/**
 * ProjectLaogai
 *
 * Copyright 2019-2020  <seil0@mosad.xyz>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 *
 */

package org.mosad.seil0.projectlaogai.controller.cache

import android.content.Context
import kotlinx.coroutines.Job
import org.mosad.seil0.projectlaogai.controller.PreferencesController.Companion.cCourse
import org.mosad.seil0.projectlaogai.controller.TCoRAPIController
import org.mosad.seil0.projectlaogai.util.Lesson
import org.mosad.seil0.projectlaogai.util.TimetableWeek

/**
 * The TimetableController contains the timetable, subjectMap
 * and lessonMap objects. It also contains the additional subjects logic.
 * All functions ro read or update cache files are located in the CacheController.
 *
 * TODO add configurable week to addSubject() and removeSubject(), updateAdditionalLessons()
 */
class TimetableController {

    companion object {
        val timetable = ArrayList<TimetableWeek>()
        val lessonMap = HashMap<String, Lesson>() // the key is courseName-subject-lessonID
        val subjectMap = HashMap<String, ArrayList<String>>() // the key is courseName

        /**
         * update the main timetable and all additional subjects, async
         */
        fun update(context: Context): List<Job> {
            return listOf(
                CacheController.updateTimetable(cCourse.courseName, 0, context),
                CacheController.updateTimetable(cCourse.courseName, 1, context),
                CacheController.updateAdditionalLessons(context)
            )
        }

        /**
         * add a subject to the subjectMap and all it's lessons
         * to the lessonMap
         * @param courseName course to which the subject belongs
         * @param subject the subjects name
         */
        fun addSubject(courseName: String, subject: String, context: Context) {
            // add subject
            if (subjectMap.containsKey(courseName)) {
                subjectMap[courseName]?.add(subject)
            } else {
                subjectMap[courseName] = arrayListOf(subject)
            }

            // add concrete lessons
            TCoRAPIController.getLessons(courseName, subject, 0).forEach { lesson ->
                addLesson(courseName, subject, lesson)
            }

            CacheController.saveAdditionalSubjects(context)
        }

        /**
         * remove a subject from the subjectMap and all it's lessons
         * from the lessonMap
         * @param courseName course to which the subject belongs
         * @param subject the subjects name
         */
        fun removeSubject(courseName: String, subject: String, context: Context) {
            // remove subject
            subjectMap[courseName]?.remove(subject)

            // remove concrete lessons
            val iterator = lessonMap.iterator()
            while (iterator.hasNext()) {
                val it = iterator.next()
                if(it.key.contains("$courseName-$subject")) {
                    // remove the lesson from the lessons list
                    iterator.remove() // use iterator to remove, otherwise ConcurrentModificationException

                    // remove the lesson from the timetable
                    val id = it.value.lessonID.split(".")
                    if(id.size == 3)
                        timetable[0].days[id[0].toInt()].timeslots[id[1].toInt()].remove(it.value)
                }
            }

            CacheController.saveAdditionalSubjects(context)
        }

        /**
         * add a lesson to the lessonMap, also add it to the timetable
         */
        fun addLesson(courseName: String, subject: String, lesson: Lesson) {
            //the courseName, subject and lessonID, separator: -
            val key = "$courseName-$subject-${lesson.lessonID}"
            lessonMap[key] = lesson

            addLessonToTimetable(lesson)
        }

        /**
         * add a lesson to the timetable
         */
        fun addLessonToTimetable(lesson: Lesson) {
            val id = lesson.lessonID.split(".")
            if(id.size == 3)
                timetable[0].days[id[0].toInt()].timeslots[id[1].toInt()].add(lesson)
        }

    }

}