//+------------------------------------------------------------------+
//|                                              CBitBuffer_Test.mq5 |
//|                                        Copyright © 2025, Amr Ali |
//|                             https://www.mql5.com/en/users/amrali |
//+------------------------------------------------------------------+
#property copyright "Amr Ali"
#property link      "https://www.mql5.com/en/users/amrali"
#property version   "1.02"

// Include the CBitBuffer class definition.
// Assuming CBitBuffer.mqh is in the same directory or MQL5/Include.
#include "CBitBuffer.mqh"

// Define a simple structure for testing WriteStruct/ReadStruct.
struct MyTestStruct
  {
   int    id;
   double price;
   long   volume;
   bool   isActive;
  };

//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart()
  {
   Print("--- CBitBuffer Capabilities Test ---");

   // --- 1. Bit-Packing Operations ---
   TestBitPacking();

   // --- 2. Basic Write and Read Operations ---
   TestBasicOperations();

   // --- 3. Mixed Read/Write Operations ---
   TestMixedOperations();

   // --- 4. Variable-Length Quantity (VLQ) Encoding Test ---
   TestVLQEncoding();

   // --- 5. String and Struct Serialization Test ---
   TestStringAndStruct();

   // --- 6. File Save and Load Test ---
   TestFileOperations();

   // --- 7. Error Handling Test ---
   TestErrorHandling();

   Print("--- CBitBuffer Test Complete ---");
  }

//+------------------------------------------------------------------+
//| Test Function: Bit-Packing Operations                      |
//+------------------------------------------------------------------+
void TestBitPacking()
  {
   Print("\n--- Test: Bit-Packing Operations ---");
   CBitBuffer buffer;

   // Write bits
   Print("Writing bits...");
   buffer.WriteBit(true);  // 1
   buffer.WriteBit(false); // 0
   buffer.WriteBit(true);  // 1
   // Writing a small integer (e.g., 5 bits for a value up to 31)
   buffer.WriteBits(27, 5); // 27 = 11011 (binary)
   // Writing a larger integer (e.g., 10 bits for a value up to 1023)
   buffer.WriteBits(789, 10); // 789 = 1100010101 (binary)
   // Writing an 8-bit value (byte)
   buffer.WriteBits(0xA5, 8); // 0xA5 = 10100101 (binary)

   PrintFormat("Total bits written: %d", buffer.GetTotalWrittenBits());
   buffer.PrintHex(); // Debug print

   // Reset read position to start
   buffer.ResetReadPosition();
   Print("Reading bits...");

   // Read and verify
   PrintFormat("Read bit 1: %s (Expected: true)", buffer.ReadBit() ? "true" : "false");
   PrintFormat("Read bit 2: %s (Expected: false)", buffer.ReadBit() ? "true" : "false");
   PrintFormat("Read bit 3: %s (Expected: true)", buffer.ReadBit() ? "true" : "false");
   PrintFormat("Read 5-bit integer: %d (Expected: 27)", (int)buffer.ReadBits(5));
   PrintFormat("Read 10-bit integer: %d (Expected: 789)", (int)buffer.ReadBits(10));
   PrintFormat("Read 8-bit value: 0x%X (Expected: 0xA5)", (int)buffer.ReadBits(8));

   if (buffer.GetLastError() == BIT_BUFFER_NO_ERROR)
     {
      Print("Bit-Packing Operations test: PASSED");
     }
   else
     {
      PrintFormat("Bit-Packing Operations test: FAILED! Error: %s", buffer.GetLastErrorString());
     }
  }

//+------------------------------------------------------------------+
//| Test Function: Basic Write and Read Operations                   |
//+------------------------------------------------------------------+
void TestBasicOperations()
  {
   Print("\n--- Test: Basic Write and Read Operations ---");
   CBitBuffer buffer;

   // Write various data types
   Print("Writing data...");
   buffer.WriteBool(true);
   buffer.WriteBit(false); // Write a single bit
   buffer.WriteChar('A');
   buffer.WriteUChar(255);
   buffer.WriteShort(-12345);
   buffer.WriteUShort(65530);
   buffer.WriteInt(123456789);
   buffer.WriteUInt(4294967295U); // Max uint
   buffer.WriteLong(9223372036854775807LL);
   buffer.WriteULong(18446744073709551615ULL); // Max ulong
   buffer.WriteFloat(3.14159f);
   buffer.WriteDouble(2.718281828459045);
   datetime now = TimeCurrent();
   buffer.WriteDatetime(now);

   PrintFormat("Total bits written: %d", buffer.GetTotalWrittenBits());
   buffer.PrintHex(); // Debug print

   // Reset read position to start
   buffer.ResetReadPosition();
   Print("Reading data...");

   // Read and verify
   PrintFormat("Read Bool: %s (Expected: true)", buffer.ReadBool() ? "true" : "false");
   PrintFormat("Read Bit: %s (Expected: false)", buffer.ReadBit() ? "true" : "false");
   PrintFormat("Read Char: %c (Expected: A)", buffer.ReadChar());
   PrintFormat("Read UChar: %d (Expected: 255)", buffer.ReadUChar());
   PrintFormat("Read Short: %d (Expected: -12345)", buffer.ReadShort());
   PrintFormat("Read UShort: %d (Expected: 65530)", buffer.ReadUShort());
   PrintFormat("Read Int: %d (Expected: 123456789)", buffer.ReadInt());
   PrintFormat("Read UInt: %u (Expected: 4294967295)", buffer.ReadUInt());
   PrintFormat("Read Long: %lli (Expected: 9223372036854775807)", buffer.ReadLong());
   PrintFormat("Read ULong: %llu (Expected: 18446744073709551615)", buffer.ReadULong());
   PrintFormat("Read Float: %.5f (Expected: 3.14159)", buffer.ReadFloat());
   PrintFormat("Read Double: %.15f (Expected: 2.718281828459045)", buffer.ReadDouble());
   PrintFormat("Read Datetime: %s (Expected: %s)", TimeToString(buffer.ReadDatetime()), TimeToString(now));

   if (buffer.GetLastError() == BIT_BUFFER_NO_ERROR)
     {
      Print("Basic operations test: PASSED");
     }
   else
     {
      PrintFormat("Basic operations test: FAILED! Error: %s", buffer.GetLastErrorString());
     }
  }

//+------------------------------------------------------------------+
//| Test Function: Mixed Read/Write Operations                       |
//+------------------------------------------------------------------+
void TestMixedOperations()
  {
   Print("\n--- Test: Mixed Read/Write Operations ---");
   CBitBuffer buffer;

   // Write some data
   buffer.WriteInt(100);
   buffer.WriteShort(200);
   PrintFormat("After initial writes: Total bits written: %d", buffer.GetTotalWrittenBits());
   buffer.PrintHex();

   // Read some data (this should trigger a flush)
   int val1 = buffer.ReadInt();
   PrintFormat("Read Int: %d (Expected: 100)", val1);
   PrintFormat("Read position after first read: %d", buffer.GetReadPosition());

   // Write more data (this should invalidate read cache)
   buffer.WriteLong(987654321L);
   buffer.WriteBool(true);
   PrintFormat("After mixed writes: Total bits written: %d", buffer.GetTotalWrittenBits());
   buffer.PrintHex();

   // Read remaining data
   short val2 = buffer.ReadShort();
   long val3 = buffer.ReadLong();
   bool val4 = buffer.ReadBool();

   PrintFormat("Read Short: %d (Expected: 200)", val2);
   PrintFormat("Read Long: %lli (Expected: 987654321)", val3);
   PrintFormat("Read Bool: %s (Expected: true)", val4 ? "true" : "false");

   if (buffer.GetLastError() == BIT_BUFFER_NO_ERROR)
     {
      Print("Mixed operations test: PASSED");
     }
   else
     {
      PrintFormat("Mixed operations test: FAILED! Error: %s", buffer.GetLastErrorString());
     }
  }

//+------------------------------------------------------------------+
//| Test Function: Variable-Length Quantity (VLQ) Encoding Test      |
//+------------------------------------------------------------------+
void TestVLQEncoding()
  {
   Print("\n--- Test: Variable-Length Quantity (VLQ) Encoding ---");
   CBitBuffer buffer;

   // Test values: small, medium, large, zero, negative
   int intValues[] = {0, 1, -1, 127, -128, 12345, -67890, 2147483647, -2147483648};
   uint uintValues[] = {0, 1, 127, 12345, 4294967295U};
   long longValues[] = {0L, 1L, -1L, 1234567890123L, -9876543210987L, 9223372036854775807L, -9223372036854775808L};
   ulong ulongValues[] = {0ULL, 1ULL, 1234567890123ULL, 18446744073709551615ULL};

   Print("Writing VLQ integers...");
   for (int i = 0; i < ArraySize(intValues); i++)
     {
      buffer.WriteVarInt(intValues[i]);
     }
   for (int i = 0; i < ArraySize(uintValues); i++)
     {
      buffer.WriteVarUInt(uintValues[i]);
     }
   for (int i = 0; i < ArraySize(longValues); i++)
     {
      buffer.WriteVarLong(longValues[i]);
     }
   for (int i = 0; i < ArraySize(ulongValues); i++)
     {
      buffer.WriteVarULong(ulongValues[i]);
     }

   PrintFormat("Total bits written (VLQ): %d", buffer.GetTotalWrittenBits());
   buffer.PrintHex();

   buffer.ResetReadPosition();
   Print("Reading VLQ integers...");

   bool vlqPassed = true;
   for (int i = 0; i < ArraySize(intValues); i++)
     {
      int readVal = buffer.ReadVarInt();
      if (readVal != intValues[i])
        {
         PrintFormat("VLQ Int Mismatch: Expected %d, Got %d", intValues[i], readVal);
         vlqPassed = false;
        }
     }
   for (int i = 0; i < ArraySize(uintValues); i++)
     {
      uint readVal = buffer.ReadVarUInt();
      if (readVal != uintValues[i])
        {
         PrintFormat("VLQ UInt Mismatch: Expected %u, Got %u", uintValues[i], readVal);
         vlqPassed = false;
        }
     }
   for (int i = 0; i < ArraySize(longValues); i++)
     {
      long readVal = buffer.ReadVarLong();
      if (readVal != longValues[i])
        {
         PrintFormat("VLQ Long Mismatch: Expected %Ld, Got %Ld", longValues[i], readVal);
         vlqPassed = false;
        }
     }
   for (int i = 0; i < ArraySize(ulongValues); i++)
     {
      ulong readVal = buffer.ReadVarULong();
      if (readVal != ulongValues[i])
        {
         PrintFormat("VLQ ULong Mismatch: Expected %lu, Got %lu", ulongValues[i], readVal);
         vlqPassed = false;
        }
     }

   if (vlqPassed && buffer.GetLastError() == BIT_BUFFER_NO_ERROR)
     {
      Print("VLQ encoding test: PASSED");
     }
   else
     {
      PrintFormat("VLQ encoding test: FAILED! Error: %s", buffer.GetLastErrorString());
     }
  }

//+------------------------------------------------------------------+
//| Test Function: String and Struct Serialization                   |
//+------------------------------------------------------------------+
void TestStringAndStruct()
  {
   Print("\n--- Test: String and Struct Serialization ---");
   CBitBuffer buffer;

   string testString1 = "Hello, MQL5 BitBuffer!";
   string testString2 = "Another string with ümlauts and special chars: éàç";
   string testString3 = ""; // Empty string
   string testString4 = NULL; // Null string

   MyTestStruct myStruct1;
   myStruct1.id = 123;
   myStruct1.price = 123.456;
   myStruct1.volume = 14432;
   myStruct1.isActive = true;

   MyTestStruct myStruct2;
   myStruct2.id = 789;
   myStruct2.price = 987.654;
   myStruct2.volume = 747;
   myStruct2.isActive = false;

   Print("Writing strings and structs...");
   buffer.WriteString(testString1);
   buffer.WriteString(testString2);
   buffer.WriteString(testString3);
   buffer.WriteString(testString4);
   buffer.WriteStruct(myStruct1);
   buffer.WriteStruct(myStruct2);

   PrintFormat("Total bits written (Strings/Structs): %d", buffer.GetTotalWrittenBits());
   buffer.PrintHex();

   buffer.ResetReadPosition();
   Print("Reading strings and structs...");

   string readString1 = buffer.ReadString();
   string readString2 = buffer.ReadString();
   string readString3 = buffer.ReadString();
   string readString4 = buffer.ReadString();
   MyTestStruct readStruct1 = buffer.ReadStruct<MyTestStruct>();
   MyTestStruct readStruct2 = buffer.ReadStruct<MyTestStruct>();

   bool structStringPassed = true;
   if (readString1 != testString1) { PrintFormat("String1 Mismatch: '%s' != '%s'", readString1, testString1); structStringPassed = false; }
   if (readString2 != testString2) { PrintFormat("String2 Mismatch: '%s' != '%s'", readString2, testString2); structStringPassed = false; }
   if (readString3 != testString3) { PrintFormat("String3 Mismatch: '%s' != '%s'", readString3, testString3); structStringPassed = false; }
   if (readString4 != testString4) { PrintFormat("String4 Mismatch: '%s' != '%s'", readString4, testString4); structStringPassed = false; }

   if (readStruct1.id != myStruct1.id || readStruct1.price != myStruct1.price ||
       readStruct1.volume != myStruct1.volume || readStruct1.isActive != myStruct1.isActive)
     {
      Print("Struct1 Mismatch!");
      PrintFormat("  Expected: ID=%d, Price=%.3f, volume='%lli', Active=%s", myStruct1.id, myStruct1.price, myStruct1.volume, myStruct1.isActive ? "true" : "false");
      PrintFormat("  Got:      ID=%d, Price=%.3f, volume='%lli', Active=%s", readStruct1.id, readStruct1.price, readStruct1.volume, readStruct1.isActive ? "true" : "false");
      structStringPassed = false;
     }

   if (readStruct2.id != myStruct2.id || readStruct2.price != myStruct2.price ||
       readStruct2.volume != myStruct2.volume || readStruct2.isActive != myStruct2.isActive)
     {
      Print("Struct2 Mismatch!");
      PrintFormat("  Expected: ID=%d, Price=%.3f, volume='%lli', Active=%s", myStruct2.id, myStruct2.price, myStruct2.volume, myStruct2.isActive ? "true" : "false");
      PrintFormat("  Got:      ID=%d, Price=%.3f, volume='%lli', Active=%s", readStruct2.id, readStruct2.price, readStruct2.volume, readStruct2.isActive ? "true" : "false");
      structStringPassed = false;
     }

   if (structStringPassed && buffer.GetLastError() == BIT_BUFFER_NO_ERROR)
     {
      Print("String and Struct serialization test: PASSED");
     }
   else
     {
      PrintFormat("String and Struct serialization test: FAILED! Error: %s", buffer.GetLastErrorString());
     }
  }

//+------------------------------------------------------------------+
//| Test Function: File Save and Load Operations                     |
//+------------------------------------------------------------------+
void TestFileOperations()
  {
   Print("\n--- Test: File Save and Load Operations ---");
   CBitBuffer bufferWrite;
   CBitBuffer bufferRead;
   string filename = "bitbuffer_test_data.bin"; // File in MQL5/Files/

   // Write some data to bufferWrite
   bufferWrite.WriteInt(12345);
   bufferWrite.WriteString("Data for file storage.");
   bufferWrite.WriteDouble(987.654321);
   bufferWrite.WriteBool(true);
   bufferWrite.WriteVarInt(-500);

   PrintFormat("Buffer to save (bits): %d", bufferWrite.GetTotalWrittenBits());
   bufferWrite.PrintHex();

   // Save to file
   if (bufferWrite.Save(filename))
     {
      PrintFormat("Buffer successfully saved to '%s'", filename);
     }
   else
     {
      PrintFormat("Failed to save buffer to file! Error: %s", bufferWrite.GetLastErrorString());
      return;
     }

   // Load from file into bufferRead
   if (bufferRead.Load(filename))
     {
      PrintFormat("Buffer successfully loaded from '%s'", filename);
      PrintFormat("Loaded buffer (bits): %d", bufferRead.GetTotalWrittenBits());
      bufferRead.PrintHex();

      // Verify loaded data
      int readInt = bufferRead.ReadInt();
      string readString = bufferRead.ReadString();
      double readDouble = bufferRead.ReadDouble();
      bool readBool = bufferRead.ReadBool();
      int readVarInt = bufferRead.ReadVarInt();

      bool fileTestPassed = true;
      if (readInt != 12345) { PrintFormat("File Load Mismatch: Int. Expected 12345, Got %d", readInt); fileTestPassed = false; }
      if (readString != "Data for file storage.") { PrintFormat("File Load Mismatch: String. Expected 'Data for file storage.', Got '%s'", readString); fileTestPassed = false; }
      if (readDouble != 987.654321) { PrintFormat("File Load Mismatch: Double. Expected 987.654321, Got %.6f", readDouble); fileTestPassed = false; }
      if (readBool != true) { PrintFormat("File Load Mismatch: Bool. Expected true, Got %s", readBool ? "true" : "false"); fileTestPassed = false; }
      if (readVarInt != -500) { PrintFormat("File Load Mismatch: VarInt. Expected -500, Got %d", readVarInt); fileTestPassed = false; }

      if (fileTestPassed && bufferRead.GetLastError() == BIT_BUFFER_NO_ERROR)
        {
         Print("File operations test: PASSED");
        }
      else
        {
         PrintFormat("File operations test: FAILED! Error: %s", bufferRead.GetLastErrorString());
        }
     }
   else
     {
      PrintFormat("Failed to load buffer from file! Error: %s", bufferRead.GetLastErrorString());
      return;
     }

   // Clean up: Delete the test file
   if (FileDelete(filename))
     {
      PrintFormat("Test file '%s' deleted successfully.", filename);
     }
   else
     {
      PrintFormat("Failed to delete test file '%s'. MQL5 Error: %d", filename, ::GetLastError());
     }
  }

//+------------------------------------------------------------------+
//| Test Function: Error Handling                                    |
//+------------------------------------------------------------------+
void TestErrorHandling()
  {
   Print("\n--- Test: Error Handling ---");
   CBitBuffer buffer;
   bool errorHandled = true;

   // Test 1: Read out of bounds
   Print("Attempting to read out of bounds...");
   buffer.Clear();
   buffer.WriteInt(10); // Write 32 bits
   buffer.ResetReadPosition();
   buffer.ReadLong(); // Try to read 64 bits
   if (buffer.GetLastError() == BIT_BUFFER_READ_OUT_OF_BOUNDS)
     {
      PrintFormat("  Caught expected error: %s", buffer.GetLastErrorString());
     }
   else
     {
      PrintFormat("  Failed to catch expected READ_OUT_OF_BOUNDS error. Got: %s", buffer.GetLastErrorString());
      errorHandled = false;
     }
   buffer.ClearLastError();

   // Test 2: Invalid bit count for WriteBits
   Print("Attempting to write with invalid bit count...");
   buffer.WriteBits(1, 0); // 0 bits
   if (buffer.GetLastError() == BIT_BUFFER_INVALID_BIT_COUNT)
     {
      PrintFormat("  Caught expected error: %s", buffer.GetLastErrorString());
     }
   else
     {
      PrintFormat("  Failed to catch expected INVALID_BIT_COUNT error. Got: %s", buffer.GetLastErrorString());
      errorHandled = false;
     }
   buffer.ClearLastError();

   // Test 3: Set read position out of bounds
   Print("Attempting to set read position out of bounds...");
   buffer.Clear();
   buffer.WriteInt(10);
   buffer.SetReadPosition(100); // Beyond total written bits
   if (buffer.GetLastError() == BIT_BUFFER_INVALID_READ_POSITION)
     {
      PrintFormat("  Caught expected error: %s", buffer.GetLastErrorString());
     }
   else
     {
      PrintFormat("  Failed to catch expected INVALID_READ_POSITION error. Got: %s", buffer.GetLastErrorString());
      errorHandled = false;
     }
   buffer.ClearLastError();

   // Test 4: String too large
   Print("Attempting to write string too large for USHORT_MAX...");
   string veryLongString = "";
   for (int i = 0; i < 70000; i++) // Create a string longer than USHORT_MAX (65535)
     {
      veryLongString += "a";
     }
   buffer.WriteString(veryLongString);
   if (buffer.GetLastError() == BIT_BUFFER_DATA_TOO_LARGE)
     {
      PrintFormat("  Caught expected error: %s", buffer.GetLastErrorString());
     }
   else
     {
      PrintFormat("  Failed to catch expected DATA_TOO_LARGE error. Got: %s", buffer.GetLastErrorString());
      errorHandled = false;
     }
   buffer.ClearLastError();

   if (errorHandled)
     {
      Print("Error handling test: PASSED");
     }
   else
     {
      Print("Error handling test: FAILED!");
     }
  }