#include <stdio.h>
#include <string.h>

#include <ncurses.h>

#ifndef PCRE2_CODE_UNIT_WIDTH
#define PCRE2_CODE_UNIT_WIDTH 8
#endif
#include <pcre2.h>

#define DX 3
#define ONLELINE 3
#define MAXSTR 80

void main() {
    pcre2_code* re;
    PCRE2_SPTR pattern; /* PCRE2_SPTR is a pointer to unsigned code units of */
    PCRE2_SPTR subject; /* the appropriate width (in this case, 8 bits). */

    int errnum;
    int i, rc;

    PCRE2_SIZE erroffs;
    PCRE2_SIZE* ovector;
    PCRE2_SIZE subject_length;

    pcre2_match_data* match_data;

    WINDOW *winA, *winB, *winO;
    char inA[MAXSTR], inB[MAXSTR];
    int c = 0;
    int half;

    initscr();
    cbreak();
    printw("Input:");
    refresh();

    half = (COLS - 2 * DX) / 2;
    winA = newwin(ONLELINE, half, DX, DX);
    winB = newwin(ONLELINE, half, DX, DX + half);
    winO = newwin(LINES - ONLELINE - DX * 2, (COLS - 2 * DX), DX + ONLELINE, DX);
    keypad(winA, TRUE);
    keypad(winB, TRUE);
    scrollok(winO, TRUE);
    wmove(winO, 1, 0);
    do {
        werase(winA);
        box(winA, 0, 0);
        mvwgetnstr(winA, 1, 1, inA, MAXSTR);
        werase(winB);
        box(winB, 0, 0);
        mvwgetnstr(winB, 1, 1, inB, MAXSTR);

        pattern = (PCRE2_SPTR)inA;
        subject = (PCRE2_SPTR)inB;
        subject_length = (PCRE2_SIZE)strlen((char*)subject);

        re = pcre2_compile(pattern, PCRE2_ZERO_TERMINATED, PCRE2_UCP, &errnum,
                           &erroffs, NULL);

        if (re == NULL) {
            PCRE2_UCHAR buffer[256];
            pcre2_get_error_message(errnum, buffer, sizeof(buffer));
            wprintw(winO, "  PCRE2 compilation failed at offset %d: %s\n",
                    (int)erroffs, buffer);
            box(winO, 0, 0);
            wrefresh(winO);
            continue;
        }

        match_data = pcre2_match_data_create_from_pattern(re, NULL);

        rc = pcre2_match(re, subject, subject_length, 0, 0, match_data, NULL);

        if (rc < 0) {
            switch (rc) {
                case PCRE2_ERROR_NOMATCH:
                    wprintw(winO, "  No match\n");
                    break;
                default:
                    wprintw(winO, "  Matching error %d\n", rc);
                    break;
            }
            box(winO, 0, 0);
            wrefresh(winO);
            continue;
        }

        ovector = pcre2_get_ovector_pointer(match_data);

        for (i = 0; i < rc; i++) {
            wprintw(winO, "  %2ld: %.*s\n", ovector[2 * i],
                    (int)(ovector[2 * i + 1] - ovector[2 * i]),
                    subject + ovector[2 * i]);
        }

        box(winO, 0, 0);
        wrefresh(winO);
    } while (*inA);

    endwin();

    pcre2_match_data_free(match_data); /* Release the memory that was used */
    pcre2_code_free(re);               /* for the match data and the pattern. */
}