package com.dano.test1

import android.content.res.Configuration
import android.net.ConnectivityManager
import android.net.Network
import android.net.NetworkCapabilities
import android.net.NetworkRequest
import android.os.Bundle
import android.view.View
import android.widget.EditText
import android.widget.LinearLayout
import android.widget.ProgressBar
import android.widget.Toast
import androidx.appcompat.app.AlertDialog
import androidx.appcompat.app.AppCompatActivity
import java.io.File

class MainActivity : AppCompatActivity() {

    private lateinit var openingScreenHandler: HandlerOpeningScreen

    var isInQuestionnaire: Boolean = false
    var isFirstQuestionnairePage: Boolean = false

    private var progress: ProgressBar? = null

    // LIVE: Network-Callback (optional für Statusleiste)
    private var netCb: ConnectivityManager.NetworkCallback? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // === Offline-Start ermöglichen ===
        // Bedingung: gespeicherter User/Token UND lokale DB vorhanden -> direkt OpeningScreen
        val hasCreds = !TokenStore.getUsername(this).isNullOrBlank() && !TokenStore.getToken(this).isNullOrBlank()
        val hasDb = hasLocalDb()
        if (hasCreds && hasDb) {
            openingScreenHandler = HandlerOpeningScreen(this)
            openingScreenHandler.init()
            return
        }

        // Sonst: Login-Dialog -> Login -> DB (einmalig) laden -> OpeningScreen
        showLoginThenDownload()
    }

    /** Prüft, ob die lokale DB-Datei vorhanden ist. */
    private fun hasLocalDb(): Boolean {
        val dbFile = getDatabasePath("questionnaire_database")
        return dbFile != null && dbFile.exists() && dbFile.length() > 0
    }

    /** Zeigt den Login-Dialog an, führt Login aus und lädt danach einmalig die DB. */
    private fun showLoginThenDownload() {
        val container = LinearLayout(this).apply {
            orientation = LinearLayout.VERTICAL
            setPadding(dp(20), dp(8), dp(20), 0)
        }
        val etUser = EditText(this).apply {
            hint = "Username"
            setSingleLine()
        }
        val etPass = EditText(this).apply {
            hint = "Passwort"
            setSingleLine()
            inputType = android.text.InputType.TYPE_CLASS_TEXT or
                    android.text.InputType.TYPE_TEXT_VARIATION_PASSWORD
        }
        container.addView(etUser)
        container.addView(etPass)

        val dialog = AlertDialog.Builder(this)
            .setTitle("Login erforderlich")
            .setView(container)
            .setCancelable(false)
            .setPositiveButton("Login") { _, _ ->
                val user = etUser.text.toString().trim()
                val pass = etPass.text.toString()
                if (user.isEmpty() || pass.isEmpty()) {
                    Toast.makeText(this, "Bitte Username & Passwort eingeben", Toast.LENGTH_SHORT).show()
                    showLoginThenDownload()
                    return@setPositiveButton
                }
                showBusy(true)
                LoginManager.loginUserWithCredentials(
                    context = this,
                    username = user,
                    password = pass,
                    onSuccess = { token ->
                        // Nach erfolgreichem Login: einmalig komplette DB ziehen
                        DatabaseDownloader.downloadAndReplaceDatabase(
                            context = this,
                            token = token
                        ) { ok ->
                            showBusy(false)

                            // Wenn Download fehlgeschlagen ist, aber evtl. schon eine DB lokal liegt,
                            // lassen wir den Nutzer trotzdem weiterarbeiten (Offline).
                            if (!ok && !hasLocalDb()) {
                                Toast.makeText(this, "Download fehlgeschlagen – keine lokale Datenbank vorhanden", Toast.LENGTH_LONG).show()
                                // Zurück zum Login, damit man es erneut probieren kann
                                showLoginThenDownload()
                                return@downloadAndReplaceDatabase
                            }

                            if (!ok) {
                                Toast.makeText(this, "Download fehlgeschlagen – arbeite offline mit vorhandener DB", Toast.LENGTH_LONG).show()
                            }

                            // Opening-Screen starten
                            openingScreenHandler = HandlerOpeningScreen(this)
                            openingScreenHandler.init()
                            openingScreenHandler.refreshHeaderStatusLive()
                        }
                    },
                    onError = { msg ->
                        showBusy(false)
                        Toast.makeText(this, msg, Toast.LENGTH_LONG).show()
                        showLoginThenDownload()
                    }
                )
            }
            .setNegativeButton("Beenden") { _, _ -> finishAffinity() }
            .create()

        dialog.show()
    }

    private fun showBusy(show: Boolean) {
        if (show) {
            if (progress == null) {
                progress = ProgressBar(this).apply {
                    isIndeterminate = true
                    (window?.decorView as? android.view.ViewGroup)?.addView(this)
                }
            }
            progress?.visibility = View.VISIBLE
        } else {
            progress?.visibility = View.GONE
        }
    }

    private fun dp(v: Int): Int = (v * resources.displayMetrics.density).toInt()

    // --- LIVE NETZSTATUS (optional, für deine Status-Leiste) ---
    override fun onResume() {
        super.onResume()
        registerNetworkCallback()
        if (::openingScreenHandler.isInitialized && !isInQuestionnaire) {
            openingScreenHandler.refreshHeaderStatusLive()
        }
    }

    override fun onPause() {
        super.onPause()
        unregisterNetworkCallback()
    }

    private fun registerNetworkCallback() {
        if (netCb != null) return
        val cm = getSystemService(ConnectivityManager::class.java)
        val req = NetworkRequest.Builder()
            .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
            .build()
        netCb = object : ConnectivityManager.NetworkCallback() {
            override fun onAvailable(network: Network) {
                runOnUiThread {
                    if (::openingScreenHandler.isInitialized && !isInQuestionnaire) {
                        openingScreenHandler.refreshHeaderStatusLive()
                    }
                }
            }
            override fun onLost(network: Network) {
                runOnUiThread {
                    if (::openingScreenHandler.isInitialized && !isInQuestionnaire) {
                        openingScreenHandler.refreshHeaderStatusLive()
                    }
                }
            }
            override fun onCapabilitiesChanged(network: Network, caps: NetworkCapabilities) {
                runOnUiThread {
                    if (::openingScreenHandler.isInitialized && !isInQuestionnaire) {
                        openingScreenHandler.refreshHeaderStatusLive()
                    }
                }
            }
        }
        cm.registerNetworkCallback(req, netCb!!)
    }

    private fun unregisterNetworkCallback() {
        val cb = netCb ?: return
        val cm = getSystemService(ConnectivityManager::class.java)
        cm.unregisterNetworkCallback(cb)
        netCb = null
    }
    // --- /LIVE NETZSTATUS ---

    override fun onConfigurationChanged(newConfig: Configuration) {
        super.onConfigurationChanged(newConfig)
    }

    fun startQuestionnaire(questionnaire: QuestionnaireBase<*>, languageID: String) {
        isInQuestionnaire = true
        isFirstQuestionnairePage = true
        questionnaire.attach(this, languageID)
        questionnaire.startQuestionnaire()
    }

    override fun onBackPressed() {
        if (!::openingScreenHandler.isInitialized || !openingScreenHandler.onBackPressed()) {
            super.onBackPressed()
        }
    }

    fun finishQuestionnaire() {
        isInQuestionnaire = false
        isFirstQuestionnairePage = false
        if (::openingScreenHandler.isInitialized) {
            openingScreenHandler.init()
        }
    }
}