ariane/app/src/main/java/oppen/ariane/ui/settings/SettingsFragment.kt

package oppen.ariane.ui.settings

import android.os.Bundle
import android.text.InputType
import android.text.Spannable
import android.text.SpannableString
import android.text.style.ForegroundColorSpan
import android.view.inputmethod.EditorInfo
import android.widget.EditText
import androidx.core.content.ContextCompat
import androidx.preference.*
import oppen.ariane.Ariane
import java.security.SecureRandom
import java.util.*
import javax.net.ssl.SSLContext
import javax.net.ssl.SSLSocket
import javax.net.ssl.SSLSocketFactory


class SettingsFragment: PreferenceFragmentCompat(), Preference.OnPreferenceChangeListener {

    lateinit var protocols: Array<String>

    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
        val context = preferenceManager.context
        val screen = preferenceManager.createPreferenceScreen(context)

        /**
         * Ariane App Settings
         */
        val appCategory = PreferenceCategory(context)
        appCategory.key = "app_category"
        appCategory.title = "Configure Ariane"
        screen.addPreference(appCategory)

        //Home
        val homePreference = EditTextPreference(context)
        homePreference.title = "Home Capsule"
        homePreference.key = "home_capsule"

        val homecapsule = preferenceManager.sharedPreferences.getString(
            "home_capsule",
            Ariane.DEFAULT_HOME_CAPSULE
        )
        homePreference.summary = homecapsule

        homePreference.positiveButtonText = getThemedSpan("Update")
        homePreference.negativeButtonText = getThemedSpan("Cancel")
        homePreference.title = getThemedSpan("Home Capsule")
        homePreference.setOnPreferenceChangeListener { _, newValue ->
            homePreference.summary = newValue.toString()
            true
        }
        homePreference.setOnBindEditTextListener{ editText ->
            editText.imeOptions = EditorInfo.IME_ACTION_DONE
            editText.setSelection(editText.text.toString().length)//Set caret position to end
        }
        appCategory.addPreference(homePreference)

        /**
         * TLS Settings
         */
        val tlsCategory = PreferenceCategory(context)
        tlsCategory.key = "tls_category"
        tlsCategory.title = "TLS Config"
        screen.addPreference(tlsCategory)

        val tlsDefaultPreference = SwitchPreferenceCompat(context)
        tlsDefaultPreference.key = "tls_Default"
        tlsDefaultPreference.title = "TLS Default"
        tlsDefaultPreference.onPreferenceChangeListener = this
        tlsCategory.addPreference(tlsDefaultPreference)

        val tlsAllSupportedPreference = SwitchPreferenceCompat(context)
        tlsAllSupportedPreference.key = "tls_All_Supported"
        tlsAllSupportedPreference.title = "TLS Enable all supported"
        tlsAllSupportedPreference.onPreferenceChangeListener = this
        tlsCategory.addPreference(tlsAllSupportedPreference)

        val sslContext = SSLContext.getInstance("TLS")
        sslContext.init(null, null, SecureRandom())
        val factory: SSLSocketFactory = sslContext.socketFactory
        val socket = factory.createSocket() as SSLSocket
        protocols = socket.supportedProtocols
        protocols.forEach { protocol ->
            val tlsPreference = SwitchPreferenceCompat(context)
            tlsPreference.key = "tls_${protocol.toLowerCase(Locale.getDefault())}"
            tlsPreference.title = protocol
            tlsPreference.onPreferenceChangeListener = this
            tlsCategory.addPreference(tlsPreference)
        }

        preferenceScreen = screen
    }

    override fun onPreferenceChange(preference: Preference?, newValue: Any?): Boolean {
        if(preference is SwitchPreferenceCompat && newValue is Boolean && newValue == true) {
            preference.key?.let { key ->
                when {
                    key.startsWith("tls_") -> {
                        if(key != "tls_Default"){
                            val default = preferenceScreen.findPreference<SwitchPreferenceCompat>("tls_Default")
                            default?.isChecked = false
                        }
                        if(key != "tls_All_Supported"){
                            val default = preferenceScreen.findPreference<SwitchPreferenceCompat>("tls_All_Supported")
                            default?.isChecked = false
                        }
                        protocols.forEach { protocol ->
                            val tlsSwitchKey = "tls_${protocol.toLowerCase(Locale.getDefault())}"
                            if (tlsSwitchKey != key) {
                                val otherTLSSwitch = preferenceScreen.findPreference<SwitchPreferenceCompat>(
                                    tlsSwitchKey
                                )
                                otherTLSSwitch?.isChecked = false
                            }
                        }
                    }
                }
            }

            when (preference.key) {
                "tls_Default" -> setTLSProtocol("TLS")
                "tls_All_Supported" -> setTLSProtocol("TLS_ALL")
                else -> {
                    val prefTitle = preference.title.toString()
                    setTLSProtocol(prefTitle)
                }
            }

            return  true
        }

        return false
    }

    private fun setTLSProtocol(protocol: String){
        preferenceManager.sharedPreferences.edit().putString(
            "tls_protocol",
            protocol
        ).apply()
    }

    /**
     * Unfortunately it doesn't look like EditTextPreference supports Day/Night theme
     * or else is otherwise broken. Use Spannable to set a suitable text colour for the dialog buttons
     */
    private fun getThemedSpan(text: String): Spannable{
        val textSpan = SpannableString(text)
        textSpan.setSpan(
            ForegroundColorSpan(
                ContextCompat.getColor(
                    requireContext(),
                    oppen.ariane.R.color.themed_text
                )
            ), 0, text.length, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
        )
        return textSpan
    }
}