#include "kernel/param.h"
#include "kernel/types.h"
#include "user/user.h"

static inline int is_ws(const char ch) {
    return ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r';
}

int main(int argc, char** argv) {
    int STDIN = 0;
    char linebuf[1024];
    char* p = linebuf;
    char* _argv[MAXARG];
    while (read(STDIN, p, 1) > 0) {
        if (*p == '\n') {
            int i;
            int in_ws = 1;
            for (i = 0; i < argc - 1; ++i) {
                _argv[i] = argv[i + 1];
            }
            for (char* p0 = linebuf; p0 <= p; ++p0) {
                if (is_ws(*p0)) {
                    if (!in_ws) {
                        in_ws = 1;
                        i++;
                    }
                    *p0 = '\0';
                } else if (in_ws) {
                    in_ws = 0;
                    _argv[i] = p0;
                }
                if (i >= MAXARG) {
                    printf("warning: too many arguments");
                    break;
                }
            }
            *p = '\0';
            _argv[i] = 0;
            // for (int j = 0; j < i; ++ j) {
            //     printf("%s\n", _argv[j]);
            // }
            if (fork() == 0) {
                exec(_argv[0], _argv);
                exit(0);
            } else {
                p = linebuf;
                while (wait(0) != -1)
                    ;
            }
        } else {
            p++;
            if (p >= linebuf + sizeof(linebuf)) {
                printf("line buffer exceeded\n");
                exit(0);
            }
        }
    }
    exit(0);
}