/*
 * Copyright (C) 2024 Leonard Kugis
 * Copyright (C) 2023 MURENA SAS
 * Copyright (C) 2021 E FOUNDATION
 *
 * 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, see <https://www.gnu.org/licenses/>.
 */

package foundation.e.advancedprivacy.features.location

import android.Manifest
import android.annotation.SuppressLint
import android.content.Context
import android.location.Location
import android.os.Bundle
import android.text.Editable
import android.view.View
import android.view.inputmethod.InputMethodManager
import android.widget.Toast
import androidx.activity.result.contract.ActivityResultContracts
import androidx.annotation.NonNull
import androidx.core.view.isVisible
import androidx.core.widget.addTextChangedListener
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.lifecycleScope
import androidx.lifecycle.repeatOnLifecycle
import android.app.Activity
import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import androidx.documentfile.provider.DocumentFile
import com.google.android.material.textfield.TextInputLayout
import com.google.android.material.textfield.TextInputLayout.END_ICON_CUSTOM
import com.google.android.material.textfield.TextInputLayout.END_ICON_NONE
import com.mapbox.android.gestures.MoveGestureDetector
import com.mapbox.mapboxsdk.Mapbox
import com.mapbox.mapboxsdk.WellKnownTileServer
import com.mapbox.mapboxsdk.camera.CameraPosition
import com.mapbox.mapboxsdk.camera.CameraUpdateFactory
import com.mapbox.mapboxsdk.geometry.LatLng
import com.mapbox.mapboxsdk.location.LocationComponent
import com.mapbox.mapboxsdk.location.LocationComponentActivationOptions
import com.mapbox.mapboxsdk.location.modes.CameraMode
import com.mapbox.mapboxsdk.location.modes.RenderMode
import com.mapbox.mapboxsdk.maps.MapboxMap
import com.mapbox.mapboxsdk.maps.Style
import foundation.e.advancedprivacy.R
import foundation.e.advancedprivacy.common.NavToolbarFragment
import foundation.e.advancedprivacy.databinding.FragmentFakeLocationBinding
import foundation.e.advancedprivacy.domain.entities.LocationMode
import foundation.e.advancedprivacy.features.location.FakeLocationViewModel.Action
import kotlinx.coroutines.Job
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import org.koin.androidx.viewmodel.ext.android.viewModel
import timber.log.Timber
import com.google.gson.Gson
import com.google.gson.reflect.TypeToken
import foundation.e.advancedprivacy.domain.entities.FakeLocationCoordinate
import java.io.BufferedReader
import java.io.IOException
import java.io.InputStream
import java.io.InputStreamReader
import android.util.Log
import kotlin.math.sqrt
import kotlin.math.pow

class FakeLocationFragment : NavToolbarFragment(R.layout.fragment_fake_location) {

    private var isFirstLaunch: Boolean = true

    private val viewModel: FakeLocationViewModel by viewModel()

    private var _binding: FragmentFakeLocationBinding? = null
    private val binding get() = _binding!!

    private var mapboxMap: MapboxMap? = null
    private var locationComponent: LocationComponent? = null

    private var inputJob: Job? = null

    private var updateLocationJob: Job? = null

    private val locationPermissionRequest = registerForActivityResult(
        ActivityResultContracts.RequestMultiplePermissions()
    ) { permissions ->
        if (permissions.getOrDefault(Manifest.permission.ACCESS_FINE_LOCATION, false) ||
            permissions.getOrDefault(Manifest.permission.ACCESS_COARSE_LOCATION, false)
        ) {
            viewModel.submitAction(Action.StartListeningLocation)
        } // TODO: else.
    }

    companion object {
        private const val MAP_STYLE = "mapbox://styles/mapbox/outdoors-v12"
    }

    override fun onAttach(context: Context) {
        super.onAttach(context)
        Mapbox.getInstance(requireContext(), getString(R.string.mapbox_key), WellKnownTileServer.Mapbox)
    }

    private fun displayToast(message: String) {
        Toast.makeText(requireContext(), message, Toast.LENGTH_SHORT)
            .show()
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        _binding = FragmentFakeLocationBinding.bind(view)

        binding.mapView.setup(savedInstanceState) { mapboxMap ->
            this.mapboxMap = mapboxMap
            mapboxMap.uiSettings.isRotateGesturesEnabled = false
            mapboxMap.setStyle(MAP_STYLE) { style ->
                enableLocationPlugin(style)

                mapboxMap.addOnMoveListener(onMoveListener)

                mapboxMap.cameraPosition = CameraPosition.Builder().zoom(8.0).build()

                // Bind click listeners once map is ready.
                bindClickListeners()

                render(viewModel.state.value)
                startUpdateLocationJob()
            }
        }

        startListening()
    }

    private val onMoveListener = object : MapboxMap.OnMoveListener {
        private val cameraIdleListener: MapboxMap.OnCameraIdleListener =
            object : MapboxMap.OnCameraIdleListener {
                override fun onCameraIdle() {
                    mapboxMap?.cameraPosition?.target?.let {
                        viewModel.submitAction(
                            Action.SetSpecificLocationAction(
                                it.latitude.toFloat(),
                                it.longitude.toFloat()
                            )
                        )
                        startUpdateLocationJob()
                    }
                    mapboxMap?.removeOnCameraIdleListener(this)
                }
            }

        override fun onMoveBegin(detector: MoveGestureDetector) {
            updateLocationJob?.cancel()
            updateLocationJob = null
            mapboxMap?.removeOnCameraIdleListener(cameraIdleListener)
        }

        override fun onMove(detector: MoveGestureDetector) {}

        override fun onMoveEnd(detector: MoveGestureDetector) {
            mapboxMap?.addOnCameraIdleListener(cameraIdleListener)
        }
    }

    private fun startListening() {
        viewLifecycleOwner.lifecycleScope.launch {
            viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
                render(viewModel.state.value)
                viewModel.state.collect(::render)
            }
        }

        viewLifecycleOwner.lifecycleScope.launch {
            viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
                viewModel.singleEvents.collect { event ->
                    when (event) {
                        is FakeLocationViewModel.SingleEvent.ErrorEvent -> {
                            displayToast(event.error)
                        }
                        is FakeLocationViewModel.SingleEvent.RequestLocationPermission -> {
                            // TODO for standalone: rationale dialog
                            locationPermissionRequest.launch(
                                arrayOf(
                                    Manifest.permission.ACCESS_FINE_LOCATION,
                                    Manifest.permission.ACCESS_COARSE_LOCATION
                                )
                            )
                        }
                    }
                }
            }
        }

        viewLifecycleOwner.lifecycleScope.launch {
            viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
                viewModel.doOnStartedState()
            }
        }
    }

    private fun startUpdateLocationJob() {
        updateLocationJob?.cancel()
        updateLocationJob = viewLifecycleOwner.lifecycleScope.launch {
            viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
                // Without this delay, onResume, map apply the updateLocation and then
                // move to an old fake location.
                delay(1000)
                viewModel.currentLocation.collect { location ->
                    updateLocation(location, viewModel.state.value.mode)
                }
            }
        }
    }

    private fun validateBounds(inputLayout: TextInputLayout, minValue: Float, maxValue: Float): Boolean {
        return try {
            val value = inputLayout.editText?.text?.toString()?.toFloat()!!

            if (value > maxValue || value < minValue) {
                throw NumberFormatException("value $value is out of bounds")
            }
            inputLayout.error = null

            inputLayout.setEndIconDrawable(R.drawable.ic_valid)
            inputLayout.endIconMode = END_ICON_CUSTOM
            true
        } catch (e: Exception) {
            inputLayout.endIconMode = END_ICON_NONE
            inputLayout.error = getString(R.string.location_error_bounds)
            false
        }
    }

    private fun validateCoordinate(
        inputLayout: TextInputLayout,
        maxValue: Float
    ): Boolean {
        return try {
            val value = inputLayout.editText?.text?.toString()?.toFloat()!!

            if (value > maxValue || value < -maxValue) {
                throw NumberFormatException("value $value is out of bounds")
            }
            inputLayout.error = null

            inputLayout.setEndIconDrawable(R.drawable.ic_valid)
            inputLayout.endIconMode = END_ICON_CUSTOM
            true
        } catch (e: Exception) {
            inputLayout.endIconMode = END_ICON_NONE
            inputLayout.error = getString(R.string.location_input_error)
            false
        }
    }

    private fun updateSpecificCoordinates() {
        try {
            val lat = binding.edittextLatitude.text.toString().toFloat()
            val lon = binding.edittextLongitude.text.toString().toFloat()
            if (lat <= 90f && lat >= -90f && lon <= 180f && lon >= -180f) {
                viewModel.submitAction(
                    Action.SetSpecificLocationAction(
                        lat,
                        lon
                    )
                )
            }
        } catch (e: NumberFormatException) {
            Timber.e("Unfiltered wrong lat lon format")
        }
    }

    private fun updateMockLocationParameters() {
        try {
            viewModel.submitAction(
                Action.UpdateMockLocationParameters(
                    binding.edittextAltitude.text.toString().toFloat(),
                    binding.edittextSpeed.text.toString().toFloat(),
                    binding.edittextJitter.text.toString().toFloat(),
                )
            )
        } catch (e: NumberFormatException) {
            Timber.e("Unfiltered wrong altitude/speed/jitter format")
        }
    }

    @Suppress("UNUSED_PARAMETER")
    private fun onAltitudeTextChanged(editable: Editable?) {
        if(!validateBounds(binding.textlayoutAltitude, -100000.0f, 100000.0f)) return
        updateMockLocationParameters()
    }

    @Suppress("UNUSED_PARAMETER")
    private fun onSpeedTextChanged(editable: Editable?) {
        if(!validateBounds(binding.textlayoutSpeed, 0.0f, 299792458.0f)) return
        updateMockLocationParameters()
    }

    @Suppress("UNUSED_PARAMETER")
    private fun onJitterTextChanged(editable: Editable?) {
        if(!validateBounds(binding.textlayoutJitter, 0.0f, 10000000.0f)) return
        updateMockLocationParameters()
    }

    @Suppress("UNUSED_PARAMETER")
    private fun onLatTextChanged(editable: Editable?) {
        if (!binding.edittextLatitude.isFocused ||
            !validateCoordinate(binding.textlayoutLatitude, 90f)
        ) return

        updateSpecificCoordinates()
    }

    @Suppress("UNUSED_PARAMETER")
    private fun onLonTextChanged(editable: Editable?) {
        if (!binding.edittextLongitude.isFocused ||
            !validateCoordinate(binding.textlayoutLongitude, 180f)
        ) return

        updateSpecificCoordinates()
    }

    private val isEditingLatLon get() = binding.edittextLongitude.isFocused || binding.edittextLatitude.isFocused

    private val latLonOnFocusChangeListener = object : View.OnFocusChangeListener {
        override fun onFocusChange(v: View?, hasFocus: Boolean) {
            if (!isEditingLatLon && !binding.edittextAltitude.isFocused && !binding.edittextSpeed.isFocused && !binding.edittextJitter.isFocused) {
                (context?.getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager)?.hideSoftInputFromWindow(
                    v?.windowToken,
                    0
                )
            }
        }
    }

    private var route: List<FakeLocationCoordinate>? = null

    private val filePickerLauncher =
        registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
            if (result.resultCode == Activity.RESULT_OK) {
                result.data?.data?.let { uri ->
                    var activity = getActivity()
                    if(uri.path != null && activity != null) {
                        var inputStream: InputStream? = null
                        var reader: BufferedReader? = null
                        var route_str: String? = null
                        try {
                            inputStream = activity.contentResolver.openInputStream(uri)
                            reader = BufferedReader(InputStreamReader(inputStream))
                            route_str = reader.readLines().joinToString("")
                        } catch(e: IOException) {
                            Log.e("FakeLocationFragment", "Error reading JSON file", e)
                        } finally {
                            try {
                                reader?.close()
                                inputStream?.close()
                            } catch (e: IOException) {
                                Log.e("FakeLocationFragment", "Error closing streams", e)
                            }
                        }
                        route = Gson().fromJson(route_str, object : TypeToken<List<FakeLocationCoordinate>>() {}.type)
                        var route_buf = route
                        route_buf?.let {
                            viewModel.submitAction(Action.SetRoute(route_buf))
                        }
                    }
                }
            }
        }

    private fun openFilePicker() {
        val intent = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
            addCategory(Intent.CATEGORY_OPENABLE)
            type = "*/*"
        }

        filePickerLauncher.launch(intent)
    }

    @SuppressLint("ClickableViewAccessibility")
    private fun bindClickListeners() {
        binding.radioUseRealLocation.setOnClickListener {
            viewModel.submitAction(Action.UseRealLocationAction)
        }
        binding.radioUseRandomLocation.setOnClickListener {
            viewModel.submitAction(Action.UseRandomLocationAction)
        }
        binding.radioUseSpecificLocation.setOnClickListener {
            mapboxMap?.cameraPosition?.target?.let {
                viewModel.submitAction(
                    Action.SetSpecificLocationAction(it.latitude.toFloat(), it.longitude.toFloat())
                )
            }
        }
        binding.radioUseRoute.setOnClickListener {
            viewModel.submitAction(Action.UseRoute)
        }

        binding.edittextAltitude.addTextChangedListener(afterTextChanged = ::onAltitudeTextChanged)
        binding.edittextSpeed.addTextChangedListener(afterTextChanged = ::onSpeedTextChanged)
        binding.edittextJitter.addTextChangedListener(afterTextChanged = ::onJitterTextChanged)
        binding.edittextLatitude.addTextChangedListener(afterTextChanged = ::onLatTextChanged)
        binding.edittextLongitude.addTextChangedListener(afterTextChanged = ::onLonTextChanged)
        binding.edittextAltitude.onFocusChangeListener = latLonOnFocusChangeListener
        binding.edittextSpeed.onFocusChangeListener = latLonOnFocusChangeListener
        binding.edittextJitter.onFocusChangeListener = latLonOnFocusChangeListener
        binding.edittextLatitude.onFocusChangeListener = latLonOnFocusChangeListener
        binding.edittextLongitude.onFocusChangeListener = latLonOnFocusChangeListener

        binding.buttonLocationRoutePathSelect.setOnClickListener { openFilePicker() }
        binding.checkboxRouteLoop.setOnCheckedChangeListener { _, isChecked -> viewModel.submitAction(Action.SetRouteLoopEnabledAction(isChecked)) }
        binding.buttonLocationRouteStart.setOnClickListener { viewModel.submitAction(Action.RouteStartAction) }
        binding.buttonLocationRouteStop.setOnClickListener { viewModel.submitAction(Action.RouteStopAction) }
    }

    @SuppressLint("MissingPermission")
    private fun render(state: FakeLocationState) {
        binding.radioUseRandomLocation.isChecked = state.mode == LocationMode.RANDOM_LOCATION

        binding.radioUseSpecificLocation.isChecked = state.mode == LocationMode.SPECIFIC_LOCATION

        binding.radioUseRealLocation.isChecked = state.mode == LocationMode.REAL_LOCATION

        binding.radioUseRoute.isChecked = state.mode == LocationMode.ROUTE

        binding.mapView.isEnabled = (state.mode == LocationMode.SPECIFIC_LOCATION)

        binding.textlayoutAltitude.isVisible = state.mode == LocationMode.SPECIFIC_LOCATION
        binding.textlayoutSpeed.isVisible = state.mode == LocationMode.SPECIFIC_LOCATION
        binding.textlayoutJitter.isVisible = state.mode == LocationMode.SPECIFIC_LOCATION

        binding.buttonLocationRoutePathSelect.isVisible = state.mode == LocationMode.ROUTE
        binding.locationRoutePath.isVisible = state.mode == LocationMode.ROUTE
        binding.checkboxRouteLoop.isVisible = state.mode == LocationMode.ROUTE
        binding.buttonLocationRouteStart.isVisible = state.mode == LocationMode.ROUTE
        binding.buttonLocationRouteStop.isVisible = state.mode == LocationMode.ROUTE

        if(binding.checkboxRouteLoop.isVisible)
            binding.checkboxRouteLoop.isChecked = state.loopRoute

        if(!binding.edittextAltitude.isFocused)
            binding.edittextAltitude.setText(state.altitude?.toString())

        if(!binding.edittextSpeed.isFocused)
            binding.edittextSpeed.setText(state.speed?.toString())

        if(!binding.edittextJitter.isFocused)
            binding.edittextJitter.setText(state.jitter?.toString())

        if (state.mode == LocationMode.REAL_LOCATION) {
            binding.centeredMarker.isVisible = false
        } else {
            binding.mapLoader.isVisible = false
            binding.mapOverlay.isVisible = state.mode != LocationMode.SPECIFIC_LOCATION
            binding.centeredMarker.isVisible = true
            mapboxMap?.moveCamera(
                CameraUpdateFactory.newLatLng(
                    LatLng(
                        state.specificLatitude?.toDouble() ?: 0.0,
                        state.specificLongitude?.toDouble() ?: 0.0
                    )
                )
            )
        }

        binding.textlayoutLatitude.isVisible = (state.mode == LocationMode.SPECIFIC_LOCATION)
        binding.textlayoutLongitude.isVisible = (state.mode == LocationMode.SPECIFIC_LOCATION)

        if (!isEditingLatLon) {
            binding.edittextLatitude.setText(state.specificLatitude?.toString())
            binding.edittextLongitude.setText(state.specificLongitude?.toString())
        }

        if(route == null) {
            binding.locationRoutePath.text = "No valid route selected"
        } else {
            binding.locationRoutePath.text = "Route valid"
        }
    }

    @SuppressLint("MissingPermission")
    private fun updateLocation(lastLocation: Location?, mode: LocationMode) {
        lastLocation?.let { location ->
            locationComponent?.isLocationComponentEnabled = true
            locationComponent?.forceLocationUpdate(location)

            if (mode == LocationMode.REAL_LOCATION) {
                binding.mapLoader.isVisible = false
                binding.mapOverlay.isVisible = false

                val update = CameraUpdateFactory.newLatLng(
                    LatLng(location.latitude, location.longitude)
                )
                if (isFirstLaunch) {
                    mapboxMap?.moveCamera(update)
                    isFirstLaunch = false
                } else {
                    mapboxMap?.animateCamera(update)
                }
            }
        } ?: run {
            locationComponent?.isLocationComponentEnabled = false
            if (mode == LocationMode.REAL_LOCATION) {
                binding.mapLoader.isVisible = true
                binding.mapOverlay.isVisible = true
            }
        }
    }

    @SuppressLint("MissingPermission")
    private fun enableLocationPlugin(@NonNull loadedMapStyle: Style) {
        // Check if permissions are enabled and if not request
        locationComponent = mapboxMap?.locationComponent
        locationComponent?.activateLocationComponent(
            LocationComponentActivationOptions.builder(
                requireContext(), loadedMapStyle
            ).useDefaultLocationEngine(false).build()
        )
        locationComponent?.isLocationComponentEnabled = true
        locationComponent?.cameraMode = CameraMode.NONE
        locationComponent?.renderMode = RenderMode.NORMAL
    }

    override fun onStart() {
        super.onStart()
        binding.mapView.onStart()
    }

    override fun onResume() {
        super.onResume()
        viewModel.submitAction(Action.StartListeningLocation)
        binding.mapView.onResume()
    }

    override fun onPause() {
        super.onPause()
        viewModel.submitAction(Action.StopListeningLocation)
        binding.mapView.onPause()
    }

    override fun onStop() {
        super.onStop()
        binding.mapView.onStop()
    }

    override fun onLowMemory() {
        super.onLowMemory()
        binding.mapView.onLowMemory()
    }

    override fun onDestroyView() {
        super.onDestroyView()
        binding.mapView.onDestroy()
        mapboxMap = null
        locationComponent = null
        inputJob = null
        _binding = null
    }
}