//

// Created by Alan Freitas on 2020-07-06.

//

#ifndef MATPLOTPLUSPLUS_POPEN_H

#define MATPLOTPLUSPLUS_POPEN_H

#include <string>

#include <string_view>

#include <cstdio> // FILE

#ifdef _WIN32

#include <windows.h> // HANDLE

/// State of a child process pipe

class proc_pipe

{

protected:

proc_pipe() = default;

HANDLE hProcess = 0; ///< WIN32 process handle

HANDLE hThread = 0; ///< WIN32 thread handle

FILE *file_ = nullptr; ///< C file handle for I/O (not both)

};

#elif defined(__linux) || defined(__APPLE__)

#include <unistd.h> // pid_t

/// State of a child process pipe

class proc_pipe

{

protected:

proc_pipe() = default;

pid_t pid = 0; ///< POSIX process identifier

FILE *file_ = nullptr; ///< C file handle for input or output (not both)

};

#else

#error "proc_pipe is not implemented for this platform"

#endif // platform specific code

/// Common operations for a child process pipe

class common_pipe : public proc_pipe

{

public:

FILE *file() const { return file_; }

int close(int *exit_code = nullptr);

bool opened() const { return file_ != nullptr; }

const std::string& error() const { return error_; }

bool exceptions() const { return exceptions_; }

void exceptions(bool exc) { exceptions_ = exc; }

protected:

common_pipe() = default;

common_pipe(const common_pipe&) = delete;

common_pipe& operator=(const common_pipe&) = delete;

common_pipe(common_pipe&&) noexcept = default;

common_pipe& operator=(common_pipe&&) noexcept = default;

~common_pipe() noexcept {

if (opened())

close();

}

bool exceptions_ = false;

std::string error_{};

int report(int err, const std::string& what);

int open(const std::string &command, char mode);

};

/// Pipe to read from process output

class ipipe : public common_pipe

{

public:

ipipe();

int open(const std::string &cmd) { return common_pipe::open(cmd, 'r'); }

int read(std::string &data);

};

/// Pipe to write into process input

class opipe : public common_pipe

{

public:

opipe();

int open(const std::string &cmd) { return common_pipe::open(cmd, 'w'); }

int write(std::string_view data);

int flush(std::string_view data = {});

};

/// Runs the shell command, writes data to its input and waits for completion, returns errno if failed

int shell_write(const std::string &command, std::string_view data = {});

/// Runs the shell command, reads data from its output and waits for completion, returns errno if failed

int shell_read(const std::string &command, std::string& data);

#endif // MATPLOTPLUSPLUS_POPEN_H