/*
 * verror.js: richer JavaScript errors
 */

var mod_assert = require('assert');
var mod_util = require('util');

var mod_extsprintf = require('extsprintf');

/*
 * Public interface
 */
exports.VError = VError;
exports.WError = WError;
exports.MultiError = MultiError;

/*
 * Like JavaScript's built-in Error class, but supports a "cause" argument and a
 * printf-style message.  The cause argument can be null.
 */
function VError(options)
{
	var args, causedBy, ctor, tailmsg;

	if (options instanceof Error || typeof (options) === 'object') {
		args = Array.prototype.slice.call(arguments, 1);
	} else {
		args = Array.prototype.slice.call(arguments, 0);
		options = undefined;
	}

	tailmsg = args.length > 0 ?
	    mod_extsprintf.sprintf.apply(null, args) : '';
	this.jse_shortmsg = tailmsg;
	this.jse_summary = tailmsg;

	if (options) {
		causedBy = options.cause;

		if (!causedBy || !(options.cause instanceof Error))
			causedBy = options;

		if (causedBy && (causedBy instanceof Error)) {
			this.jse_cause = causedBy;
			this.jse_summary += ': ' + causedBy.message;
		}
	}

	this.message = this.jse_summary;
	Error.call(this, this.jse_summary);

	if (Error.captureStackTrace) {
		ctor = options ? options.constructorOpt : undefined;
		ctor = ctor || arguments.callee;
		Error.captureStackTrace(this, ctor);
	}
}

mod_util.inherits(VError, Error);
VError.prototype.name = 'VError';

VError.prototype.toString = function ve_toString()
{
	var str = (this.hasOwnProperty('name') && this.name ||
		this.constructor.name || this.constructor.prototype.name);
	if (this.message)
		str += ': ' + this.message;

	return (str);
};

VError.prototype.cause = function ve_cause()
{
	return (this.jse_cause);
};


/*
 * Represents a collection of errors for the purpose of consumers that generally
 * only deal with one error.  Callers can extract the individual errors
 * contained in this object, but may also just treat it as a normal single
 * error, in which case a summary message will be printed.
 */
function MultiError(errors)
{
	mod_assert.ok(errors.length > 0);
	this.ase_errors = errors;

	VError.call(this, errors[0], 'first of %d error%s',
	    errors.length, errors.length == 1 ? '' : 's');
}

mod_util.inherits(MultiError, VError);



/*
 * Like JavaScript's built-in Error class, but supports a "cause" argument which
 * is wrapped, not "folded in" as with VError.	Accepts a printf-style message.
 * The cause argument can be null.
 */
function WError(options)
{
	Error.call(this);

	var args, cause, ctor;
	if (typeof (options) === 'object') {
		args = Array.prototype.slice.call(arguments, 1);
	} else {
		args = Array.prototype.slice.call(arguments, 0);
		options = undefined;
	}

	if (args.length > 0) {
		this.message = mod_extsprintf.sprintf.apply(null, args);
	} else {
		this.message = '';
	}

	if (options) {
		if (options instanceof Error) {
			cause = options;
		} else {
			cause = options.cause;
			ctor = options.constructorOpt;
		}
	}

	Error.captureStackTrace(this, ctor || this.constructor);
	if (cause)
		this.cause(cause);

}

mod_util.inherits(WError, Error);
WError.prototype.name = 'WError';


WError.prototype.toString = function we_toString()
{
	var str = (this.hasOwnProperty('name') && this.name ||
		this.constructor.name || this.constructor.prototype.name);
	if (this.message)
		str += ': ' + this.message;
	if (this.we_cause && this.we_cause.message)
		str += '; caused by ' + this.we_cause.toString();

	return (str);
};

WError.prototype.cause = function we_cause(c)
{
	if (c instanceof Error)
		this.we_cause = c;

	return (this.we_cause);
};