"use strict";

angular.module("vocabulary")
    .service("categoryService", ["$q", "categoryApi", "messageHandler", "FeatureCheck", function ($q, categoryApi, messageHandler, FeatureCheck) {
        var categoryList = [];
        var entireCategoryTree = [];


        function getCategoryTree() {
            var apiCall;

            if(categoryList.length === 0) {
                apiCall = categoryApi.getCategoryList().then(function (categoryTree) {
                    if (categoryTree.length === 0) {
                        messageHandler.publishError("There was a problem processing your request");
                    }
                    categoryList = categoryTree;
                    return categoryList;
                }).catch(function (reason) {
                    messageHandler.publishError("There was a problem processing your request");
                    return [];
                });
            }else{
                apiCall = $q.resolve(categoryList);
            }
            return apiCall.then(function(result){
                return result;
            });
        }

        function getEntireCategoryTree(refresh) {
            var apiCall;

            if (refresh) {
                entireCategoryTree = [];
            }
            if(entireCategoryTree.length === 0) {
                apiCall = categoryApi.getEntireCategoryTree().then(function (categoryTree) {
                    if (categoryTree.length === 0) {
                        messageHandler.publishError("There was a problem processing your request");
                    }
                    entireCategoryTree = categoryTree;
                    return entireCategoryTree;
                }).catch(function (reason) {
                    messageHandler.publishError("There was a problem processing your request");
                    return [];
                });
            }else{
                apiCall = $q.resolve(entireCategoryTree);
            }
            return apiCall.then(function(result){
                return result;
            });
        }

        function getCategoryLessons(id){
            return categoryApi.getLessonsForCategory(id).then( function(categoryLessons){
                return categoryLessons;
            }).catch(function(reason){
                messageHandler.publishError("There was a problem processing your request");
                return [];
            });
        }

        function getPremadeCategoryDescription(id){
            if(FeatureCheck.isFeatureEnabled('VAZ_TOPIC_DESCRIPTIONS')) {
                return categoryApi.getPremadeCategoryDescription(id).then(function (data) {
                    return data[0]['category_description'];
                }).catch(function (reason) {
                    messageHandler.publishError("There was a problem processing your request");
                    return [];
                });
            }else{
                return undefined;
            }
        }

        function getCategoryList() {
           return categoryList;
        }

        function getCategory(id) {
            return categoryList.filter(function (category) {
                return category.categoryId === id;
            }).pop();
        }

        function getCategoryName(id) {
            var category = getCategory(id);
            if(!category) {
                return refreshCategoryList()
                    .then(function () {
                        category = getCategory(id);
                        return category ? category.categoryName : '';
                    });
            }
            return $q.resolve(category ? category.categoryName : '');
        }

        function deleteCategory(categoryId, parentCategoryId){

            return categoryApi.deleteCategory(categoryId, parentCategoryId)
                .then(function(responseData){
                    return responseData
                });
        }

        function updateCategoryName(newCategoryName, categoryId){
            return categoryApi.updateCategoryName(categoryId, newCategoryName)
                .then(function(responseData){
                    return responseData;
                })
        }

        function createCategory(newCategoryName, parentCategoryId) {
            var newCategory = null;
            return categoryApi.createCategory(new NewCategoryData(newCategoryName, parentCategoryId))
                .then(function (newCatData) {
                    newCategory = newCatData;
                })
                .then(refreshCategoryList)
                .then(function () {
                    return newCategory;
                });
        }

        function refreshCategoryList() {
            return categoryApi.getCategoryList()
                .then(function(categories){
                    categoryList = categories;
                });
        }

        function NewCategoryData(name, parentId) {
            this.categoryName = name;
            this.parentCategoryId = parentId;
        }

      return {
            getCategoryTree : getCategoryTree,
            getEntireCategoryTree: getEntireCategoryTree,
            getCategoryList: getCategoryList,
            getCategory: getCategory,
            getCategoryName: getCategoryName,
            getPremadeCategoryDescription: getPremadeCategoryDescription,
            createCategory: createCategory,
            refreshCategoryList: refreshCategoryList,
            getCategoryLessons: getCategoryLessons,
            updateCategoryName: updateCategoryName,
            deleteCategory: deleteCategory

        };
    }]);