf *vgabuf, int n)
{
	if (n == 2)
	{
		vgabuf->scr_bot_line = ADDLINE(vgabuf->scr_top_line, SCR_HEIGHT - 1);
		for (int i = 0; i < SCR_HEIGHT; i++)
		{
			vgabuf->scr_cur_line = NEXTLINE(vgabuf->scr_cur_line);
			vgabuf->scr_bot_line = NEXTLINE(vgabuf->scr_bot_line);
			// kprintf("af %x\n", vgabuf->scr_cur_line);
			vgabuf->cur_row = CYCLE_SUB(vgabuf->scr_top_line, vgabuf->scr_bot_line, SCR_MAXLINE);
			if (vgabuf->cur_row == SCR_HEIGHT)
			{
				// auto scroll
				vgabuf->scr_top_line = NEXTLINE(vgabuf->scr_top_line);
			}
			if (vgabuf->scr_bot_line == vgabuf->head_line)
			{
				vgabuf->head_line = NEXTLINE(vgabuf->head_line);
				// remember to fill blank the old line
				u32 *ptr_buf = (u32 *)(vgabuf->buf + sizeof(u16) * vgabuf->scr_bot_line * SCR_WIDTH);
				for (int i = 0; i < SCR_WIDTH * sizeof(u16) / sizeof(u32); ++i)
				{
					*ptr_buf++ = (BLANK << 16) | BLANK; // bg-black, fg-white, ascii-space
				}
			}
		}
	}
	if (n == 3)
	{
		int line = vgabuf->head_line;
		while (line != vgabuf->scr_top_line)
		{
			u32 *ptr_buf = (u32 *)(vgabuf->buf + sizeof(u16) * line * SCR_WIDTH);
			for (int i = 0; i < SCR_WIDTH * sizeof(u16) / sizeof(u32); ++i)
			{
				*ptr_buf++ = (BLANK << 16) | BLANK; // bg-black, fg-white, ascii-space
			}
			line = NEXTLINE(line);
		}
		vgabuf->head_line = vgabuf->scr_top_line;
	}
}
static void CSI_handler(u8 terminator, vga_buf *vgabuf)
{
	vgabuf->CSI = CSI_ESC;
	switch (terminator)
	{
	case 'A':
		if (vgabuf->param1 == 0)
			vgabuf->param1 == 1;
		cursor_move(-vgabuf->param1, 0, vgabuf);
		break;
	case 'B':
		if (vgabuf->param1 == 0)
			vgabuf->param1 == 1;
		cursor_move(+vgabuf->param1, 0, vgabuf);
		break;
	case 'C':
		if (vgabuf->param1 == 0)
			vgabuf->param1 == 1;
		cursor_move(0, +vgabuf->param1, vgabuf);
		break;
	case 'D':
		if (vgabuf->param1 == 0)
			vgabuf->param1 == 1;
		cursor_move(0, -vgabuf->param1, vgabuf); // nothing
		break;
	case 'E':
		if (vgabuf->param1 == 0)
			vgabuf->param1 == 1;
		cursor_move(+vgabuf->param1, -vgabuf->cur_col, vgabuf);
		break;
	case 'F':
		if (vgabuf->param1 == 0)
			vgabuf->param1 == 1;
		cursor_move(-vgabuf->param1, -vgabuf->cur_col, vgabuf);
		break;
	case 'G': // added
		if (vgabuf->param1 == 0)
			vgabuf->param1 == 1;
		cursor_locate(CYCLE_SUB(vgabuf->scr_top_line, vgabuf->scr_cur_line, SCR_MAXLINE), vgabuf->param1 - 1, vgabuf);
		break;
	case 'H':
	case 'f':
		if (vgabuf->param1 == 0)
			vgabuf->param1 == 1;
		if (vgabuf->param2 == 0)
			vgabuf->param2 == 1;
		cursor_locate(vgabuf->param1 - 1, vgabuf->param2 - 1, vgabuf);
		break;
	case 'J':
		if (vgabuf->param1 == 0)
			clear_screen(vgabuf, vgabuf->scr_cur_line, vgabuf->cur_col, ADDLINE(vgabuf->scr_top_line, SCR_HEIGHT - 1), SCR_WIDTH - 1);
		else if (vgabuf->param1 == 1)
			clear_screen(vgabuf, vgabuf->scr_top_line, 0, vgabuf->scr_cur_line, vgabuf->cur_col);
		else if (vgabuf->param1 == 2)
			CSI_Erase_handler(vgabuf, 2);
		else if (vgabuf->param1 == 3)
			CSI_Erase_handler(vgabuf, 3);
		break;
	case 'K':
		if (vgabuf->param1 == 0)
			clear_screen(vgabuf, vgabuf->scr_cur_line, vgabuf->cur_col, vgabuf->scr_cur_line, SCR_WIDTH - 1);
		else if (vgabuf->param1 == 1)
			clear_screen(vgabuf, vgabuf->scr_cur_line, 0, vgabuf->scr_cur_line, vgabuf->cur_col);
		else if (vgabuf->param1 == 2)
			clear_screen(vgabuf, vgabuf->scr_cur_line, 0, vgabuf->scr_cur_line, SCR_WIDTH - 1);
		break;
	case 'S': // Scroll Up
		if (vgabuf->param1 == 0)
			vgabuf->param1 = 1;
		csi_scroll(vgabuf, -vgabuf->param1);
		break;
	case 'T': // Scroll Down
		if (vgabuf->param1 == 0)
			vgabuf->param1 = 1;
		csi_scroll(vgabuf, +vgabuf->param1);
		break;
	case 'm':
		set_color(vgabuf);
		break;
	}
}

void vga_tty_write(NTTY *tty, char ch)
{
	// assert(tty->driver_type == 1);
	// assert(tty->output_buf);
	vga_buf *vga = tty->output_buf;
	u16 *buf = vga->buf;
	// kprintf("vga_tty_write %c to %d %d\n", ch, vga->scr_cur_line, vga->cur_col);
	if (vga->CSI == CSI_ESC)
	{
		switch (ch)
		{
		case '\t':
			if (INDEX(vga->scr_cur_line, vga->cur_col) == SCR_BUFSIZE - 1)
				break;
			while (vga->cur_col % 4 != 1)
			{
				nextcol(vga);
			}
			break;
		case '\n':
			newline(vga);
			break;
		case '\r':
			vga->cur_col = 0;
			break;
		case '\b':
			// this implementation is mimic to usual linux shell
			// it moves cursor left but neither crosses line nor delete character
			if (vga->cur_col > 0)
			{
				vga->cur_col--;
			}
			break;
		case '\x1b':
			vga->CSI = CSI_BRACKET;
			vga->Is2param = false;
			break;
		default:
			if (vga->color == 0)
			{
				buf[INDEX(vga->scr_cur_line, vga->cur_col)] = MAKE_CELL(DEFAULT_CHAR_COLOR, ch);
			}
			else
			{
				buf[INDEX(vga->scr_cur_line, vga->cur_col)] = MAKE_CELL(vga->color, ch);
			}
			// buf[INDEX(vga->scr_cur_line, vga->cur_col)] = MAKE_CELL(DEFAULT_CHAR_COLOR, ch);
			nextcol(vga);
			break;
		}
	}
	else if (vga->CSI == CSI_BRACKET)
	{
		switch (ch)
		{
		case '[':
			vga->CSI = CSI_PARAM1;
			vga->param1 = vga->param2 = 0;
			break;
		default:
			vga->CSI = CSI_ESC;
			break;
		}
	}
	else
	{
		switch (ch)
		{
		case '0':
		case '1':
		case '2':
		case '3':
		case '4':
		case '5':
		case '6':
		case '7':
		case '8':
		case '9':
			if (vga->CSI == CSI_PARAM1)
				vga->param1 = vga->param1 * 10 + ch - '0';
			else if (vga->CSI == CSI_PARAM2)
				vga->param2 = vga->param2 * 10 + ch - '0';
			else
				; // do nothing
			break;
		case ';':
			vga->CSI = CSI_PARAM2;
			vga->Is2param = true;
			break;
		default:
			if (!(0x20 <= ch && ch <= 0x7e))
				vga->CSI = CSI_ESC;
			if (0x40 <= ch && ch <= 0x7e)
				CSI_handler(ch, vga);
			break;
		}
	}
	vga->cur_row = CYCLE_SUB(vga->scr_top_line, vga->scr_cur_line, SCR_MAXLINE);
	if (CYCLE_SUB(vga->head_line, vga->scr_cur_line, SCR_MAXLINE) >= CYCLE_SUB(vga->head_line, vga->scr_bot_line, SCR_MAXLINE))
	{
		vga->scr_bot_line = vga->scr_cur_line;
	}
	// kprintf("row: %d; ", vga->cur_row);
}

void vga_tty_backspace(NTTY *tty)
{
	vga_buf *vga = tty->output_buf;
	u16 *buf = vga->buf;
	if (vga->cur_col == 0)
	{
		vga->cur_col = SCR_WIDTH - 1;
		vga->scr_cur_line = LASTLINE(vga->scr_cur_line);
	}
	else
	{
		vga->cur_col--;
	}
	buf[INDEX(vga->scr_cur_line, vga->cur_col)] = BLANK;
	vga->cur_row = CYCLE_SUB(vga->scr_top_line, vga->scr_cur_line, SCR_MAXLINE);
}

void vga_tty_flush(NTTY *tty)
{
	vga_buf *vga = tty->output_buf;
	u16 *buf = vga->buf;
	int i, cur_line;
	vga_set_cursor(INDEX(vga->cur_row, vga->cur_col));
	vga->cur_row = CYCLE_SUB(vga->scr_top_line, vga->scr_cur_line, SCR_MAXLINE);
	int bottom = min(max(vga->cur_row, CYCLE_SUB(vga->scr_top_line, vga->scr_bot_line, SCR_MAXLINE)), SCR_HEIGHT);
	// if (vga->cur_row == SCR_HEIGHT - 1)
	// {
	// 	vga_flush_screen(&buf[INDEX(vga->scr_top_line, 0)]);

	// }
	// else
	// {
	cur_line = vga->scr_top_line;
	for (i = 0; i <= bottom; ++i)
	{
		vga_flush_line(&buf[INDEX(cur_line, 0)], i);
		cur_line = NEXTLINE(cur_line);
	}
	for (; i < SCR_HEIGHT; ++i)
	{
		vga_flush_blankline(i);
	}
	// }
	// kprintf("flush: row=%d, top=%d, cur=%d\n", vga->cur_row, vga->scr_top_line, vga->scr_cur_line);
}

void vga_tty_scroll(NTTY *tty, int direction)
{
	vga_buf *vga = tty->output_buf;
	u16 *buf = vga->buf;
	if (direction == MOUSESCR_DOWN)
	{
		// down
		if (vga->scr_top_line == vga->scr_cur_line)
			return;
		vga->scr_top_line = NEXTLINE(vga->scr_top_line);
	}
	else if (direction == MOUSESCR_UP)
	{
		if (vga->scr_top_line == vga->head_line)
			return;
		vga->scr_top_line = LASTLINE(vga->scr_top_line);
	}
	else
	{
		if (CYCLE_SUB(vga->scr_top_line, vga->scr_cur_line, SCR_MAXLINE) >= SCR_HEIGHT)
		{

			vga->scr_top_line = CYCLE_SUB(SCR_HEIGHT / 2, vga->scr_cur_line, SCR_MAXLINE);
		}
		// kprintf("scroll to cur top-%d, cur-%d\n", vga->scr_top_line, vga->scr_cur_line);
	}
	vga->cur_row = CYCLE_SUB(vga->scr_top_line, vga->scr_cur_line, SCR_MAXLINE);
	if (vga->cur_row >= SCR_HEIGHT)
	{
		vga_disable_cursor();
		// kprintf("disable cursor: %d\n", vga->cur_row);
	}
	else
	{
		vga_enable_cursor(14, 15);
	}
	vga_tty_flush(tty);
}

void vga_tty_select(NTTY *tty)
{
	disable_int();
	cur_ntty = tty;
	enable_int();
	vga_tty_flush(cur_ntty);
}