package mx.trackermap.TrackerMap.android.details.reports

import android.util.Log
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.SavedStateHandle
import androidx.lifecycle.ViewModel
import androidx.lifecycle.asFlow
import androidx.lifecycle.viewModelScope
import java.text.SimpleDateFormat
import java.util.Calendar
import java.util.Date
import kotlinx.coroutines.flow.collect
import kotlinx.coroutines.launch
import mx.trackermap.TrackerMap.client.apis.ReportsApi
import mx.trackermap.TrackerMap.client.models.Event
import mx.trackermap.TrackerMap.client.models.Position
import mx.trackermap.TrackerMap.client.models.Stop
import org.koin.core.component.KoinComponent

class UnitReportsViewModel(
    private val reportsApi: ReportsApi,
    savedStateHandle: SavedStateHandle
) : ViewModel(), KoinComponent {

    sealed class Report {
        class PositionsReport(val positions: Array<Position>) : Report()
        class EventsReport(val events: Array<Event>) : Report()
        class StopsReport(val stops: Array<Stop>) : Report()
    }

    enum class ReportType {
        POSITIONS, EVENTS, STOPS
    }

    enum class ReportPeriod {
        DAY, WEEK, MONTH
    }

    var deviceId = savedStateHandle.getLiveData("deviceId", 0)
    val reportType: MutableLiveData<ReportType> = savedStateHandle.getLiveData("reportType", null)
    val reportPeriod: MutableLiveData<ReportPeriod> =
        savedStateHandle.getLiveData("reportPeriod", null)
    val report: MutableLiveData<Report> = MutableLiveData()

    val dateFormat = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'")

    init {
        viewModelScope.launch {
            setupTypeObserver()
        }
        viewModelScope.launch {
            setupPeriodObserver()
        }
    }

    private suspend fun setupTypeObserver() {
        reportType.asFlow().collect {
            fetchReport()
        }
    }

    private suspend fun setupPeriodObserver() {
        reportPeriod.asFlow().collect {
            fetchReport()
        }
    }

    private fun fetchReport() {
        if (reportType.value == null || reportPeriod.value == null) {
            return
        }

        val (currentDate, previousDate) = getDates()
        Log.d("UnitReportsVM", "Current report type: ${reportType.value.toString()}")
        Log.d("UnitReportsVM", "Current report period: ${reportPeriod.value.toString()}")
        Log.d("UnitReportsVM", "Current date:${dateFormat.format(currentDate)}")
        Log.d("UnitReportsVM", "Previous date:${dateFormat.format(previousDate)}")

        viewModelScope.launch {
            when (reportType.value!!) {
                ReportType.POSITIONS -> fetchPositions(previousDate, currentDate)
                ReportType.EVENTS -> fetchEvents(previousDate, currentDate)
                ReportType.STOPS -> fetchStops(previousDate, currentDate)
            }
        }
    }

    private fun getDates(): Pair<Date, Date> {
        val calendar = Calendar.getInstance()
        val currentDate = calendar.time

        calendar.add(
            Calendar.DATE, when (reportPeriod.value!!) {
                ReportPeriod.DAY -> -1
                ReportPeriod.WEEK -> -7
                ReportPeriod.MONTH -> -30
            }
        )
        val previousDate = calendar.time

        return Pair(currentDate, previousDate)
    }

    private suspend fun fetchPositions(from: Date, to: Date) {
        Log.d("UnitReportsVM", "Fetching positions")

        val result = reportsApi.reportsRouteGet(
            dateFormat.format(from),
            dateFormat.format(to),
            deviceId.value!!
        )

        Log.d("UnitReportsVM", "Positions report: $result")
        report.postValue(Report.PositionsReport(result))
    }

    private suspend fun fetchEvents(from: Date, to: Date) {
        Log.d("UnitReportsVM", "Fetching events")

        val result = reportsApi.reportsEventsGet(
            dateFormat.format(from),
            dateFormat.format(to),
            deviceId.value!!
        )

        Log.d("UnitReportsVM", "Events report: $result")
        report.postValue(Report.EventsReport(result))
    }

    private suspend fun fetchStops(from: Date, to: Date) {
        Log.d("UnitReportsVM", "Fetching stops")

        val result = reportsApi.reportsStopsGet(
            dateFormat.format(from),
            dateFormat.format(to),
            deviceId.value!!
        )

        Log.d("UnitReportsVM", "Stops report: $result")
        report.postValue(Report.StopsReport(result))
    }
}