/*
 * termcap.c: termcap for an xterm-like terminal that curses.c draws (see termcap.h and README.md).
 * tgetent() starts the screen; tputs() hands the strings to cw_ansi_write(), so a program that does its own
 * cursor addressing with termcap draws on the canvas. The program must not initialise curses itself.
 * Copyright (C) 2026 FredyGames. Distributed under the MIT License (see LICENSE).
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "curses.h"
#include "termcap.h"

__attribute__((weak)) char PC = 0;
__attribute__((weak)) char *BC = "\b";
__attribute__((weak)) char *UP = "\033[A";
__attribute__((weak)) short ospeed = 15;

static const struct {
    const char *id;
    const char *value;
} strings[] = {
    {"cm", "\033[%i%d;%dH"}, {"cl", "\033[H\033[2J"}, {"ce", "\033[K"}, {"cd", "\033[J"}, {"ho", "\033[H"},
    {"up", "\033[A"}, {"do", "\n"}, {"nd", "\033[C"}, {"le", "\b"}, {"bc", "\b"}, {"cr", "\r"}, {"nl", "\n"},
    {"sf", "\n"}, {"sr", "\033M"}, {"ta", "\t"}, {"bl", "\007"},
    {"so", "\033[7m"}, {"se", "\033[27m"}, {"us", "\033[4m"}, {"ue", "\033[24m"}, {"md", "\033[1m"},
    {"mr", "\033[7m"}, {"mb", "\033[5m"}, {"mh", "\033[2m"}, {"me", "\033[0m"},
    {"al", "\033[L"}, {"dl", "\033[M"}, {"ic", "\033[@"}, {"dc", "\033[P"}, {"cs", "\033[%i%d;%dr"},
    {"sc", "\033[s"}, {"rc", "\033[u"}, {"vi", "\033[?25l"}, {"ve", "\033[?25h"}, {"vs", "\033[?25h"},
    {"ti", ""}, {"te", ""}, {"ks", ""}, {"ke", ""}, {"is", ""}, {"pc", ""},
    {"ku", "\033[A"}, {"kd", "\033[B"}, {"kr", "\033[C"}, {"kl", "\033[D"}, {"kh", "\033[H"},
};

int tgetent(char *bp, const char *name) {
    (void)name;
    if (bp != NULL) bp[0] = 0;
    cw_ansi_stdout(1); /* starts the screen if needed; keeps the cursor where it is */
    return 1;
}

int tgetflag(const char *id) {
    return strcmp(id, "am") == 0 || strcmp(id, "bs") == 0 || strcmp(id, "xn") == 0 || strcmp(id, "ms") == 0 ||
           strcmp(id, "mi") == 0;
}

int tgetnum(const char *id) {
    if (strcmp(id, "co") == 0) return COLS;
    if (strcmp(id, "li") == 0) return LINES;
    if (strcmp(id, "sg") == 0 || strcmp(id, "ug") == 0) return 0; /* no magic cookies */
    return -1;
}

char *tgetstr(const char *id, char **area) {
    for (size_t i = 0; i < sizeof(strings) / sizeof(strings[0]); i++) {
        if (strcmp(strings[i].id, id) == 0) {
            const char *v = strings[i].value;
            if (area != NULL && *area != NULL) {
                char *dst = *area;
                strcpy(dst, v);
                *area += strlen(v) + 1;
                return dst;
            }
            return (char *)v;
        }
    }
    return NULL;
}

/* %d %2 %3 %. %+x %i %r %% %> as in termcap(5); the first parameter is the line (row), the second the column. */
char *tgoto(const char *cap, int col, int row) {
    static char buf[64];
    int args[2] = {row, col};
    int ai = 0;
    size_t n = 0;
    for (const char *p = cap; *p != 0 && n + 8 < sizeof(buf); p++) {
        if (*p != '%') {
            buf[n++] = *p;
            continue;
        }
        p++;
        switch (*p) {
        case 'd': n += (size_t)snprintf(buf + n, sizeof(buf) - n, "%d", args[ai++ & 1]); break;
        case '2': n += (size_t)snprintf(buf + n, sizeof(buf) - n, "%02d", args[ai++ & 1]); break;
        case '3': n += (size_t)snprintf(buf + n, sizeof(buf) - n, "%03d", args[ai++ & 1]); break;
        case '.': buf[n++] = (char)args[ai++ & 1]; break;
        case '+':
            p++;
            buf[n++] = (char)(args[ai++ & 1] + *p);
            break;
        case 'i': args[0]++; args[1]++; break;
        case 'r': { int t = args[0]; args[0] = args[1]; args[1] = t; break; }
        case '%': buf[n++] = '%'; break;
        case '>':
            if (args[ai & 1] > p[1]) args[ai & 1] += p[2];
            p += 2;
            break;
        default: break;
        }
    }
    buf[n] = 0;
    return buf;
}

int tputs(const char *str, int affcnt, int (*putc_fn)(int)) {
    (void)affcnt;
    if (str == NULL) return 0;
    while (*str >= '0' && *str <= '9') str++; /* padding: ignored */
    if (*str == '.') {
        str++;
        while (*str >= '0' && *str <= '9') str++;
    }
    if (*str == '*') str++;
    for (; *str != 0; str++) putc_fn((unsigned char)*str);
    return 0;
}