//
// Copyright (c) 2023 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#include "util/base64.hpp"

#include <boost/core/span.hpp>
#include <boost/test/unit_test.hpp>

#include <string_view>

using namespace chat;
using namespace std::string_view_literals;

// Some test cases have been copied from CPython's and Android's base64 test suites

BOOST_AUTO_TEST_SUITE(base64)

constexpr struct
{
 std::string_view raw;
 std::string_view encoded;
 std::string_view encoded_no_padding;
} success_cases[] = {
 {"0円"sv, "AA==", "AA"},
 {"a"sv, "YQ==", "YQ"},
 {"ab"sv, "YWI=", "YWI"},
 {"abc"sv, "YWJj", "YWJj"},
 {""sv, "", ""},
 {
 "abcdefghijklmnopqrstuvwxyz"
 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 "0123456789!@#0^&*();:<>,. []{}"sv, "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXpBQkNE"
 "RUZHSElKS0xNTk9QUVJTVFVWV1hZWjAxMjM0NT"
 "Y3ODkhQCMwXiYqKCk7Ojw+LC4gW117fQ==", "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXpBQkNE"
 "RUZHSElKS0xNTk9QUVJTVFVWV1hZWjAxMjM0NT"
 "Y3ODkhQCMwXiYqKCk7Ojw+LC4gW117fQ", },
 {"\xff"sv, "/w==", "/w"},
 {"\xff\xee"sv, "/+4=", "/+4"},
 {"\xff\xee\xdd"sv, "/+7d", "/+7d"},
 {"\xff\xee\xdd\xcc"sv, "/+7dzA==", "/+7dzA"},
 {"\xff\xee\xdd\xcc\xbb"sv, "/+7dzLs=", "/+7dzLs"},
 {"\xff\xee\xdd\xcc\xbb\xaa"sv, "/+7dzLuq", "/+7dzLuq"},
 {"\xff\xee\xdd\xcc\xbb\xaa\x99"sv, "/+7dzLuqmQ==", "/+7dzLuqmQ"},
 {"\xff\xee\xdd\xcc\xbb\xaa\x99\x88"sv, "/+7dzLuqmYg=", "/+7dzLuqmYg"},
};

BOOST_AUTO_TEST_CASE(encode)
{
 for (auto tc : success_cases)
 {
 BOOST_TEST_CONTEXT(tc.encoded)
 {
 auto actual = base64_encode({reinterpret_cast<const unsigned char*>(tc.raw.data()), tc.raw.size()}
 );
 BOOST_TEST(actual == tc.encoded);
 }
 }
}

BOOST_AUTO_TEST_CASE(encode_without_padding)
{
 for (auto tc : success_cases)
 {
 BOOST_TEST_CONTEXT(tc.encoded)
 {
 auto actual = base64_encode(
 {reinterpret_cast<const unsigned char*>(tc.raw.data()), tc.raw.size()},
 false
 );
 BOOST_TEST(actual == tc.encoded_no_padding);
 }
 }
}

BOOST_AUTO_TEST_CASE(decode_success)
{
 for (auto tc : success_cases)
 {
 BOOST_TEST_CONTEXT(tc.encoded)
 {
 auto actual = base64_decode(tc.encoded);
 BOOST_TEST_REQUIRE(actual.error() == error_code());
 auto actual_str = std::string_view(reinterpret_cast<const char*>(actual->data()), actual->size());
 BOOST_TEST(actual_str == tc.raw);
 }
 }
}

BOOST_AUTO_TEST_CASE(decode_success_without_padding)
{
 for (auto tc : success_cases)
 {
 BOOST_TEST_CONTEXT(tc.encoded_no_padding)
 {
 auto actual = base64_decode(tc.encoded_no_padding, false);
 BOOST_TEST_REQUIRE(actual.error() == error_code());
 auto actual_str = std::string_view(reinterpret_cast<const char*>(actual->data()), actual->size());
 BOOST_TEST(actual_str == tc.raw);
 }
 }
}

BOOST_AUTO_TEST_CASE(decode_error)
{
 constexpr std::string_view cases[] = {
 // Invalid characters
 "%3d=="sv,
 "3ドルd=="sv,
 "[=="sv,
 "YW]3="sv,
 "3{d=="sv,
 "3d}=="sv,
 "@@"sv,
 "!"sv,
 "YWJj\n"sv,
 "YWJj\nYWI="sv,

 // Bad padding
 "aGVsbG8sIHdvcmxk="sv,
 "aGVsbG8sIHdvcmxk=="sv,
 "aGVsbG8sIHdvcmxkPyE=="sv,
 "aGVsbG8sIHdvcmxkLg="sv,

 // Extra bytes
 "AA==A"sv,
 "AA==="sv,
 };

 for (auto tc : cases)
 {
 BOOST_TEST_CONTEXT(tc)
 {
 BOOST_TEST(base64_decode(tc).error() == error_code(errc::invalid_base64));
 BOOST_TEST(base64_decode(tc, false).error() == error_code(errc::invalid_base64));
 }
 }
}

BOOST_AUTO_TEST_SUITE_END()