TheCitadelofRicks/src/main/kotlin/org/mosad/thecitadelofricks/APIController.kt

/**
 * TheCitadelofRicks
 *
 * 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.thecitadelofricks

import org.mosad.thecitadelofricks.CacheController.Companion.courseList
import org.mosad.thecitadelofricks.CacheController.Companion.mensaMenu
import org.mosad.thecitadelofricks.CacheController.Companion.timetableList
import org.slf4j.Logger
import org.slf4j.LoggerFactory
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.RequestParam
import org.springframework.web.bind.annotation.RestController
import java.net.HttpURLConnection
import java.net.URL
import java.time.LocalDateTime
import java.util.*
import kotlin.collections.ArrayList
import kotlin.collections.HashSet

@RestController
class APIController {

    private val logger: Logger = LoggerFactory.getLogger(APIController::class.java)
    private val cache = CacheController()

    private val apiVersion = "1.1.3"
    private val softwareVersion = "1.1.5"
    private val startTime = System.currentTimeMillis() / 1000

    private var totalRequests = 0
    private var mensaMenuRequests = 0
    private var timetableRequests = ArrayList<TimetableCounter>()

    @Deprecated("courses is replaced by courseList", replaceWith = ReplaceWith("courseList()"))
    @RequestMapping("/courses")
    fun courses(): CourseList {
        return courseList()
    }

    @RequestMapping("/courseList")
    fun courseList(): CourseList {
        logger.info("courseList request at ${LocalDateTime.now()}!")
        totalRequests++
        return courseList
    }

    @RequestMapping("/mensamenu")
    fun mensamenu(): MensaMenu {
        logger.info("mensamenu request at ${LocalDateTime.now()}!")
        mensaMenuRequests++
        totalRequests++
        return mensaMenu
    }

    @RequestMapping("/timetable")
    fun timetable(
        @RequestParam(value = "courseName", defaultValue = "AI4") courseName: String,
        @RequestParam(value = "week", defaultValue = "0") week: Int
    ): TimetableCourseWeek {
        logger.info("timetable request at ${LocalDateTime.now()}!")
        updateTimetableRequests(courseName)
        totalRequests++
        return cache.getTimetable(courseName, week)
    }

    @RequestMapping("/lessonSubjectList")
    fun lessonSubjectList(
        @RequestParam(value = "courseName", defaultValue = "AI4") courseName: String,
        @RequestParam(value = "week", defaultValue = "0") week: Int
    ): HashSet<String> {
        logger.info("lessonSubjectList request at ${LocalDateTime.now()}!")
        totalRequests++
        return getLessonSubjectList(courseName, week)
    }

    @RequestMapping("/lessons")
    fun lesson(
        @RequestParam(value = "courseName", defaultValue = "AI4") courseName: String,
        @RequestParam(value = "lessonSubject", defaultValue = "Mathematik 4") lessonSubject: String,
        @RequestParam(value = "week", defaultValue = "0") week: Int
    ): ArrayList<Lesson> {
        logger.info("lesson request at ${LocalDateTime.now()}!")
        totalRequests++
        return getLesson(courseName, lessonSubject, week)
    }

    @RequestMapping("/status")
    fun status(): Status {
        return getStatus()
    }

    // non direct api functions

    /**
     * get every explicit lesson in a week
     * @param courseName the name of the course to be requested
     * @param weekIndex request week number (current week = 0)
     * @return a HashSet of explicit lessons for one week
     */
    private fun getLessonSubjectList(courseName: String, weekIndex: Int): HashSet<String> {
        val lessonSubjectList = ArrayList<String>()

        // get every lesson subject for the given week
        val flatMap = cache.getTimetable(courseName, weekIndex).timetable.days.flatMap { it.timeslots.asIterable() }
        flatMap.forEach {
            it.stream().filter { x -> x.lessonSubject.isNotEmpty() }.findAny().ifPresent { x -> lessonSubjectList.add(x.lessonSubject) }
        }

        return HashSet(lessonSubjectList)
    }

    /**
     * get every explicit lesson in a week
     * @param courseName the name of the course to be requested
     * @param lessonSubject the lesson subject to be requested
     * @param weekIndex request week number (current week = 0)
     * @return a ArrayList of every lesson with lessonSubject for one week
     */
    private fun getLesson(courseName: String, lessonSubject: String, weekIndex: Int): ArrayList<Lesson> {
        val lessonList = ArrayList<Lesson>()

        // get all lessons from the weeks timetable
        val flatMap = cache.getTimetable(courseName, weekIndex).timetable.days.flatMap { it.timeslots.asIterable() }
        flatMap.forEach {
            it.forEach { lesson ->
                if(lesson.lessonSubject.contains(lessonSubject)) {
                    lessonList.add(lesson)
                }
            }

            //it.stream().filter { x -> x.lessonSubject.contains(lessonSubject) }.findAny().ifPresent { x -> println("${x.lessonSubject}, ${x.lessonTeacher}") }
        }

        return lessonList
    }

    /**
     * if a timetable is requested update the request counter
     */
    private fun updateTimetableRequests(courseName: String) {
        timetableRequests.stream().filter { it.courseName == courseName }.findFirst().ifPresentOrElse({
            it.requests++
        }, {
            timetableRequests.add(TimetableCounter(courseName, 1))
        })
    }

    private fun getStatus(): Status {
        val currentTime = System.currentTimeMillis() / 1000
        val minutes = (currentTime - startTime) % 3600 / 60
        val hours = (currentTime - startTime) % 86400 / 3600
        val days = (currentTime - startTime) / 86400

        var hsoCode = 999
        var swfrCode = 999
        logger.info("status request at ${LocalDateTime.now()}!")

        try {
            val hsoURL = URL("https://www.hs-offenburg.de/")
            val swfrURL = URL("https://www.swfr.de/")

            var connection = hsoURL.openConnection() as HttpURLConnection
            connection.requestMethod = "HEAD"

            connection.connectTimeout = 15000
            hsoCode = connection.responseCode

            connection = swfrURL.openConnection() as HttpURLConnection
            connection.connectTimeout = 15000
            swfrCode = connection.responseCode
        } catch (e: Exception) {
            logger.error("Error while fetching url response codes!", e)
        }

        return Status(
            LocalDateTime.now(),
            "$days days, $hours:$minutes",
            apiVersion,
            softwareVersion,
            totalRequests,
            mensaMenuRequests,
            timetableRequests,
            timetableList.size,
            Date(courseList.meta.updateTime * 1000),
            Date(mensaMenu.meta.updateTime * 1000),
            hsoCode,
            swfrCode
        )
    }

}