#include "Log.h"

/*
 * class Log
 */

// static members
std::vector<Log::Output*> Log::outputs;

Log::LeveledSink Log::fatal(Log::Level::FATAL);
Log::LeveledSink Log::error(Log::Level::ERROR);
Log::LeveledSink Log::warn(Log::Level::WARN);
Log::LeveledSink Log::note(Log::Level::NOTE);
Log::LeveledSink Log::info(Log::Level::INFO);
Log::LeveledSink Log::debug(Log::Level::DEBUG);
Log::LeveledSink Log::trace(Log::Level::TRACE);

void Log::init() {
	// add default console logger
	if (outputs.empty())
		outputs.push_back(new Log::ConsoleOutput());
}

void Log::stop() {
	for (auto output : outputs)
		delete output;
	outputs.clear();
}

void Log::addLogfile(const std::string& filename, Level max) {
	outputs.push_back(new Log::FileOutput(filename, max));
}

void Log::addLogfile(const std::string& filename, Level min, Level max) {
	outputs.push_back(new Log::FileOutput(filename, min, max));
}

void Log::setConsoleLogLevel(Level lvl) {
	outputs.at(0)->setLogLevel(lvl); // has to exist
}

void Log::setColoredOutput(bool enabled) {
	((Log::ConsoleOutput*) outputs.at(0))->setColoredOutput(enabled); // has to exist
}

void Log::log(Level lvl, std::stringbuf* strb) {
	for (Output* out : outputs) {
		out->log(lvl, strb);
		// reset stringbuffer read pointer to the beginning
		strb->pubseekpos(0);
	}
}

/*
 * abstract class Output
 *   default implementations
 */

Log::Output::Output() {}
Log::Output::Output(Log::Level lvl_max) : lvl_max(lvl_max) {}
Log::Output::~Output() {}

void Log::Output::log(Log::Level lvl, std::stringbuf* sbuf) {
	std::ostream* os = getOs(lvl);
	if (os) {
		printLogHeader(os, lvl);
		*os << sbuf << std::endl;
	}
}

void Log::Output::setLogLevel(Log::Level lvl) {
	lvl_max = lvl;
}

void Log::Output::printLogHeader(std::ostream* os, Level lvl) {
	static const char* LevelTag[] = {"",         "[FATAL] ", "[ERROR] ", "[WARN ] ",
	                                 "[NOTE ] ", "[INFO ] ", "[DEBUG] ", "[TRACE] "};

	// get current date/time
	auto now          = std::chrono::system_clock::now();
	std::time_t now_c = std::chrono::system_clock::to_time_t(now);

	*os << "[" << std::put_time(std::localtime(&now_c), "%F %T") << "]" << LevelTag[lvl];
}

/*
 * class ConsoleOutput
 */

Log::ConsoleOutput::ConsoleOutput() : Output() {}

bool Log::ConsoleOutput::setColoredOutput(bool enabled) {
	// TODO: check the terminals compatibility for colors
	coloredOutput = enabled;
	return true;
}

void Log::ConsoleOutput::log(Log::Level lvl, std::stringbuf* sbuf) {
	static const char* esc_seq_start = "\033[";
	static const char* esc_seq_reset = "\033[0m";
	//                                  OFF    FATAL    ERROR  WARN   NOTE   INFO   DEBUG TRACE
	static const char* color_codes[] = {"", "1;31;40m", "31m", "33m", "96m", "32m", "0m", "0m"};

	std::ostream* os = getOs(lvl);

	if (os) {
		// print colors if enabled
		if (coloredOutput)
			*os << esc_seq_start << color_codes[lvl];

		Output::printLogHeader(os, lvl);
		*os << sbuf;

		// reset color at end of the line
		if (coloredOutput)
			*os << esc_seq_reset;

		*os << std::endl;
	}
}

std::ostream* Log::ConsoleOutput::getOs(Log::Level lvl) {
	// out of scope?
	if (!lvl || lvl > lvl_max)
		return nullptr;

	// stderr for FATAL, ERROR, WARN
	if (lvl <= Log::Level::WARN)
		return osErr;
	else
		return osStd;
}

/*
 * class FileOutput
 *   logging to file
 */

Log::FileOutput::FileOutput(const std::string& filename, Log::Level lvl_max)
    : Output(lvl_max), filename(filename), ofs(filename, std::ofstream::out | std::ofstream::app) {}

Log::FileOutput::FileOutput(const std::string& filename, Log::Level lvl_min, Log::Level lvl_max)
    : Output(lvl_max), filename(filename), ofs(filename, std::ofstream::out | std::ofstream::app), lvl_min(lvl_min) {}

std::ostream* Log::FileOutput::getOs(Log::Level lvl) {
	if (lvl_min <= lvl && lvl <= lvl_max)
		return &ofs;
	return nullptr;
}

Log::LeveledSink::LeveledSink(Log::Level level) : level(level) {}