/*******************************************************************************
 * Copyright (c) 2015 Jeff Martin.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser General Public
 * License v3.0 which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl.html
 * <p>
 * Contributors:
 * Jeff Martin - initial API and implementation
 ******************************************************************************/
package cuchaz.enigma.convert;

import com.google.common.collect.Lists;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Collection;
import java.util.List;

import cuchaz.enigma.mapping.*;


public class MatchesReader {

    public static ClassMatches readClasses(File file)
            throws IOException {
        try (BufferedReader in = new BufferedReader(new FileReader(file))) {
            ClassMatches matches = new ClassMatches();
            String line = null;
            while ((line = in.readLine()) != null) {
                matches.add(readClassMatch(line));
            }
            return matches;
        }
    }

    private static ClassMatch readClassMatch(String line)
            throws IOException {
        String[] sides = line.split(":", 2);
        return new ClassMatch(readClasses(sides[0]), readClasses(sides[1]));
    }

    private static Collection<ClassEntry> readClasses(String in) {
        List<ClassEntry> entries = Lists.newArrayList();
        for (String className : in.split(",")) {
            className = className.trim();
            if (className.length() > 0) {
                entries.add(new ClassEntry(className));
            }
        }
        return entries;
    }

    public static <T extends Entry> MemberMatches<T> readMembers(File file)
            throws IOException {
        try (BufferedReader in = new BufferedReader(new FileReader(file))) {
            MemberMatches<T> matches = new MemberMatches<T>();
            String line = null;
            while ((line = in.readLine()) != null) {
                readMemberMatch(matches, line);
            }
            return matches;
        }
    }

    private static <T extends Entry> void readMemberMatch(MemberMatches<T> matches, String line) {
        if (line.startsWith("!")) {
            T source = readEntry(line.substring(1));
            matches.addUnmatchableSourceEntry(source);
        } else {
            String[] parts = line.split(":", 2);
            T source = readEntry(parts[0]);
            T dest = readEntry(parts[1]);
            if (source != null && dest != null) {
                matches.addMatch(source, dest);
            } else if (source != null) {
                matches.addUnmatchedSourceEntry(source);
            } else if (dest != null) {
                matches.addUnmatchedDestEntry(dest);
            }
        }
    }

    @SuppressWarnings("unchecked")
    private static <T extends Entry> T readEntry(String in) {
        if (in.length() <= 0) {
            return null;
        }
        String[] parts = in.split(" ");
        if (parts.length == 3 && parts[2].indexOf('(') < 0) {
            return (T) new FieldEntry(
                    new ClassEntry(parts[0]),
                    parts[1],
                    new Type(parts[2])
            );
        } else {
            assert (parts.length == 2 || parts.length == 3);
            if (parts.length == 2) {
                return (T) EntryFactory.getBehaviorEntry(parts[0], parts[1]);
            } else if (parts.length == 3) {
                return (T) EntryFactory.getBehaviorEntry(parts[0], parts[1], parts[2]);
            } else {
                throw new Error("Malformed behavior entry: " + in);
            }
        }
    }
}