#pragma once

#include <filesystem>
#include <optional>
#include <string>
#include <utility>
#include <vector>

/// Running other programs. Arguments are passed as a vector, never through a shell, so nothing
/// needs quoting by the caller.
namespace breeze::proc
{

	struct Options
	{
		/// Working directory; empty keeps the current one.
		std::filesystem::path cwd;
		/// Variables set (or replaced) for the child only.
		std::vector<std::pair<std::string, std::string>> env;
		/// Collect the child's standard output into Result::output instead of showing it.
		bool capture = false;
		/// With capture, standard error is collected too (merged into the same string).
		bool mergeStderr = false;
		/// Throw the child's output away.
		bool silent = false;
	};

	struct Result
	{
		int exitCode = 0;
		std::string output;
	};

	/// Runs argv[0] with the rest as arguments (looked up on PATH when it has no directory part)
	/// and waits. A program that can't be started is exit code 127. Throws Error only for failures
	/// of this function itself (nothing to run, the system refusing to create a process).
	Result run(const std::vector<std::string>& argv, const Options& options = {});

	/// Runs a .bat/.cmd script on Windows through cmd.exe, or the script itself elsewhere.
	Result runScript(const std::filesystem::path& script, const std::vector<std::string>& args,
					 const Options& options = {});

	/// Replaces this process with argv (POSIX), or runs it and exits with its status (Windows).
	/// Does not return. Throws Error when it can't be started.
	[[noreturn]] void execReplace(const std::vector<std::string>& argv);

	/// The first match for `program` on PATH, if any.
	std::optional<std::filesystem::path> findInPath(const std::string& program);

	/// Sets an environment variable for this process and the programs it starts from now on.
	void setEnvironment(const std::string& name, const std::string& value);

	bool stdinIsTerminal();
	bool stdoutIsTerminal();

}