/**
 * Some parser functions, and quite a bunch of stubs of parser functions.
 * There are still quite a few missing, see
 * http://www.mediawiki.org/wiki/Help:Magic_words and
 * http://www.mediawiki.org/wiki/Help:Extension:ParserFunctions.
 * Instantiated and called by the TemplateHandler extension. Any pf_<prefix>
 * matching a lower-cased template name prefix up to the first colon will
 * override that template.
 *
 * TODO: Implement these more thoroughly, and test against
 * extensions/ParserFunction/
 *     convertTests.txt
 *     exprTests.txt
 *     funcsParserTests.txt
 *     stringFunctionTests.txt
 *
 * @author Gabriel Wicke <gwicke@wikimedia.org>
 */


function ParserFunctions ( manager ) {
	this.manager = manager;
}

ParserFunctions.prototype['pf_#if'] = function ( target, argList, argDict ) {
	if ( target.trim() !== '' ) {
		this.manager.env.dp('#if, first branch', target.trim(), argDict[1] );
		return argDict[1] || [];
	} else {
		this.manager.env.dp('#if, second branch', target.trim(), argDict[2] );
		return argDict[2] || [];
	}
};

ParserFunctions.prototype._switchLookupFallback = function ( kvs, key ) {
	if ( ! kvs ) {
		return null;
	}
	var kv;
	for ( var i = 0, l = kvs.length; i < l; i++ ) {
		kv = kvs[i];
		// XXX: tokensToString actually strips too much here! Anything
		// non-stringish should not match at all.
		if ( this.manager.env.tokensToString( kv.v ) === key ) {
			// found. now look for the next entry with a non-empty key.
			for ( var j = i; j < l; j++) {
				kv = kvs[j];
				// XXX: make sure the key is always one of these!
				if ( kv.k !== '' && kv.k !== [] ) {
					return kv;
				}
			}
			// no fall-through found, return.
			return null;
		}
	}
	// value not found!
	return null;
};

// TODO: Implement 
// http://www.mediawiki.org/wiki/Help:Extension:ParserFunctions#Grouping_results
ParserFunctions.prototype['pf_#switch'] = function ( target, argList, argDict, unnamedArgs ) {
	this.manager.env.dp( 'switch enter: ' + target.trim() +
			' looking in ', argDict );
	target = target.trim();
	if ( argDict[target] !== undefined ) {
		this.manager.env.dp( 'switch found: ' + target +
				' res=', argDict[target] );
		return argDict[target];
	} else {
		var fallThrough = this._switchLookupFallback( unnamedArgs, target );
		//console.warn( 'fallThrough: ' + JSON.stringify( [ unnamedArgs, fallThrough ] ) );
		if ( fallThrough !== null ) {
			return fallThrough.v;
		} else if ( '#default' in argDict ) {
			return argDict['#default'];
		} else { 
			var lastKV = argList[argList.length - 1];
			if ( lastKV && ! lastKV.v.length ) {
				return lastKV.v;
			} else {
				return [];
			}
		}
	}
};

// #ifeq
ParserFunctions.prototype['pf_#ifeq'] = function ( target, argList, argDict ) {
	if ( argList.length < 2 ) {
		return [];
	} else {
		if ( target.trim() === this.manager.env.tokensToString( argList[0].v ).trim() ) {
			return ( argList[1] && argList[1].v) || [];
		} else {
			return ( argList[2] && argList[2].v) || [];
		}
	}
};

ParserFunctions.prototype['pf_lc'] = function ( target, argList, argDict ) {
	return [ target.toLowerCase() ];
};

ParserFunctions.prototype['pf_uc'] = function ( target, argList, argDict ) {
	return [ target.toUpperCase() ];
};

ParserFunctions.prototype['pf_ucfirst'] = function ( target, argList, argDict ) {
	if ( target ) {
		return [ target[0].toUpperCase() + target.substr(1) ];
	} else {
		return [];
	}
};

ParserFunctions.prototype['pf_lcfirst'] = function ( target, argList, argDict ) {
	if ( target ) {
		return [ target[0].toLowerCase() + target.substr(1) ];
	} else {
		return [];
	}
};
ParserFunctions.prototype['pf_padleft'] = function ( target, argList, argDict ) {
	if ( '1' in argDict ) {
		var n = argDict[1];
		while ( target.length < n ) {
			target = '0' + target;
		}
		return [target];
	} else {
		return [];
	}
};

ParserFunctions.prototype['pf_#tag'] = function ( target, argList, argDict ) {
	// TODO: handle things like {{#tag:nowiki|{{{input1|[[shouldnotbelink]]}}}}}
	// https://www.mediawiki.org/wiki/Future/Parser_development#Token_stream_transforms
	return [ new TagTk( target ) ] 
		.concat( argList[0].v, 
			 [ new EndTagTk( target ) ] );
};

// TODO: These are just quick wrappers for now, optimize!
ParserFunctions.prototype['pf_currentyear'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'Y', [], {} );
};
ParserFunctions.prototype['pf_currentmonth'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'm', [], {} );
};
ParserFunctions.prototype['pf_currentmonthname'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'F', [], {} );
};
// XXX Actually use genitive form!
ParserFunctions.prototype['pf_currentmonthnamegen'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'F', [], {} );
};
ParserFunctions.prototype['pf_currentmonthabbrev'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'M', [], {} );
};
ParserFunctions.prototype['pf_currentweek'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'W', [], {} );
};
ParserFunctions.prototype['pf_currentdow'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'w', [], {} );
};
ParserFunctions.prototype['pf_currentday'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'j', [], {} );
};
ParserFunctions.prototype['pf_currentday2'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'd', [], {} );
};
ParserFunctions.prototype['pf_currentdayname'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'l', [], {} );
};
ParserFunctions.prototype['pf_currenttime'] = function ( target, argList, argDict ) {
	return this['pf_#time']( 'H:i', [], {} );
};

// A first approximation of time stuff.
// TODO: Implement time spec (+ 1 day etc), check if formats are complete etc.
// See http://www.mediawiki.org/wiki/Help:Extension:ParserFunctions#.23time
// for the full list of requirements!
//
// First (very rough) approximation below based on
// http://jacwright.com/projects/javascript/date_format/, MIT licensed.
ParserFunctions.prototype['pf_#time'] = function ( target, argList, argDict ) {
	var res,
		tpl = target.trim();
	//try {
	//	var date = new Date( this.manager.env.tokensToString( argList[0].v ) );
	//	res = [ date.format( target ) ];
	//} catch ( e ) {
	//	this.manager.env.dp( 'ERROR: #time ' + e );
	
		try {
			res = [ new Date().format ( tpl ) ];
		} catch ( e2 ) {
			this.manager.env.dp( 'ERROR: #time ' + e2 );
			res = [ new Date().toString() ];
		}
	//}
	return res;
};

// Simulates PHP's date function
// XXX: don't patch Date.prototype?
Date.prototype.format = function(format) {
    var returnStr = '';
    var replace = Date.replaceChars;
    for (var i = 0; i < format.length; i++) {       
		var curChar = format.charAt(i);         
		if (i - 1 >= 0 && format.charAt(i - 1) == "\\") {
            returnStr += curChar;
        }
        else if (replace[curChar]) {
            returnStr += replace[curChar].call(this);
        } else if (curChar != "\\"){
            returnStr += curChar;
        }
    }
    return returnStr;
};

// XXX: support localization
Date.replaceChars = {
    shortMonths: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug',
					'Sep', 'Oct', 'Nov', 'Dec'],
    longMonths: ['January', 'February', 'March', 'April', 'May', 'June', 
				'July', 'August', 'September', 'October', 'November', 'December'],
    shortDays: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
    longDays: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday',
				'Friday', 'Saturday'],

    // Day
    d: function() { return (this.getDate() < 10 ? '0' : '') + this.getDate(); },
    D: function() { return Date.replaceChars.shortDays[this.getDay()]; },
    j: function() { return this.getDate(); },
    l: function() { return Date.replaceChars.longDays[this.getDay()]; },
    N: function() { return this.getDay() + 1; },
    S: function() { 
		return (this.getDate() % 10 == 1 && 
			this.getDate() != 11 ? 'st' : (this.getDate() % 10 == 2 && 
				this.getDate() != 12 ? 'nd' : (this.getDate() % 10 == 3 && 
					this.getDate() != 13 ? 'rd' : 'th'))); 
	},
    w: function() { return this.getDay(); },
    z: function() { 
		var d = new Date(this.getFullYear(),0,1); 
		return Math.ceil((this - d) / 86400000); 
	},
    // Week
    W: function() { 
		var d = new Date(this.getFullYear(), 0, 1); 
		return Math.ceil((((this - d) / 86400000) + d.getDay() + 1) / 7); 
	},
    // Month
    F: function() { return Date.replaceChars.longMonths[this.getMonth()]; },
    m: function() { return (this.getMonth() < 9 ? '0' : '') + (this.getMonth() + 1); },
    M: function() { return Date.replaceChars.shortMonths[this.getMonth()]; },
    n: function() { return this.getMonth() + 1; },
    t: function() { 
		var d = new Date(); 
		return new Date(d.getFullYear(), d.getMonth(), 0).getDate(); 
	},
    // Year
    L: function() { 
		var year = this.getFullYear(); 
		return (year % 400 === 0 || (year % 100 !== 0 && year % 4 === 0)); 
	},
    o: function() { 
		var d  = new Date(this.valueOf());  
		d.setDate(d.getDate() - ((this.getDay() + 6) % 7) + 3); 
		return d.getFullYear();
	},
    Y: function() { return this.getFullYear(); },
    y: function() { return ('' + this.getFullYear()).substr(2); },
    // Time
    a: function() { return this.getHours() < 12 ? 'am' : 'pm'; },
    A: function() { return this.getHours() < 12 ? 'AM' : 'PM'; },
    B: function() { 
		return Math.floor((((this.getUTCHours() + 1) % 24) + 
					this.getUTCMinutes() / 60 + 
					this.getUTCSeconds() / 3600) * 1000 / 24); 
	},
    g: function() { return this.getHours() % 12 || 12; },
    G: function() { return this.getHours(); },
    h: function() { 
		return ((this.getHours() % 12 || 12) < 10 ? '0' : '') + 
			(this.getHours() % 12 || 12); 
	},
    H: function() { return (this.getHours() < 10 ? '0' : '') + this.getHours(); },
    i: function() { return (this.getMinutes() < 10 ? '0' : '') + this.getMinutes(); },
    s: function() { return (this.getSeconds() < 10 ? '0' : '') + this.getSeconds(); },
    u: function() { 
		var m = this.getMilliseconds(); 
		return (m < 10 ? '00' : (m < 100 ? '0' : '')) + m; 
	},
    // Timezone
    e: function() { return "Not Yet Supported"; },
    I: function() { return "Not Yet Supported"; },
    O: function() { 
		return (-this.getTimezoneOffset() < 0 ? '-' : '+') + 
			(Math.abs(this.getTimezoneOffset() / 60) < 10 ? '0' : '') + 
			(Math.abs(this.getTimezoneOffset() / 60)) + '00'; 
	},
    P: function() { 
		return (-this.getTimezoneOffset() < 0 ? '-' : '+') + 
			(Math.abs(this.getTimezoneOffset() / 60) < 10 ? '0' : '') + 
			(Math.abs(this.getTimezoneOffset() / 60)) + ':00'; 
	},
    T: function() { 
		var m = this.getMonth(); 
		this.setMonth(0); 
		var result = this.toTimeString().replace(/^.+ \(?([^\)]+)\)?$/, '$1'); 
		this.setMonth(m); 
		return result;
	},
    Z: function() { return -this.getTimezoneOffset() * 60; },
    // Full Date/Time
    c: function() { return this.format("Y-m-d\\TH:i:sP"); },
    r: function() { return this.toString(); },
    U: function() { return this.getTime() / 1000; }
};

ParserFunctions.prototype['pf_#ifexpr'] = function ( target, argList, argDict ) {
	this.manager.env.dp( '#ifexp: ' + JSON.stringify( argList ) );
	var res;
	if ( target ) {
		try {
			var f = new Function ( 'return (' + target + ')' );
			res = f();
		} catch ( e ) {
			return [ 'class="error" in expression ' + target ];
		}
	} else {
		res = target;
	}
	if ( res ) {
		return ( argList[0] && argList[0].v ) || [];
	} else {
		return ( argList[1] && argList[1].v ) || [];
	}
};
ParserFunctions.prototype['pf_#iferror'] = function ( target, argList, argDict ) {
	if ( target.indexOf( 'class="error"' ) >= 0 ) {
		return ( argList[0] && argList[0].v ) || [];
	} else {
		return argList[1] && argList[1].v || [ target ] ;
	}
};
ParserFunctions.prototype['pf_#expr'] = function ( target, argList, argDict ) {
	var res;
	if ( target ) {
		try {
			var f = new Function ( 'return (' + target + ')' );
			res = f();
		} catch ( e ) {
			return [ 'class="error" in expression ' + target ];
		}
	} else { 
		res = '';
	}
	return [ res.toString() ];
};

ParserFunctions.prototype['pf_localurl'] = function ( target, argList, argDict ) {
	return ( this.manager.env.wgScriptPath + 'index' +
				this.manager.env.wgScriptExtension + '?title=' +
				this.manager.env.normalizeTitle( target ) + '&' +
				argList.map( 
					function( kv ) { 
						//console.warn( JSON.stringify( kv ) );
						return (kv.v !== '' && kv.k + '=' + kv.v ) || kv.k;
					} 
				).join('&') 
		   );
};


/**
 * Stub section: Pick any of these and actually implement them!
 */

// The page name and similar information should be carried around in
// this.manager.env
ParserFunctions.prototype['pf_formatnum'] = function ( target, argList, argDict ) {
	return [ target ];
};
ParserFunctions.prototype['pf_currentpage'] = function ( target, argList, argDict ) {
	return [ target ];
};
ParserFunctions.prototype['pf_pagenamee'] = function ( target, argList, argDict ) {
	return [ target ];
};
ParserFunctions.prototype['pf_fullpagename'] = function ( target, argList, argDict ) {
	return [target];
};
ParserFunctions.prototype['pf_fullpagenamee'] = function ( target, argList, argDict ) {
	return [target];
};
// This should be doable with the information in the envirionment
// (this.manager.env) already.
ParserFunctions.prototype['pf_fullurl'] = function ( target, argList, argDict ) {
	return [target];
};
ParserFunctions.prototype['pf_urlencode'] = function ( target, argList, argDict ) {
	this.manager.env.tp( 'urlencode: ' + target  );
	return [target.trim()];
};

// The following items all depends on information from the Wiki, so are hard
// to implement independently. Some might require using action=parse in the
// API to get the value. See
// http://www.mediawiki.org/wiki/Parsoid#Token_stream_transforms,
// http://etherpad.wikimedia.org/ParserNotesExtensions and
// http://www.mediawiki.org/wiki/Wikitext_parser/Environment.
// There might be better solutions for some of these.
ParserFunctions.prototype['pf_#ifexist'] = function ( target, argList, argDict ) {
	return ( argList[0] && argList[0].v ) || [];
};
ParserFunctions.prototype['pf_pagesize'] = function ( target, argList, argDict ) {
	return [ '100' ];
};
ParserFunctions.prototype['pf_sitename'] = function ( target, argList, argDict ) {
	return [ "MediaWiki" ];
};
ParserFunctions.prototype['pf_anchorencode'] = function ( target, argList, argDict ) {
	return [target];
};
ParserFunctions.prototype['pf_protectionlevel'] = function ( target, argList, argDict ) {
	return [''];
};
ParserFunctions.prototype['pf_ns'] = function ( target, argList, argDict ) {
	return [target];
};
ParserFunctions.prototype['pf_subjectspace'] = function ( target, argList, argDict ) {
	return ['Main'];
};
ParserFunctions.prototype['pf_talkspace'] = function ( target, argList, argDict ) {
	return ['Talk'];
};
ParserFunctions.prototype['pf_numberofarticles'] = function ( target, argList, argDict ) {
	return ["1"];
};
ParserFunctions.prototype['pf_#language'] = function ( target, argList, argDict ) {
	return [target];
};
ParserFunctions.prototype['pf_contentlang'] = function ( target, argList, argDict ) {
	return ['en'];
};
ParserFunctions.prototype['pf_numberoffiles'] = function ( target, argList, argDict ) {
	return ['2'];
};
ParserFunctions.prototype['pf_namespace'] = function ( target, argList, argDict ) {
	return [target.split(':').pop() || 'Main'];
};
ParserFunctions.prototype['pf_namespacee'] = function ( target, argList, argDict ) {
	return [target.split(':').pop() || 'Main'];
};
ParserFunctions.prototype['pf_pagename'] = function ( target, argList, argDict ) {
	return ['Main page'];
};
ParserFunctions.prototype['pf_scriptpath'] = function ( target, argList, argDict ) {
	return [this.manager.env.wgScriptPath];
};


if (typeof module == "object") {
	module.exports.ParserFunctions = ParserFunctions;
}