// IACore-OSS; The Core Library for All IA Open Source Projects 
// Copyright (C) 2025 IAS (ias@iasoft.dev)
// 
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

#include <IACore/BinaryStreamReader.hpp>

#include <IACore/IATest.hpp>

using namespace IACore;

// -----------------------------------------------------------------------------
// Test Block Definition
// -----------------------------------------------------------------------------

IAT_BEGIN_BLOCK(Core, BinaryStreamReader)

    // -------------------------------------------------------------------------
    // 1. Basic Primitive Reading (UINT8)
    // -------------------------------------------------------------------------
    BOOL TestReadUint8() 
    {
        UINT8 data[] = { 0xAA, 0xBB, 0xCC };
        BinaryStreamReader reader(data);

        // Read First Byte
        auto val1 = reader.Read<UINT8>();
        IAT_CHECK(val1.has_value());
        IAT_CHECK_EQ(*val1, 0xAA);
        IAT_CHECK_EQ(reader.Cursor(), (SIZE_T)1);

        // Read Second Byte
        auto val2 = reader.Read<UINT8>();
        IAT_CHECK_EQ(*val2, 0xBB);

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 2. Multi-byte Reading (Endianness check)
    // -------------------------------------------------------------------------
    BOOL TestReadMultiByte() 
    {
        // 0x04030201 in Little Endian memory layout
        UINT8 data[] = { 0x01, 0x02, 0x03, 0x04 }; 
        BinaryStreamReader reader(data);

        auto val = reader.Read<UINT32>();
        IAT_CHECK(val.has_value());
        
        // Assuming standard x86/ARM Little Endian for this test
        // If your engine supports Big Endian, you'd check architecture here
        IAT_CHECK_EQ(*val, (UINT32)0x04030201); 
        
        IAT_CHECK_EQ(reader.Cursor(), (SIZE_T)4);
        IAT_CHECK(reader.IsEOF());

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 3. Floating Point (Approx check)
    // -------------------------------------------------------------------------
    BOOL TestReadFloat() 
    {
        FLOAT32 pi = 3.14159f;
        // Bit-cast float to bytes for setup
        UINT8 data[4];
        std::memcpy(data, &pi, 4);

        BinaryStreamReader reader(data);
        auto val = reader.Read<FLOAT32>();

        IAT_CHECK(val.has_value());
        IAT_CHECK_APPROX(*val, pi);

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 4. String Reading
    // -------------------------------------------------------------------------
    BOOL TestReadString() 
    {
        const char* raw = "HelloIA";
        BinaryStreamReader reader(std::span<const UINT8>((const UINT8*)raw, 7));

        // Read "Hello" (5 bytes)
        auto str = reader.ReadString(5);
        IAT_CHECK(str.has_value());
        IAT_CHECK_EQ(*str, String("Hello"));
        IAT_CHECK_EQ(reader.Cursor(), (SIZE_T)5);

        // Read remaining "IA"
        auto str2 = reader.ReadString(2);
        IAT_CHECK_EQ(*str2, String("IA"));

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 5. Batch Buffer Reading
    // -------------------------------------------------------------------------
    BOOL TestReadBuffer() 
    {
        UINT8 src[] = { 1, 2, 3, 4, 5 };
        UINT8 dst[3] = { 0 };
        BinaryStreamReader reader(src);

        // Read 3 bytes into dst
        auto res = reader.Read(dst, 3);
        IAT_CHECK(res.has_value());

        // Verify dst content
        IAT_CHECK_EQ(dst[0], 1);
        IAT_CHECK_EQ(dst[1], 2);
        IAT_CHECK_EQ(dst[2], 3);
        
        // Verify cursor
        IAT_CHECK_EQ(reader.Cursor(), (SIZE_T)3);

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 6. Navigation (Seek, Skip, Remaining)
    // -------------------------------------------------------------------------
    BOOL TestNavigation() 
    {
        UINT8 data[10] = { 0 }; // Zero init
        BinaryStreamReader reader(data);

        IAT_CHECK_EQ(reader.Remaining(), (SIZE_T)10);

        // Skip
        reader.Skip(5);
        IAT_CHECK_EQ(reader.Cursor(), (SIZE_T)5);
        IAT_CHECK_EQ(reader.Remaining(), (SIZE_T)5);

        // Skip clamping
        reader.Skip(100); // Should clamp to 10
        IAT_CHECK_EQ(reader.Cursor(), (SIZE_T)10);
        IAT_CHECK(reader.IsEOF());

        // Seek
        reader.Seek(2);
        IAT_CHECK_EQ(reader.Cursor(), (SIZE_T)2);
        IAT_CHECK_EQ(reader.Remaining(), (SIZE_T)8);
        IAT_CHECK_NOT(reader.IsEOF());

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 7. Error Handling (EOF Protection)
    // -------------------------------------------------------------------------
    BOOL TestBoundaryChecks() 
    {
        UINT8 data[] = { 0x00, 0x00 };
        BinaryStreamReader reader(data);

        // Valid read
        UNUSED(reader.Read<UINT16>()); 
        IAT_CHECK(reader.IsEOF());

        // Invalid Read Primitive
        auto val = reader.Read<UINT8>();
        IAT_CHECK_NOT(val.has_value()); // Should be unexpected

        // Invalid Read String
        auto str = reader.ReadString(1);
        IAT_CHECK_NOT(str.has_value());

        // Invalid Batch Read
        UINT8 buf[1];
        auto batch = reader.Read(buf, 1);
        IAT_CHECK_NOT(batch.has_value());

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // Registration
    // -------------------------------------------------------------------------
    IAT_BEGIN_TEST_LIST()
        IAT_ADD_TEST(TestReadUint8);
        IAT_ADD_TEST(TestReadMultiByte);
        IAT_ADD_TEST(TestReadFloat);
        IAT_ADD_TEST(TestReadString);
        IAT_ADD_TEST(TestReadBuffer);
        IAT_ADD_TEST(TestNavigation);
        IAT_ADD_TEST(TestBoundaryChecks);
    IAT_END_TEST_LIST()

IAT_END_BLOCK()

int main(int argc, char* argv[])
{
    UNUSED(argc);
    UNUSED(argv);

    // Define runner (StopOnFail=false, Verbose=true)
    ia::iatest::runner<false, true> testRunner;
    
    // Run the BinaryStreamReader block
    testRunner.testBlock<Core_BinaryReader>();

    return 0;
}