#include "lisp.h"
#include "read.h"

#include <setjmp.h>
#include <stdio.h>

static jmp_buf toplevel_error_jmp_buf;

static void toplevel_error_handler(LispVal *name, LispVal *data,
                                   void *ignored) {
    fprintf(stderr, "Caught exception: ");
    Fprint_condition(name, data, Qerror_write_byte);
    fprintf(stderr, "\nBacktrace (toplevel comes last):\n");
    LispVal *backtrace = Fbacktrace();
    DOLIST(frame, backtrace) {
        LispVal *name = FIRST(frame);
        bool evaled = !NILP(THIRD(frame));
        LispVal *args = FOURTH(frame);
        fprintf(stderr, " %c ", evaled ? '-' : '*');
        Fprinc(name, Qerror_write_byte);
        if (NILP(args)) {
            fprintf(stderr, "()\n");
        } else {
            Fprinc(args, Qerror_write_byte);
            fputc('\n', stderr);
        }
    }
    longjmp(toplevel_error_jmp_buf, 1);
}

int main(int argc, const char **argv) {
    FILE *in = fopen(argv[1], "r");
    fseek(in, 0, SEEK_END);
    off_t src_len = ftello(in);
    char *src = malloc(src_len);
    rewind(in);
    fread(src, 1, src_len, in);
    fclose(in);
    lisp_init();
    push_local_reference_frame();
    StackFrame *toplevel = LISP_STACK_REF();
    ReadStream s;
    read_stream_init(&s, src, src_len);
    LispVal *r;
    push_handler_bind_frame(LIST(Qt), toplevel_error_handler, NULL, NULL);
    volatile bool had_toplevel_error = false;
    if (setjmp(toplevel_error_jmp_buf) == 0) {
        while ((r = read(&s))) {
            Feval(r, Qnil);
        }
    } else {
        had_toplevel_error = true;
    }
    unwind_to(toplevel);
    lisp_shutdown();
    free(src);
    return had_toplevel_error ? EXIT_FAILURE : EXIT_SUCCESS;
}