package com.box.sdk;

import com.eclipsesource.json.JsonObject;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.Collections;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * The abstract base class for all resource types (files, folders, comments, collaborations, etc.)
 * used by the API.
 *
 * <p>Every API resource has an ID and a {@link BoxAPIConnection} that it uses to communicate with
 * the API. Some resources also have an associated {@link Info} class that contains information
 * about the resource.
 */
public abstract class BoxResource {

  /** @see #initResourceClassByType() */
  private static final Map<String, Class<? extends BoxResource>> RESOURCE_CLASS_BY_TYPE =
      initResourceClassByType();

  private final BoxAPIConnection api;
  private final String id;

  /**
   * Constructs a BoxResource for a resource with a given ID.
   *
   * @param api the API connection to be used by the resource.
   * @param id the ID of the resource.
   */
  public BoxResource(BoxAPIConnection api, String id) {
    this.api = api;
    this.id = id;
  }

  /**
   * @return Builds {@link Map} between String {@link #getResourceType(Class)} and {@link
   *     BoxResource} type.
   */
  private static Map<String, Class<? extends BoxResource>> initResourceClassByType() {
    Map<String, Class<? extends BoxResource>> result =
        new ConcurrentHashMap<String, Class<? extends BoxResource>>();
    result.put(getResourceType(BoxFolder.class), BoxFolder.class);
    result.put(getResourceType(BoxFile.class), BoxFile.class);
    result.put(getResourceType(BoxComment.class), BoxComment.class);
    result.put(getResourceType(BoxCollaboration.class), BoxCollaboration.class);
    result.put(getResourceType(BoxTask.class), BoxTask.class);
    result.put(getResourceType(BoxTaskAssignment.class), BoxTaskAssignment.class);
    result.put(getResourceType(BoxUser.class), BoxUser.class);
    result.put(getResourceType(BoxGroup.class), BoxGroup.class);
    result.put(getResourceType(BoxGroupMembership.class), BoxGroupMembership.class);
    result.put(getResourceType(BoxEvent.class), BoxEvent.class);
    result.put(getResourceType(BoxWebHook.class), BoxWebHook.class);
    result.put(getResourceType(BoxCollection.class), BoxCollection.class);
    result.put(getResourceType(BoxDevicePin.class), BoxDevicePin.class);
    result.put(getResourceType(BoxRetentionPolicy.class), BoxRetentionPolicy.class);
    result.put(
        getResourceType(BoxRetentionPolicyAssignment.class), BoxRetentionPolicyAssignment.class);
    result.put(getResourceType(BoxFileVersionRetention.class), BoxFileVersionRetention.class);
    result.put(getResourceType(BoxLegalHoldPolicy.class), BoxLegalHoldPolicy.class);
    result.put(getResourceType(BoxLegalHoldAssignment.class), BoxLegalHoldAssignment.class);
    result.put(getResourceType(BoxFileVersionLegalHold.class), BoxFileVersionLegalHold.class);
    result.put(getResourceType(BoxFileUploadSession.class), BoxFileUploadSession.class);
    result.put(getResourceType(BoxWebLink.class), BoxWebLink.class);
    result.put(getResourceType(BoxStoragePolicy.class), BoxStoragePolicy.class);
    result.put(getResourceType(BoxStoragePolicyAssignment.class), BoxStoragePolicyAssignment.class);
    result.put(getResourceType(BoxFolderLock.class), BoxFolderLock.class);
    result.put(getResourceType(BoxFileRequest.class), BoxFileRequest.class);

    return Collections.unmodifiableMap(result);
  }

  /**
   * Resolves {@link BoxResourceType} for a provided {@link BoxResource} {@link Class}.
   *
   * @param clazz {@link BoxResource} type
   * @return resolved {@link BoxResourceType#value()}
   */
  public static String getResourceType(Class<? extends BoxResource> clazz) {
    BoxResourceType resource = clazz.getAnnotation(BoxResourceType.class);
    if (resource == null) {
      throw new IllegalArgumentException(
          "Provided BoxResource type does not have @BoxResourceType annotation.");
    }
    return resource.value();
  }

  static BoxResource.Info parseInfo(BoxAPIConnection api, JsonObject jsonObject) {
    String type = jsonObject.get("type").asString();
    String id = jsonObject.get("id").asString();

    try {
      Class<? extends BoxResource> resourceClass = RESOURCE_CLASS_BY_TYPE.get(type);
      Constructor<? extends BoxResource> resourceConstructor =
          resourceClass.getConstructor(BoxAPIConnection.class, String.class);

      Class<?> infoClass =
          resourceClass.getClassLoader().loadClass(resourceClass.getCanonicalName() + "$Info");
      Constructor<?> infoConstructor =
          infoClass.getDeclaredConstructor(resourceClass, JsonObject.class);

      BoxResource resource = resourceConstructor.newInstance(api, id);
      return (BoxResource.Info) infoConstructor.newInstance(resource, jsonObject);

    } catch (ClassNotFoundException e) {
      return null;
    } catch (NoSuchMethodException e) {
      return null;
    } catch (IllegalAccessException e) {
      throw new BoxAPIException("Can not create BoxResource.Info instance:", e);
    } catch (InvocationTargetException e) {
      throw new BoxAPIException("Can not create BoxResource.Info instance:", e);
    } catch (InstantiationException e) {
      throw new BoxAPIException("Can not create BoxResource.Info instance:", e);
    }
  }

  /**
   * Gets the API connection used by this resource.
   *
   * @return the API connection used by this resource.
   */
  public BoxAPIConnection getAPI() {
    return this.api;
  }

  /**
   * Gets the ID of this resource.
   *
   * @return the ID of this resource.
   */
  public String getID() {
    return this.id;
  }

  /**
   * Indicates whether this BoxResource is equal to another BoxResource. Two BoxResources are equal
   * if they have the same type and ID.
   *
   * @param other the other BoxResource to compare.
   * @return true if the type and IDs of the two resources are equal; otherwise false.
   */
  @Override
  public boolean equals(Object other) {
    if (other == null) {
      return false;
    }

    if (this.getClass().equals(other.getClass())) {
      BoxResource otherResource = (BoxResource) other;
      return this.getID().equals(otherResource.getID());
    }

    return false;
  }

  /**
   * Returns a hash code value for this BoxResource.
   *
   * @return a hash code value for this BoxResource.
   */
  @Override
  public int hashCode() {
    return this.getID().hashCode();
  }

  /** Contains information about a BoxResource. */
  public abstract class Info extends BoxJSONObject {
    /** Constructs an empty Info object. */
    public Info() {
      super();
    }

    /**
     * Constructs an Info object by parsing information from a JSON string.
     *
     * @param json the JSON string to parse.
     */
    public Info(String json) {
      super(json);
    }

    /**
     * Constructs an Info object using an already parsed JSON object.
     *
     * @param jsonObject the parsed JSON object.
     */
    Info(JsonObject jsonObject) {
      super(jsonObject);
    }

    /**
     * Gets the ID of the resource associated with this Info.
     *
     * @return the ID of the associated resource.
     */
    public String getID() {
      return BoxResource.this.getID();
    }

    /**
     * Gets the resource associated with this Info.
     *
     * @return the associated resource.
     */
    public abstract BoxResource getResource();
  }
}