module util;

import std.getopt : GetOptException;
import std.stdio  : File;

public @safe:

File stderr;

private {
	string[] mainArgs;

	version (OpenBSD) {
		immutable(char) *promises;
	}
}

/++
 + Common initialisation function shared between esv and esvsearch
 +/
void
sharedInit(string[] args)
{
	mainArgs = args;
	stderr = File("/dev/stderr", "w");

	version (OpenBSD) () @trusted {
		import core.sys.openbsd.unistd : pledge;
		import std.string : toStringz;

		promises = toStringz("stdio rpath wpath cpath inet dns tty proc exec prot_exec");
		pledge(promises, null);
	}();
}

void
enforceDie(A...)(bool cond, string fmt, A a)
{
	import std.format : format;

	if (!cond)
		die(format(fmt, a));
}

string
extractFlag(in GetOptException e)
{
	import std.regex : matchFirst;

	return e.msg.matchFirst("-.")[0];
}

string
parseBook(in string book)
{
	import std.string : tr;

	return book.tr("-_", "  ");
}

ushort
terminalColumns() @trusted
{
	import core.sys.posix.sys.ioctl;

	winsize w;

	ioctl(1, TIOCGWINSZ, &w);
	return w.ws_col > 72 ? 72 : w.ws_col;
}

void
warn(string mesg)
{
	import std.path : baseName;

	stderr.writeln(baseName(mainArgs[0]) ~ ": " ~ mesg);
}

void
die(string mesg) @trusted
{
	import core.runtime : Runtime;
	import core.stdc.stdlib : exit;

	warn(mesg);
	Runtime.terminate();
	exit(1);
}