package com.example.aiapp

import android.Manifest
import android.content.Intent
import android.os.Build
import android.os.Bundle
import android.widget.Toast
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.activity.result.contract.ActivityResultContracts
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.navigationBarsPadding
import androidx.compose.foundation.layout.statusBarsPadding
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Surface
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.drawWithContent
import androidx.compose.ui.graphics.luminance
import androidx.compose.ui.layout.layout
import androidx.core.view.WindowCompat

class MainActivity : ComponentActivity() {
    // Bumped whenever enrollment lands via an aiapp:// intent so the
    // composition below re-reads the stored settings.
    private var settingsVersion by mutableIntStateOf(0)

    // The session a notification tap asked for, or null if nothing has. The
    // serial is what makes a second tap on the same session's notification a
    // second request: without it the two compare equal and the composition
    // below has nothing to react to.
    private var openRequest by mutableStateOf<SessionOpenRequest?>(null)
    private var opens = 0

    // Registered up front since permission launchers must be registered
    // before the activity reaches STARTED.
    private val requestLocalNetworkPermission =
        registerForActivityResult(ActivityResultContracts.RequestPermission()) {}

    /**
     * The service starts either way, and posts nothing if this is refused.
     *
     * Deliberately not gated on the answer: the permission can be granted later from Android's own
     * settings, and a service that only ever started at the moment it was granted would then stay
     * down until the app was launched again -- which is the case notifications exist to avoid.
     */
    private val requestNotificationPermission =
        registerForActivityResult(ActivityResultContracts.RequestPermission()) {}

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

        // Before anything else that could throw, so the first crash of a launch is caught too.
        installCrashLog(this)

        // Transparent status bar on every version; the Surface below paints
        // through underneath it and content insets itself. Same reasoning
        // as dev-updater's MainActivity.
        enableEdgeToEdge()
        // Dark status-bar icons only over a light background, decided from the scheme rather
        // than fixed. It was hardcoded to `true` -- dark icons -- which was right against the
        // default light surface and became unreadable the moment the app wore Catppuccin Mocha.
        // Asking the colour means a future palette change cannot reintroduce that: whatever
        // `background` becomes, the icons follow it.
        WindowCompat.getInsetsController(window, window.decorView).isAppearanceLightStatusBars =
            AiAppColors.background.luminance() > 0.5f

        // Android 17+ silently drops local-network traffic without this;
        // requested up front because a denial is invisible at the socket
        // layer (it just times out).
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.CINNAMON_BUN) {
            requestLocalNetworkPermission.launch(Manifest.permission.ACCESS_LOCAL_NETWORK)
        }

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
            requestNotificationPermission.launch(Manifest.permission.POST_NOTIFICATIONS)
        }

        handleIntent(intent)
        // After enrollment, so a first launch that arrives with a token
        // starts the service with something to connect to rather than
        // stopping it and waiting for the next launch.
        NotificationService.sync(this)

        setContent {
            MaterialTheme(colorScheme = AiAppColors) {
                Surface(modifier = Modifier.fillMaxSize()) {
                    Box(
                        modifier =
                            // Timed like the transcript times itself, and for the same reason:
                            // the frame's draw phase is where Compose's measurement lands, and
                            // a report saying "draw is high" cannot otherwise say whether the
                            // cost is the transcript or the chrome around it. The keyboard is
                            // the case that made it matter -- every frame of the IME animation
                            // relays out and re-records this whole box.
                            Modifier.layout { measurable, constraints ->
                                    val started = System.nanoTime()
                                    val placeable = measurable.measure(constraints)
                                    DebugStats.record(
                                        "measure: the app root",
                                        System.nanoTime() - started,
                                    )
                                    layout(placeable.width, placeable.height) {
                                        val placing = System.nanoTime()
                                        placeable.place(0, 0)
                                        DebugStats.record(
                                            "place: the app root",
                                            System.nanoTime() - placing,
                                        )
                                    }
                                }
                                .drawWithContent {
                                    val started = System.nanoTime()
                                    drawContent()
                                    DebugStats.record(
                                        "record: the app root",
                                        System.nanoTime() - started,
                                    )
                                }
                                .fillMaxSize()
                                .statusBarsPadding()
                                // The gesture strip at the bottom of most
                                // phones. Without it the send row sits under
                                // the swipe area, where a tap is as likely to
                                // navigate away as to press a button.
                                //
                                // No imePadding here, deliberately: applied at the root it
                                // resizes this whole box on every frame of the keyboard
                                // animation, which re-measures, re-places and re-records every
                                // screen's entire tree per frame -- measured above as most of
                                // the frame budget. Each screen takes the keyboard itself
                                // (AppRoot wraps the ordinary ones; the session screen moves
                                // only its composer and transcript), so the per-frame cost is
                                // scoped to what actually moves.
                                .navigationBarsPadding()
                    ) {
                        AppRoot(settingsVersion, openRequest)
                    }
                }
            }
        }
    }

    // launchMode="singleTop": an enrollment scan, or a notification tapped
    // while the app is open, lands here rather than in a second activity
    // instance.
    override fun onNewIntent(intent: Intent) {
        super.onNewIntent(intent)
        handleIntent(intent)
    }

    /**
     * The one place an incoming `aiapp://` URI is sorted into what it means.
     *
     * Two things arrive this way -- an enrollment code and a notification naming a session -- and
     * they are told apart by the URI's host rather than by two entry points, so a third kind is a
     * branch here rather than another intent to remember to handle.
     */
    private fun handleIntent(intent: Intent?) {
        val uri = intent?.data ?: return
        val sessionId = notifiedSessionId(uri)
        if (sessionId != null) {
            opens++
            openRequest = SessionOpenRequest(sessionId, opens)
            return
        }
        val settings = parseEnrollmentUri(uri)
        if (settings == null) {
            Toast.makeText(this, "Not a valid enrollment code", Toast.LENGTH_LONG).show()
            return
        }
        saveServerSettings(this, settings)
        settingsVersion++
        // Enrolling is the moment there is a backend to watch, and
        // re-enrolling elsewhere is the moment the old one stops being it.
        NotificationService.sync(this)
        Toast.makeText(this, "Enrolled with ${settings.baseUrl}", Toast.LENGTH_LONG).show()
    }
}