#include <gtest/gtest.h>

#include "../src/nfc.hh" // for illegal_utf8 exception
#include <vector>

using namespace pEp;
using std::string_view;

namespace {

    struct TestEntry {
        string_view input;
        bool is_nfc;
        IsNFC quick;
        string_view nfc;
    };

    typedef TestEntry TE;


    std::ostream& operator<<(std::ostream& o, const TestEntry& tt)
    {
        return o << "input=«" << tt.input << "», isNfc=" << tt.is_nfc << ", quick=" << tt.quick
                 << ".  ";
    }


    const char nullo[4] = { 0, 0, 0, 0 };

    const std::vector<TestEntry> testValues = {
        { "", true, IsNFC::Yes, "" },             // always start with the simple case ;-)
        { "123", true, IsNFC::Yes, "123" },       // some ASCII digits. Still easy.
        { "\n\\\b", true, IsNFC::Yes, "\n\\\b" }, // backslash escapes for ASCII and control chars
        { "ä", true, IsNFC::Yes, "ä" },           // <U+00E4> small a with diaeresis
        { "\xc4\x85", true, IsNFC::Yes, "\xc4\x85" }, // <U+0105> small a with ogonek

        { "a\xcc\x88", false, IsNFC::Maybe, "ä" },        // a + <U+0308> combining diaresis
        { "a\xcc\xa8", false, IsNFC::Maybe, "\xc4\x85" }, // a + <U+0328> combining ogonek
        { "a\xcc\xa8\xcc\x88",
          false,
          IsNFC::Maybe,
          "\xc4\x85\xcc\x88" }, // a + <U+0328> + <U+0308> (ogonek + diaeresis)
        { "a\xcc\x88\xcc\xa8",
          false,
          IsNFC::Maybe,
          "\xc4\x85\xcc\x88" }, // a + <U+0308> + <U+0328> (diaeresis + ogonek)

        { "\xc4\x85\xcc\x88",
          true,
          IsNFC::Maybe,
          "\xc4\x85\xcc\x88" }, // <U+0105> small a with ogonek + combining diaeresis
        { "ä\xcc\xa8", false, IsNFC::Maybe, "\xc4\x85\xcc\x88" }, // a diaeresis + <U+0328> combining ogonek

        // Already implemented, because <U+305> and <U+33C> have neither "No" nor "Maybe" NFC class:
        { "a\xcc\x85\xcc\xbc",
          false,
          IsNFC::No,
          "a\xcc\xbc\xcc\x85" }, // a + <U+0305> + <U+033C> (overline + seagull_below)
        { "a\xcc\xbc\xcc\x85",
          true,
          IsNFC::Yes,
          "a\xcc\xbc\xcc\x85" }, // a + <U+033C> + <U+0305> (seagull_below + overline)

        { string_view(nullo, 1), true, IsNFC::Yes, string_view(nullo, 1) }, // Yeah, 1 NUL byte
        { string_view(nullo, 4), true, IsNFC::Yes, string_view(nullo, 4) }, // Yeah, 4 NUL bytes

        { "EOF", true, IsNFC::Yes, "EOF" }
    };

} // namespace

class NfcTest : public ::testing::TestWithParam<TestEntry> {
    // intentionally left blank for now.
};

INSTANTIATE_TEST_SUITE_P(NfcTestInstance, NfcTest, testing::ValuesIn(testValues));

TEST_P(NfcTest, Meh)
{
    const auto& v = GetParam();
    EXPECT_EQ(v.quick, UTF8::isNFC_quick_check(v.input));

    EXPECT_EQ(v.is_nfc, UTF8::isNFC(v.input));
    EXPECT_EQ(v.nfc, UTF8::toNFC(v.input));

    if (v.is_nfc) {
        EXPECT_EQ(v.input, UTF8::toNFC(v.input));
    }
}