package org.nutz.dao.impl.sql;

import java.util.ArrayList;
import java.util.List;

import org.nutz.lang.Strings;
import org.nutz.lang.util.LinkedIntArray;

/**
 * It will record the date like
 * 
 * <pre>
 * chain: [str1][...][str2][...][...][str3]
 * indexes [1,3,4]   // 0 base indexes
 * </pre>
 */
class WorkingStack {

    WorkingStack() {
        sb = new StringBuilder();
        chain = new ArrayList<String>();
        indexes = new LinkedIntArray(20);
    }

    private String first;
    private StringBuilder sb;
    private List<String> chain;
    private LinkedIntArray indexes;

    void push(char c) {
        sb.append(c);
    }

    void finish() {
        if (sb.length() > 0)
            chain.add(sb.toString());
        if (chain.size() > 0) {
            first = chain.get(0);
            char[] cs = Strings.trim(first).toCharArray();
            int i = 0;
            for (; i < cs.length; i++) {
                char c = cs[i];
                if (c > 0 && c <= 32)
                    break;
            }
            first = String.valueOf(cs, 0, i).toUpperCase();
        }
    }

    int markToken() {
        // int re = indexes.size();
        if (sb.length() > 0) {
            chain.add(sb.toString());
            sb = new StringBuilder();
        }
        indexes.push(chain.size());
        chain.add("");
        return chain.size() - 1;
    }

    String[] cloneChain() {
        return chain.toArray(new String[chain.size()]);
    }

    int size() {
        return chain.size();
    }

    boolean firstEquals(String str) {
        if (null == first)
            return false;
        return first.equals(str);
    }

}