#include "vxBoot/terminal.h"

#include <gint/display.h>

#include <string.h>


//---
//	Update the internal buffer
//---

/* terminal_buffer_insert() : insert string anywhere in the output buffer */
void terminal_buffer_insert(char *buffer, size_t nb)
{
	size_t dump;
	void *start;

	/* calculate the "real" number of byte to dump into the buffer */
	dump = nb;
	start = &buffer[0];
	if (dump > terminal.buffer.size) {
		dump -= terminal.buffer.size;
		start = &buffer[nb - dump];
	}

	/* dump the buffer (be carful with the circular effect) */
	if (terminal.buffer.cursor + dump > terminal.buffer.size) {
		memcpy(
			&terminal.buffer.data[terminal.buffer.cursor],
			start,
			terminal.buffer.size - terminal.buffer.cursor
		);
		dump -= terminal.buffer.size - terminal.buffer.cursor;
		terminal.buffer.cursor = 0;
	}
	memcpy(&terminal.buffer.data[terminal.buffer.cursor], start, dump);
	terminal.buffer.cursor += dump;
}


//---
//	Display the internal buffer
//---

/* terminal_vertical_update() - Update vertical cursor */
static void terminal_vertical_update(void)
{
	if (terminal.cursor.y + 1 < terminal.winsize.ws_col) {
		terminal.cursor.y = terminal.cursor.y + 1;
		return;
	}
}

/* earlyterm_horizontal_update() - Update horizotal cursor */
static int terminal_horizontal_update(void)
{
	terminal.cursor.x = terminal.cursor.x + 1;
	if (terminal.cursor.x >= terminal.winsize.ws_col) {
		terminal_vertical_update();
		terminal.cursor.x = 0;
		return (1);
	}
	return (0);
}

/* line_discipline() - Check "special" char */
static int terminal_line_discipline(char n)
{
	int offset;

	switch (n) {
	case '\0':
		return (1);
	case '\n':
		terminal.cursor.x = 0;
		terminal_vertical_update();
		return (1);
	case '\b':
		if (terminal.cursor.x > 0)
			terminal.cursor.x = terminal.cursor.x - 1;
		return (1);
	case '\v':
		terminal_vertical_update();
		return (1);
	case '\r':
		terminal.cursor.x = 0;
		return (1);
	case '\t':
		/* Check if we need a new line or not. */
		offset = terminal.cursor.x - ((terminal.cursor.x / 5) * 5);
		offset = 5 - offset;
		while (--offset >= 0)
			terminal_horizontal_update();
		return (1);
	default:
		return (0);
	}
}

/* terminal_buffer_write() : display the buffer on screen */
void terminal_buffer_display(void)
{
	uint8_t *buffer;
	uint16_t tmp;
	int cursor;
	int x;
	int y;
	int i;

	/* Due to potential special char, we sould find the "real" starting
	   index for the internal buffer */
	terminal.cursor.x = 0;
	terminal.cursor.y = 0;
	i = terminal.buffer.cursor - 1;
	buffer = &terminal.buffer.data[0];
	while (1) {
		/* decrease the cursor and avoid circular effect */
		if (--i < 0)
			i = terminal.buffer.size - 1;

		/* check loop condition */
		if (i == (int)terminal.buffer.cursor)
			break;

		/* check EOL */
		if (buffer[i] == '\0') {
			break;
		}

		/* handle the character (only to force update cursors) */
		if (terminal_line_discipline(buffer[i] & 0x7f) == 0)
			terminal_horizontal_update();
		if (terminal.cursor.y >= terminal.winsize.ws_row)
			break;
	}

	/* Display character per character because we need to check special
	   behaviour (like cariege return, line feed, ...) */
	terminal.cursor.x = 0;
	terminal.cursor.y = 0;
	while (1) {
		/* update the index */
		if (++i >= (int)terminal.buffer.size)
			i = 0;
		if (i == (int)terminal.buffer.cursor)
			break;

		/* get the cursor and remove the potential cursor marker */
		cursor = ((buffer[i] & 0x80) != 0);
		buffer[i] &= 0x7f;

		/* display part (character + cursor if needed) */
		x = terminal.cursor.x * terminal.winsize.ft_xpixel;
		y = terminal.cursor.y * terminal.winsize.ft_ypixel;
		if (terminal_line_discipline(buffer[i]) == 0) {
			tmp = buffer[i] << 8;
			dtext(x, y, terminal.private.color.fg, (void*)&tmp);
			terminal_horizontal_update();
		}
		if (cursor != 0) {
			dline(x,
				y + terminal.winsize.ft_ypixel,
				x + terminal.winsize.ft_xpixel - 2,
				y + terminal.winsize.ft_ypixel,
				terminal.private.color.fg);
		}
	}
}