CLK/Outputs/Log.hpp

//
//  Log.hpp
//  Clock Signal
//
//  Created by Thomas Harte on 18/06/2018.
//  Copyright © 2018 Thomas Harte. All rights reserved.
//

#pragma once

#include <cstdio>
#include <cstdarg>

namespace Log {
// TODO: if adopting C++20, std::format would be a better model to apply below.
// But I prefer C files to C++ streams, so here it is for now.

enum class Source {
	ADBDevice,
	ADBGLU,
	Amiga,
	AmigaDisk,
	AmigaCopper,
	AmigaChipset,
	AmigaBlitter,
	AppleIISCSICard,
	Archimedes,
	ARMIOC,
	ARMMEMC,
	ARMVIDC,
	AtariST,
	AtariSTDMAController,
	CommodoreStaticAnalyser,
	CMOSRTC,
	DirectAccessDevice,
	Enterprise,
	i8272,
	I2C,
	IntelligentKeyboard,	// Could probably be subsumed into 'Keyboard'?
	IWM,
	Keyboard,
	M50740,
	Macintosh,
	MasterSystem,
	MultiMachine,
	MFP68901,
	MOS6526,
	MSX,
	NCR5380,
	OpenGL,
	PCMTrack,
	SCC,
	SCSI,
	SZX,
	TapeUEF,
	TMS9918,
	TZX,
	Vic20,
	WDFDC,
};

constexpr bool is_enabled(const Source source) {
#ifdef NDEBUG
	return false;
#endif

	// Allow for compile-time source-level enabling and disabling of different sources.
	switch(source) {
		default: return true;

		// The following are all things I'm not actively working on.
		case Source::AmigaBlitter:
		case Source::AmigaChipset:
		case Source::AmigaCopper:
		case Source::AmigaDisk:
		case Source::DirectAccessDevice:
		case Source::IWM:
		case Source::MFP68901:
		case Source::NCR5380:
		case Source::SCC:
		case Source::SCSI:
		case Source::I2C:
		case Source::Keyboard:
			return false;
	}
}

constexpr const char *prefix(Source source) {
	switch(source) {
		default: return nullptr;

		case Source::ADBDevice:					return "ADB device";
		case Source::ADBGLU:					return "ADB GLU";
		case Source::AmigaBlitter:				return "Blitter";
		case Source::AmigaChipset:				return "Chipset";
		case Source::AmigaCopper:				return "Copper";
		case Source::AmigaDisk:					return "Disk";
		case Source::AppleIISCSICard:			return "SCSI card";
		case Source::Archimedes:				return "Archimedes";
		case Source::ARMIOC:					return "IOC";
		case Source::ARMMEMC:					return "MEMC";
		case Source::ARMVIDC:					return "VIDC";
		case Source::AtariST:					return "AtariST";
		case Source::AtariSTDMAController:		return "DMA";
		case Source::CommodoreStaticAnalyser:	return "Commodore Static Analyser";
		case Source::CMOSRTC:					return "CMOSRTC";
		case Source::DirectAccessDevice:		return "Direct Access Device";
		case Source::Enterprise:				return "Enterprise";
		case Source::i8272:						return "i8272";
		case Source::I2C:						return "I2C";
		case Source::IntelligentKeyboard:		return "IKYB";
		case Source::IWM:						return "IWM";
		case Source::Keyboard:					return "Keyboard";
		case Source::M50740:					return "M50740";
		case Source::Macintosh:					return "Macintosh";
		case Source::MasterSystem:				return "SMS";
		case Source::MOS6526:					return "MOS6526";
		case Source::MFP68901:					return "MFP68901";
		case Source::MultiMachine:				return "Multi-machine";
		case Source::MSX:						return "MSX";
		case Source::NCR5380:					return "5380";
		case Source::OpenGL:					return "OpenGL";
		case Source::PCMTrack:					return "PCM Track";
		case Source::SCSI:						return "SCSI";
		case Source::SCC:						return "SCC";
		case Source::SZX:						return "SZX";
		case Source::TapeUEF:					return "UEF";
		case Source::TZX:						return "TZX";
		case Source::Vic20:						return "Vic20";
		case Source::WDFDC:						return "WD FDC";
	}
}

template <Source source>
class Logger {
public:
	static constexpr bool enabled = is_enabled(source);

	struct LogLine {
		public:
			LogLine(FILE *const stream) : stream_(stream) {
				if constexpr (!enabled) return;

				const auto source_prefix = prefix(source);
				if(source_prefix) {
					fprintf(stream_, "[%s] ", source_prefix);
				}
			}

			~LogLine() {
				if constexpr (!enabled) return;
				fprintf(stream_, "\n");
			}

			void append(const char *const format, ...) {
				if constexpr (!enabled) return;
				va_list args;
				va_start(args, format);
				vfprintf(stream_, format, args);
				va_end(args);
			}

		private:
			FILE *stream_;
	};

	LogLine info()	{	return LogLine(stdout);		}
	LogLine error()	{	return LogLine(stderr);		}
};

}