package com.box.sdk;

import java.net.URL;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;

import com.eclipsesource.json.JsonArray;
import com.eclipsesource.json.JsonObject;
import com.eclipsesource.json.JsonValue;

/**
 * Represents a collaboration between a user and another user or group. Collaborations are Box's equivalent of access
 * control lists. They can be used to set and apply permissions for users or groups to folders.
 *
 * <p>Unless otherwise noted, the methods in this class can throw an unchecked {@link BoxAPIException} (unchecked
 * meaning that the compiler won't force you to handle it) if an error occurs. If you wish to implement custom error
 * handling for errors related to the Box REST API, you should capture this exception explicitly.</p>
 */
@BoxResourceType("collaboration")
public class BoxCollaboration extends BoxResource {
    private static final URLTemplate COLLABORATIONS_URL_TEMPLATE = new URLTemplate("collaborations");
    private static final URLTemplate PENDING_COLLABORATIONS_URL = new URLTemplate("collaborations?status=pending");
    private static final URLTemplate COLLABORATION_URL_TEMPLATE = new URLTemplate("collaborations/%s");
    private static final URLTemplate GET_ALL_FILE_COLLABORATIONS_URL = new URLTemplate("files/%s/collaborations/");

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


    /**
     * Gets all pending collaboration invites for the current user.
     *
     * @param api the API connection to use.
     * @return a collection of pending collaboration infos.
     */
    public static Collection<Info> getPendingCollaborations(BoxAPIConnection api) {
        URL url = PENDING_COLLABORATIONS_URL.build(api.getBaseURL());

        BoxAPIRequest request = new BoxAPIRequest(api, url, "GET");
        BoxJSONResponse response = (BoxJSONResponse) request.send();
        JsonObject responseJSON = JsonObject.readFrom(response.getJSON());

        int entriesCount = responseJSON.get("total_count").asInt();
        Collection<BoxCollaboration.Info> collaborations = new ArrayList<BoxCollaboration.Info>(entriesCount);
        JsonArray entries = responseJSON.get("entries").asArray();
        for (JsonValue entry : entries) {
            JsonObject entryObject = entry.asObject();
            BoxCollaboration collaboration = new BoxCollaboration(api, entryObject.get("id").asString());
            BoxCollaboration.Info info = collaboration.new Info(entryObject);
            collaborations.add(info);
        }

        return collaborations;
    }

    /**
     * Gets information about this collaboration.
     *
     * @return info about this collaboration.
     */
    public Info getInfo() {
        BoxAPIConnection api = this.getAPI();
        URL url = COLLABORATION_URL_TEMPLATE.build(api.getBaseURL(), this.getID());

        BoxAPIRequest request = new BoxAPIRequest(api, url, "GET");
        BoxJSONResponse response = (BoxJSONResponse) request.send();
        JsonObject jsonObject = JsonObject.readFrom(response.getJSON());
        return new Info(jsonObject);
    }

    /**
     * Updates the information about this collaboration with any info fields that have been modified locally.
     *
     * @param info the updated info.
     */
    public void updateInfo(Info info) {
        BoxAPIConnection api = this.getAPI();
        URL url = COLLABORATION_URL_TEMPLATE.build(api.getBaseURL(), this.getID());

        BoxJSONRequest request = new BoxJSONRequest(api, url, "PUT");
        request.setBody(info.getPendingChanges());
        BoxAPIResponse boxAPIResponse = request.send();

        if (boxAPIResponse instanceof BoxJSONResponse) {
            BoxJSONResponse response = (BoxJSONResponse) boxAPIResponse;
            JsonObject jsonObject = JsonObject.readFrom(response.getJSON());
            info.update(jsonObject);
        }
    }

    /**
     * Deletes this collaboration.
     */
    public void delete() {
        BoxAPIConnection api = this.getAPI();
        URL url = COLLABORATION_URL_TEMPLATE.build(api.getBaseURL(), this.getID());

        BoxAPIRequest request = new BoxAPIRequest(api, url, "DELETE");
        BoxAPIResponse response = request.send();
        response.disconnect();
    }

    /**
     * Contains information about a BoxCollaboration.
     */
    public class Info extends BoxResource.Info {
        private BoxUser.Info createdBy;
        private Date createdAt;
        private Date modifiedAt;
        private Date expiresAt;
        private Status status;
        private BoxCollaborator.Info accessibleBy;
        private Role role;
        private Date acknowledgedAt;
        private BoxFolder.Info item;
        private BoxFile.Info fileItem;

        /**
         * 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);
        }

        Info(JsonObject jsonObject) {
            super(jsonObject);
        }

        /**
         * Gets the user who created the collaboration.
         *
         * @return the user who created the collaboration.
         */
        public BoxUser.Info getCreatedBy() {
            return this.createdBy;
        }

        /**
         * Gets the time the collaboration was created.
         *
         * @return the time the collaboration was created.
         */
        public Date getCreatedAt() {
            return this.createdAt;
        }

        /**
         * Gets the time the collaboration was last modified.
         *
         * @return the time the collaboration was last modified.
         */
        public Date getModifiedAt() {
            return this.modifiedAt;
        }

        /**
         * Gets the time the collaboration will expire.
         *
         * @return the time the collaboration will expire.
         */
        public Date getExpiresAt() {
            return this.expiresAt;
        }

        /**
         * Gets the status of the collaboration.
         *
         * @return the status of the collaboration.
         */
        public Status getStatus() {
            return this.status;
        }

        /**
         * Sets the status of the collaboration in order to accept or reject the collaboration if it's pending.
         *
         * @param status the new status of the collaboration.
         */
        public void setStatus(Status status) {
            this.status = status;
            this.addPendingChange("status", status.name().toLowerCase());
        }

        /**
         * Gets the collaborator who this collaboration applies to.
         *
         * @return the collaborator who this collaboration applies to.
         */
        public BoxCollaborator.Info getAccessibleBy() {
            return this.accessibleBy;
        }

        /**
         * Gets the level of access the collaborator has.
         *
         * @return the level of access the collaborator has.
         */
        public Role getRole() {
            return this.role;
        }

        /**
         * Sets the level of access the collaborator has.
         *
         * @param role the new level of access to give the collaborator.
         */
        public void setRole(Role role) {
            this.role = role;
            this.addPendingChange("role", role.toJSONString());
        }

        /**
         * Gets the time the collaboration's status was changed.
         *
         * @return the time the collaboration's status was changed.
         */
        public Date getAcknowledgedAt() {
            return this.acknowledgedAt;
        }

        /**
         * Gets the folder the collaboration is related to.
         *
         * @return the folder the collaboration is related to.
         */
        public BoxFolder.Info getItem() {
            return this.item;
        }

        @Override
        public BoxCollaboration getResource() {
            return BoxCollaboration.this;
        }

        @Override
        protected void parseJSONMember(JsonObject.Member member) {
            super.parseJSONMember(member);

            String memberName = member.getName();
            JsonValue value = member.getValue();
            try {
                if (memberName.equals("created_by")) {
                    JsonObject userJSON = value.asObject();
                    if (this.createdBy == null) {
                        String userID = userJSON.get("id").asString();
                        BoxUser user = new BoxUser(getAPI(), userID);
                        this.createdBy = user.new Info(userJSON);
                    } else {
                        this.createdBy.update(userJSON);
                    }

                } else if (memberName.equals("created_at")) {
                    this.createdAt = BoxDateFormat.parse(value.asString());

                } else if (memberName.equals("modified_at")) {
                    this.modifiedAt = BoxDateFormat.parse(value.asString());

                } else if (memberName.equals("expires_at")) {
                    this.expiresAt = BoxDateFormat.parse(value.asString());

                } else if (memberName.equals("status")) {
                    String statusString = value.asString().toUpperCase();
                    this.status = Status.valueOf(statusString);

                } else if (memberName.equals("accessible_by")) {
                    JsonObject accessibleByJSON = value.asObject();
                    if (this.accessibleBy == null) {
                        this.accessibleBy = this.parseAccessibleBy(accessibleByJSON);
                    } else {
                        this.updateAccessibleBy(accessibleByJSON);
                    }
                } else if (memberName.equals("role")) {
                    this.role = Role.fromJSONString(value.asString());

                } else if (memberName.equals("acknowledged_at")) {
                    this.acknowledgedAt = BoxDateFormat.parse(value.asString());

                } else if (memberName.equals("item")) {
                    JsonObject folderJSON = value.asObject();
                    if (this.item == null) {
                        String folderID = folderJSON.get("id").asString();
                        BoxFolder folder = new BoxFolder(getAPI(), folderID);
                        this.item = folder.new Info(folderJSON);
                    } else {
                        this.item.update(folderJSON);
                    }
                }
            } catch (ParseException e) {
                assert false : "A ParseException indicates a bug in the SDK.";
            }
        }

        private void updateAccessibleBy(JsonObject json) {
            String type = json.get("type").asString();
            if ((type.equals("user") && this.accessibleBy instanceof BoxUser.Info)
                    || (type.equals("group") && this.accessibleBy instanceof BoxGroup.Info)) {

                this.accessibleBy.update(json);
            } else {
                this.accessibleBy = this.parseAccessibleBy(json);
            }
        }

        private BoxCollaborator.Info parseAccessibleBy(JsonObject json) {
            String id = json.get("id").asString();
            String type = json.get("type").asString();
            BoxCollaborator.Info parsedInfo = null;
            if (type.equals("user")) {
                BoxUser user = new BoxUser(getAPI(), id);
                parsedInfo = user.new Info(json);
            } else if (type.equals("group")) {
                BoxGroup group = new BoxGroup(getAPI(), id);
                parsedInfo = group.new Info(json);
            }

            return parsedInfo;
        }
    }

    /**
     * Enumerates the possible statuses that a collaboration can have.
     */
    public enum Status {
        /**
         * The collaboration has been accepted.
         */
        ACCEPTED,

        /**
         * The collaboration is waiting to be accepted or rejected.
         */
        PENDING,

        /**
         * The collaboration has been rejected.
         */
        REJECTED;
    }

    /**
     * Enumerates the possible access levels that a collaborator can have.
     */
    public enum Role {
        /**
         * An Editor has full read/write access to a folder. Once invited to a folder, they will be able to view,
         * download, upload, edit, delete, copy, move, rename, generate shared links, make comments, assign tasks,
         * create tags, and invite/remove collaborators. They will not be able to delete or move root level folders.
         */
        EDITOR("editor"),

        /**
         * The viewer role has full read access to a folder. Once invited to a folder, they will be able to preview,
         * download, make comments, and generate shared links.  They will not be able to add tags, invite new
         * collaborators, upload, edit, or delete items in the folder.
         */
        VIEWER("viewer"),

        /**
         * The previewer role has limited read access to a folder. They will only be able to preview the items in the
         * folder using the integrated content viewer. They will not be able to share, upload, edit, or delete any
         * content. This role is only available to enterprise accounts.
         */
        PREVIEWER("previewer"),

        /**
         * The uploader has limited write access to a folder. They will only be able to upload and see the names of the
         * items in a folder. They will not able to download or view any content. This role is only available to
         * enterprise accounts.
         */
        UPLOADER("uploader"),

        /**
         * The previewer-uploader role is a combination of previewer and uploader. A user with this access level will be
         * able to preview files using the integrated content viewer as well as upload items into the folder. They will
         * not be able to download, edit, or share, items in the folder. This role is only available to enterprise
         * accounts.
         */
        PREVIEWER_UPLOADER("previewer uploader"),

        /**
         * The viewer-uploader role is a combination of viewer and uploader. A viewer-uploader has full read access to a
         * folder and limited write access. They are able to preview, download, add comments, generate shared links, and
         * upload content to the folder. They will not be able to add tags, invite new collaborators, edit, or delete
         * items in the folder. This role is only available to enterprise accounts.
         */
        VIEWER_UPLOADER("viewer uploader"),

        /**
         * The co-owner role has all of the functional read/write access that an editor does. This permission level has
         * the added ability of being able to manage users in the folder. A co-owner can add new collaborators, change
         * access levels of existing collaborators, and remove collaborators. However, they will not be able to
         * manipulate the owner of the folder or transfer ownership to another user. This role is only available to
         * enterprise accounts.
         */
        CO_OWNER("co-owner"),

        /**
         * The owner role has all of the functional capabilities of a co-owner. However, they will be able to manipulate
         * the owner of the folder or transfer ownership to another user. This role is only available to enterprise
         * accounts.
         */
        OWNER("owner");

        private final String jsonValue;

        private Role(String jsonValue) {
            this.jsonValue = jsonValue;
        }

        static Role fromJSONString(String jsonValue) {
            if (jsonValue.equals("editor")) {
                return EDITOR;
            } else if (jsonValue.equals("viewer")) {
                return VIEWER;
            } else if (jsonValue.equals("previewer")) {
                return PREVIEWER;
            } else if (jsonValue.equals("uploader")) {
                return UPLOADER;
            } else if (jsonValue.equals("previewer uploader")) {
                return PREVIEWER_UPLOADER;
            } else if (jsonValue.equals("viewer uploader")) {
                return VIEWER_UPLOADER;
            } else if (jsonValue.equals("co-owner")) {
                return CO_OWNER;
            } else if (jsonValue.equals("owner")) {
                return OWNER;
            } else {
                throw new IllegalArgumentException("The provided JSON value isn't a valid Role.");
            }
        }

        String toJSONString() {
            return this.jsonValue;
        }
    }

    /**
     * Used to retrieve all collaborations associated with the item.
     *
     * @param api   BoxAPIConnection from the associated file.
     * @param fileID   FileID of the assocyaed file
     * @param pageSize   page size for server pages of the Iterable
     * @param fields the optional fields to retrieve.
     * @return An iterable of BoxCollaboration.Info instances associated with the item.
     */
    public static BoxResourceIterable<Info> getAllFileCollaborations(final BoxAPIConnection api, String fileID,
                                                                           int pageSize, String... fields) {
        QueryStringBuilder builder = new QueryStringBuilder();
        if (fields.length > 0) {
            builder.appendParam("fields", fields);
        }
        return new BoxResourceIterable<BoxCollaboration.Info>(
                api, GET_ALL_FILE_COLLABORATIONS_URL.buildWithQuery(api.getBaseURL(), builder.toString(), fileID),
                pageSize) {

            @Override
            protected BoxCollaboration.Info factory(JsonObject jsonObject) {
                String id = jsonObject.get("id").asString();
                return new BoxCollaboration(api, id).new Info(jsonObject);
            }
        };
    }
}