/**
 * jira-client - a simple JIRA REST client
 * Copyright (c) 2013 Bob Carroll (bob.carroll@alum.rit.edu)
 * <p>
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * <p>
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * <p>
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

package net.rcarz.jiraclient.agile;

import net.rcarz.jiraclient.Field;
import net.rcarz.jiraclient.JiraException;
import net.rcarz.jiraclient.RestClient;
import net.sf.json.JSON;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import org.apache.commons.lang.BooleanUtils;
import org.apache.commons.lang.math.NumberUtils;

import java.lang.reflect.Constructor;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * A base class for Agile resources.
 *
 * @see "https://docs.atlassian.com/jira-software/REST/cloud/"
 */
public abstract class AgileResource {

    public static final String ATTR_ID = "id";
    public static final String ATTR_NAME = "name";
    public static final String ATTR_SELF = "self";

    protected static final String RESOURCE_URI = "/rest/agile/1.0/";

    private RestClient restclient = null;
    private int id = 0;
    private String name;
    private String self;
    private Map<String, Object> attributes = new HashMap<String, Object>();

    /**
     * Creates a new Agile resource.
     *
     * @param restclient REST client instance
     * @param json       JSON payload
     */
    public AgileResource(RestClient restclient, JSONObject json) {
        this.restclient = restclient;
        if (json != null) {
            deserialize(json);
        }
    }

    /**
     * @return Internal JIRA ID.
     */
    public int getId() {
        return id;
    }

    /**
     * @return The resource name.
     */
    public String getName() {
        return name;
    }

    /**
     * @return The resource URL.
     */
    public String getSelfURL() {
        return self;
    }

    /**
     * @return The REST client used to access the current resource.
     */
    protected RestClient getRestclient() {
        return restclient;
    }

    /**
     * Retrieve the specified attribute as a generic object.
     *
     * @param name The name of the attribute to retrieve.
     * @return The value of the attribute.
     */
    public String getAttribute(String name) {
        return (String) attributes.get(name);
    }

    /**
     * Retrieve the specified attribute as a generic object.
     *
     * @param name The name of the attribute to retrieve.
     * @return The value of the attribute.
     */
    public int getAttributeAsInt(String name) {
        return NumberUtils.toInt(getAttribute(name), 0);
    }

    /**
     * Retrieve the specified attribute as a generic object.
     *
     * @param name The name of the attribute to retrieve.
     * @return The value of the attribute.
     */
    public boolean getAttributeAsBoolean(String name) {
        return BooleanUtils.toBoolean(getAttribute(name));
    }

    /**
     * Deserialize the json to extract standard attributes and keep a reference of
     * other attributes.
     *
     * @param json The JSON object to read.
     */
    protected void deserialize(JSONObject json) {
        Map<String, Object> map = json;

        id = Field.getInteger(map.get("id"));
        name = Field.getString(map.get("name"));
        self = Field.getString(map.get("self"));
        attributes.putAll(map);
    }

    @Override
    public String toString() {
        return String.format("%s{id=%s, name='%s'}", getClass().getSimpleName(), id, name);
    }

    /**
     * Gets an Agile resource from the given object.
     *
     * @param type       Resource data type
     * @param r          a JSONObject instance
     * @param restclient REST client instance
     * @return a Resource instance or null if r isn't a JSONObject instance
     */
    private static <T extends AgileResource> T getResource(
            Class<T> type, Object r, RestClient restclient) throws JiraException {

        if (!(r instanceof JSONObject)) {
            throw new JiraException("JSON payload is malformed");
        }

        T result = null;

        if (!((JSONObject) r).isNullObject()) {
            try {
                Constructor<T> constructor = type.getDeclaredConstructor(RestClient.class, JSONObject.class);
                result = constructor.newInstance(restclient, r);
            } catch (Exception e) {
                throw new JiraException("Failed to deserialize object array.");
            }
        }

        return result;
    }

    /**
     * Gets a list of GreenHopper resources from the given object.
     *
     * @param type       Resource data type
     * @param ra         a JSONArray instance
     * @param restclient REST client instance
     * @return a list of Resources found in ra
     */
    private static <T extends AgileResource> List<T> getResourceArray(
            Class<T> type, Object ra, RestClient restclient) throws JiraException {
        if (!(ra instanceof JSONObject)) {
            throw new JiraException("JSON payload is malformed");
        }

        JSONObject jo = (JSONObject) ra;

        if (!jo.containsKey("values") || !(jo.get("values") instanceof JSONArray)) {
            throw new JiraException(type.getSimpleName() + " result is malformed");
        }

        List<T> results = new ArrayList<T>();

        for (Object v : (JSONArray) jo.get("values")) {
            T item = getResource(type, v, restclient);
            if (item != null)
                results.add(item);
        }

        return results;
    }

    /**
     * Retrieves all boards visible to the session user.
     *
     * @param restclient REST client instance
     * @return a list of boards
     * @throws JiraException when the retrieval fails
     */
    static <T extends AgileResource> List<T> list(RestClient restclient, Class<T> type, String url) throws JiraException {

        JSON result = null;
        try {
            result = restclient.get(url);
        } catch (Exception ex) {
            throw new JiraException("Failed to retrieve boards", ex);
        }

        return getResourceArray(
                type,
                result,
                restclient
        );
    }

    /**
     * Retrieves all boards visible to the session user.
     *
     * @param restclient REST client instance
     * @return a list of boards
     * @throws JiraException when the retrieval fails
     */
    static <T extends AgileResource> T get(RestClient restclient, Class<T> type, String url) throws JiraException {

        JSON result = null;
        try {
            result = restclient.get(url);
        } catch (Exception ex) {
            throw new JiraException("Failed to retrieve boards", ex);
        }

        return getResource(
                type,
                result,
                restclient
        );
    }
}