/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you 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.
 */
package org.elasticsearch.test.rest.spec;

import org.elasticsearch.common.xcontent.XContentParser;

import java.io.IOException;

/**
 * Parser for a REST api spec (single json file)
 */
public class RestApiParser {

    public RestApi parse(XContentParser parser) throws IOException {

        try {
            while ( parser.nextToken() != XContentParser.Token.FIELD_NAME ) {
                //move to first field name
            }

            RestApi restApi = new RestApi(parser.currentName());

            int level = -1;
            while (parser.nextToken() != XContentParser.Token.END_OBJECT || level >= 0) {

                if (parser.currentToken() == XContentParser.Token.FIELD_NAME) {
                    if ("methods".equals(parser.currentName())) {
                        parser.nextToken();
                        while (parser.nextToken() == XContentParser.Token.VALUE_STRING) {
                            restApi.addMethod(parser.text());
                        }
                    }

                    if ("url".equals(parser.currentName())) {
                        String currentFieldName = "url";
                        int innerLevel = -1;
                        while(parser.nextToken() != XContentParser.Token.END_OBJECT || innerLevel >= 0) {
                            if (parser.currentToken() == XContentParser.Token.FIELD_NAME) {
                                currentFieldName = parser.currentName();
                            }

                            if (parser.currentToken() == XContentParser.Token.START_ARRAY && "paths".equals(currentFieldName)) {
                                while (parser.nextToken() == XContentParser.Token.VALUE_STRING) {
                                    restApi.addPath(parser.text());
                                }
                            }

                            if (parser.currentToken() == XContentParser.Token.START_OBJECT && "parts".equals(currentFieldName)) {
                                while (parser.nextToken() == XContentParser.Token.FIELD_NAME) {
                                    restApi.addPathPart(parser.currentName());
                                    parser.nextToken();
                                    if (parser.currentToken() != XContentParser.Token.START_OBJECT) {
                                        throw new IOException("Expected parts field in rest api definition to contain an object");
                                    }
                                    parser.skipChildren();
                                }
                            }

                            if (parser.currentToken() == XContentParser.Token.START_OBJECT && "params".equals(currentFieldName)) {
                                while (parser.nextToken() == XContentParser.Token.FIELD_NAME) {
                                    restApi.addParam(parser.currentName());
                                    parser.nextToken();
                                    if (parser.currentToken() != XContentParser.Token.START_OBJECT) {
                                        throw new IOException("Expected params field in rest api definition to contain an object");
                                    }
                                    parser.skipChildren();
                                }
                            }

                            if (parser.currentToken() == XContentParser.Token.START_OBJECT) {
                                innerLevel++;
                            }
                            if (parser.currentToken() == XContentParser.Token.END_OBJECT) {
                                innerLevel--;
                            }
                        }
                    }

                    if ("body".equals(parser.currentName())) {
                        parser.nextToken();
                        if (parser.currentToken() != XContentParser.Token.VALUE_NULL) {
                            boolean requiredFound = false;
                            while(parser.nextToken() != XContentParser.Token.END_OBJECT) {
                                if (parser.currentToken() == XContentParser.Token.FIELD_NAME) {
                                    if ("required".equals(parser.currentName())) {
                                        requiredFound = true;
                                        parser.nextToken();
                                        if (parser.booleanValue()) {
                                            restApi.setBodyRequired();
                                        } else {
                                            restApi.setBodyOptional();
                                        }
                                    }
                                }
                            }
                            if (!requiredFound) {
                                restApi.setBodyOptional();
                            }
                        }
                    }
                }

                if (parser.currentToken() == XContentParser.Token.START_OBJECT) {
                    level++;
                }
                if (parser.currentToken() == XContentParser.Token.END_OBJECT) {
                    level--;
                }

            }

            parser.nextToken();
            assert parser.currentToken() == XContentParser.Token.END_OBJECT : "Expected [END_OBJECT] but was ["  + parser.currentToken() +"]";
            parser.nextToken();

            return restApi;

        } finally {
            parser.close();
        }
    }

}
