/*
    * 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.ThrowableUtils.*;
  import static org.apache.juneau.commons.utils.Utils.*;
  import static org.apache.juneau.internal.ConverterUtils.*;
  
  import java.util.*;
  
  import org.apache.juneau.commons.collections.*;
  import org.apache.juneau.json.*;
  import org.apache.juneau.objecttools.*;
  
  /**
   * This is the root document object for the OpenAPI specification.
   *
   * <p>
   * The OpenAPI Object is the root document that describes an entire API. It contains metadata about the API,
   * available paths and operations, parameters, responses, authentication methods, and other information.
   *
   * <h5 class='section'>OpenAPI Specification:</h5>
   * <p>
   * The OpenAPI Object is composed of the following fields:
   * <ul class='spaced-list'>
   * 	<li><c>openapi</c> (string, REQUIRED) - The OpenAPI Specification version (e.g., "3.0.0")
   * 	<li><c>info</c> ({@link Info}, REQUIRED) - Provides metadata about the API
   * 	<li><c>servers</c> (array of {@link Server}) - An array of Server Objects providing connectivity information
   * 	<li><c>paths</c> (map of {@link PathItem}) - The available paths and operations for the API
   * 	<li><c>components</c> ({@link Components}) - An element to hold various schemas for reuse
   * 	<li><c>security</c> (array of {@link SecurityRequirement}) - Security mechanisms applied to all operations
   * 	<li><c>tags</c> (array of {@link Tag}) - A list of tags for API documentation control
   * 	<li><c>externalDocs</c> ({@link ExternalDocumentation}) - Additional external documentation
   * </ul>
   *
   * <h5 class='section'>Example:</h5>
   * <p class='bjava'>
   * 	<jc>// Create an OpenAPI document</jc>
   * 	OpenApi <jv>doc</jv> = <jk>new</jk> OpenApi()
   * 		.setOpenapi(<js>"3.0.0"</js>)
   * 		.setInfo(
   * 			<jk>new</jk> Info()
   * 				.setTitle(<js>"My API"</js>)
   * 				.setVersion(<js>"1.0.0"</js>)
   * 		)
   * 		.setPaths(
   * 			JsonMap.<jsm>of</jsm>(
   * 				<js>"/pets"</js>, <jk>new</jk> PathItem()
   * 					.setGet(<jk>new</jk> Operation()
   * 						.setSummary(<js>"List all pets"</js>)
   * 					)
   * 			)
   * 		);
   * </p>
   *
   * <h5 class='section'>See Also:</h5><ul>
   * 	<li class='link'><a class="doclink" href="https://spec.openapis.org/oas/v3.0.0#openapi-object">OpenAPI Specification &gt; OpenAPI Object</a>
   * 	<li class='link'><a class="doclink" href="https://swagger.io/docs/specification/basic-structure/">OpenAPI Basic Structure</a>
   * 	<li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauBeanOpenApi3">juneau-bean-openapi-v3</a>
   * </ul>
   */
  public class OpenApi extends OpenApiElement {
  
  	/** Represents a null OpenAPI document */
  	public static final OpenApi NULL = new OpenApi();
  
  	private static final Comparator<String> PATH_COMPARATOR = (o1, o2) -> o1.replace('{', '@').compareTo(o2.replace('{', '@'));
  
  	private String openapi = "3.0.0";
  	private Info info;
  	private List<Server> servers = list();
  	private Map<String,PathItem> paths;
  	private Components components;
  	private List<SecurityRequirement> security = list();
  	private List<Tag> tags = list();
  	private ExternalDocumentation externalDocs;
  
  	/**
  	 * Default constructor.
  	 */
  	public OpenApi() {}
  
  	/**
 	 * Copy constructor.
 	 *
 	 * @param copyFrom The object to copy.
 	 */
 	public OpenApi(OpenApi copyFrom) {
 		super(copyFrom);
 		this.openapi = copyFrom.openapi;
 		this.info = copyFrom.info;
 		if (nn(copyFrom.servers))
 			this.servers.addAll(copyOf(copyFrom.servers, Server::copy));
 		this.paths = copyOf(copyFrom.paths);
 		this.components = copyFrom.components;
 		if (nn(copyFrom.security))
 			this.security.addAll(copyOf(copyFrom.security, SecurityRequirement::copy));
 		if (nn(copyFrom.tags))
 			this.tags.addAll(copyOf(copyFrom.tags, Tag::copy));
 		this.externalDocs = copyFrom.externalDocs;
 	}
 
 	/**
 	 * Adds a path to this OpenAPI document.
 	 *
 	 * @param path The path string.  Must not be <jk>null</jk>.
 	 * @param pathItem The path item.  Must not be <jk>null</jk>.
 	 * @return This object.
 	 */
 	public OpenApi addPath(String path, PathItem pathItem) {
 		assertArgNotNull("path", path);
 		assertArgNotNull("pathItem", pathItem);
 		if (paths == null)
 			paths = new TreeMap<>(PATH_COMPARATOR);
 		getPaths().put(path, pathItem);
 		return this;
 	}
 
 	/**
 	 * Bean property fluent setter:  <property>security</property>.
 	 *
 	 * <p>
 	 * A declaration of which security mechanisms can be used across the API.
 	 *
 	 * @param values
 	 * 	The values to add to this property.
 	 * 	<br>Ignored if <jk>null</jk>.
 	 * @return This object.
 	 */
 	public OpenApi addSecurity(Collection<SecurityRequirement> values) {
 		security = listb(SecurityRequirement.class).sparse().addAny(security, values).build();
 		return this;
 	}
 
 	/**
 	 * Bean property fluent setter:  <property>security</property>.
 	 *
 	 * <p>
 	 * A declaration of which security mechanisms can be used across the API.
 	 *
 	 * @param values
 	 * 	The values to add to this property.
 	 * 	<br>Ignored if <jk>null</jk>.
 	 * @return This object.
 	 */
 	public OpenApi addSecurity(SecurityRequirement...values) {
 		security = listb(SecurityRequirement.class).sparse().addAll(security).addAny((Object)values).build();
 		return this;
 	}
 
 	/**
 	 * Bean property fluent setter:  <property>servers</property>.
 	 *
 	 * <p>
 	 * An array of Server Objects, which provide connectivity information to a target server.
 	 *
 	 * @param values
 	 * 	The values to add to this property.
 	 * 	<br>Ignored if <jk>null</jk>.
 	 * @return This object.
 	 */
 	public OpenApi addServers(Collection<Server> values) {
 		if (nn(values))
 			servers.addAll(values);
 		return this;
 	}
 
 	/**
 	 * Bean property fluent setter:  <property>servers</property>.
 	 *
 	 * <p>
 	 * An array of Server Objects, which provide connectivity information to a target server.
 	 *
 	 * @param values
 	 * 	The values to add to this property.
 	 * 	<br>Ignored if <jk>null</jk>.
 	 * @return This object.
 	 */
 	public OpenApi 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 used by the specification with additional metadata.
 	 *
 	 * @param values
 	 * 	The values to add to this property.
 	 * 	<br>Ignored if <jk>null</jk>.
 	 * @return This object.
 	 */
 	public OpenApi addTags(Collection<Tag> values) {
 		if (nn(values))
 			tags.addAll(values);
 		return this;
 	}
 
 	/**
 	 * Bean property appender:  <property>tags</property>.
 	 *
 	 * <p>
 	 * A list of tags used by the specification with additional metadata.
 	 *
 	 * @param values
 	 * 	The values to add to this property.
 	 * 	<br>Ignored if <jk>null</jk>.
 	 * @return This object.
 	 */
 	public OpenApi addTags(Tag...values) {
 		if (nn(values))
 			for (var v : values)
 				if (nn(v))
 					tags.add(v);
 		return this;
 	}
 
 	/**
 	 * Make a deep copy of this object.
 	 *
 	 * @return A deep copy of this object.
 	 */
 	public OpenApi copy() {
 		return new OpenApi(this);
 	}
 
 	/**
 	 * Finds a reference within this OpenAPI document.
 	 *
 	 * @param ref The reference string (e.g., <js>"#/components/schemas/User"</js>).  Must not be <jk>null</jk> or blank.
 	 * @param c The expected class type.  Must not be <jk>null</jk>.
 	 * @return The referenced node, or <jk>null</jk> if not found.
 	 */
 	public <T> T findRef(String ref, Class<T> c) {
 		assertArgNotNullOrBlank("ref", ref);
 		assertArgNotNull("c", c);
 		if (! ref.startsWith("#/"))
 			throw rex("Unsupported reference:  ''{0}''", ref);
 		try {
 			return new ObjectRest(this).get(ref.substring(1), c);
 		} catch (Exception e) {
 			throw bex(e, c, "Reference ''{0}'' could not be converted to type ''{1}''.", ref, cn(c));
 		}
 	}
 
 	@Override /* Overridden from OpenApiElement */
 	public <T> T get(String property, Class<T> type) {
 		assertArgNotNull("property", property);
 		return switch (property) {
 			case "openapi" -> toType(getOpenapi(), type);
 			case "info" -> toType(getInfo(), type);
 			case "servers" -> toType(getServers(), type);
 			case "paths" -> toType(getPaths(), type);
 			case "components" -> toType(getComponents(), type);
 			case "security" -> toType(getSecurity(), type);
 			case "tags" -> toType(getTags(), type);
 			case "externalDocs" -> toType(getExternalDocs(), type);
 			default -> super.get(property, type);
 		};
 	}
 
 	/**
 	 * Returns the components object.
 	 *
 	 * @return The components object.
 	 */
 	public Components getComponents() { return components; }
 
 	/**
 	 * Returns the external documentation.
 	 *
 	 * @return The external documentation.
 	 */
 	public ExternalDocumentation getExternalDocs() { return externalDocs; }
 
 	/**
 	 * Returns the info object.
 	 *
 	 * @return The info object.
 	 */
 	public Info getInfo() { return info; }
 
 	/**
 	 * Returns the OpenAPI version.
 	 *
 	 * @return The OpenAPI version.
 	 */
 	public String getOpenapi() { return openapi; }
 
 	/**
 	 * Returns the paths map.
 	 *
 	 * @return The paths map.
 	 */
 	public Map<String,PathItem> getPaths() { return paths; }
 
 	/**
 	 * 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 tags list.
 	 *
 	 * @return The tags list.
 	 */
 	public List<Tag> getTags() { return nullIfEmpty(tags); }
 
 	@Override /* Overridden from OpenApiElement */
 	public Set<String> keySet() {
 		// @formatter:off
 		var s = setb(String.class)
 			.addIf(nn(components), "components")
 			.addIf(nn(externalDocs), "externalDocs")
 			.addIf(nn(info), "info")
 			.addIf(nn(openapi), "openapi")
 			.addIf(nn(paths), "paths")
 			.addIf(ne(security), "security")
 			.addIf(ne(servers), "servers")
 			.addIf(ne(tags), "tags")
 			.build();
 		// @formatter:on
 		return new MultiSet<>(s, super.keySet());
 	}
 
 	@Override /* Overridden from OpenApiElement */
 	public OpenApi set(String property, Object value) {
 		assertArgNotNull("property", property);
 		return switch (property) {
 			case "components" -> setComponents(toType(value, Components.class));
 			case "externalDocs" -> setExternalDocs(toType(value, ExternalDocumentation.class));
 			case "info" -> setInfo(toType(value, Info.class));
 			case "openapi" -> setOpenapi(s(value));
 			case "paths" -> setPaths(toMapBuilder(value, String.class, PathItem.class).sparse().build());
 			case "security" -> setSecurity(listb(SecurityRequirement.class).addAny(value).sparse().build());
 			case "servers" -> setServers(listb(Server.class).addAny(value).sparse().build());
 			case "tags" -> setTags(listb(Tag.class).addAny(value).sparse().build());
 			default -> {
 				super.set(property, value);
 				yield this;
 			}
 		};
 	}
 
 	/**
 	 * Sets the components object.
 	 *
 	 * @param value The new value for this property.
 	 * @return This object.
 	 */
 	public OpenApi setComponents(Components value) {
 		components = value;
 		return this;
 	}
 
 	/**
 	 * Sets the external documentation.
 	 *
 	 * @param value The new value for this property.
 	 * @return This object.
 	 */
 	public OpenApi setExternalDocs(ExternalDocumentation value) {
 		externalDocs = value;
 		return this;
 	}
 
 	/**
 	 * Sets the info object.
 	 *
 	 * @param value The new value for this property.
 	 * @return This object.
 	 */
 	public OpenApi setInfo(Info value) {
 		info = value;
 		return this;
 	}
 
 	/**
 	 * Sets the OpenAPI version.
 	 *
 	 * @param value The new value for this property.
 	 * @return This object.
 	 */
 	public OpenApi setOpenapi(String value) {
 		openapi = value;
 		return this;
 	}
 
 	/**
 	 * Sets the paths map.
 	 *
 	 * @param value The new value for this property.
 	 * @return This object.
 	 */
 	public OpenApi setPaths(Map<String,PathItem> value) {
 		this.paths = toMapBuilder(value, String.class, PathItem.class).sparse().sorted(PATH_COMPARATOR).build();
 		return this;
 	}
 
 	/**
 	 * Sets the security requirements list.
 	 *
 	 * @param value The new value for this property.
 	 * @return This object.
 	 */
 	public OpenApi setSecurity(List<SecurityRequirement> value) {
 		security.clear();
 		if (nn(value))
 			security.addAll(value);
 		return this;
 	}
 
 	/**
 	 * Sets the servers list.
 	 *
 	 * @param value The new value for this property.
 	 * @return This object.
 	 */
 	public OpenApi setServers(List<Server> value) {
 		servers.clear();
 		if (nn(value))
 			servers.addAll(value);
 		return this;
 	}
 
 	/**
 	 * Sets the tags list.
 	 *
 	 * @param value The new value for this property.
 	 * @return This object.
 	 */
 	public OpenApi setTags(List<Tag> value) {
 		tags.clear();
 		if (nn(value))
 			tags.addAll(value);
 		return this;
 	}
 
 	/**
 	 * Bean property setter:  <property>tags</property>.
 	 *
 	 * <p>
 	 * A list of tags used by the specification with additional metadata.
 	 *
 	 * @param value
 	 * 	The new value for this property.
 	 * 	<br>Ignored if <jk>null</jk>.
 	 * @return This object.
 	 */
 	public OpenApi setTags(Tag...value) {
 		setTags(listb(Tag.class).add(value).sparse().build());
 		return this;
 	}
 
 	@Override /* Overridden from OpenApiElement */
 	public OpenApi strict() {
 		super.strict();
 		return this;
 	}
 
 	@Override /* Overridden from OpenApiElement */
 	public OpenApi strict(Object value) {
 		super.strict(value);
 		return this;
 	}
 
 	@Override
 	public String toString() {
 		return JsonSerializer.DEFAULT.toString(this);
 	}
 }