tailscale-android/android/src/main/java/com/tailscale/ipn/ui/viewModel/SettingsViewModel.kt

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause

package com.tailscale.ipn.ui.viewModel

import androidx.compose.ui.graphics.Color
import androidx.compose.ui.text.AnnotatedString
import androidx.compose.ui.text.SpanStyle
import androidx.compose.ui.text.buildAnnotatedString
import androidx.compose.ui.text.withStyle
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import com.tailscale.ipn.ui.service.IpnActions
import com.tailscale.ipn.ui.service.IpnModel
import com.tailscale.ipn.ui.service.toggleCorpDNS
import com.tailscale.ipn.ui.view.SettingsNav
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.launch

enum class SettingType { NAV, SWITCH, NAV_WITH_TEXT }

// Represents a UI setting.
// title: The title of the setting
// type: The type of setting
// enabled: Whether the setting is enabled
// value: The value of the setting for textual settings
// isOn: The value of the setting for switch settings
// onClick: The action to take when the setting is clicked (typicall for navigation)
// onToggle: The action to take when the setting is toggled (typically for switches)
//
// Behavior is undefined if you mix the types here. Switch settings should supply an
// isOn and onToggle, while navigation settings should supply an onClick and an optional
// value
data class Setting(
        val title: String,
        val type: SettingType,
        val enabled: MutableStateFlow<Boolean> = MutableStateFlow(false),
        val value: MutableStateFlow<String?>? = null,
        val isOn: MutableStateFlow<Boolean?>? = null,
        val onClick: () -> Unit = {},
        val onToggle: (Boolean) -> Unit = {})

data class SettingBundle(val title: String? = null, val settings: List<Setting>)

class SettingsViewModel(val model: IpnModel, val ipnActions: IpnActions, val navigation: SettingsNav) : ViewModel() {
    // The logged in user
    val user = model.loggedInUser.value

    // Display name for the logged in user
    val userName = user?.UserProfile?.DisplayName ?: ""
    val tailnetName = user?.Name ?: ""
    val isAdmin = model.netmap.value?.SelfNode?.isAdmin ?: false

    val useDNSSetting = Setting(
            "Use Tailscale DNS",
            SettingType.SWITCH,
            isOn = MutableStateFlow(model.prefs.value?.CorpDNS),
            onToggle = {
                model.toggleCorpDNS {
                    // (jonathan) TODO: Error handling
                }
            })

    init {
        viewModelScope.launch {
            // Monitor our prefs for changes and update the displayed values accordingly
            model.prefs.collect { prefs ->
                useDNSSetting.isOn?.value = prefs?.CorpDNS
                useDNSSetting.enabled?.value = prefs != null
            }
        }
    }

    val settings: List<SettingBundle> = listOf(
            SettingBundle(settings = listOf(
                    useDNSSetting,
            )),
            // General settings, always enabled
            SettingBundle(settings = listOf(
                    Setting("About", SettingType.NAV, onClick = { navigation.onNavigateToAbout() }, enabled = MutableStateFlow(true)),
                    Setting("Bug Report", SettingType.NAV, onClick = { navigation.onNavigateToBugReport() }, enabled = MutableStateFlow(true))
            ))
    )

    fun adminText(): AnnotatedString {
        val annotatedString = buildAnnotatedString {
            append("You can manage your account from the admin console. ")

            pushStringAnnotation(tag = "policy", annotation = "https://google.com/policy")
            withStyle(style = SpanStyle(color = Color.Blue)) {
                append("View admin console...")
            }
            pop()
        }
        return annotatedString
    }
}