// $Id$
/*
 * Copyright (C) 2010 sk89q <http://www.sk89q.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

package com.sk89q.minecraft.util.commands;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class CommandContext {
    protected final String[] args;
    protected final Set<Character> booleanFlags = new HashSet<Character>();
    protected final Map<Character, String> valueFlags = new HashMap<Character, String>();

    public CommandContext(String args) throws CommandException {
        this(args.split(" "), null);
    }

    public CommandContext(String[] args) throws CommandException {
        this(args, null);
    }

    public CommandContext(String args, Set<Character> valueFlags) throws CommandException {
        this(args.split(" "), valueFlags);
    }

    /**
     * @param args An array with arguments. Empty strings outside quotes will be removed.
     * @param valueFlags A set containing all value flags. Pass null to disable value flag parsing.
     * @throws CommandException This is thrown if flag fails for some reason.
     */
    public CommandContext(String[] args, Set<Character> valueFlags) throws CommandException {
        if (valueFlags == null) {
            valueFlags = Collections.emptySet();
        }

        final String command = args[0];

        List<String> argList = new ArrayList<String>(args.length);
        argList.add(command);
        // Go through empty args and multiword args first
        for (int i = 1; i < args.length; ++i) {
            String arg = args[i];
            if (arg.isEmpty()) {
                continue;
            }

            switch (arg.charAt(0)) {
            case '\'':
            case '"':
                final StringBuilder build = new StringBuilder();
                final char quotedChar = arg.charAt(0);

                int endIndex;
                for (endIndex = i; endIndex < args.length; ++endIndex) {
                    final String arg2 = args[endIndex];
                    if (arg2.charAt(arg2.length() - 1) == quotedChar) {
                        if (endIndex != i) build.append(' ');
                        build.append(arg2.substring(endIndex == i ? 1 : 0, arg2.length() - 1));
                        break;
                    } else if (endIndex == i) {
                        build.append(arg2.substring(1));
                    } else {
                        build.append(' ').append(arg2);
                    }
                }

                if (endIndex < args.length) {
                    arg = build.toString();
                    i = endIndex;
                }
                // else raise exception about hanging quotes?
            }
            argList.add(arg);
        }

        List<String> argList2 = new ArrayList<String>(argList.size());
        argList2.add(command);

        // Then flags
        int nextArg = 1;

        while (nextArg < argList.size()) {
            // Fetch argument
            String arg = argList.get(nextArg++);

            // No more flags?
            if (arg.charAt(0) != '-' || arg.length() == 1 || !arg.matches("^-[a-zA-Z]+$")) {
                argList2.add(arg);
                continue;
            }

            // Handle flag parsing terminator --
            if (arg.equals("--")) {
                while (nextArg < argList.size()) {
                    argList2.add(argList.get(nextArg++));
                }
                break;
            }

            // Go through the flags
            for (int i = 1; i < arg.length(); ++i) {
                char flagName = arg.charAt(i);

                if (valueFlags.contains(flagName)) {
                    if (this.valueFlags.containsKey(flagName)) {
                        throw new CommandException("Value flag '" + flagName + "' already given");
                    }

                    if (nextArg >= argList.size())
                        throw new CommandException("No value specified for the '-"+flagName+"' flag.");

                    // If it is a value flag, read another argument and add it
                    this.valueFlags.put(flagName, argList.get(nextArg++));
                }
                else {
                    booleanFlags.add(flagName);
                }
            }
        }

        this.args = args = argList2.toArray(new String[argList2.size()]);
    }

    public String getCommand() {
        return args[0];
    }

    public boolean matches(String command) {
        return args[0].equalsIgnoreCase(command);
    }

    public String getString(int index) {
        return args[index + 1];
    }

    public String getString(int index, String def) {
        return index + 1 < args.length ? args[index + 1] : def;
    }

    public String getJoinedStrings(int initialIndex) {
        initialIndex = initialIndex + 1;
        StringBuilder buffer = new StringBuilder(args[initialIndex]);
        for (int i = initialIndex + 1; i < args.length; ++i) {
            buffer.append(" ").append(args[i]);
        }
        return buffer.toString();
    }

    public int getInteger(int index) throws NumberFormatException {
        return Integer.parseInt(args[index + 1]);
    }

    public int getInteger(int index, int def) throws NumberFormatException {
        return index + 1 < args.length ? Integer.parseInt(args[index + 1]) : def;
    }

    public double getDouble(int index) throws NumberFormatException {
        return Double.parseDouble(args[index + 1]);
    }

    public double getDouble(int index, double def) throws NumberFormatException {
        return index + 1 < args.length ? Double.parseDouble(args[index + 1]) : def;
    }

    public String[] getSlice(int index) {
        String[] slice = new String[args.length - index];
        System.arraycopy(args, index, slice, 0, args.length - index);
        return slice;
    }

    public String[] getPaddedSlice(int index, int padding) {
        String[] slice = new String[args.length - index + padding];
        System.arraycopy(args, index, slice, padding, args.length - index);
        return slice;
    }

    public boolean hasFlag(char ch) {
        return booleanFlags.contains(ch) || valueFlags.containsKey(ch);
    }

    public Set<Character> getFlags() {
        return booleanFlags;
    }

    public Map<Character, String> getValueFlags() {
        return valueFlags;
    }

    public String getFlag(char ch) {
        return valueFlags.get(ch);
    }

    public String getFlag(char ch, String def) {
        final String value = valueFlags.get(ch);
        if (value == null)
            return def;

        return value;
    }

    public int getFlagInteger(char ch) throws NumberFormatException {
        return Integer.parseInt(valueFlags.get(ch));
    }

    public int getFlagInteger(char ch, int def) throws NumberFormatException {
        final String value = valueFlags.get(ch);
        if (value == null)
            return def;

        return Integer.parseInt(value);
    }

    public double getFlagDouble(char ch) throws NumberFormatException {
        return Double.parseDouble(valueFlags.get(ch));
    }

    public double getFlagDouble(char ch, double def) throws NumberFormatException {
        final String value = valueFlags.get(ch);
        if (value == null)
            return def;

        return Double.parseDouble(value);
    }

    public int argsLength() {
        return args.length - 1;
    }
}