#include <gtest/gtest.h>

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

using namespace pEp;
using std::u16string_view;

namespace pEp {
    std::string escape_utf16(u16string_view s);
}

namespace {

    struct TestEntry {
        u16string_view input;
        bool is_nfc;
        IsNFC quick;
        u16string_view nfc;
    };

    typedef TestEntry TE;


    std::ostream& operator<<(std::ostream& o, const TestEntry& tt)
    {
        return o << "input=«" << pEp::escape_utf16(tt.input) << "», isNfc=" << tt.is_nfc
                 << ", quick=" << tt.quick << ".  ";
    }


    const char16_t nullo[4] = { 0, 0, 0, 0 };

    const std::vector<TestEntry> testValues = {
        { u"", true, IsNFC::Yes, u"" },             // always start with the simple case ;-)
        { u"123", true, IsNFC::Yes, u"123" },       // some ASCII digits. Still easy.
        { u"\n\\\b", true, IsNFC::Yes, u"\n\\\b" }, // backslash escapes for ASCII and control chars
        { u"ä", true, IsNFC::Yes, u"ä" },           // <U+00E4> small a with diaeresis
        { u"\u0105", true, IsNFC::Yes, u"\u0105" }, // <U+0105> small a with ogonek

        { u"a\u0308", false, IsNFC::Maybe, u"ä" },      // a + <U+0308> combining diaresis
        { u"a\u0328", false, IsNFC::Maybe, u"\u0105" }, // a + <U+0328> combining ogonek
        { u"a\u0328\u0308", false, IsNFC::Maybe, u"\u0105\u0308" }, // a + <U+0328> + <U+0308> (ogonek + diaeresis)
        { u"a\u0308\u0328", false, IsNFC::Maybe, u"\u0105\u0308" }, // a + <U+0308> + <U+0328> (diaeresis + ogonek)

        { u"\u0105\u0308", true, IsNFC::Maybe, u"\u0105\u0308" }, // <U+0105> small a with ogonek + combining diaeresis
        { u"ä\u0328", false, IsNFC::Maybe, u"\u0105\u0308" }, // a diaeresis + <U+0328> combining ogonek

        // Already implemented, because <U+305> and <U+33C> have neither "No" nor "Maybe" NFC class:
        { u"a\u0305\u033c", false, IsNFC::No, u"a\u033c\u0305" }, // a + <U+0305> + <U+033C> (overline + seagull_below)
        { u"a\u033c\u0305", true, IsNFC::Yes, u"a\u033c\u0305" }, // a + <U+033C> + <U+0305> (seagull_below + overline)

        // MUSICAL SYMBOL SIXTEENTH NOTE -> will be decomposed and not re-composed according to Unicode data, for whatever reason. :-/
        { u"\U0001D161", false, IsNFC::No, u"\U0001d15f\U0001d16f" },
        { u16string_view(nullo, 1), true, IsNFC::Yes, u16string_view(nullo, 1) }, // Yeah, 1 NUL byte
        { u16string_view(nullo, 4), true, IsNFC::Yes, u16string_view(nullo, 4) }, // Yeah, 4 NUL bytes

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

} // end of anonymous namespace


class Nfc16Test : public ::testing::TestWithParam<TestEntry> {
    // intentionally left blank for now.
};

INSTANTIATE_TEST_SUITE_P(Nfc16TestInstance, Nfc16Test, testing::ValuesIn(testValues));

TEST_P(Nfc16Test, Meh)
{
    const auto& v = GetParam();
    EXPECT_EQ(v.quick, UTF16::isNFC_quick_check(v.input));

    EXPECT_EQ(v.is_nfc, UTF16::isNFC(v.input));
    EXPECT_EQ(v.nfc, UTF16::toNFC(v.input));

    if (v.is_nfc) {
        EXPECT_EQ(v.input, UTF16::toNFC(v.input));
    }
}