#!/usr/bin/env node

/* jshint node: true */

( function () {
	var i, count, group, symbol, symbols, symbolObject,
		symbolsData, cssData, cssLines, index,
		cssRules = [],
		cssClasses = [],
		symbolList = [],
		symbolsFile = '../symbols.json',
		cssFile = '../ve.ui.MWMathSymbols.css',
		cssPrefix = '.ve-ui-mwMathSymbol-',
		fs = require( 'fs' ),
		http = require( 'http' ),
		querystring = require( 'querystring' ),
		SVGO = require( 'svgo' ),
		svgo = new SVGO( {
			plugins: [
				{ convertTransform: false }
			]
		} ),
		mathoidMaxConnections = 5;

	symbolsData = fs.readFileSync( symbolsFile ).toString();
	try {
		cssData = fs.readFileSync( cssFile ).toString();
	} catch ( e ) {}

	function encodeURIComponentForCSS( str ) {
		return encodeURIComponent( str )
			.replace( /[!'\(\)\*]/g, function ( chr ) {
				return '%' + chr.charCodeAt( 0 ).toString( 16 );
			} );
	}

	function texToClass( tex ) {
		// Make the className, replacing any non-alphanumerics with their character code
		return tex.replace( /[^\w]/g, function ( c ) {
			return '_' + c.charCodeAt( 0 ) + '_';
		} );
	}

	function makeRequest( symbol ) {
		var request,
			data = querystring.stringify( {
				q: symbol
			} ),
			// API call to mathoid
			options = {
				host: '192.168.37.177',
				port: '10044',
				path: '/',
				method: 'POST',
				headers: {
					'Content-Type': 'application/x-www-form-urlencoded',
					'Content-Length': Buffer.byteLength( data )
				}
			};

		// Populate and make the API call
		request = http.request( options, function ( res ) {
			var body = '';
			res.setEncoding( 'utf8' );

			res.on( 'data', function ( data ) {
				body += data;
			} );

			res.on( 'end', function () {
				var className = texToClass( symbol ),
					svg = JSON.parse( body ).svg;

				if ( !svg ) {
					console.log( symbol + ' FAILED: ' + body );
					onEnd();
					return;
				}

				svgo.optimize( svg, function ( result ) {
					// write to the css file
					cssRules.push(
						cssPrefix + className + ' {\n' +
						'\tbackground-image: url(data:image/svg+xml,' + encodeURIComponentForCSS( result.data ) + ');\n' +
						'}'
					);
					console.log( symbol + ' -> ' + className );
				} );
				onEnd();

			} );
		} );
		request.setTimeout( 10000 );
		request.write( data );
		request.end();
		runNext();
	}

	function onEnd() {
		count--;
		runNext();
	}

	function runNext() {
		if ( count < mathoidMaxConnections && symbolList.length ) {
			count++;
			makeRequest( symbolList.shift() );
		}
		if ( !symbolList.length && !count ) {
			cssRules.sort();
			fs.writeFileSync(
				cssFile,
				'/*!\n' +
				' * This file is GENERATED by tools/makeSvgsAndCss.js\n' +
				' * DO NOT EDIT\n' +
				' */\n' +
				'\n' +
				cssRules.join( '\n\n' ) +
				'\n'
			);
		}
	}

	if ( cssData ) {
		cssLines = cssData.split( '\n' );
		for ( i = 0; i < cssLines.length; i++ ) {
			if ( cssLines[ i ].indexOf( cssPrefix ) === 0 ) {
				cssRules.push( cssLines.slice( i, i + 3 ).join( '\n' ) );
				cssClasses.push( cssLines[ i ].slice( cssPrefix.length, -2 ) );
			}
		}
	}

	symbolObject = JSON.parse( symbolsData );
	for ( group in symbolObject ) {
		symbols = symbolObject[ group ];
		for ( i = 0; i < symbols.length; i++ ) {
			symbol = symbols[ i ];
			if ( symbol.duplicate || symbol.notWorking ) {
				continue;
			}
			index = cssClasses.indexOf( texToClass( symbol.tex ) );
			if ( index === -1 ) {
				symbolList.push( symbol.tex );
			} else {
				// Remove CSS classes we found in the symbol list so that
				// and the end of this loop, cssClasses contains classes
				// that have been deleted from the symbol list
				cssClasses.splice( index, 1 );
			}
		}
	}

	// Remove classes that are no longer in the JSON
	cssRules = cssRules.filter( function ( rule ) {
		return cssClasses.indexOf( rule.split( '\n' )[ 0 ].slice( cssPrefix.length, -2 ) ) === -1;
	} );

	count = 0;
	runNext();

} )();