/*
 * ImageToolbox is an image editor for android
 * Copyright (c) 2026 T8RIN (Malik Mukhametzyanov)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * You should have received a copy of the Apache License
 * along with this program.  If not, see <http://www.apache.org/licenses/LICENSE-2.0>.
 */

package com.t8rin.imagetoolbox.feature.erase_background.presentation.screenLogic

import android.graphics.Bitmap
import android.net.Uri
import androidx.compose.runtime.MutableState
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.Path
import androidx.core.net.toUri
import com.arkivanov.decompose.ComponentContext
import com.arkivanov.essenty.lifecycle.doOnDestroy
import com.t8rin.imagetoolbox.core.domain.coroutines.DispatchersHolder
import com.t8rin.imagetoolbox.core.domain.image.ImageCompressor
import com.t8rin.imagetoolbox.core.domain.image.ImageGetter
import com.t8rin.imagetoolbox.core.domain.image.ImageScaler
import com.t8rin.imagetoolbox.core.domain.image.ImageShareProvider
import com.t8rin.imagetoolbox.core.domain.image.model.ImageFormat
import com.t8rin.imagetoolbox.core.domain.image.model.ImageInfo
import com.t8rin.imagetoolbox.core.domain.saving.FileController
import com.t8rin.imagetoolbox.core.domain.saving.model.ImageSaveTarget
import com.t8rin.imagetoolbox.core.domain.utils.update
import com.t8rin.imagetoolbox.core.ui.utils.BaseComponent
import com.t8rin.imagetoolbox.core.ui.utils.helper.AppToastHost
import com.t8rin.imagetoolbox.core.ui.utils.navigation.Screen
import com.t8rin.imagetoolbox.core.ui.utils.state.savable
import com.t8rin.imagetoolbox.core.ui.utils.state.update
import com.t8rin.imagetoolbox.core.ui.widget.modifier.HelperGridParams
import com.t8rin.imagetoolbox.feature.draw.domain.DrawPathMode
import com.t8rin.imagetoolbox.feature.draw.domain.ImageDrawApplier
import com.t8rin.imagetoolbox.feature.draw.presentation.components.UiPathPaint
import com.t8rin.imagetoolbox.feature.erase_background.domain.AutoBackgroundRemover
import com.t8rin.imagetoolbox.feature.erase_background.domain.model.BgModelType
import dagger.assisted.Assisted
import dagger.assisted.AssistedFactory
import dagger.assisted.AssistedInject
import kotlinx.coroutines.Job

class EraseBackgroundComponent @AssistedInject internal constructor(
    @Assisted componentContext: ComponentContext,
    @Assisted val initialUri: Uri?,
    @Assisted val onGoBack: () -> Unit,
    @Assisted val onNavigate: (Screen) -> Unit,
    private val imageScaler: ImageScaler<Bitmap>,
    private val imageGetter: ImageGetter<Bitmap>,
    private val imageCompressor: ImageCompressor<Bitmap>,
    private val fileController: FileController,
    private val imageDrawApplier: ImageDrawApplier<Bitmap, Path, Color>,
    private val autoBackgroundRemover: AutoBackgroundRemover<Bitmap>,
    private val shareProvider: ImageShareProvider<Bitmap>,
    dispatchersHolder: DispatchersHolder,
) : BaseComponent(dispatchersHolder, componentContext) {

    init {
        debounce {
            initialUri?.let(::setUri)
        }

        doOnDestroy {
            autoBackgroundRemover.cleanup()
        }
    }

    private val _internalBitmap: MutableState<Bitmap?> = mutableStateOf(null)
    val internalBitmap: Bitmap? by _internalBitmap

    private val _isRecoveryOn: MutableState<Boolean> = mutableStateOf(false)
    val isRecoveryOn: Boolean by _isRecoveryOn

    private val _saveExif: MutableState<Boolean> = mutableStateOf(false)
    val saveExif: Boolean by _saveExif

    private val _trimImage: MutableState<Boolean> = mutableStateOf(true)
    val trimImage: Boolean by _trimImage

    private val _paths = mutableStateOf(listOf<UiPathPaint>())
    val paths: List<UiPathPaint> by _paths

    private val _lastPaths = mutableStateOf(listOf<UiPathPaint>())
    val lastPaths: List<UiPathPaint> by _lastPaths

    private val _undonePaths = mutableStateOf(listOf<UiPathPaint>())
    val undonePaths: List<UiPathPaint> by _undonePaths

    private val _drawPathMode: MutableState<DrawPathMode> = mutableStateOf(DrawPathMode.Free)
    val drawPathMode: DrawPathMode by _drawPathMode

    private val _isSaving: MutableState<Boolean> = mutableStateOf(false)
    val isSaving: Boolean by _isSaving

    private val _isErasingBG: MutableState<Boolean> = mutableStateOf(false)
    val isErasingBG: Boolean by _isErasingBG

    private val _imageFormat: MutableState<ImageFormat> = mutableStateOf(ImageFormat.Default)
    val imageFormat: ImageFormat by _imageFormat

    private val _uri: MutableState<Uri> = mutableStateOf(Uri.EMPTY)

    private val _bitmap: MutableState<Bitmap?> = mutableStateOf(null)
    val bitmap: Bitmap? by _bitmap

    private val _helperGridParams = fileController.savable(
        scope = componentScope,
        initial = HelperGridParams()
    )
    val helperGridParams: HelperGridParams by _helperGridParams

    private fun updateBitmap(bitmap: Bitmap?) {
        componentScope.launch {
            _isImageLoading.value = true
            _bitmap.value = imageScaler.scaleUntilCanShow(bitmap)
            _internalBitmap.value = _bitmap.value
            _isImageLoading.value = false
        }
    }

    fun setUri(
        uri: Uri
    ) {
        _uri.value = uri
        autoEraseCount = 0
        _isImageLoading.value = true
        componentScope.launch {
            _paths.value = listOf()
            _lastPaths.value = listOf()
            _undonePaths.value = listOf()

            imageGetter.getImageAsync(
                uri = uri.toString(),
                originalSize = true,
                onGetImage = { data ->
                    updateBitmap(data.image)
                    _imageFormat.update {
                        data.imageInfo.imageFormat
                    }
                },
                onFailure = AppToastHost::showFailureToast
            )
        }
    }

    fun setImageFormat(imageFormat: ImageFormat) {
        _imageFormat.value = imageFormat
        registerChanges()
    }

    private var savingJob: Job? = null

    fun saveBitmap(
        oneTimeSaveLocationUri: String?
    ) {
        _isSaving.value = false
        savingJob?.cancel()
        savingJob = trackProgress {
            _isSaving.value = true
            getErasedBitmap(true)?.let { localBitmap ->
                parseSaveResult(
                    fileController.save(
                        saveTarget = ImageSaveTarget(
                            imageInfo = ImageInfo(
                                originalUri = _uri.value.toString(),
                                imageFormat = imageFormat,
                                width = localBitmap.width,
                                height = localBitmap.height
                            ),
                            originalUri = _uri.value.toString(),
                            sequenceNumber = null,
                            data = imageCompressor.compressAndTransform(
                                image = localBitmap,
                                imageInfo = ImageInfo(
                                    originalUri = _uri.value.toString(),
                                    imageFormat = imageFormat,
                                    width = localBitmap.width,
                                    height = localBitmap.height
                                )
                            )
                        ),
                        keepOriginalMetadata = _saveExif.value,
                        oneTimeSaveLocationUri = oneTimeSaveLocationUri
                    ).onSuccess(::registerSave)
                )
            }
            _isSaving.value = false
        }
    }

    private suspend fun getErasedBitmap(canTrim: Boolean): Bitmap? {
        return if (autoEraseCount == 0) {
            imageDrawApplier.applyEraseToImage(
                pathPaints = _paths.value,
                imageUri = _uri.value.toString()
            )
        } else {
            imageDrawApplier.applyEraseToImage(
                pathPaints = _paths.value,
                image = _bitmap.value,
                shaderSourceUri = _uri.value.toString()
            )
        }?.let {
            if (trimImage && canTrim) autoBackgroundRemover.trimEmptyParts(it)
            else it
        }
    }

    fun shareBitmap() {
        componentScope.launch {
            getErasedBitmap(true)?.let {
                _isSaving.value = true
                shareProvider.shareImage(
                    imageInfo = ImageInfo(
                        originalUri = _uri.value.toString(),
                        imageFormat = imageFormat,
                        width = it.width,
                        height = it.height
                    ),
                    image = it,
                    onComplete = AppToastHost::showConfetti
                )
            } ?: AppToastHost.showConfetti()
            _isSaving.value = false
        }.also {
            _isSaving.value = false
            savingJob?.cancel()
            savingJob = it
        }
    }

    fun undo() {
        if (paths.isEmpty() && lastPaths.isNotEmpty()) {
            _paths.value = lastPaths
            _lastPaths.value = listOf()
            return
        }
        if (paths.isEmpty()) return

        val lastPath = paths.last()

        _paths.update { it - lastPath }
        _undonePaths.update { it + lastPath }
        registerChanges()
    }

    fun redo() {
        if (undonePaths.isEmpty()) return

        val lastPath = undonePaths.last()
        _paths.update { it + lastPath }
        _undonePaths.update { it - lastPath }
        registerChanges()
    }

    fun addPath(pathPaint: UiPathPaint) {
        _paths.update { it + pathPaint }
        _undonePaths.value = listOf()
        registerChanges()
    }

    fun clearDrawing() {
        if (paths.isNotEmpty()) {
            _lastPaths.value = paths
            _paths.value = listOf()
            _undonePaths.value = listOf()
            registerChanges()
        }
    }

    fun setSaveExif(bool: Boolean) {
        _saveExif.value = bool
        registerChanges()
    }

    fun setTrimImage(boolean: Boolean) {
        _trimImage.value = boolean
        registerChanges()
    }

    private var autoEraseCount: Int = 0

    fun autoEraseBackground(
        modelType: BgModelType,
    ) {
        componentScope.launch {
            getErasedBitmap(false)?.let { image ->
                _isErasingBG.value = true
                autoBackgroundRemover.removeBackgroundFromImage(
                    image = image,
                    modelType = modelType,
                    onSuccess = {
                        _bitmap.value = it
                        _paths.value = listOf()
                        _lastPaths.value = listOf()
                        _undonePaths.value = listOf()
                        _isErasingBG.value = false
                        AppToastHost.showConfetti()
                        autoEraseCount++
                        registerChanges()
                    },
                    onFailure = {
                        _isErasingBG.value = false
                        AppToastHost.showFailureToast(it)
                    }
                )
            }
        }
    }

    fun resetImage() {
        componentScope.launch {
            autoEraseCount = 0
            _bitmap.value = _internalBitmap.value
            _paths.value = listOf()
            _lastPaths.value = listOf()
        }
    }

    fun toggleEraser() {
        _isRecoveryOn.update { !it }
    }

    fun cancelSaving() {
        savingJob?.cancel()
        savingJob = null
        _isSaving.value = false
    }

    fun cacheCurrentImage(onComplete: (Uri) -> Unit) {
        _isSaving.value = false
        savingJob?.cancel()
        savingJob = trackProgress {
            _isSaving.value = true
            getErasedBitmap(true)?.let { image ->
                shareProvider.cacheImage(
                    image = image,
                    imageInfo = ImageInfo(
                        originalUri = _uri.value.toString(),
                        imageFormat = imageFormat,
                        width = image.width,
                        height = image.height
                    )
                )?.let { uri ->
                    onComplete(uri.toUri())
                }
            }
            _isSaving.value = false
        }
    }

    fun updateDrawPathMode(drawPathMode: DrawPathMode) {
        _drawPathMode.update { drawPathMode }
    }

    fun getFormatForFilenameSelection(): ImageFormat = imageFormat

    fun updateHelperGridParams(params: HelperGridParams) {
        _helperGridParams.update { params }
    }

    @AssistedFactory
    fun interface Factory {
        operator fun invoke(
            componentContext: ComponentContext,
            initialUri: Uri?,
            onGoBack: () -> Unit,
            onNavigate: (Screen) -> Unit,
        ): EraseBackgroundComponent
    }

}