#include "buffer.h"
#include "cursor.h"
#include "history.h"
#include "hook.h"
#include "line-ed.h"
#include "prompt.h"
#include "refresh.h"

#include <stdio.h>

void put_char(struct line_ed *ed, char c)
{
	if (ed->l_buf_ptr > ed->l_line_end + 1) {
		return;
	}

	struct refresh_state state = {
		.r_prev_cursor_x = ed->l_cursor_x,
		.r_prev_cursor_y = ed->l_cursor_y,
	};

	size_t prev_cursor = ed->l_buf_ptr - ed->l_buf;

	char *dest = ed->l_buf_ptr;
	size_t len = ed->l_line_end - ed->l_buf_ptr + 1;

	if (dest < ed->l_line_end) {
		memmove(dest + 1, dest, len);
	}

	ed->l_cursor_x++;
	ed->l_line_end++;
	ed->l_buf_ptr++;
	*dest = c;

	if (ed->l_buf_ptr == ed->l_line_end) {
		*ed->l_buf_ptr = '\0';
	}

	hook_buffer_modified(ed);

	put_refresh(ed, &state);
}

static void backspace_simple(struct line_ed *ed)
{
	if (ed->l_buf_ptr == ed->l_buf) {
		return;
	}

	struct refresh_state state = {
		.r_prev_cursor_x = ed->l_cursor_x,
		.r_prev_cursor_y = ed->l_cursor_y,
	};

	size_t prev_cursor = ed->l_buf_ptr - ed->l_buf;

	char *dest = ed->l_buf_ptr;
	size_t len = ed->l_line_end - ed->l_buf_ptr + 1;
	memmove(dest - 1, dest, len);

	ed->l_cursor_x--;
	ed->l_line_end--;
	ed->l_buf_ptr--;

	hook_buffer_modified(ed);

	backspace_simple_refresh(ed, &state);
}

static void backspace_nl(struct line_ed *ed)
{
	size_t prev_line_len = line_length(ed, ed->l_cursor_y - 1);

	struct refresh_state state = {
		.r_prev_cursor_x = ed->l_cursor_x,
		.r_prev_cursor_y = ed->l_cursor_y,
		.r_prev_line_len = prev_line_len,
	};

	char *dest = ed->l_buf_ptr;
	size_t len = ed->l_line_end - ed->l_buf_ptr + 1;
	memmove(dest - 1, dest, len);

	ed->l_cursor_x = prev_line_len - 1;
	ed->l_cursor_y--;
	ed->l_buf_ptr--;
	ed->l_line_end--;

	hook_buffer_modified(ed);

	backspace_nl_refresh(ed, &state);
}

void backspace(struct line_ed *ed)
{
	if (ed->l_buf_ptr == ed->l_buf) {
		return;
	}

	if (ed->l_cursor_x == 0 && ed->l_cursor_y <= ed->l_continuations) {
		return;
	}

	if (ed->l_cursor_x == 0 && ed->l_cursor_y > 0) {
		backspace_nl(ed);
	} else {
		backspace_simple(ed);
	}
}

void cursor_left(struct line_ed *ed)
{
	if (ed->l_cursor_x != 0) {
		//fputs("\010", stdout);
		b_tty_move_cursor_x(ed->l_tty, B_TTY_POS_CURSOR, -1);
		fflush(stdout);
		ed->l_cursor_x--;
		ed->l_buf_ptr--;
		return;
	}

	if (ed->l_cursor_y <= ed->l_continuations || ed->l_buf_ptr <= ed->l_buf) {
		return;
	}

	ed->l_cursor_y--;
	ed->l_buf_ptr--;
	size_t prompt_len = 0;
	if (ed->l_cursor_y == 0) {
		prompt_len = prompt_length(ed, PROMPT_MAIN);
	}

	size_t len = line_length(ed, ed->l_cursor_y);
	ed->l_cursor_x = len - 1;

	//printf("\033[A\033[%dG", len + prompt_len);
	b_tty_move_cursor_y(ed->l_tty, B_TTY_POS_CURSOR, -1);
	b_tty_move_cursor_x(ed->l_tty, B_TTY_POS_START, (int)(len + prompt_len));

	fflush(stdout);
}

void cursor_right(struct line_ed *ed)
{
	if (ed->l_buf_ptr >= ed->l_line_end) {
		return;
	}

	if (*ed->l_buf_ptr != '\n') {
		ed->l_cursor_x++;
		ed->l_buf_ptr++;
		//fputs("\033[C", stdout);
		b_tty_move_cursor_x(ed->l_tty, B_TTY_POS_CURSOR, 1);
		fflush(stdout);
		return;
	}

	if (ed->l_buf_ptr >= ed->l_line_end) {
		return;
	}

	ed->l_cursor_y++;
	ed->l_cursor_x = 0;
	ed->l_buf_ptr++;

	//printf("\033[B\033[G");
	b_tty_move_cursor_y(ed->l_tty, B_TTY_POS_CURSOR, 1);
	b_tty_move_cursor_x(ed->l_tty, B_TTY_POS_START, 0);
	fflush(stdout);
}

void arrow_up(struct line_ed *ed)
{
	if (ed->l_history_pos == 0) {
		return;
	}

	if (ed->l_cursor_y > 0) {
		//printf("\033[%uA", ed->l_cursor_y);
		b_tty_move_cursor_y(ed->l_tty, B_TTY_POS_CURSOR, (long long)ed->l_cursor_y);
	}

	//printf("\033[%zuG\033[J", prompt_length(ed, PROMPT_MAIN) + 1);
	b_tty_move_cursor_x(
		ed->l_tty, B_TTY_POS_START, (long long)prompt_length(ed, PROMPT_MAIN));
	b_tty_clear(ed->l_tty, B_TTY_CLEAR_SCREEN | B_TTY_CLEAR_FROM_CURSOR);

	save_buf_to_history(ed);
	ed->l_history_pos--;
	load_buf_from_history(ed);

	print_buffer(ed);
	fflush(stdout);
}

void arrow_down(struct line_ed *ed)
{
	if (ed->l_history_pos == b_array_size(ed->l_history) - 1) {
		return;
	}

	if (ed->l_cursor_y > 0) {
		//printf("\033[%uA", ed->l_cursor_y);
		b_tty_move_cursor_y(ed->l_tty, B_TTY_POS_CURSOR, (int)ed->l_cursor_y);
	}

	//printf("\033[%zuG\033[J", prompt_length(ed, PROMPT_MAIN) + 1);
	b_tty_move_cursor_x(
		ed->l_tty, B_TTY_POS_START, prompt_length(ed, PROMPT_MAIN) + 1);

	save_buf_to_history(ed);
	ed->l_history_pos++;
	load_buf_from_history(ed);

	print_buffer(ed);
	fflush(stdout);
}