/**
 * ============LICENSE_START====================================================
 * org.onap.aaf
 * ===========================================================================
 * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
 * ===========================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ============LICENSE_END====================================================
 *
 */

package org.onap.aaf.misc.rosetta;

import java.io.IOException;
import java.io.Reader;

import org.onap.aaf.misc.env.Env;
import org.onap.aaf.misc.env.TimeTaken;
import org.onap.aaf.misc.rosetta.InJson.State;

public class InJson implements Parse<Reader, State> {
    public Parsed<State> parse(Reader r, Parsed<State> parsed) throws ParseException {
        // First things first, if there's a "leftover" event, process that immediately
        State state = (State)parsed.state;
        if (state.unsent > 0) {
            parsed.event = state.unsent;
            state.unsent = 0;
            return parsed;
        }

        int ch;
        char c;
        StringBuilder sb = parsed.sb;
        boolean inQuotes = false, escaped = false;
        boolean go = true;
        try {
            // Gather data from Reader, looking for special characters when not in Quotes
            while (go && (ch=r.read())>=0) {
                if (state.braces>=0 || ch==Parse.START_OBJ) { // ignore garbage/whitespace before content
                    c=(char)ch;
                    // Character is a quote.
                    if (c=='"') {
                        if (inQuotes) {
                            if (escaped) {  // if escaped Quote, add to data.
                                sb.append(c);
                                escaped = false;
                            } else {
                                inQuotes = false;
                            }
                        } else {
                            parsed.isString=true;
                            inQuotes = true;
                        }
                    } else { // Not a Quote
                        if (inQuotes) {
                            if (c=='\\') {
                                if (escaped) {
                                    sb.append("\\\\");
                                    escaped = false;
                                } else {
                                    escaped = true;
                                }
                            } else {
                                sb.append(c);
                            }
                        } else {
                            switch(c) {
                                case ':':
                                    parsed.dataIsName();
                                    parsed.isString = false;
                                    break;
                                case Parse.START_OBJ:
                                    if (state.braces++ == 0) {
                                        parsed.event = START_DOC;
                                        state.unsent = c;
                                    } else {
                                        parsed.event = c;
                                    }
                                    go = false;
                                    break;
                                case Parse.END_OBJ:
                                    if (--state.braces == 0) {
                                        parsed.event = c;
                                        state.unsent = END_DOC;
                                    } else {
                                        parsed.event = c;
                                    }
                                    go = false;
                                    break;
                                // These three end the data gathering, and send it along with the event that is ending the data gathering
                                case Parse.NEXT:
                                    if (parsed.name.startsWith("__")) {
                                        parsed.event = Parse.ATTRIB;
                                        parsed.name = parsed.name.substring(2);
                                    } else {
                                        parsed.event = c;
                                    }
                                    go = false;
                                    break;
                                case Parse.START_ARRAY:
                                case Parse.END_ARRAY:
                                    parsed.event = c;
                                    go = false;
                                    break;

                                // The Escape Sequence, for Quote marks within Quotes
                                case '\\':
                                // Ignore these, unless within quotes, at which point data-gather
                                case ' ':
                                case '\b':
                                case '\f':
                                case '\n':
                                case '\r':
                                case '\t':
                                    break;
                                // Normal data... gather it
                                default:
                                    sb.append(c);
                            }
                        }
                    }
                }
            }
            return parsed;
        } catch (IOException e) {
            throw new ParseException(e);
        }
    }

    public static class State {
        public int braces = 0;
        public char unsent = 0;
    }

//    @Override
    public Parsed<State> newParsed() {
        return new Parsed<State>(new State()); // no State needed
    }

//    @Override
    public TimeTaken start(Env env) {
        return env.start("Rosetta JSON In", Env.JSON);
    }
}