// 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/BinaryStreamWriter.hpp>

#include <IACore/IATest.hpp>

using namespace IACore;

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

IAT_BEGIN_BLOCK(Core, BinaryStreamWriter)

    // -------------------------------------------------------------------------
    // 1. Vector Mode (Dynamic Growth)
    // -------------------------------------------------------------------------
    BOOL TestVectorGrowth() 
    {
        std::vector<UINT8> buffer;
        // Start empty
        BinaryStreamWriter writer(buffer);

        // Write 1 Byte
        writer.Write<UINT8>(0xAA);
        IAT_CHECK_EQ(buffer.size(), (SIZE_T)1);
        IAT_CHECK_EQ(buffer[0], 0xAA);

        // Write 4 Bytes (UINT32)
        // 0xDDCCBBAA -> Little Endian: AA BB CC DD
        writer.Write<UINT32>(0xDDCCBBAA);
        
        IAT_CHECK_EQ(buffer.size(), (SIZE_T)5);
        
        // Verify Memory Layout
        IAT_CHECK_EQ(buffer[1], 0xAA);
        IAT_CHECK_EQ(buffer[2], 0xBB);
        IAT_CHECK_EQ(buffer[3], 0xCC);
        IAT_CHECK_EQ(buffer[4], 0xDD);

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 2. Vector Mode (Appending to Existing Data)
    // -------------------------------------------------------------------------
    BOOL TestVectorAppend() 
    {
        // Vector starts with existing data
        std::vector<UINT8> buffer = { 0x01, 0x02 };
        BinaryStreamWriter writer(buffer);

        // Should append to end, not overwrite 0x01
        writer.Write<UINT8>(0x03);

        IAT_CHECK_EQ(buffer.size(), (SIZE_T)3);
        IAT_CHECK_EQ(buffer[0], 0x01);
        IAT_CHECK_EQ(buffer[2], 0x03);

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 3. Fixed Mode (Span / No Allocation)
    // -------------------------------------------------------------------------
    BOOL TestFixedBuffer() 
    {
        UINT8 rawData[10];
        // Initialize with zeros
        std::memset(rawData, 0, 10);

        BinaryStreamWriter writer(rawData); // Implicit conversion to span

        // Write UINT8
        writer.Write<UINT8>(0xFF);
        IAT_CHECK_EQ(rawData[0], 0xFF);

        // Write UINT16
        writer.Write<UINT16>(0x2211);
        IAT_CHECK_EQ(rawData[1], 0x11);
        IAT_CHECK_EQ(rawData[2], 0x22);

        // Verify we haven't touched the rest
        IAT_CHECK_EQ(rawData[3], 0x00);

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 4. WriteBytes (Bulk Write)
    // -------------------------------------------------------------------------
    BOOL TestWriteBytes() 
    {
        std::vector<UINT8> buffer;
        BinaryStreamWriter writer(buffer);

        const char* msg = "IA";
        writer.WriteBytes((PVOID)msg, 2);
        writer.Write<UINT8>(0x00); // Null term

        IAT_CHECK_EQ(buffer.size(), (SIZE_T)3);
        IAT_CHECK_EQ(buffer[0], 'I');
        IAT_CHECK_EQ(buffer[1], 'A');
        IAT_CHECK_EQ(buffer[2], 0x00);

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 5. Random Access (WriteAt)
    // -------------------------------------------------------------------------
    BOOL TestRandomAccess() 
    {
        std::vector<UINT8> buffer;
        BinaryStreamWriter writer(buffer);

        // Fill with placeholders
        writer.Write<UINT32>(0xFFFFFFFF);
        writer.Write<UINT32>(0xFFFFFFFF);

        // Overwrite the first integer with 0x00000000
        writer.WriteAt<UINT32>(0, 0);

        // Overwrite the byte at index 4 (start of second int)
        writer.WriteAt<UINT8>(4, 0xAA);

        IAT_CHECK_EQ(buffer[0], 0x00);
        IAT_CHECK_EQ(buffer[3], 0x00);
        IAT_CHECK_EQ(buffer[4], 0xAA); // Modified
        IAT_CHECK_EQ(buffer[5], 0xFF); // Unmodified

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 6. Floating Point Writing
    // -------------------------------------------------------------------------
    BOOL TestWriteFloat() 
    {
        std::vector<UINT8> buffer;
        BinaryStreamWriter writer(buffer);

        FLOAT32 val = 1.234f;
        writer.Write<FLOAT32>(val);

        IAT_CHECK_EQ(buffer.size(), (SIZE_T)4);

        // Read it back via memcpy to verify
        FLOAT32 readBack;
        std::memcpy(&readBack, buffer.data(), 4);

        IAT_CHECK_APPROX(readBack, val);

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // 7. GetPtrAt (Pointer Arithmetic Check)
    // -------------------------------------------------------------------------
    BOOL TestGetPtr() 
    {
        std::vector<UINT8> buffer = { 0x10, 0x20, 0x30 };
        BinaryStreamWriter writer(buffer);

        PUINT8 p1 = writer.GetPtrAt(1);
        IAT_CHECK(p1 != nullptr);
        IAT_CHECK_EQ(*p1, 0x20);

        // Bounds check (Valid boundary)
        PUINT8 pLast = writer.GetPtrAt(2);
        IAT_CHECK(pLast != nullptr);

        // Bounds check (Invalid)
        // Note: We don't test Panic here, but we check if it returns valid ptrs
        PUINT8 pInvalid = writer.GetPtrAt(3); 
        IAT_CHECK(pInvalid == nullptr);

        return TRUE;
    }

    // -------------------------------------------------------------------------
    // Registration
    // -------------------------------------------------------------------------
    IAT_BEGIN_TEST_LIST()
        IAT_ADD_TEST(TestVectorGrowth);
        IAT_ADD_TEST(TestVectorAppend);
        IAT_ADD_TEST(TestFixedBuffer);
        IAT_ADD_TEST(TestWriteBytes);
        IAT_ADD_TEST(TestRandomAccess);
        IAT_ADD_TEST(TestWriteFloat);
        IAT_ADD_TEST(TestGetPtr);
    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 BinaryReader block
    testRunner.testBlock<Core_BinaryStreamWriter>();

    return 0;
}