#include "saltywitch.h"

ERL_NIF_TERM saltywitch_pwhash(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
{
	ErlNifBinary pass, salt;
	ERL_NIF_TERM term;

	uint64_t len, ops, mem;
	unsigned char *out;
	int alg;

	ERL_NIF_TERM err    = atom_badarg;
	ERL_NIF_TERM reason = atom_err_opaque;

	if (enif_get_uint64(env, argv[0], &len) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (enif_inspect_iolist_as_binary(env, argv[1], &pass) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (enif_inspect_binary(env, argv[2], &salt) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (salt.size != crypto_pwhash_SALTBYTES) {
		reason = atom_err_invalid_salt_size;
		goto badarg_FAULT;
	}

	if (enif_get_uint64(env, argv[3], &ops) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (ops > crypto_pwhash_OPSLIMIT_MAX) {
		reason = atom_err_pwhash_ops_too_large;
		goto badarg_FAULT;
	} else if (ops < crypto_pwhash_OPSLIMIT_MIN) {
		reason = atom_err_pwhash_ops_too_small;
		goto badarg_FAULT;
	}

	if (enif_get_uint64(env, argv[4], &mem) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (mem > crypto_pwhash_OPSLIMIT_MAX) {
		reason = atom_err_pwhash_mem_too_large;
		goto badarg_FAULT;
	} else if (mem < crypto_pwhash_OPSLIMIT_MIN) {
		reason = atom_err_pwhash_mem_too_small;
		goto badarg_FAULT;
	}

	if (enif_get_int(env, argv[5], &alg) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	out = enif_make_new_binary(env, len, &term);
	if (out == NULL) {
		reason = atom_err_nif_alloc;
		goto error_FAULT;
	}

	if (crypto_pwhash(out, len, (char *) pass.data, pass.size, salt.data, ops, mem, alg) != 0) {
		goto error_FAULT;
	}

	return term;

error_FAULT:
	err = atom_error;
badarg_FAULT:
	return saltywitch_exception(env, err, reason);
}

ERL_NIF_TERM saltywitch_pwhash_str(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
{
	char out[crypto_pwhash_STRBYTES];
	uint64_t ops, mem;
	ErlNifBinary pass;

	ERL_NIF_TERM err    = atom_badarg;
	ERL_NIF_TERM reason = atom_err_opaque;

	(void) argc;

	if (enif_inspect_iolist_as_binary(env, argv[0], &pass) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (enif_get_uint64(env, argv[1], &ops) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (enif_get_uint64(env, argv[2], &mem) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (crypto_pwhash_str(out, (char *) pass.data, pass.size, ops, mem) != 0) {
		goto error_FAULT;
	}

	return enif_make_string(env, out, ERL_NIF_LATIN1);

error_FAULT:
	err = atom_error;
badarg_FAULT:
	return saltywitch_exception(env, err, reason);
}

#include <stdio.h>
ERL_NIF_TERM saltywitch_pwhash_str_verify(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
{
	ErlNifBinary hash, pass;

	ERL_NIF_TERM err    = atom_badarg;
	ERL_NIF_TERM reason = atom_err_opaque;

	(void) argc;

	if (enif_inspect_iolist_as_binary(env, argv[0], &hash) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (hash.size > crypto_pwhash_STRBYTES) {
		reason = atom_err_pwhash_too_long;
		goto badarg_FAULT;
	}

	if (enif_inspect_iolist_as_binary(env, argv[1], &pass) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (crypto_pwhash_str_verify((char *) hash.data, (char *) pass.data, pass.size) != 0) {
		reason = atom_err_verification_failed;
		goto error_FAULT;
	}

	return atom_ok;

error_FAULT:
	err = atom_error;
badarg_FAULT:
	return saltywitch_exception(env, err, reason);
}

ERL_NIF_TERM saltywitch_pwhash_str_needs_rehash(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
{
	ErlNifBinary hash;
	uint64_t ops, mem;

	ERL_NIF_TERM err    = atom_badarg;
	ERL_NIF_TERM reason = atom_err_opaque;

	if (enif_inspect_binary(env, argv[0], &hash) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (hash.size > crypto_pwhash_STRBYTES) {
		reason = atom_err_pwhash_too_long;
		goto badarg_FAULT;
	}

	if (enif_get_uint64(env, argv[1], &ops) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	if (enif_get_uint64(env, argv[2], &mem) == false) {
		reason = atom_err_invalid_type;
		goto badarg_FAULT;
	}

	switch (crypto_pwhash_str_needs_rehash((char *) hash.data, ops, mem)) {
	case 0:
		return atom_ok;
	case 1:
		reason = atom_err_pwhash_needs_rehash;
	}

	err = atom_error;

badarg_FAULT:
	return saltywitch_exception(env, err, reason);
}