package moj;

import java.util.*;

import java.util.regex.Pattern;

public class LanguageAutoDetection {

final static String[] CPLUSPLUS_MARKERS = {

"#\\s*include", "#\\s*define",

"private:", "public:", "protected:",

"struct\\s",

"using\\s+namespace",

"template\\s*<",

"inline\\s*",

"vector\\s*<",

"::",

};

final static String[] JAVA_MARKERS = {

"import\\s+java\\.",

"public \\w",

"String\\s*\\[\\]", "int\\s*\\[\\]", "long\\s*\\[\\]",

"HashMap", "TreeMap"

};

final static String[] CSHARP_MARKERS = {

"using\\s+System",

"string\\s*\\[\\]",

"\\[,\\]", "\\[,,\\]", "\\[,,,\\]", "\\[,,,,\\]",

};

static String filterComments(String source) {

StringBuilder sb = new StringBuilder();

for (int i=0; i<source.length();) {

if (i+2 <= source.length()) {

if (source.substring(i, i+2).equals("//")) {

int nextpos = source.indexOf("\n", i+2);

if (nextpos == -1) break;

i = nextpos;

continue;

} else if (source.substring(i, i+2).equals("/*")){

int nextpos = source.indexOf("*/", i+2);

if (nextpos == -1) break;

sb.append(' ');

i = nextpos+2;

continue;

}

}

sb.append(source.charAt(i++));

}

return sb.toString();

}

static boolean isMostLikely(String source, String candidate) {

source = filterComments(source);

Map<String, String[]> markers = new TreeMap<String, String[]>();

markers.put("C++", CPLUSPLUS_MARKERS);

markers.put("Java", JAVA_MARKERS);

markers.put("C#", CSHARP_MARKERS);

System.err.printf("moj language auto detection:");

int best = 0;

String ret = "C++";

boolean first = true;

for (String language : markers.keySet()) {

int matched = 0, total = 0;

for (String m : markers.get(language)) {

if (Pattern.compile(m, Pattern.MULTILINE).matcher(source).find())

++matched;

++total;

}

if (matched > best ||

matched == best && language.equals(candidate)) {

best = matched;

ret = language;

}

if (!first) System.err.printf(",");

first = false;

System.err.printf(" %s %d markers", language, matched);

}

System.err.printf("\n");

return ret.equals(candidate);

}

}