#include <stdint.h>

#include <stddef.h>

#include <janet.h>

#define JANET_PEG_FUZZ_MAX_INPUT (1U << 20)

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {

    if (size < 2 || size > JANET_PEG_FUZZ_MAX_INPUT)

        return 0;

    /* Byte 0 selects the split point for a Janet PEG pattern and subject. */

    size_t patlen = (size_t)data[0] % (size - 1);

    const uint8_t *patsrc = data + 1;

    const uint8_t *text = data + 1 + patlen;

    size_t textlen = size - 1 - patlen;

    janet_init();

    JanetParser parser;

    janet_parser_init(&parser);

    Janet matchfn = janet_resolve_core("peg/match");

    if (janet_checktype(matchfn, JANET_CFUNCTION)) {

        JanetCFunction cfun = janet_unwrap_cfunction(matchfn);

        /* Stop after parser errors: consuming again would panic. */

        for (size_t i = 0; i < patlen; i++) {

            janet_parser_consume(&parser, patsrc[i]);

            if (janet_parser_status(&parser) == JANET_PARSE_ERROR)

                break;

        }

        if (janet_parser_status(&parser) != JANET_PARSE_ERROR)

            janet_parser_eof(&parser);

        if (janet_parser_status(&parser) != JANET_PARSE_ERROR &&

                janet_parser_has_more(&parser)) {

            Janet pattern = janet_parser_produce(&parser);

            JanetTryState tstate;

            if (janet_try(&tstate) == JANET_SIGNAL_OK) {

                Janet argv[2];

                argv[0] = pattern;

                argv[1] = janet_stringv(text, (int32_t)textlen);

                cfun(2, argv);

            }

            janet_restore(&tstate);

        }

    }

    janet_parser_deinit(&parser);

    janet_deinit();

    return 0;

}