#include "line-ed.h"

#include <fx/collections/array.h>
#include <fx/string.h>

void alloc_empty_history_entry(struct line_ed *ed)
{
	fx_value *str_v = fx_array_get_ref(
		ed->l_history,
		fx_array_get_size(ed->l_history) - 1);
	fx_string *str = NULL;
	fx_value_get_object(str_v, &str);
	if (!str || fx_string_get_size(str, FX_STRLEN_NORMAL) > 0) {
		str = fx_string_create();
		fx_array_push_back(ed->l_history, FX_VALUE_OBJECT(str));
		fx_string_unref(str);
	}

	ed->l_history_pos = fx_array_get_size(ed->l_history) - 1;
}

void save_buf_to_history(struct line_ed *ed)
{
	fx_value *cur_v = fx_array_get_ref(ed->l_history, ed->l_history_pos);
	fx_string *cur = NULL;
	fx_value_get_object(cur_v, &cur);
	fx_string_clear(cur);
	fx_string_append_wstr(cur, ed->l_buf);
}

void append_buf_to_history(struct line_ed *ed)
{
	fx_value *cur_v = fx_array_get_ref(ed->l_history, ed->l_history_pos);
	fx_string *cur = NULL;
	fx_value_get_object(cur_v, &cur);
	char s[] = {'\n', 0};
	fx_string_append_cstr(cur, s);
	fx_string_append_wstr(cur, ed->l_buf);
}

void load_buf_from_history(struct line_ed *ed)
{
	fx_value *cur_v = fx_array_get_ref(ed->l_history, ed->l_history_pos);
	fx_string *cur = NULL;
	fx_value_get_object(cur_v, &cur);
	size_t len = fx_min(
		size_t,
		(size_t)(ed->l_buf_end - ed->l_buf - 1),
		fx_string_get_size(cur, FX_STRLEN_CODEPOINTS));

	const char *src = fx_string_get_cstr(cur);
	for (size_t i = 0; i < len; i++) {
		fx_wchar ch_src = fx_wchar_utf8_codepoint_decode(src);
		ed->l_buf[i] = ch_src;
		src += fx_wchar_utf8_codepoint_stride(src);
	}

	ed->l_buf[len] = '\0';

	unsigned int x = 0, y = 0;
	for (size_t i = 0; ed->l_buf[i]; i++) {
		if (ed->l_buf[i] == '\n') {
			x = 0;
			y++;
		} else {
			x++;
		}
	}

	ed->l_buf_ptr = ed->l_buf + len;
	ed->l_line_end = ed->l_buf_ptr;
	ed->l_cursor_x = x;
	ed->l_cursor_y = y;
}

const char *last_history_line(struct line_ed *ed)
{
	size_t nlines = fx_array_get_size(ed->l_history);
	if (nlines < 2) {
		return NULL;
	}

	fx_value *last_v = fx_array_get_ref(ed->l_history, nlines - 2);
	fx_string *last = NULL;
	fx_value_get_object(last_v, &last);
	return fx_string_get_cstr(last);
}