/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.apache.juneau.bean.openapi3;

import static org.apache.juneau.commons.utils.AssertionUtils.*;
import static org.apache.juneau.commons.utils.CollectionUtils.*;
import static org.apache.juneau.commons.utils.Utils.*;
import static org.apache.juneau.internal.ConverterUtils.*;

import java.util.*;

import org.apache.juneau.commons.collections.*;

/**
 * Describes a single API operation on a path.
 *
 * <p>
 * The Operation Object describes a single operation (such as GET, POST, PUT, DELETE) that can be performed on a path.
 * Operations are the core of the API specification, defining what actions can be taken, what parameters they accept,
 * and what responses they return.
 *
 * <h5 class='section'>OpenAPI Specification:</h5>
 * <p>
 * The Operation Object is composed of the following fields:
 * <ul class='spaced-list'>
 *    <li><c>tags</c> (array of string) - A list of tags for API documentation control
 *    <li><c>summary</c> (string) - A short summary of what the operation does
 *    <li><c>description</c> (string) - A verbose explanation of the operation behavior (CommonMark syntax may be used)
 *    <li><c>externalDocs</c> ({@link ExternalDocumentation}) - Additional external documentation for this operation
 *    <li><c>operationId</c> (string) - Unique string used to identify the operation
 *    <li><c>parameters</c> (array of {@link Parameter}) - A list of parameters that are applicable for this operation
 *    <li><c>requestBody</c> ({@link RequestBodyInfo}) - The request body applicable for this operation
 *    <li><c>responses</c> (map of {@link Response}, REQUIRED) - The list of possible responses as they are returned from executing this operation
 *    <li><c>callbacks</c> (map of {@link Callback}) - A map of possible out-of band callbacks related to the parent operation
 *    <li><c>deprecated</c> (boolean) - Declares this operation to be deprecated
 *    <li><c>security</c> (array of {@link SecurityRequirement}) - A declaration of which security mechanisms can be used for this operation
 *    <li><c>servers</c> (array of {@link Server}) - An alternative server array to service this operation
 * </ul>
 *
 * <h5 class='section'>Example:</h5>
 * <p class='bjava'>
 *    <jc>// Create an Operation object for a GET endpoint</jc>
 *    Operation <jv>operation</jv> = <jk>new</jk> Operation()
 *       .setTags(<js>"pet"</js>)
 *       .setSummary(<js>"Find pets by status"</js>)
 *       .setDescription(<js>"Multiple status values can be provided with comma separated strings"</js>)
 *       .setOperationId(<js>"findPetsByStatus"</js>)
 *       .setParameters(
 *          <jk>new</jk> Parameter()
 *             .setName(<js>"status"</js>)
 *             .setIn(<js>"query"</js>)
 *             .setDescription(<js>"Status values that need to be considered for filter"</js>)
 *             .setRequired(<jk>true</jk>)
 *             .setSchema(
 *                <jk>new</jk> SchemaInfo().setType(<js>"string"</js>)
 *             )
 *       )
 *       .setResponses(
 *          JsonMap.<jsm>of</jsm>(
 *             <js>"200"</js>, <jk>new</jk> Response()
 *                .setDescription(<js>"successful operation"</js>)
 *                .setContent(
 *                   JsonMap.<jsm>of</jsm>(
 *                      <js>"application/json"</js>, <jk>new</jk> MediaType()
 *                         .setSchema(<jk>new</jk> SchemaInfo().<jsm>setType</jsm>(<js>"array"</js>))
 *                   )
 *                )
 *          )
 *       );
 * </p>
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://spec.openapis.org/oas/v3.0.0#operation-object">OpenAPI Specification &gt; Operation Object</a>
 *    <li class='link'><a class="doclink" href="https://swagger.io/docs/specification/paths-and-operations/">OpenAPI Paths and Operations</a>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauBeanOpenApi3">juneau-bean-openapi-v3</a>
 * </ul>
 */
public class Operation extends OpenApiElement {

   private List<String> tags = list();
   private String summary, description, operationId;
   private ExternalDocumentation externalDocs;
   private List<Parameter> parameters = list();
   private RequestBodyInfo requestBody;
   private Map<String,Response> responses = map();
   private Map<String,Callback> callbacks = map();
   private Boolean deprecated;
   private List<SecurityRequirement> security = list();
   private List<Server> servers = list();

   /**
    * Default constructor.
    */
   public Operation() {}

   /**
    * Copy constructor.
    *
    * @param copyFrom The object to copy.
    */
   public Operation(Operation copyFrom) {
      super(copyFrom);
      if (nn(copyFrom.tags))
         tags.addAll(copyFrom.tags);
      this.summary = copyFrom.summary;
      this.description = copyFrom.description;
      this.operationId = copyFrom.operationId;
      this.externalDocs = copyFrom.externalDocs;
      if (nn(copyFrom.parameters))
         parameters.addAll(copyOf(copyFrom.parameters, Parameter::copy));
      this.requestBody = copyFrom.requestBody;
      if (nn(copyFrom.responses))
         responses.putAll(copyFrom.responses);
      if (nn(copyFrom.callbacks))
         callbacks.putAll(copyFrom.callbacks);
      this.deprecated = copyFrom.deprecated;
      if (nn(copyFrom.security))
         security.addAll(copyOf(copyFrom.security, SecurityRequirement::copy));
      if (nn(copyFrom.servers))
         servers.addAll(copyOf(copyFrom.servers, Server::copy));
   }

   /**
    * Bean property fluent setter:  <property>callbacks</property>.
    *
    * <p>
    * A map of possible out-of band callbacks related to the parent operation.
    *
    * @param name
    *    The name of the callback.
    *    <br>Must not be <jk>null</jk>.
    * @param callback
    *    The callback object.
    *    <br>Must not be <jk>null</jk>.
    * @return This object.
    */
   public Operation addCallback(String name, Callback callback) {
      assertArgNotNull("name", name);
      assertArgNotNull("callback", callback);
      callbacks.put(name, callback);
      return this;
   }

   /**
    * Bean property fluent setter:  <property>parameters</property>.
    *
    * <p>
    * A list of parameters that are applicable for this operation.
    *
    * @param values
    *    The values to add to this property.
    *    <br>Ignored if <jk>null</jk>.
    * @return This object.
    */
   public Operation addParameters(Collection<Parameter> values) {
      if (nn(values))
         parameters.addAll(values);
      return this;
   }

   /**
    * Bean property fluent setter:  <property>parameters</property>.
    *
    * <p>
    * A list of parameters that are applicable for this operation.
    *
    * @param values
    *    The values to add to this property.
    *    <br>Ignored if <jk>null</jk>.
    * @return This object.
    */
   public Operation addParameters(Parameter...values) {
      if (nn(values))
         for (var v : values)
            if (nn(v))
               parameters.add(v);
      return this;
   }

   /**
    * Bean property fluent setter:  <property>responses</property>.
    *
    * <p>
    * The list of possible responses as they are returned from executing this operation.
    *
    * @param statusCode
    *    The status code for the response.
    *    <br>Must not be <jk>null</jk>.
    * @param response
    *    The response object.
    *    <br>Must not be <jk>null</jk>.
    * @return This object.
    */
   public Operation addResponse(String statusCode, Response response) {
      assertArgNotNull("statusCode", statusCode);
      assertArgNotNull("response", response);
      responses.put(statusCode, response);
      return this;
   }

   /**
    * Bean property fluent setter:  <property>security</property>.
    *
    * <p>
    * A declaration of which security mechanisms can be used for this operation.
    *
    * @param values
    *    The values to add to this property.
    *    <br>Ignored if <jk>null</jk>.
    * @return This object.
    */
   public Operation addSecurity(Collection<SecurityRequirement> values) {
      if (nn(values))
         security.addAll(values);
      return this;
   }

   /**
    * Bean property fluent setter:  <property>security</property>.
    *
    * <p>
    * A declaration of which security mechanisms can be used for this operation.
    *
    * @param values
    *    The values to add to this property.
    *    <br>Ignored if <jk>null</jk>.
    * @return This object.
    */
   public Operation addSecurity(SecurityRequirement...values) {
      if (nn(values))
         for (var v : values)
            if (nn(v))
               security.add(v);
      return this;
   }

   /**
    * Bean property fluent setter:  <property>servers</property>.
    *
    * <p>
    * An alternative server array to service this operation.
    *
    * @param values
    *    The values to add to this property.
    *    <br>Ignored if <jk>null</jk>.
    * @return This object.
    */
   public Operation addServers(Collection<Server> values) {
      if (nn(values))
         servers.addAll(values);
      return this;
   }

   /**
    * Bean property fluent setter:  <property>servers</property>.
    *
    * <p>
    * An alternative server array to service this operation.
    *
    * @param values
    *    The values to add to this property.
    *    <br>Ignored if <jk>null</jk>.
    * @return This object.
    */
   public Operation addServers(Server...values) {
      if (nn(values))
         for (var v : values)
            if (nn(v))
               servers.add(v);
      return this;
   }

   /**
    * Bean property appender:  <property>tags</property>.
    *
    * <p>
    * A list of tags for API documentation control.
    *
    * @param values
    *    The values to add to this property.
    *    <br>Ignored if <jk>null</jk>.
    * @return This object.
    */
   public Operation addTags(Collection<String> values) {
      if (nn(values))
         tags.addAll(values);
      return this;
   }

   /**
    * Bean property appender:  <property>tags</property>.
    *
    * <p>
    * A list of tags for API documentation control.
    *
    * @param values
    *    The values to add to this property.
    *    <br>Ignored if <jk>null</jk>.
    * @return This object.
    */
   public Operation addTags(String...values) {
      if (nn(values))
         for (var v : values)
            if (nn(v))
               tags.add(v);
      return this;
   }

   /**
    * Creates a copy of this object.
    *
    * @return A copy of this object.
    */
   public Operation copy() {
      return new Operation(this);
   }

   @Override /* Overridden from OpenApiElement */
   public <T> T get(String property, Class<T> type) {
      assertArgNotNull("property", property);
      return switch (property) {
         case "tags" -> toType(getTags(), type);
         case "summary" -> toType(getSummary(), type);
         case "description" -> toType(getDescription(), type);
         case "operationId" -> toType(getOperationId(), type);
         case "externalDocs" -> toType(getExternalDocs(), type);
         case "parameters" -> toType(getParameters(), type);
         case "requestBody" -> toType(getRequestBody(), type);
         case "responses" -> toType(getResponses(), type);
         case "callbacks" -> toType(getCallbacks(), type);
         case "deprecated" -> toType(getDeprecated(), type);
         case "security" -> toType(getSecurity(), type);
         case "servers" -> toType(getServers(), type);
         default -> super.get(property, type);
      };
   }

   /**
    * Returns the callbacks map.
    *
    * @return The callbacks map.
    */
   public Map<String,Callback> getCallbacks() { return nullIfEmpty(callbacks); }

   /**
    * Returns the deprecated flag.
    *
    * @return The deprecated flag.
    */
   public Boolean getDeprecated() { return deprecated; }

   /**
    * Returns the description.
    *
    * @return The description.
    */
   public String getDescription() { return description; }

   /**
    * Returns the external documentation.
    *
    * @return The external documentation.
    */
   public ExternalDocumentation getExternalDocs() { return externalDocs; }

   /**
    * Returns the operation ID.
    *
    * @return The operation ID.
    */
   public String getOperationId() { return operationId; }

   /**
    * Returns the parameter with the specified type and name.
    *
    * @param in The parameter in.  Must not be <jk>null</jk>.
    * @param name The parameter name.  Must not be <jk>null</jk>.
    * @return The matching parameter, or <jk>null</jk> if not found.
    */
   public Parameter getParameter(String in, String name) {
      assertArgNotNull("in", in);
      assertArgNotNull("name", name);
      for (var p : parameters)
         if (eq(p.getIn(), in) && eq(p.getName(), name))
            return p;
      return null;
   }

   /**
    * Returns the parameters list.
    *
    * @return The parameters list.
    */
   public List<Parameter> getParameters() { return nullIfEmpty(parameters); }

   /**
    * Returns the request body.
    *
    * @return The request body.
    */
   public RequestBodyInfo getRequestBody() { return requestBody; }

   /**
    * Returns the response with the given status code.
    *
    * @param status The HTTP status code.
    * @return The response, or <jk>null</jk> if not found.
    */
   public Response getResponse(int status) {
      return getResponse(String.valueOf(status));
   }

   /**
    * Returns the response with the given status code.
    *
    * @param status The HTTP status code.  Must not be <jk>null</jk>.
    * @return The response, or <jk>null</jk> if not found.
    */
   public Response getResponse(String status) {
      assertArgNotNull("status", status);
      return responses.get(status);
   }

   /**
    * Returns the responses map.
    *
    * @return The responses map.
    */
   public Map<String,Response> getResponses() { return nullIfEmpty(responses); }

   /**
    * Returns the security requirements list.
    *
    * @return The security requirements list.
    */
   public List<SecurityRequirement> getSecurity() { return nullIfEmpty(security); }

   /**
    * Returns the servers list.
    *
    * @return The servers list.
    */
   public List<Server> getServers() { return nullIfEmpty(servers); }

   /**
    * Returns the summary.
    *
    * @return The summary.
    */
   public String getSummary() { return summary; }

   /**
    * Returns the tags list.
    *
    * @return The tags list.
    */
   public List<String> getTags() { return nullIfEmpty(tags); }

   @Override /* Overridden from OpenApiElement */
   public Set<String> keySet() {
      // @formatter:off
      var s = setb(String.class)
         .addIf(ne(callbacks), "callbacks")
         .addIf(nn(deprecated), "deprecated")
         .addIf(nn(description), "description")
         .addIf(nn(externalDocs), "externalDocs")
         .addIf(nn(operationId), "operationId")
         .addIf(ne(parameters), "parameters")
         .addIf(nn(requestBody), "requestBody")
         .addIf(ne(responses), "responses")
         .addIf(ne(security), "security")
         .addIf(ne(servers), "servers")
         .addIf(nn(summary), "summary")
         .addIf(ne(tags), "tags")
         .build();
      // @formatter:on
      return new MultiSet<>(s, super.keySet());
   }

   @Override /* Overridden from OpenApiElement */
   public Operation set(String property, Object value) {
      assertArgNotNull("property", property);
      return switch (property) {
         case "callbacks" -> setCallbacks(toMapBuilder(value, String.class, Callback.class).sparse().build());
         case "deprecated" -> setDeprecated(toType(value, Boolean.class));
         case "description" -> setDescription(s(value));
         case "externalDocs" -> setExternalDocs(toType(value, ExternalDocumentation.class));
         case "operationId" -> setOperationId(s(value));
         case "parameters" -> setParameters(toListBuilder(value, Parameter.class).sparse().build());
         case "requestBody" -> setRequestBody(toType(value, RequestBodyInfo.class));
         case "responses" -> setResponses(toMapBuilder(value, String.class, Response.class).sparse().build());
         case "security" -> setSecurity(toListBuilder(value, SecurityRequirement.class).sparse().build());
         case "servers" -> setServers(toListBuilder(value, Server.class).sparse().build());
         case "summary" -> setSummary(s(value));
         case "tags" -> setTags(toListBuilder(value, String.class).sparse().build());
         default -> {
            super.set(property, value);
            yield this;
         }
      };
   }

   /**
    * Sets the callbacks map.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setCallbacks(Map<String,Callback> value) {
      callbacks.clear();
      if (nn(value))
         callbacks.putAll(value);
      return this;
   }

   /**
    * Sets the deprecated flag.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setDeprecated(Boolean value) {
      deprecated = value;
      return this;
   }

   /**
    * Sets the description.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setDescription(String value) {
      description = value;
      return this;
   }

   /**
    * Sets the external documentation.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setExternalDocs(ExternalDocumentation value) {
      externalDocs = value;
      return this;
   }

   /**
    * Sets the operation ID.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setOperationId(String value) {
      operationId = value;
      return this;
   }

   /**
    * Sets the parameters list.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setParameters(List<Parameter> value) {
      parameters.clear();
      if (nn(value))
         parameters.addAll(value);
      return this;
   }

   /**
    * Sets the parameters list.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setParameters(Parameter...value) {
      setParameters(toListBuilder(value, Parameter.class).sparse().build());
      return this;
   }

   /**
    * Sets the request body.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setRequestBody(RequestBodyInfo value) {
      requestBody = value;
      return this;
   }

   /**
    * Sets the responses map.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setResponses(Map<String,Response> value) {
      responses.clear();
      if (nn(value))
         responses.putAll(value);
      return this;
   }

   /**
    * Sets the security requirements list.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setSecurity(List<SecurityRequirement> value) {
      security.clear();
      if (nn(value))
         security.addAll(value);
      return this;
   }

   /**
    * Sets the security requirements list.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setSecurity(SecurityRequirement...value) {
      setSecurity(toListBuilder(value, SecurityRequirement.class).sparse().build());
      return this;
   }

   /**
    * Sets the servers list.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setServers(List<Server> value) {
      servers.clear();
      if (nn(value))
         servers.addAll(value);
      return this;
   }

   /**
    * Sets the servers list.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setServers(Server...value) {
      setServers(toListBuilder(value, Server.class).sparse().build());
      return this;
   }

   /**
    * Sets the summary.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setSummary(String value) {
      summary = value;
      return this;
   }

   /**
    * Sets the tags list.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setTags(List<String> value) {
      tags.clear();
      if (nn(value))
         tags.addAll(value);
      return this;
   }

   /**
    * Sets the tags list.
    *
    * @param value The new value for this property.
    * @return This object.
    */
   public Operation setTags(String...value) {
      setTags(toListBuilder(value, String.class).sparse().build());
      return this;
   }

   @Override /* Overridden from OpenApiElement */
   public Operation strict() {
      super.strict();
      return this;
   }

   @Override /* Overridden from OpenApiElement */
   public Operation strict(Object value) {
      super.strict(value);
      return this;
   }
}