// CommandOutput.h

// Declares various classes that process command output





/** Interface for a callback that receives command output
The Out() function is called for any output the command has produced.
Descendants override that function to provide specific processing of the output.
*/
class cCommandOutputCallback
{
public:
	virtual ~cCommandOutputCallback() {}  // Force a virtual destructor in subclasses
	
	/// Syntax sugar function, calls Out() with Printf()-ed parameters; appends a newline"
	void Out(const char * a_Fmt, ...) FORMATSTRING(2, 3);
	
	/// Called when the command wants to output anything; may be called multiple times
	virtual void Out(const AString & a_Text) = 0;
	
	/// Called when the command processing has been finished
	virtual void Finished(void) {}
} ;





/// Class that discards all command output
class cNullCommandOutputCallback :
	public cCommandOutputCallback
{
	// cCommandOutputCallback overrides:
	virtual void Out(const AString & a_Text) override
	{
		// Do nothing
		UNUSED(a_Text);
	}
} ;






/// Sends all command output to a log, line by line, when the command finishes processing
class cLogCommandOutputCallback :
	public cCommandOutputCallback
{
public:
	// cCommandOutputCallback overrides:
	virtual void Out(const AString & a_Text) override;
	virtual void Finished(void) override;
	
protected:
	/// Output is stored here until the command finishes processing
	AString m_Buffer;
} ;





/// Sends all command output to a log, line by line; deletes self when command finishes processing
class cLogCommandDeleteSelfOutputCallback :
	public cLogCommandOutputCallback
{
	typedef cLogCommandOutputCallback super;
	
	virtual void Finished(void) override
	{
		super::Finished();
		delete this;
	}
} ;