package no.naiv.tiltshift.ui

import android.graphics.SurfaceTexture
import android.location.Location
import android.opengl.GLSurfaceView
import android.view.Surface
import androidx.compose.animation.AnimatedVisibility
import androidx.compose.animation.fadeIn
import androidx.compose.animation.fadeOut
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.navigationBarsPadding
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.layout.statusBarsPadding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Check
import androidx.compose.material.icons.filled.Close
import androidx.compose.material.icons.filled.FlipCameraAndroid
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.Slider
import androidx.compose.material3.SliderDefaults
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.DisposableEffect
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.collectAsState
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.runtime.rememberUpdatedState
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.platform.LocalContext
import androidx.lifecycle.compose.LocalLifecycleOwner
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import androidx.compose.ui.viewinterop.AndroidView
import kotlinx.coroutines.delay
import kotlinx.coroutines.flow.collectLatest
import kotlinx.coroutines.launch
import no.naiv.tiltshift.camera.CameraManager
import no.naiv.tiltshift.camera.ImageCaptureHandler
import no.naiv.tiltshift.effect.BlurMode
import no.naiv.tiltshift.effect.BlurParameters
import no.naiv.tiltshift.effect.TiltShiftRenderer
import no.naiv.tiltshift.storage.PhotoSaver
import no.naiv.tiltshift.storage.SaveResult
import no.naiv.tiltshift.util.HapticFeedback
import no.naiv.tiltshift.util.LocationProvider
import no.naiv.tiltshift.util.OrientationDetector

/**
 * Main camera screen with tilt-shift controls.
 */
@Composable
fun CameraScreen(
    modifier: Modifier = Modifier
) {
    val context = LocalContext.current
    val lifecycleOwner = LocalLifecycleOwner.current
    val scope = rememberCoroutineScope()

    // Camera and effect state
    val cameraManager = remember { CameraManager(context) }
    val photoSaver = remember { PhotoSaver(context) }
    val captureHandler = remember { ImageCaptureHandler(context, photoSaver) }
    val haptics = remember { HapticFeedback(context) }
    val orientationDetector = remember { OrientationDetector(context) }
    val locationProvider = remember { LocationProvider(context) }

    // State
    var blurParams by remember { mutableStateOf(BlurParameters.DEFAULT) }
    var surfaceTexture by remember { mutableStateOf<SurfaceTexture?>(null) }
    var renderer by remember { mutableStateOf<TiltShiftRenderer?>(null) }
    var glSurfaceView by remember { mutableStateOf<GLSurfaceView?>(null) }

    var isCapturing by remember { mutableStateOf(false) }
    var showSaveSuccess by remember { mutableStateOf(false) }
    var showSaveError by remember { mutableStateOf<String?>(null) }
    var showControls by remember { mutableStateOf(false) }

    var currentRotation by remember { mutableStateOf(Surface.ROTATION_0) }
    var currentLocation by remember { mutableStateOf<Location?>(null) }

    val zoomRatio by cameraManager.zoomRatio.collectAsState()
    val minZoom by cameraManager.minZoomRatio.collectAsState()
    val maxZoom by cameraManager.maxZoomRatio.collectAsState()
    val isFrontCamera by cameraManager.isFrontCamera.collectAsState()

    // Collect orientation updates
    LaunchedEffect(Unit) {
        orientationDetector.orientationFlow().collectLatest { rotation ->
            currentRotation = rotation
        }
    }

    // Collect location updates
    LaunchedEffect(Unit) {
        locationProvider.locationFlow().collectLatest { location ->
            currentLocation = location
        }
    }

    // Update renderer with blur params
    LaunchedEffect(blurParams) {
        renderer?.updateParameters(blurParams)
        glSurfaceView?.requestRender()
    }

    // Update renderer when camera switches (front/back)
    LaunchedEffect(isFrontCamera) {
        renderer?.setFrontCamera(isFrontCamera)
        glSurfaceView?.requestRender()
    }

    // Start camera when surface texture is available
    LaunchedEffect(surfaceTexture) {
        surfaceTexture?.let {
            cameraManager.startCamera(lifecycleOwner) { surfaceTexture }
        }
    }

    // Cleanup
    DisposableEffect(Unit) {
        onDispose {
            cameraManager.release()
            renderer?.release()
        }
    }

    Box(
        modifier = modifier
            .fillMaxSize()
            .background(Color.Black)
    ) {
        // OpenGL Surface for camera preview with effect
        AndroidView(
            factory = { ctx ->
                GLSurfaceView(ctx).apply {
                    setEGLContextClientVersion(2)

                    val newRenderer = TiltShiftRenderer(ctx) { st ->
                        surfaceTexture = st
                    }
                    renderer = newRenderer

                    setRenderer(newRenderer)
                    renderMode = GLSurfaceView.RENDERMODE_CONTINUOUSLY

                    glSurfaceView = this
                }
            },
            modifier = Modifier.fillMaxSize()
        )

        // Tilt-shift overlay (gesture handling + visualization)
        TiltShiftOverlay(
            params = blurParams,
            onParamsChange = { newParams ->
                blurParams = newParams
                haptics.tick()
            },
            onZoomChange = { zoomDelta ->
                val newZoom = (zoomRatio * zoomDelta).coerceIn(minZoom, maxZoom)
                cameraManager.setZoom(newZoom)
            },
            modifier = Modifier.fillMaxSize()
        )

        // Top bar with controls
        Column(
            modifier = Modifier
                .fillMaxWidth()
                .statusBarsPadding()
                .padding(16.dp)
        ) {
            Row(
                modifier = Modifier.fillMaxWidth(),
                horizontalArrangement = Arrangement.SpaceBetween,
                verticalAlignment = Alignment.CenterVertically
            ) {
                // Zoom indicator
                ZoomIndicator(currentZoom = zoomRatio)

                Row(verticalAlignment = Alignment.CenterVertically) {
                    // Camera flip button
                    IconButton(
                        onClick = {
                            cameraManager.switchCamera()
                            haptics.click()
                        }
                    ) {
                        Icon(
                            imageVector = Icons.Default.FlipCameraAndroid,
                            contentDescription = "Switch Camera",
                            tint = Color.White
                        )
                    }

                    // Toggle controls button
                    IconButton(
                        onClick = {
                            showControls = !showControls
                            haptics.tick()
                        }
                    ) {
                        Text(
                            text = if (showControls) "Hide" else "Ctrl",
                            color = Color.White,
                            fontSize = 12.sp
                        )
                    }
                }
            }

            // Mode toggle
            Row(
                modifier = Modifier
                    .fillMaxWidth()
                    .padding(top = 8.dp),
                horizontalArrangement = Arrangement.Center
            ) {
                ModeToggle(
                    currentMode = blurParams.mode,
                    onModeChange = { mode ->
                        blurParams = blurParams.copy(mode = mode)
                        haptics.click()
                    }
                )
            }
        }

        // Control panel (sliders)
        AnimatedVisibility(
            visible = showControls,
            enter = fadeIn(),
            exit = fadeOut(),
            modifier = Modifier
                .align(Alignment.CenterEnd)
                .padding(end = 16.dp)
        ) {
            ControlPanel(
                params = blurParams,
                onParamsChange = { newParams ->
                    blurParams = newParams
                }
            )
        }

        // Bottom controls
        Column(
            modifier = Modifier
                .align(Alignment.BottomCenter)
                .navigationBarsPadding()
                .padding(bottom = 24.dp),
            horizontalAlignment = Alignment.CenterHorizontally
        ) {
            // Zoom presets (only show for back camera)
            if (!isFrontCamera) {
                ZoomControl(
                    currentZoom = zoomRatio,
                    minZoom = minZoom,
                    maxZoom = maxZoom,
                    onZoomSelected = { zoom ->
                        cameraManager.setZoom(zoom)
                        haptics.click()
                    }
                )

                Spacer(modifier = Modifier.height(24.dp))
            }

            // Capture button
            CaptureButton(
                isCapturing = isCapturing,
                onClick = {
                    if (!isCapturing) {
                        isCapturing = true
                        haptics.heavyClick()

                        scope.launch {
                            val imageCapture = cameraManager.imageCapture
                            if (imageCapture != null) {
                                val result = captureHandler.capturePhoto(
                                    imageCapture = imageCapture,
                                    executor = cameraManager.getExecutor(),
                                    blurParams = blurParams,
                                    deviceRotation = currentRotation,
                                    location = currentLocation,
                                    isFrontCamera = isFrontCamera
                                )

                                when (result) {
                                    is SaveResult.Success -> {
                                        haptics.success()
                                        showSaveSuccess = true
                                        delay(1500)
                                        showSaveSuccess = false
                                    }
                                    is SaveResult.Error -> {
                                        haptics.error()
                                        showSaveError = result.message
                                        delay(2000)
                                        showSaveError = null
                                    }
                                }
                            }
                            isCapturing = false
                        }
                    }
                }
            )
        }

        // Success indicator
        AnimatedVisibility(
            visible = showSaveSuccess,
            enter = fadeIn(),
            exit = fadeOut(),
            modifier = Modifier.align(Alignment.Center)
        ) {
            Box(
                modifier = Modifier
                    .size(80.dp)
                    .clip(CircleShape)
                    .background(Color(0xFF4CAF50)),
                contentAlignment = Alignment.Center
            ) {
                Icon(
                    imageVector = Icons.Default.Check,
                    contentDescription = "Saved",
                    tint = Color.White,
                    modifier = Modifier.size(48.dp)
                )
            }
        }

        // Error indicator
        AnimatedVisibility(
            visible = showSaveError != null,
            enter = fadeIn(),
            exit = fadeOut(),
            modifier = Modifier
                .align(Alignment.Center)
                .padding(32.dp)
        ) {
            Column(
                horizontalAlignment = Alignment.CenterHorizontally,
                modifier = Modifier
                    .clip(RoundedCornerShape(16.dp))
                    .background(Color(0xFFF44336))
                    .padding(24.dp)
            ) {
                Icon(
                    imageVector = Icons.Default.Close,
                    contentDescription = "Error",
                    tint = Color.White,
                    modifier = Modifier.size(32.dp)
                )
                Spacer(modifier = Modifier.height(8.dp))
                Text(
                    text = showSaveError ?: "Error",
                    color = Color.White,
                    fontSize = 14.sp
                )
            }
        }
    }
}

/**
 * Mode toggle for Linear / Radial blur modes.
 */
@Composable
private fun ModeToggle(
    currentMode: BlurMode,
    onModeChange: (BlurMode) -> Unit,
    modifier: Modifier = Modifier
) {
    Row(
        modifier = modifier
            .clip(RoundedCornerShape(20.dp))
            .background(Color(0x80000000))
            .padding(4.dp),
        horizontalArrangement = Arrangement.Center
    ) {
        ModeButton(
            text = "Linear",
            isSelected = currentMode == BlurMode.LINEAR,
            onClick = { onModeChange(BlurMode.LINEAR) }
        )
        Spacer(modifier = Modifier.width(4.dp))
        ModeButton(
            text = "Radial",
            isSelected = currentMode == BlurMode.RADIAL,
            onClick = { onModeChange(BlurMode.RADIAL) }
        )
    }
}

@Composable
private fun ModeButton(
    text: String,
    isSelected: Boolean,
    onClick: () -> Unit
) {
    Box(
        modifier = Modifier
            .clip(RoundedCornerShape(16.dp))
            .background(if (isSelected) Color(0xFFFFB300) else Color.Transparent)
            .clickable(onClick = onClick)
            .padding(horizontal = 16.dp, vertical = 8.dp),
        contentAlignment = Alignment.Center
    ) {
        Text(
            text = text,
            color = if (isSelected) Color.Black else Color.White,
            fontSize = 14.sp
        )
    }
}

/**
 * Control panel with sliders for blur parameters.
 */
@Composable
private fun ControlPanel(
    params: BlurParameters,
    onParamsChange: (BlurParameters) -> Unit,
    modifier: Modifier = Modifier
) {
    // Use rememberUpdatedState to avoid stale closure capture during slider drags
    val currentParams by rememberUpdatedState(params)
    val currentOnParamsChange by rememberUpdatedState(onParamsChange)

    Column(
        modifier = modifier
            .width(200.dp)
            .clip(RoundedCornerShape(16.dp))
            .background(Color(0xCC000000))
            .padding(16.dp),
        verticalArrangement = Arrangement.spacedBy(16.dp)
    ) {
        // Blur intensity slider
        SliderControl(
            label = "Blur",
            value = params.blurAmount,
            valueRange = BlurParameters.MIN_BLUR..BlurParameters.MAX_BLUR,
            onValueChange = { currentOnParamsChange(currentParams.copy(blurAmount = it)) }
        )

        // Falloff slider
        SliderControl(
            label = "Falloff",
            value = params.falloff,
            valueRange = BlurParameters.MIN_FALLOFF..BlurParameters.MAX_FALLOFF,
            onValueChange = { currentOnParamsChange(currentParams.copy(falloff = it)) }
        )

        // Aspect ratio slider (radial mode only)
        if (params.mode == BlurMode.RADIAL) {
            SliderControl(
                label = "Shape",
                value = params.aspectRatio,
                valueRange = BlurParameters.MIN_ASPECT..BlurParameters.MAX_ASPECT,
                onValueChange = { currentOnParamsChange(currentParams.copy(aspectRatio = it)) }
            )
        }
    }
}

@Composable
private fun SliderControl(
    label: String,
    value: Float,
    valueRange: ClosedFloatingPointRange<Float>,
    onValueChange: (Float) -> Unit
) {
    Column {
        Row(
            modifier = Modifier.fillMaxWidth(),
            horizontalArrangement = Arrangement.SpaceBetween
        ) {
            Text(
                text = label,
                color = Color.White,
                fontSize = 12.sp
            )
            Text(
                text = "${(value * 100).toInt()}%",
                color = Color.White.copy(alpha = 0.7f),
                fontSize = 12.sp
            )
        }
        Slider(
            value = value,
            onValueChange = onValueChange,
            valueRange = valueRange,
            colors = SliderDefaults.colors(
                thumbColor = Color(0xFFFFB300),
                activeTrackColor = Color(0xFFFFB300),
                inactiveTrackColor = Color.White.copy(alpha = 0.3f)
            ),
            modifier = Modifier.height(24.dp)
        )
    }
}

/**
 * Capture button with animation for capturing state.
 */
@Composable
private fun CaptureButton(
    isCapturing: Boolean,
    onClick: () -> Unit,
    modifier: Modifier = Modifier
) {
    val outerSize = 72.dp
    val innerSize = if (isCapturing) 48.dp else 60.dp

    Box(
        modifier = modifier
            .size(outerSize)
            .clip(CircleShape)
            .border(4.dp, Color.White, CircleShape)
            .clickable(enabled = !isCapturing, onClick = onClick),
        contentAlignment = Alignment.Center
    ) {
        Box(
            modifier = Modifier
                .size(innerSize)
                .clip(CircleShape)
                .background(if (isCapturing) Color(0xFFFFB300) else Color.White)
        )
    }
}