//  Implementing URI-specific functions
//
//	See RFC 2386
//
// This is or was   http://www.w3.org/2005/10/ajaw/uri.js
// 2005 W3C open source licence
//
//
//  Take a URI given in relative or absolute form and a base
//  URI, and return an absolute URI
//
//  See also http://www.w3.org/2000/10/swap/uripath.py
//

if (typeof Util == "undefined") { Util = {}}
if (typeof Util.uri == "undefined") { Util.uri = {}}

Util.uri.join = function (given, base) {
    // if (typeof tabulator.log.debug != 'undefined') tabulator.log.debug("   URI given="+given+" base="+base)
    var baseHash = base.indexOf('#')
    if (baseHash > 0) base = base.slice(0, baseHash)
    if (given.length==0) return base // before chopping its filename off
    if (given.indexOf('#')==0) return base + given
    var colon = given.indexOf(':')
    if (colon >= 0) return given	// Absolute URI form overrides base URI
    var baseColon = base.indexOf(':')
    if (base == "") return given;
    if (baseColon < 0) {
        alert("Invalid base: "+ base + ' in join with ' +given);
        return given
    }
    var baseScheme = base.slice(0,baseColon+1)  // eg http:
    if (given.indexOf("//") == 0)     // Starts with //
	return baseScheme + given;
    if (base.indexOf('//', baseColon)==baseColon+1) {  // Any hostpart?
	    var baseSingle = base.indexOf("/", baseColon+3)
	if (baseSingle < 0) {
	    if (base.length-baseColon-3 > 0) {
		return base + "/" + given
	    } else {
		return baseScheme + given
	    }
	}
    } else {
	var baseSingle = base.indexOf("/", baseColon+1)
	if (baseSingle < 0) {
	    if (base.length-baseColon-1 > 0) {
		return base + "/" + given
	    } else {
		return baseScheme + given
	    }
	}
    }

    if (given.indexOf('/') == 0)	// starts with / but not //
	return base.slice(0, baseSingle) + given
    
    var path = base.slice(baseSingle)
    var lastSlash = path.lastIndexOf("/")
    if (lastSlash <0) return baseScheme + given
    if ((lastSlash >=0) && (lastSlash < (path.length-1)))
	path = path.slice(0, lastSlash+1) // Chop trailing filename from base
    
    path = path + given
    while (path.match(/[^\/]*\/\.\.\//)) // must apply to result of prev
	path = path.replace( /[^\/]*\/\.\.\//, '') // ECMAscript spec 7.8.5
    path = path.replace( /\.\//g, '') // spec vague on escaping
    path = path.replace( /\/\.$/, '/' )
    return base.slice(0, baseSingle) + path
}

var tIOService;
if (typeof( isExtension ) != "undefined" && isExtension) {
    tIOService = Components.classes['@mozilla.org/network/io-service;1']
                        .getService(Components.interfaces.nsIIOService);
    Util.uri.join2 = function (given, base){
       var baseURI = tIOService.newURI(base, null, null);
       return tIOService.newURI(baseURI.resolve(given), null, null).spec;
    }
} else
    Util.uri.join2 = Util.uri.join;
    
//  refTo:    Make a URI relative to a given base
//
// based on code in http://www.w3.org/2000/10/swap/uripath.py
//
Util.uri.commonHost = new RegExp("^[-_a-zA-Z0-9.]+:(//[^/]*)?/[^/]*$");
Util.uri.refTo = function(base, uri) {
    if (!base) return uri;
    if (base == uri) return "";
    var i =0; // How much are they identical?
    while (i<uri.length && i < base.length)
        if (uri[i] == base[i]) i++;
        else break;
    if (base.slice(0,i).match(Util.uri.commonHost)) {
        var k = uri.indexOf('//');
        if (k<0) k=-2; // no host
        var l = uri.indexOf('/', k+2);   // First *single* slash
        if (uri.slice(l+1, l+2) != '/' && base.slice(l+1, l+2) != '/'
                           && uri.slice(0,l) == base.slice(0,l)) // common path to single slash
            return uri.slice(l); // but no other common path segments
    }
     // fragment of base?
    if (uri.slice(i, i+1) == '#' && base.length == i) return uri.slice(i);
    while (i>0 && uri[i-1] != '/') i--;

    if (i<3) return uri; // No way
    if ((base.indexOf('//', i-2) > 0) || uri.indexOf('//', i-2) > 0)
        return uri; // an unshared '//'
    if (base.indexOf(':', i) >0) return uri; // unshared ':'
    var n = 0;
    for (var j=i; j<base.length; j++) if (base[j]=='/') n++;
    if (n==0 && i < uri.length && uri[i] =='#') return './' + uri.slice(i);
    if (n==0 && i == uri.length) return './';
    var str = '';
    for (var j=0; j<n; j++) str+= '../';
    return str + uri.slice(i);
}


/** returns URI without the frag **/
Util.uri.docpart = function (uri) {
    var i = uri.indexOf("#")
    if (i < 0) return uri
    return uri.slice(0,i)
} 

/** return the protocol of a uri **/
/** return null if there isn't one **/
Util.uri.protocol = function (uri) {
    var index = uri.indexOf(':');
    if (index >= 0)
        return uri.slice(0, index);
    else
        return null;
} //protocol

URIjoin = Util.uri.join
uri_docpart = Util.uri.docpart
uri_protocol = Util.uri.protocol


//ends