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

#include "apfl.h"

static bool
repl_source_reader(void *context, char *buf, size_t *len, bool need)
{
    (void)context;

    printf(need ? "... " : "> ");
    fflush(stdout);

    size_t maxlen = *len;

    if (fgets(buf, maxlen, stdin) == NULL) {
        if (feof(stdin)) {
            *len = 0;
            return true;
        } else {
            return false;
        }
    }

    *len = strlen(buf);
    return true;
}

int
main(int argc, const char **argv)
{
    (void)argc;
    (void)argv;

    int rv = 0;

    apfl_tokenizer_ptr tokenizer = NULL;
    apfl_parser_ptr parser = NULL;

    if ((tokenizer = apfl_tokenizer_new(repl_source_reader, NULL)) == NULL) {
        fprintf(stderr, "Failed initializing tokenizer\n");
        goto exit;
    }

    if ((parser = apfl_parser_new(apfl_tokenizer_as_token_source(tokenizer))) == NULL) {
        fprintf(stderr, "Failed initializing parser\n");
        goto exit;
    }

    while (true) {
        struct apfl_error err;
        struct apfl_expr expr;

        switch (apfl_parser_next(parser)) {
        case APFL_PARSE_OK:
            expr = apfl_parser_get_expr(parser);
            apfl_expr_print(expr, stdout);
            apfl_expr_deinit(&expr);

            break;
        case APFL_PARSE_EOF:
            goto exit;
        case APFL_PARSE_ERROR:
            err = apfl_parser_get_error(parser);
            apfl_error_print(err, stderr);

            if (APFL_ERROR_IS_FATAL(err)) {
                rv = 1;
                goto exit;
            }
            break;
        }
    }

exit:
    apfl_tokenizer_destroy(tokenizer);
    apfl_parser_destroy(parser);

    return rv;
}