/*
 * keyhandlers.c
 *
 * Copyright (C) 2012 - 2014 James Booth <boothj5@gmail.com>
 *
 * This file is part of Profanity.
 *
 * Profanity is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Profanity is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Profanity.  If not, see <http://www.gnu.org/licenses/>.
 *
 * In addition, as a special exception, the copyright holders give permission to
 * link the code of portions of this program with the OpenSSL library under
 * certain conditions as described in each individual source file, and
 * distribute linked combinations including the two.
 *
 * You must obey the GNU General Public License in all respects for all of the
 * code used other than OpenSSL. If you modify file(s) with this exception, you
 * may extend this exception to your version of the file(s), but you are not
 * obligated to do so. If you do not wish to do so, delete this exception
 * statement from your version. If you delete this exception statement from all
 * source files in the program, then also delete it here.
 *
 */

#include <stdlib.h>
#include <string.h>
#include <wchar.h>

#include <glib.h>

#include "ui/inputwin.h"
#include "common.h"

void
key_printable(char * const line, int * const line_utf8_pos, int * const col, int * const pad_start, const wint_t ch, const int maxx)
{
    int utf8_len = g_utf8_strlen(line, -1);

    // handle insert if not at end of input
    if (*line_utf8_pos < utf8_len) {
        char bytes[MB_CUR_MAX];
        size_t utf8_ch_len = wcrtomb(bytes, ch, NULL);
        bytes[utf8_ch_len] = '\0';
        gchar *start = g_utf8_substring(line, 0, *line_utf8_pos);
        gchar *end = g_utf8_substring(line, *line_utf8_pos, utf8_len);
        GString *new_line_str = g_string_new(start);
        g_string_append(new_line_str, bytes);
        g_string_append(new_line_str, end);
        char *new_line = new_line_str->str;
        g_free(start);
        g_free(end);
        g_string_free(new_line_str, FALSE);

        strncpy(line, new_line, INP_WIN_MAX);
        free(new_line);

        gunichar uni = g_utf8_get_char(bytes);
        if (*col == (*pad_start + maxx)) {
            (*pad_start)++;
            if (g_unichar_iswide(uni)) {
                (*pad_start)++;
            }
        }

        (*line_utf8_pos)++;

        (*col)++;
        if (g_unichar_iswide(uni)) {
            (*col)++;
        }

    // otherwise just append
    } else {
        char bytes[MB_CUR_MAX+1];
        size_t utf8_ch_len = wcrtomb(bytes, ch, NULL);
        if (utf8_ch_len < MB_CUR_MAX) {
            int i;
            int bytes_len = strlen(line);

            for (i = 0 ; i < utf8_ch_len; i++) {
                line[bytes_len++] = bytes[i];
            }
            line[bytes_len] = '\0';

            (*line_utf8_pos)++;

            (*col)++;
            bytes[utf8_ch_len] = '\0';
            gunichar uni = g_utf8_get_char(bytes);
            if (g_unichar_iswide(uni)) {
                (*col)++;
            }

            if (*col - *pad_start > maxx-1) {
                (*pad_start)++;
                if (g_unichar_iswide(uni)) {
                    (*pad_start)++;
                }
            }
        }
    }
}

void
key_ctrl_left(const char * const line, int * const line_utf8_pos, int * const col, int * const pad_start, const int maxx)
{
    if (*line_utf8_pos == 0) {
        return;
    }

    gchar *curr_ch = g_utf8_offset_to_pointer(line, *line_utf8_pos);
    gunichar curr_uni = g_utf8_get_char(curr_ch);

    (*line_utf8_pos)--;
    (*col)--;
    if (g_unichar_iswide(curr_uni)) {
        (*col)--;
    }

    curr_ch = g_utf8_find_prev_char(line, curr_ch);

    gchar *prev_ch;
    gunichar prev_uni;
    while (curr_ch != NULL) {
        curr_uni = g_utf8_get_char(curr_ch);
        if (g_unichar_isspace(curr_uni)) {
            curr_ch = g_utf8_find_prev_char(line, curr_ch);
            (*line_utf8_pos)--;
            (*col)--;
        } else {
            prev_ch = g_utf8_find_prev_char(line, curr_ch);
            if (prev_ch == NULL) {
                curr_ch = NULL;
                break;
            } else {
                prev_uni = g_utf8_get_char(prev_ch);
                (*line_utf8_pos)--;
                (*col)--;
                if (g_unichar_iswide(curr_uni)) {
                    (*col)--;
                }
                if (g_unichar_isspace(prev_uni)) {
                    break;
                } else {
                    curr_ch = prev_ch;
                }
            }
        }
    }

    if (curr_ch == NULL) {
        (*col) = 0;
        (*line_utf8_pos) = 0;
    } else {
        (*col)++;
        (*line_utf8_pos)++;
    }

    if (*col < *pad_start) {
        *pad_start = *col;
    }
}

void
key_ctrl_right(const char * const line, int * const line_utf8_pos, int * const col, int * const pad_start, const int maxx)
{
    int utf8_len = g_utf8_strlen(line, -1);
    if (*line_utf8_pos >= utf8_len) {
        return;
    }

    gchar *curr_ch = g_utf8_offset_to_pointer(line, *line_utf8_pos);
    gunichar curr_uni = g_utf8_get_char(curr_ch);

    // find next word if in whitespace
    while (g_unichar_isspace(curr_uni)) {
        (*col)++;
        (*line_utf8_pos)++;
        curr_ch = g_utf8_find_next_char(curr_ch, NULL);
        if (!curr_ch) {
            break;
        }
        curr_uni = g_utf8_get_char(curr_ch);
    }

    if (curr_ch) {
        while (!g_unichar_isspace(curr_uni)) {
            (*line_utf8_pos)++;
            (*col)++;
            if (g_unichar_iswide(curr_uni)) {
                (*col)++;
            }
            curr_ch = g_utf8_find_next_char(curr_ch, NULL);
            if (!curr_ch || *line_utf8_pos >= utf8_len) {
                break;
            }
            curr_uni = g_utf8_get_char(curr_ch);
        }
    }

    // if gone off screen to right, jump right (half a screen worth)
//    if (col > pad_start + wcols) {
//        pad_start = pad_start + (wcols / 2);
//        _inp_win_update_virtual();
//    }
}