#include "serialize/gs_byte_buffer.h"
#include "common/gs_util.h"

void gs_byte_buffer_init( gs_byte_buffer* buffer )
{
	buffer->buffer 			= gs_malloc( gs_byte_buffer_default_capacity );
	buffer->capacity 		= gs_byte_buffer_default_capacity;
	buffer->size 			= 0;
	buffer->position 		= 0;
}

gs_byte_buffer gs_byte_buffer_new()
{
	gs_byte_buffer buffer;
	gs_byte_buffer_init( &buffer );
	return buffer;
}

void gs_byte_buffer_free( gs_byte_buffer* buffer )
{
	if ( buffer && buffer->buffer ) {
		gs_free( buffer->buffer );
	}
}

void gs_byte_buffer_clear( gs_byte_buffer* buffer )
{
	buffer->size = 0;
	buffer->position = 0;	
}

void gs_byte_buffer_resize( gs_byte_buffer* buffer, usize sz )
{
	u8* data = gs_realloc( buffer->buffer, sz );

	if ( data == NULL ) {
		return;
	}

	buffer->buffer = data;	
	buffer->capacity = sz;
}

void gs_byte_buffer_seek_to_beg( gs_byte_buffer* buffer )
{
	buffer->position = 0;
}

void gs_byte_buffer_seek_to_end( gs_byte_buffer* buffer )
{
	buffer->position = buffer->size;
}

void gs_byte_buffer_advance_position( gs_byte_buffer* buffer, usize sz )
{
	buffer->position += sz;	
}

void gs_byte_buffer_bulk_write( gs_byte_buffer* buffer, void* src, u32 size )
{
	// Check for necessary resize
	u32 total_write_size = buffer->position + size;
	if ( total_write_size >= buffer->capacity )
	{
		usize capacity = buffer->capacity * 2;
		while( capacity <= total_write_size )
		{
			capacity *= 2;
		}

		gs_byte_buffer_resize( buffer, capacity );
	}

	// memcpy data
	memcpy( ( buffer->buffer + buffer->position ), src, size );

	buffer->size += size;
	buffer->position += size;
}

void gs_byte_buffer_bulk_read( gs_byte_buffer* buffer, void* dst, u32 size )
{
	memcpy( dst, ( buffer->buffer + buffer->position ), size );
	buffer->position += size;
}

void gs_byte_buffer_write_str( gs_byte_buffer* buffer, const char* str )
{
	// Write size of string
	u32 str_len = gs_string_length( str );
	gs_byte_buffer_write( buffer, u16, str_len );

	usize i; for ( i = 0; i < str_len; ++i )
	{
		gs_byte_buffer_write( buffer, u8, str[ i ] );
	}
}

void gs_byte_buffer_read_str( gs_byte_buffer* buffer, char* str )
{
	// Read in size of string from buffer
	u16 sz = gs_byte_buffer_read( buffer, u16 );

	u32 i;
	for ( i = 0; i < sz; ++i )
	{
		str[ i ] = gs_byte_buffer_read( buffer, u8 );		
	}
	str[ i ] = '\0';
}

gs_result 
gs_byte_buffer_write_to_file
( 
	gs_byte_buffer* buffer, 
	const char* output_path 
)
{
	FILE* fp = fopen( output_path, "wb" );
	if ( fp ) 
	{
		s32 ret = fwrite( buffer->buffer, sizeof( u8 ), buffer->size, fp );
		if ( ret == buffer->size )
		{
			return gs_result_success;
		}
	}
	return gs_result_failure;
}

gs_result 
gs_byte_buffer_read_from_file
( 
	gs_byte_buffer* buffer, 
	const char* file_path 
)
{
	buffer->buffer = ( u8* )gs_read_file_contents_into_string_null_term( file_path, "rb", ( usize* )&buffer->size );
	if ( !buffer->buffer ) {
		gs_assert( false );	
		return gs_result_failure;
	}
	buffer->position = 0;
	buffer->capacity = buffer->size;
	return gs_result_success;
}

// "Generic" read function
#define __gs_byte_buffer_read_func( T )\
	__gs_byte_buffer_func( T )\
	{\
		gs_byte_buffer* _buffer = bb;\
		usize sz = sizeof( T );\
		T val = *( T* )( _buffer->buffer + _buffer->position );\
		_buffer->position += sz;\
		return val;\
	}

__gs_byte_buffer_read_func( usize );
__gs_byte_buffer_read_func( s8 );
__gs_byte_buffer_read_func( u8 );
__gs_byte_buffer_read_func( u16 );
__gs_byte_buffer_read_func( s16 );
__gs_byte_buffer_read_func( s32 );
__gs_byte_buffer_read_func( u32 );
__gs_byte_buffer_read_func( b32 );
__gs_byte_buffer_read_func( s64 );
__gs_byte_buffer_read_func( u64 );
__gs_byte_buffer_read_func( f32 );
__gs_byte_buffer_read_func( f64 );
__gs_byte_buffer_read_func( gs_vec2 );
__gs_byte_buffer_read_func( gs_vec3 );
__gs_byte_buffer_read_func( gs_vec4 );
__gs_byte_buffer_read_func( gs_quat );
__gs_byte_buffer_read_func( gs_mat4 );
__gs_byte_buffer_read_func( gs_vqs );