(function(){
    "use strict";

    angular.module("raz")
        .service("lcmGradeService", ['lcmApiService', 'messageHandler', '$q', '$window', 'TEACHER_GRADE_ID', 'IS_FOUNDATIONAL_SKILLS',
            function(lcmApiService, messageHandler, $q, $window, TEACHER_GRADE_ID, IS_FOUNDATIONAL_SKILLS){

            var service = this;

            var lcmCache = {};

            var currentGradeId = null;

            var storageKey = 'grade-id';

            var genericErrorText = 'Could not read Literacy Curriculum info.';

            initFromSession();

            return {
                getLCMFolderTreeById: getLCMFolderTreeById,
                getLCMGroupFoldersForWeek: getLCMGroupFoldersForWeek,
                getLCMSSUnitsTreeById: getLCMSSUnitsTreeById,
                getLCMSSUnitTree: getLCMSSUnitTree,
                getFSSSWeeksTreeById: getFSSSWeeksTreeById,
                getCurrentGradeId: getCurrentGradeId,
                setCurrentGradeId: setCurrentGradeId
            };

            function fromStorage() {
                var sessionGrade = $window.sessionStorage.getItem(storageKey);
                if (sessionGrade) {
                    return sessionGrade;
                } else if (hasValidTeacherGrade()) {
                    return TEACHER_GRADE_ID;
                } else {
                    return null;
                }
            }

            function hasValidTeacherGrade() {
                switch(TEACHER_GRADE_ID) {
                    case 'K':
                    case '1':
                    case '2':
                        return true;
                    case '3':
                    case '4':
                    case '5':
                        return !IS_FOUNDATIONAL_SKILLS;
                    default:
                        return false;
                }
            }

            function toStorage() {
                $window.sessionStorage.setItem(storageKey, currentGradeId);
            }

            function initFromSession() {
                var storageValue = fromStorage();
                var grade = (storageValue !== null) ? storageValue : 'K';
                setCurrentGradeId(grade);
            }

            function getCurrentGradeId() {
                return currentGradeId;
            }

            function setCurrentGradeId(gradeId) {
                currentGradeId = gradeId;
                toStorage();
            }

            function getFromCache(folderId) {
                var deferred = $q.defer();
                deferred.resolve(lcmCache[folderId]);
                return deferred.promise;
            }

            function setInCache(folderId, data) {
                lcmCache[folderId] = data;
            }

            function checkCache(folderId) {
                if (lcmCache[folderId]) {
                    return getFromCache(folderId);
                }

                return null;
            }

            function getLCMSSUnitsTreeById(folderId) {
                var cachedData = checkCache('ss_' + folderId);

                if (cachedData) {
                    return cachedData;
                }

                var defer = $q.defer();

                lcmApiService.getLCMSSUnitsTreeById(folderId)
                    .then(function (data) {
                        if (data) {
                            setInCache('ss_' + folderId, data);
                            defer.resolve(data);
                        } else {
                            handleDataError('getLCMSSUnitsTreeById');
                        }
                    })
                    .catch(function (e) {
                        handleExceptionError(e);
                    });

                return defer.promise;
            }

            function getFSSSWeeksTreeById(folderId) {
                var cachedData = checkCache('fsss_' + folderId);

                if (cachedData) {
                    return cachedData;
                }

                var defer = $q.defer();

                lcmApiService.getFSSSWeeksTreeById(folderId)
                    .then(function (data) {
                        if (data) {
                            setInCache('fsss_' + folderId, data);
                            defer.resolve(data);
                        } else {
                            handleDataError('getFSSSWeeksTreeById');
                        }
                    })
                    .catch(function (e) {
                        handleExceptionError(e);
                    });

                return defer.promise;
            }

            function getLCMSSUnitTree(folder) {

                var cachedData = checkCache('ss_' + folder.id);

                if (cachedData) {
                    return cachedData;
                }

                var defer = $q.defer();

                lcmApiService.getLCMSSUnitTree(folder)
                    .then(function (data) {
                        if (data) {
                            setInCache(folder.id, data);
                            defer.resolve(data);
                        } else {
                            handleDataError('getLCMSSUnitTree');
                        }
                    })
                    .catch(function (e) {
                        handleExceptionError(e);
                    });

                return defer.promise;
            }

            function getLCMFolderTreeById(folderId) {
                var cachedData = checkCache(folderId);

                if (cachedData) {
                    return cachedData;
                }

                var defer = $q.defer();

                lcmApiService.getLCMFolderTreeById(folderId)
                    .then(function (data) {
                        if (data) {
                            setInCache(folderId, data);
                            defer.resolve(data);
                        } else {
                            handleDataError('getLCMFolderTreeById');
                        }
                    })
                    .catch(function (e) {
                        handleExceptionError(e);
                    })

                return defer.promise;
            }

            function getLCMGroupFoldersForWeek(folder) {

                var cachedData = checkCache(folder.id);

                if (cachedData) {
                    return cachedData;
                }

                var defer = $q.defer();

                lcmApiService.getLCMGroupFoldersForWeek(folder)
                    .then(function (data) {
                        if (data) {
                            setInCache(folder.id, data);
                            defer.resolve(data);
                        } else {
                            handleDataError('getLCMGroupFoldersForWeek');
                        }
                    })
                    .catch(function (e) {
                        handleExceptionError(e);
                    })

                return defer.promise;
            }

            function handleDataError(functionName) {
                //console.log('No results returned from ' + functionName);
                messageHandler.publishError(genericErrorText);
            }

            function handleExceptionError(error) {
                //console.log('LCM Error: ', error);
                messageHandler.publishError(genericErrorText);
            }

        }]);

})();