// 
// Decompiled by Procyon v0.6.0
// 

package org.jline.style;

import java.util.function.Function;

public final class InterpolationHelper
{
    private static final char ESCAPE_CHAR = '\\';
    private static final String DELIM_START = "@{";
    private static final String DELIM_STOP = "}";
    private static final String MARKER = "@__";
    
    private InterpolationHelper() {
    }
    
    public static String substVars(final String val, final Function<String, String> callback, final boolean defaultsToEmptyString) throws IllegalArgumentException {
        return unescape(doSubstVars(val, callback, defaultsToEmptyString));
    }
    
    private static String doSubstVars(String val, final Function<String, String> callback, final boolean defaultsToEmptyString) throws IllegalArgumentException {
        int stopDelim = -1;
        int startDelim;
        do {
            for (stopDelim = val.indexOf("}", stopDelim + 1); stopDelim > 0 && val.charAt(stopDelim - 1) == '\\'; stopDelim = val.indexOf("}", stopDelim + 1)) {}
            startDelim = val.indexOf("@{");
            while (stopDelim >= 0) {
                final int idx = val.indexOf("@{", startDelim + "@{".length());
                if (idx < 0) {
                    break;
                }
                if (idx > stopDelim) {
                    break;
                }
                if (idx >= stopDelim) {
                    continue;
                }
                startDelim = idx;
            }
        } while (startDelim >= 0 && stopDelim >= 0 && stopDelim < startDelim + "@{".length());
        if (startDelim < 0 || stopDelim < 0) {
            return val;
        }
        final String variable = val.substring(startDelim + "@{".length(), stopDelim);
        String substValue = null;
        if (variable.length() > 0 && callback != null) {
            substValue = callback.apply(variable);
        }
        if (substValue == null) {
            if (defaultsToEmptyString) {
                substValue = "";
            }
            else {
                substValue = "@__{" + variable + "}";
            }
        }
        val = val.substring(0, startDelim) + substValue + val.substring(stopDelim + "}".length());
        val = doSubstVars(val, callback, defaultsToEmptyString);
        return val;
    }
    
    private static String unescape(String val) {
        val = val.replaceAll("@__", "@");
        for (int escape = val.indexOf(92); escape >= 0 && escape < val.length() - 1; escape = val.indexOf(92, escape + 1)) {
            final char c = val.charAt(escape + 1);
            if (c == '{' || c == '}' || c == '\\') {
                val = val.substring(0, escape) + val.substring(escape + 1);
            }
        }
        return val;
    }
}