#include "../lib/io/io.h"
#include "../lib/sys/sizes.h"
#include "../lib/tctl/tctl.h"
#include "../lib/aec/aec.h"

#define TOGGLE(mask, type, sgron, sgroff) \
					if (mask & type) { \
						mask ^= type; \
						wstdf("%S", sgroff); \
					} else { \
						mask |= type; \
						wstdf("%S", sgron); \
					}

u16 heading_numbers[6] = { 0 };
window_size_t ws;
u8 left_padding;
u8 MAX_WIDTH = 80;

enum Style {
	ITALIC       = 1,
	BOLD         = 2,
	STRIKETROUGH = 4,
	MARKED       = 8,
};


void put_leftpadding()
{
	for (int i = 0; i < left_padding; ++i) {
		putchar(' ');
	}
}


void wstdp(const char *buf)
{
	for (; *buf; ++buf) {
		putchar(*buf);
		if (*buf == '\n')
			put_leftpadding();
	}
}


void next_heading(int type)
{
	heading_numbers[type]++;

	for (int i = type + 1; i < 5; ++i)
		heading_numbers[i] = 0;
}


void show_box()
{
	char c;
	u8 width = 0;
	read(STDIN_FD, &c, 1);
	read(STDIN_FD, &c, 1);
	read(STDIN_FD, &c, 1);
	u8 use_backup = 0;
	char backup[3];

	wstd("┌");
	for (int i = 0; i < MAX_WIDTH - 3; ++i) wstd("─");
	wstdp("┐\n│ ");

	while (use_backup || read(STDIN_FD, &c, 1)) {
		if (use_backup) {
			c = backup[3 - use_backup];
			use_backup--;
		}

		if (c == '\n') {
			for (int i = width + 1; i < MAX_WIDTH - 4; ++i) wstd(" ");

			width = 0;
			read(STDIN_FD, backup, 3);

			if (backup[0] == '`' && backup[1] == '`' && backup[2] == '`')
				break;
			
			use_backup = 3;

			wstdp(" │\n│ ");
		} else {
			++width;

			if (width == MAX_WIDTH - 4) {
				wstdp(" │\n│ ");
				width = 1;
			}

			putchar(c);
		}
	}

	wstdp(" │\n└");
	for (int i = 0; i < MAX_WIDTH - 3; ++i) wstd("─");
	wstdp("┘\n\n");
}


void show_and_replace_leading_char(char leading, char *replace)
{
	char c;
	u8 last_was_newline = 0;
	wstdf("  %s", replace);

	while (read(STDIN_FD, &c, 1)) {
		if (c == '\n') {
			if (last_was_newline)
				break;

			last_was_newline = 1;
			wstdp("\n  ");
		} else {
			last_was_newline = 0;

			if (c == leading)
				wstd(replace);
			else
				putchar(c);
		}
	}

	wstdp("\n");
}


void show_numbered_list()
{
	char c;
	u8 last_was_newline = 0;
	read(STDIN_FD, &c, 1);

	wstd("  1.");

	while (read(STDIN_FD, &c, 1)) {
		if (c == '\n') {
			if (last_was_newline)
				break;

			last_was_newline = 1;
			wstdp("\n  ");
		} else {
			last_was_newline = 0;
			putchar(c);
		}
	}

	wstdp("\n");
}


void show_paragraph()
{
	u8 last_was_newline = 0;
	char c;
	u8 width = 1;
	u8 markup_mask = 0;

	while (read(STDIN_FD, &c, 1)) {
		if (c == '\n') {
			if (last_was_newline)
				break;

			last_was_newline = 1;
		} else {
			last_was_newline = 0;
			if (width == MAX_WIDTH) {
				wstdp("\n");
				width = 0;
			}

			switch (c) {
				case '*':
					read(STDIN_FD, &c, 1);
					if (c == '*') {
						TOGGLE(markup_mask, BOLD, SGR_BOLD, SGR_INTENSITY_OFF);
					} else {
						TOGGLE(markup_mask, ITALIC, SGR_ITALIC, SGR_ITALIC_OFF);

						if (c == '\n') {
							last_was_newline = 1;
						} else {
							putchar(c);
						}
					}
					break;
				case '~': TOGGLE(markup_mask, STRIKETROUGH, SGR_CROSSED_OUT, SGR_CROSSED_OUT_OFF); break;
				case '`': TOGGLE(markup_mask, MARKED, SGR_REVERSE, SGR_REVERSE_OFF); break;
				default: putchar(c); break;
			}

			++width;
		}
	}

	wstdf("\n\n%S", SGR_RESET);
	put_leftpadding();
}


void show_heading()
{
	u8 heading_type = 1;
	char c;

	while (read(STDIN_FD, &c, 1) && c == '#') heading_type++;

	if (heading_type > 5)
		heading_type = 5;

	next_heading(heading_type - 1);

	wstdf("%S%i", SGR_FAINT, heading_numbers[0]);

	for (int i = 1; heading_numbers[i]; ++i)
		wstdf(".%i", heading_numbers[i]);
	
	wstdf("%S  ", SGR_RESET);

	wstdf("%S", SGR_BOLD);

	if (c != ' ') putchar(c);

	while (read(STDIN_FD, &c, 1) && c != '\n') putchar(c);
	wstdf("\n\n%S", SGR_RESET);
	put_leftpadding();
}

int main(int argc, char **argv)
{
	if (argc != 1) {
		wf(STDERR_FD, "mdv\n");
		return -1;
	}

	ws = tctl_get_fd_window_size(STDERR_FD);
	if (ws.width < MAX_WIDTH)
		MAX_WIDTH = ws.width;
	left_padding = (ws.width - MAX_WIDTH) / 2;

	char c;

	put_leftpadding();

	while (read(STDIN_FD, &c, 1)) {
		switch(c) {
			case '\n': break;
			case '#':  show_heading();                          break;
			case '1':  show_numbered_list();                    break;
			case '`':  show_box();                              break;
			case '-':  show_and_replace_leading_char('-', "•"); break;
			case '>':  show_and_replace_leading_char('>', "│"); break;
			default: putchar(c); show_paragraph();
		}
	}

	putchar('\n');

	return 0;
}