package com.temp.shared.utils;

/**
 * Code to Treat a String as a sorta Iterator...
 */
public class CharSource {
    private String mSource;
    private int mFrom, mTo;

    public CharSource(String pSource, int pFrom) {
        mSource = StringUtils.deNull(pSource);
        if ((mFrom = pFrom) < 0) {
            throw new IllegalArgumentException("'From' not allowed to be negative");
        }
        mTo = mSource.length();
    }

    public CharSource(String pSource) {
        this(pSource, 0);
    }

    public CharSource(String pSource, int pFrom, int pTo) {
        this(pSource, pFrom);
        if (pTo > mTo) {
            throw new IllegalArgumentException("'To' not allowed to be greater than the length of the 'Source' string");
        }
        if (pTo < 0) {
            mTo += pTo;
        } else {
            mTo = pTo;
        }
    }

    public boolean anyRemaining() {
        return (mFrom < mTo);
    }

    public int peek() {
        return anyRemaining() ? mSource.charAt(mFrom) : -1;
    }

    public int get() {
        return anyRemaining() ? mSource.charAt(mFrom++) : -1;
    }

    public char getRequired() {
        if (anyRemaining()) {
            return mSource.charAt(mFrom++);
        }
        throw new IllegalArgumentException("Unexpected EOD encountered at index " + mFrom + " in " + mSource);
    }

    public String getUpTo(char c) {
        int at = mSource.indexOf(c, mFrom);
        if (at == -1) {
            return "";
        }
        String rv = mSource.substring(mFrom, at);
        mFrom = at;
        return rv;
    }

    public boolean consumeSpaces() {
        while (peek() == ' ') {
            mFrom++;
        }
        return anyRemaining();
    }

    public String getUpToNonVisible7BitAscii() {
        if (!anyRemaining()) {
            return "";
        }
        int zFrom = mFrom;
        for (int c = peek(); (c != -1) && ((' ' < c) && (c <= 126)); c = peek()) {
            mFrom++;
        }
        return mSource.substring(zFrom, mFrom);
    }

    public boolean consumeNonVisible7BitAscii() {
        for (int c = peek(); (c != -1) && ((c <= ' ') || (126 < c)); c = peek()) {
            mFrom++;
        }
        return anyRemaining();
    }

    public int getFrom() {
        return mFrom;
    }

    public int getLastFrom() {
        return mFrom - 1;
    }

    @Override
    public String toString() {
        return mSource.substring(mFrom, mTo);
    }
}