Ticket #748: arguments_example.d

/*******************************************************************************
        Illustrates use of the Arguments class.
*******************************************************************************/

import tetra.app.Arguments;
import tango.io.Stdout;
import tango.io.FileConduit;
import tango.text.stream.LineIterator;

void _usage()
{
    Stdout("Usage: [OPTIONS]... FILES...").newline;
    Stdout("This is a program that does something.").newline;
    Stdout.newline;
    Stdout("OPTIONS: ").newline;
    Stdout("Output this help message:          -?,      --help").newline;
    Stdout("Do cool things to your files:      -c, -C,  --cool").newline;
    Stdout("Use filename as response file:     -r, -R,  --response").newline;
}

void main(char[][] cmdlArgs)
{
    char[][] implicitArguments = ["files"];
    
    char[][][] argumentAliases;
    argumentAliases ~= ["help",          "?"];
    argumentAliases ~= ["cool",     "C", "c"];
    argumentAliases ~= ["response", "R", "r"];
    
    auto args = new Arguments(cmdlArgs, implicitArguments, argumentAliases);

    bool _fileExistsValidation(char[] arg)
    {
        bool rtn;
        FilePath argFile = new FilePath(arg);
        rtn = argFile.exists;
        if (!rtn)
            Stdout.format("Specified path does not exist: {}", arg).newline;
        return rtn;
    }
    bool _singleFileValidation(char[][] args, inout char[] invalidArg)
    {
        if (args.length > 1)
        {
            Stdout("Cannot specify multiple paths for argument.").newline;
            invalidArg = args[1];
        }
        else
            return true;
        return false;
    }
    args.addValidation("response", &_fileExistsValidation);
    args.addValidation("response", &_singleFileValidation);
    args.addValidation("files", true, true);

    bool argsValidated = true;
    try
        args.validate;
    catch (ArgumentException ex)
    {
        if (ex.reason == ArgumentException.ExceptionReason.MISSING_ARGUMENT)
            Stdout.format("Missing Argument: {} ({})", ex.name, ex.msg).newline;
        else if (ex.reason == ArgumentException.ExceptionReason.MISSING_PARAMETER)
            Stdout.format("Missing Parameter to Argument: {} ({})", ex.name, ex.msg).newline;
        else if (ex.reason == ArgumentException.ExceptionReason.INVALID_PARAMETER)
            Stdout.format("Invalid Parameter: {} ({})", ex.name, ex.msg).newline;
        Stdout.newline;
        argsValidated = false;
    }

    if ((!argsValidated) || ("help" in args))
        _usage();
    else
    {// ready to run
        if ("response" in args)
        {
            auto file = new FileConduit(args["response"]);
            auto lines = new LineIterator!(char)(file);
            char[][] arguments;
            foreach (line; lines)
                arguments ~= line;
            args.parse(arguments, implicitArguments, argumentAliases);
        }
        if ("cool" in args)
        {
            Stdout ("Listing the files to be actioned in a cool way.").newline;
            foreach (char[] file; args.getArray("files"))
                Stdout.format("{}", file).newline;
            Stdout ("Cool and secret action performed.").newline;
        }
        if ("x" in args)
            Stdout.format("User set the X factor to '{}'", args["x"]).newline;
    }
}