// procfile.h :
//

#if !defined(AGD_PROCFILE_H__2D6A6629_BE8B_45D1_949D_3A434336E4DF__INCLUDED_)
#define AGD_PROCFILE_H__2D6A6629_BE8B_45D1_949D_3A434336E4DF__INCLUDED_

#include <unistd.h>
#include <string>
#include <vector>
#include <map>

#ifdef __cplusplus

// https://man7.org/linux/man-pages/man5/proc.5.html

/////////////////////////////////////////////////////////////////////////////
// procfile.h - Declarations:

#define _DEFAULT_REGEX_EXPRESSION			"[^\\s]+"

class CProcFile
{
public:
	typedef std::map<std::string, std::vector<std::string>> KeyMultiValueMap;

public:
	CProcFile(void);
	virtual ~CProcFile(void);

	virtual bool ReadFile(const char *pszFilePath);
	
	const std::string & GetValue(const std::string &sKey, int index) {
		if(index >= 0)
		{
			const std::vector<std::string> &m = m_vMap[sKey];
			if(m.size() > (size_t)index)
				return m[index];
		}
		return m_sEmpty;
	}

	const std::vector<std::string> & operator[] (const std::string &sKey) {
		return m_vMap[sKey];
	}

public:
	static std::string FormatString(const char *fmt, ...);
	static int SplitLine(const std::string &str, std::vector<std::string> &vec, const char *rxe = _DEFAULT_REGEX_EXPRESSION);
	static long long StrToIntegral(const std::string &str, long long nDefault = 0, int nBase = 10);
	static double StrToReal(const std::string &str, double fDefault = 0.0);

protected:
	long m_nClkPerSec;

private:
	static const std::string m_sEmpty;
	KeyMultiValueMap m_vMap;
};

/////////////////////////////////////////////////////////////////////////////

class CProcStatFile : public CProcFile
{
public:
	virtual bool ReadFile(void) {
		return CProcFile::ReadFile("/proc/stat");}

	double utime(void) {
		double val = StrToReal(GetValue("cpu", 1));
		return (val / (double)m_nClkPerSec);
	}

	double stime(void) {
		double val = StrToReal(GetValue("cpu", 3));
		return (val / (double)m_nClkPerSec);
	}
};

/////////////////////////////////////////////////////////////////////////////

class CProcPidStatFile : public CProcStatFile
{
public:
	virtual bool ReadFile(pid_t pid) {
		m_sPid = FormatString("%d", pid);
		std::string s = FormatString("/proc/%d/stat", pid);
		return CProcFile::ReadFile(s.c_str());
	}

	virtual bool ReadFile(const char *pszProcName);

	const std::string & operator[] (int index) {
		return GetValue(m_sPid, index);
	}
	
	pid_t pid(void) {
		return (pid_t)StrToIntegral((*this)[0]);
	}
	
	double utime(void) {
		double val = StrToReal((*this)[13]);
		return (val / (double)m_nClkPerSec);
	}
	
	double stime(void) {
		double val = StrToReal((*this)[14]);
		return (val / (double)m_nClkPerSec);
	}

	unsigned long long starttime(void) {
		double val = StrToReal((*this)[21]);
		return (val / (double)m_nClkPerSec);
	}

private:
	std::string m_sPid;
};

/////////////////////////////////////////////////////////////////////////////
#endif	//	__cplusplus
#endif	//	!defined(AGD_PROCFILE_H__2D6A6629_BE8B_45D1_949D_3A434336E4DF__INCLUDED_)