spdlog/include/spdlog/sinks/wincolor_sink.h

//
// Copyright(c) 2016 spdlog
// Distributed under the MIT License (http://opensource.org/licenses/MIT)
//

#pragma once

#include "sink.h"
#include "../common.h"
#include "../details/null_mutex.h"
#include "../details/traits.h"


#include <mutex>
#include <memory>
#include <string>
#include <unordered_map>
#include <wincon.h>

namespace spdlog {
	namespace sinks {
		/*
		 * Windows color console sink. Uses WriteConsoleA to write to the console with colors
		 */
		template<class HandleTrait, class ConsoleMutexTrait>
		class wincolor_sink : public sink
		{
		public:

			const WORD BOLD = FOREGROUND_INTENSITY;
			const WORD RED = FOREGROUND_RED;
			const WORD GREEN = FOREGROUND_GREEN;
			const WORD CYAN = FOREGROUND_GREEN | FOREGROUND_BLUE;
			const WORD WHITE = FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE;
			const WORD YELLOW = FOREGROUND_RED | FOREGROUND_GREEN;

			wincolor_sink()
				: out_handle_(HandleTrait::handle()),
				_mutex(ConsoleMutexTrait::console_mutex())
			{
				colors_[level::trace] = WHITE;
				colors_[level::debug] = CYAN;
				colors_[level::info] = GREEN;
				colors_[level::warn] = YELLOW | BOLD;
				colors_[level::err] = RED | BOLD;                         // red bold
				colors_[level::critical] = BACKGROUND_RED | WHITE | BOLD; // white bold on red background
				colors_[level::off] = 0;
			}


			~wincolor_sink() override
			{
				this->flush();
			}

			wincolor_sink(const wincolor_sink &other) = delete;
			wincolor_sink &operator=(const wincolor_sink &other) = delete;

			// change the color for the given level
			void set_color(level::level_enum level, WORD color)
			{
				std::lock_guard<mutex_t> lock(_mutex);
				colors_[level] = color;
			}

			void log(const details::log_msg &msg) SPDLOG_FINAL override
			{
				std::lock_guard<mutex_t> lock(_mutex);

				if (msg.color_range_end > msg.color_range_start)
				{
					// before color range
					_print_range(msg, 0, msg.color_range_start);

					// in color range
					auto orig_attribs = set_console_attribs(colors_[msg.level]);
					_print_range(msg, msg.color_range_start, msg.color_range_end);
					::SetConsoleTextAttribute(out_handle_, orig_attribs); // reset to orig colors
																		  // after color range
					_print_range(msg, msg.color_range_end, msg.formatted.size());
				}
				else // print without colors if color range is invalid
				{
					_print_range(msg, 0, msg.formatted.size());
				}
			}

			void flush() SPDLOG_FINAL override
			{
				// windows console always flushed?
			}

		private:
			using mutex_t = typename ConsoleMutexTrait::mutex_t;
			// set color and return the orig console attributes (for resetting later)
			WORD set_console_attribs(WORD attribs)
			{
				CONSOLE_SCREEN_BUFFER_INFO orig_buffer_info;
				::GetConsoleScreenBufferInfo(out_handle_, &orig_buffer_info);
				WORD back_color = orig_buffer_info.wAttributes;
				// retrieve the current background color
				back_color &= static_cast<WORD>(~(FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_INTENSITY));
				// keep the background color unchanged
				::SetConsoleTextAttribute(out_handle_, attribs | back_color);
				return orig_buffer_info.wAttributes; // return orig attribs
			}

			// print a range of formatted message to console
			void _print_range(const details::log_msg &msg, size_t start, size_t end)
			{
				auto size = static_cast<DWORD>(end - start);
				::WriteConsoleA(out_handle_, msg.formatted.data() + start, size, nullptr, nullptr);
			}

			HANDLE out_handle_;
			mutex_t &_mutex;
			std::unordered_map<level::level_enum, WORD, level::level_hasher> colors_;
		};


		using wincolor_stdout_sink_mt = wincolor_sink<details::console_stdout_trait, details::console_mutex_trait>;
		using wincolor_stdout_sink_st = wincolor_sink<details::console_stdout_trait, details::console_null_mutex_trait>;

		using wincolor_stderr_sink_mt = wincolor_sink<details::console_stderr_trait, details::console_mutex_trait>;
		using wincolor_stderr_sink_st = wincolor_sink<details::console_stderr_trait, details::console_null_mutex_trait>;

	} // namespace sinks
} // namespace spdlog