/*
 * =====================================================================================
 *
 *       Filename:  box.cpp
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年04月13日 15时21分44秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), lichao@aiotlink.com
 *   Organization:  
 *
 * =====================================================================================
 */
#include "box.h"
#include <boost/filesystem/path.hpp>
#include <map>
#include <unordered_map>

namespace fs = boost::filesystem;

namespace
{

class Box
{
public:
	bool Install(const std::string &name, MainFunc const &func, const std::string &desc)
	{
		return functions_.emplace(name, FuncInfo{name, func, desc}).second;
	}
	bool Find(const std::string &name, MainFunc &func)
	{
		auto pos = functions_.find(name);
		if (pos != functions_.end()) {
			func = pos->second.func_;
			return true;
		}
		return false;
	}
	void Apply(std::function<void(const std::string &id, const std::string &desc)> const &f) const
	{
		for (auto &kv : functions_) {
			f(kv.second.id_, kv.second.desc_);
		}
	}

private:
	struct FuncInfo {
		std::string id_;
		MainFunc func_;
		std::string desc_;
	};
	std::unordered_map<std::string, FuncInfo> functions_;
};

Box &TheBox()
{
	static Box box;
	return box;
}

} // namespace

bool BoxInstall(const std::string &name, MainFunc const &func, const std::string &desc)
{
	return TheBox().Install(name, func, desc);
}

bool BoxFind(const std::string &name, MainFunc &func)
{
	return TheBox().Find(name, func);
}

const std::string kOrigName("bhshmqbox");

inline void PrintLn() { putchar('\n'); }

template <class... Params>
void PrintLn(const char *fmt, Params &&...t)
{
	printf(fmt, std::forward<decltype(t)>(t)...);
	PrintLn();
}

void Help()
{
	PrintLn("%s : bhome shared memory message queue box application.", kOrigName.c_str());
	PrintLn("%s", "usage:");
	PrintLn("\t1) %s [function [options]...]", kOrigName.c_str());
	PrintLn("\t2) rename or link %s to a function name then run it directly.", kOrigName.c_str());
	PrintLn();
	PrintLn("%s", "supported functions:");
	std::map<std::string, std::string> funcs;
	auto getInfo = [&](const std::string &name, const std::string &desc) {
		funcs[name] = desc;
	};
	TheBox().Apply(getInfo);
	auto cmp_name_len = [](auto &a, auto &b) { return a.first.size() < b.first.size(); };
	int max_len = std::max_element(funcs.begin(), funcs.end(), cmp_name_len)->first.size();
	for (auto &kv : funcs) {
		int npad = max_len - kv.first.size();
		PrintLn();
		PrintLn("\t%s%s : %s", kv.first.c_str(), std::string(npad, ' ').c_str(), kv.second.c_str());
	}
	PrintLn();
}

int BoxMain(int argc, const char *argv[])
{
	fs::path exe(argv[0]);
	auto name = exe.filename().string();

	MainFunc func;
	if (BoxFind(name, func)) {
		return func(argc, argv);
	} else {
		PrintLn("%s : function not found!", name.c_str());
		// Help();
	}
	return 0;
}

int main(int argc, const char *argv[])
{
	BoxInstall(
	    "help", [](int, const char **) { Help(); return 0; }, "show this help message.");

	fs::path exe(argv[0]);
	auto name = exe.filename().string();
	// PrintLn("name: %s", name.c_str());

	if (name == kOrigName) {
		if (argc > 1) {
			argc--;
			argv++;
		} else {
			Help();
			return 0;
		}
	}
	return BoxMain(argc, argv);
}