/**
 * ProjectLaogai
 *
 * Copyright 2019  <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

import android.content.Context
import com.google.gson.Gson
import com.google.gson.GsonBuilder
import com.google.gson.JsonParser
import java.io.BufferedReader
import java.io.File
import java.io.FileReader
import com.google.gson.reflect.TypeToken
import org.mosad.seil0.projectlaogai.hsoparser.*
import kotlin.collections.ArrayList

class CacheController(cont: Context) {

    private val context = cont

    init {
        // TODO move cache check here
    }

    companion object {
        var coursesList = ArrayList<Course>()
        var timetables = ArrayList<TimetableWeek>()
        var mensaMenu = MensaMenu(MensaMeta(0, ""), MensaWeek(), MensaWeek())

        /**
         * get the MensaMenu object from the cached json,
         * if cache is empty create the cache file
         */
        fun readMensa(context: Context) {
            val file = File(context.filesDir, "mensa.json")

            // make sure the file exists
            if (!file.exists()) {
                TCoRAPIController.getMensa(context).get()
            }

            val fileReader = FileReader(file)
            val bufferedReader = BufferedReader(fileReader)
            val mensaObject = JsonParser().parse(bufferedReader.readLine()).asJsonObject

            mensaMenu = GsonBuilder().create().fromJson(mensaObject, MensaMenu(MensaMeta(0, ""), MensaWeek(), MensaWeek()).javaClass)
        }

        /**
         * read the weeks timetable from the cached file
         * @param courseName the course name (e.g AI1)
         * @param week the week to read (0 for the current and so on)
         */
        fun readTimetable(courseName: String, week: Int, context: Context) {
            val file = File(context.filesDir, "timetable-$courseName-$week.json")

            // make sure the file exists
            if (!file.exists())
                TCoRAPIController.getTimetable(courseName, week, context).get()

            val fileReader = FileReader(file)
            val bufferedReader = BufferedReader(fileReader)
            val timetableObject = JsonParser().parse(bufferedReader.readLine()).asJsonObject

            // make sure you add the single weeks in the exact order!
            if (timetables.size == week) {
                timetables.add(Gson().fromJson(timetableObject.getAsJsonObject("timetable"), TimetableWeek().javaClass))
            } else if (timetables.size >= week) {
                timetables[week] = Gson().fromJson(timetableObject.getAsJsonObject("timetable"), TimetableWeek().javaClass)
            }
        }
    }

    /**
     * read coursesList, mensa (current and next week), timetable (current and next week)
     * @param courseName the course name (e.g AI1)
     */
    fun readStartCache(courseName: String) {
        readCoursesList()
        readMensa(context)
        readTimetable(courseName, 0, context)
        readTimetable(courseName, 1, context)
    }

    /**
     * read the courses list from the cached file
     * add them to the coursesList object
     */
    private fun readCoursesList() {
        val file = File(context.filesDir, "courses.json")

        // make sure the file exists
        if (!file.exists())
            TCoRAPIController(context).getCoursesList().get()

        val fileReader = FileReader(file)
        val bufferedReader = BufferedReader(fileReader)
        val coursesObject = JsonParser().parse(bufferedReader.readLine()).asJsonObject

        coursesList = Gson().fromJson(coursesObject.getAsJsonArray("courses"), object : TypeToken<List<Course>>() {}.type)
    }

}