LatinIME.kt

package org.futo.inputmethod.latin

import android.content.res.Configuration
import android.inputmethodservice.InputMethodService
import android.os.Build
import android.os.Bundle
import android.view.KeyEvent
import android.view.View
import android.view.inputmethod.CompletionInfo
import android.view.inputmethod.EditorInfo
import android.view.inputmethod.InlineSuggestion
import android.view.inputmethod.InlineSuggestionsRequest
import android.view.inputmethod.InlineSuggestionsResponse
import android.view.inputmethod.InputMethodSubtype
import androidx.annotation.RequiresApi
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.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.material3.ColorScheme
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Surface
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.MutableState
import androidx.compose.runtime.key
import androidx.compose.ui.Alignment.Companion.CenterVertically
import androidx.compose.ui.Modifier
import androidx.compose.ui.layout.onSizeChanged
import androidx.compose.ui.platform.ComposeView
import androidx.compose.ui.platform.LocalDensity
import androidx.compose.ui.platform.ViewCompositionStrategy
import androidx.compose.ui.res.painterResource
import androidx.compose.ui.unit.dp
import androidx.compose.ui.viewinterop.AndroidView
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleOwner
import androidx.lifecycle.LifecycleRegistry
import androidx.lifecycle.ViewModelStore
import androidx.lifecycle.ViewModelStoreOwner
import androidx.lifecycle.findViewTreeLifecycleOwner
import androidx.lifecycle.findViewTreeViewModelStoreOwner
import androidx.lifecycle.setViewTreeLifecycleOwner
import androidx.lifecycle.setViewTreeViewModelStoreOwner
import androidx.savedstate.SavedStateRegistry
import androidx.savedstate.SavedStateRegistryController
import androidx.savedstate.SavedStateRegistryOwner
import androidx.savedstate.findViewTreeSavedStateRegistryOwner
import androidx.savedstate.setViewTreeSavedStateRegistryOwner
import kotlinx.coroutines.Job
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.runBlocking
import org.futo.inputmethod.latin.common.Constants
import org.futo.inputmethod.latin.uix.Action
import org.futo.inputmethod.latin.uix.ActionBar
import org.futo.inputmethod.latin.uix.BasicThemeProvider
import org.futo.inputmethod.latin.uix.DynamicThemeProvider
import org.futo.inputmethod.latin.uix.DynamicThemeProviderOwner
import org.futo.inputmethod.latin.uix.KeyboardManagerForAction
import org.futo.inputmethod.latin.uix.THEME_KEY
import org.futo.inputmethod.latin.uix.createInlineSuggestionsRequest
import org.futo.inputmethod.latin.uix.deferGetSetting
import org.futo.inputmethod.latin.uix.deferSetSetting
import org.futo.inputmethod.latin.uix.differsFrom
import org.futo.inputmethod.latin.uix.inflateInlineSuggestion
import org.futo.inputmethod.latin.uix.theme.DarkColorScheme
import org.futo.inputmethod.latin.uix.theme.ThemeOption
import org.futo.inputmethod.latin.uix.theme.ThemeOptions
import org.futo.inputmethod.latin.uix.theme.Typography
import org.futo.inputmethod.latin.uix.theme.UixThemeWrapper
import org.futo.inputmethod.latin.uix.theme.presets.ClassicMaterialDark
import org.futo.inputmethod.latin.uix.theme.presets.DynamicSystemTheme
import org.futo.inputmethod.latin.uix.theme.presets.VoiceInputTheme

class LatinIME : InputMethodService(), LifecycleOwner, ViewModelStoreOwner, SavedStateRegistryOwner,
    LatinIMELegacy.SuggestionStripController, DynamicThemeProviderOwner, KeyboardManagerForAction {

    private val mSavedStateRegistryController = SavedStateRegistryController.create(this)

    override val savedStateRegistry: SavedStateRegistry
        get() = mSavedStateRegistryController.savedStateRegistry

    private val mLifecycleRegistry = LifecycleRegistry(this)
    private fun handleLifecycleEvent(event: Lifecycle.Event) =
        mLifecycleRegistry.handleLifecycleEvent(event)

    override val lifecycle
        get() = mLifecycleRegistry

    private val store = ViewModelStore()
    override val viewModelStore
        get() = store

    private fun setOwners() {
        val decorView = window.window?.decorView
        if (decorView?.findViewTreeLifecycleOwner() == null) {
            decorView?.setViewTreeLifecycleOwner(this)
        }
        if (decorView?.findViewTreeViewModelStoreOwner() == null) {
            decorView?.setViewTreeViewModelStoreOwner(this)
        }
        if (decorView?.findViewTreeSavedStateRegistryOwner() == null) {
            decorView?.setViewTreeSavedStateRegistryOwner(this)
        }
    }

    private var composeView: ComposeView? = null

    private val latinIMELegacy = LatinIMELegacy(
        this as InputMethodService,
        this as LatinIMELegacy.SuggestionStripController
    )

    private var activeThemeOption: ThemeOption? = null
    private var activeColorScheme = DarkColorScheme
    private var colorSchemeLoaderJob: Job? = null

    private var drawableProvider: DynamicThemeProvider? = null

    private var currWindowAction: Action? = null
    private fun isActionWindowOpen(): Boolean {
        return currWindowAction != null
    }

    private var inlineSuggestions: List<MutableState<View?>> = listOf()

    private fun recreateKeyboard() {
        legacyInputView = latinIMELegacy.onCreateInputView()
        latinIMELegacy.loadKeyboard()
    }

    private fun updateDrawableProvider(colorScheme: ColorScheme) {
        activeColorScheme = colorScheme
        drawableProvider = BasicThemeProvider(this, overrideColorScheme = colorScheme)

        // recreate the keyboard if not in action window, if we are in action window then
        // it'll be recreated when we exit
        if (!isActionWindowOpen()) recreateKeyboard()

        window.window?.navigationBarColor = drawableProvider!!.primaryKeyboardColor
        setContent()
    }

    override fun getDrawableProvider(): DynamicThemeProvider {
        if (drawableProvider == null) {
            if (colorSchemeLoaderJob != null && !colorSchemeLoaderJob!!.isCompleted) {
                // Must have completed by now!
                runBlocking {
                    colorSchemeLoaderJob!!.join()
                }
            }
            drawableProvider = BasicThemeProvider(this, activeColorScheme)
        }

        return drawableProvider!!
    }

    private fun updateColorsIfDynamicChanged() {
        if(activeThemeOption?.dynamic == true) {
            val currColors = activeColorScheme
            val nextColors = activeThemeOption!!.obtainColors(this)

            if(currColors.differsFrom(nextColors)) {
                updateDrawableProvider(nextColors)
            }
        }
    }

    override fun onCreate() {
        super.onCreate()

        colorSchemeLoaderJob = deferGetSetting(THEME_KEY, DynamicSystemTheme.key) {
            var themeKey = it
            var themeOption = ThemeOptions[themeKey]
            if (themeOption == null || !themeOption.available(this@LatinIME)) {
                themeKey = VoiceInputTheme.key
                themeOption = ThemeOptions[themeKey]!!
            }

            activeThemeOption = themeOption
            activeColorScheme = themeOption.obtainColors(this@LatinIME)
        }

        mSavedStateRegistryController.performRestore(null)
        handleLifecycleEvent(Lifecycle.Event.ON_RESUME)

        latinIMELegacy.onCreate()
    }

    override fun onDestroy() {
        latinIMELegacy.onDestroy()
        super.onDestroy()
    }

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

    override fun onInitializeInterface() {
        latinIMELegacy.onInitializeInterface()
    }

    private var legacyInputView: View? = null
    private var touchableHeight: Int = 0
    override fun onCreateInputView(): View {
        legacyInputView = latinIMELegacy.onCreateInputView()
        composeView = ComposeView(this).apply {
            setViewCompositionStrategy(ViewCompositionStrategy.DisposeOnViewTreeLifecycleDestroyed)
            setParentCompositionContext(null)

            this@LatinIME.setOwners()
        }

        setContent()

        latinIMELegacy.setComposeInputView(composeView)

        return composeView!!
    }

    private fun onActionActivated(action: Action) {
        if (action.windowImpl != null) {
            enterActionWindowView(action)
        } else if (action.simplePressImpl != null) {
            action.simplePressImpl.invoke(this)
        } else {
            throw IllegalStateException("An action must have either a window implementation or a simple press implementation")
        }
    }

    private var inputViewHeight: Int = -1
    private var shouldShowSuggestionStrip: Boolean = true
    private var suggestedWords: SuggestedWords? = null

    @Composable
    private fun LegacyKeyboardView() {
        key(legacyInputView) {
            AndroidView(factory = {
                legacyInputView!!
            }, update = { }, modifier = Modifier.onSizeChanged {
                inputViewHeight = it.height
            })
        }
    }

    @Composable
    private fun MainKeyboardViewWithActionBar() {
        Column {
            // Don't show suggested words when it's not meant to be shown
            val suggestedWordsOrNull = if(shouldShowSuggestionStrip) {
                suggestedWords
            } else {
                null
            }

            ActionBar(
                suggestedWordsOrNull,
                latinIMELegacy,
                inlineSuggestions = inlineSuggestions,
                onActionActivated = { onActionActivated(it) }
            )
            
            LegacyKeyboardView()
        }
    }

    private fun enterActionWindowView(action: Action) {
        assert(action.windowImpl != null)
        currWindowAction = action

        setContent()
    }

    private fun returnBackToMainKeyboardViewFromAction() {
        assert(currWindowAction != null)
        currWindowAction = null

        // Keyboard acts buggy in many ways after being detached from window then attached again,
        // so let's recreate it
        recreateKeyboard()

        setContent()
    }

    @Composable
    private fun ActionViewWithHeader(action: Action) {
        val windowImpl = action.windowImpl!!
        Column {
            Surface(
                modifier = Modifier
                    .fillMaxWidth()
                    .height(40.dp), color = MaterialTheme.colorScheme.background
            )
            {
                Row {
                    IconButton(onClick = {
                        returnBackToMainKeyboardViewFromAction()
                    }) {
                        Icon(
                            painter = painterResource(id = R.drawable.arrow_left),
                            contentDescription = "Back"
                        )
                    }

                    Text(
                        windowImpl.windowName(),
                        style = Typography.titleMedium,
                        modifier = Modifier.align(CenterVertically)
                    )
                }
            }

            Box(modifier = Modifier
                .fillMaxWidth()
                .height(with(LocalDensity.current) { inputViewHeight.toDp() })
            ) {
                windowImpl.WindowContents(manager = this@LatinIME)
            }
        }
    }

    private fun setContent() {
        composeView?.setContent {
            UixThemeWrapper(activeColorScheme) {
                Column {
                    Spacer(modifier = Modifier.weight(1.0f))
                    Surface(modifier = Modifier.onSizeChanged {
                        touchableHeight = it.height
                    }) {
                        when {
                            currWindowAction != null -> ActionViewWithHeader(currWindowAction!!)
                            else -> MainKeyboardViewWithActionBar()
                        }
                    }
                }
            }
        }
    }

    // necessary for when KeyboardSwitcher updates the theme
    fun updateLegacyView(newView: View) {
        legacyInputView = newView
        setContent()

        if (composeView != null) {
            latinIMELegacy.setComposeInputView(composeView)
        }

        latinIMELegacy.setInputView(legacyInputView)
    }

    override fun setInputView(view: View?) {
        super.setInputView(view)

        if (composeView != null) {
            latinIMELegacy.setComposeInputView(composeView)
        }

        latinIMELegacy.setInputView(legacyInputView)
    }

    override fun setCandidatesView(view: View?) {
        return latinIMELegacy.setCandidatesView(view)
    }

    override fun onStartInput(attribute: EditorInfo?, restarting: Boolean) {
        super.onStartInput(attribute, restarting)
        latinIMELegacy.onStartInput(attribute, restarting)
    }

    override fun onStartInputView(info: EditorInfo?, restarting: Boolean) {
        super.onStartInputView(info, restarting)
        latinIMELegacy.onStartInputView(info, restarting)
    }

    override fun onFinishInputView(finishingInput: Boolean) {
        super.onFinishInputView(finishingInput)
        latinIMELegacy.onFinishInputView(finishingInput)
    }

    override fun onFinishInput() {
        super.onFinishInput()
        latinIMELegacy.onFinishInput()
    }

    override fun onCurrentInputMethodSubtypeChanged(newSubtype: InputMethodSubtype?) {
        super.onCurrentInputMethodSubtypeChanged(newSubtype)
        latinIMELegacy.onCurrentInputMethodSubtypeChanged(newSubtype)
    }

    override fun onWindowShown() {
        super.onWindowShown()
        latinIMELegacy.onWindowShown()

        updateColorsIfDynamicChanged()
    }

    override fun onWindowHidden() {
        super.onWindowHidden()
        latinIMELegacy.onWindowHidden()
    }

    override fun onUpdateSelection(
        oldSelStart: Int,
        oldSelEnd: Int,
        newSelStart: Int,
        newSelEnd: Int,
        candidatesStart: Int,
        candidatesEnd: Int
    ) {
        super.onUpdateSelection(
            oldSelStart,
            oldSelEnd,
            newSelStart,
            newSelEnd,
            candidatesStart,
            candidatesEnd
        )

        latinIMELegacy.onUpdateSelection(
            oldSelStart,
            oldSelEnd,
            newSelStart,
            newSelEnd,
            candidatesStart,
            candidatesEnd
        )
    }

    override fun onExtractedTextClicked() {
        latinIMELegacy.onExtractedTextClicked()
        super.onExtractedTextClicked()
    }

    override fun onExtractedCursorMovement(dx: Int, dy: Int) {
        latinIMELegacy.onExtractedCursorMovement(dx, dy)
        super.onExtractedCursorMovement(dx, dy)
    }

    override fun hideWindow() {
        latinIMELegacy.hideWindow()
        super.hideWindow()
    }

    override fun onDisplayCompletions(completions: Array<out CompletionInfo>?) {
        latinIMELegacy.onDisplayCompletions(completions)
    }

    override fun onComputeInsets(outInsets: Insets?) {
        // This method may be called before {@link #setInputView(View)}.
        if (legacyInputView == null || composeView == null) {
            return
        }

        val inputHeight: Int = composeView!!.height
        if (latinIMELegacy.isImeSuppressedByHardwareKeyboard && !legacyInputView!!.isShown) {
            // If there is a hardware keyboard and a visible software keyboard view has been hidden,
            // no visual element will be shown on the screen.
            latinIMELegacy.setInsets(outInsets!!.apply {
                contentTopInsets = inputHeight
                visibleTopInsets = inputHeight
            })
            return
        }

        val visibleTopY = inputHeight - touchableHeight

        val touchLeft = 0
        val touchTop = visibleTopY
        val touchRight = composeView!!.width
        val touchBottom = inputHeight

        latinIMELegacy.setInsets(outInsets!!.apply {
            touchableInsets = Insets.TOUCHABLE_INSETS_REGION;
            touchableRegion.set(touchLeft, touchTop, touchRight, touchBottom);
            contentTopInsets = visibleTopY
            visibleTopInsets = visibleTopY
        })
    }

    override fun onShowInputRequested(flags: Int, configChange: Boolean): Boolean {
        return latinIMELegacy.onShowInputRequested(
            flags,
            configChange
        ) || super.onShowInputRequested(flags, configChange)
    }

    override fun onEvaluateInputViewShown(): Boolean {
        return latinIMELegacy.onEvaluateInputViewShown() || super.onEvaluateInputViewShown()
    }

    override fun onEvaluateFullscreenMode(): Boolean {
        return latinIMELegacy.onEvaluateFullscreenMode(super.onEvaluateFullscreenMode())
    }

    override fun updateFullscreenMode() {
        super.updateFullscreenMode()
        latinIMELegacy.updateFullscreenMode()
    }

    override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
        return latinIMELegacy.onKeyDown(keyCode, event) || super.onKeyDown(keyCode, event)
    }

    override fun onKeyUp(keyCode: Int, event: KeyEvent?): Boolean {
        return latinIMELegacy.onKeyUp(keyCode, event) || super.onKeyUp(keyCode, event)
    }

    override fun updateVisibility(shouldShowSuggestionsStrip: Boolean, fullscreenMode: Boolean) {
        this.shouldShowSuggestionStrip = shouldShowSuggestionsStrip
        setContent()
    }

    override fun setSuggestions(suggestedWords: SuggestedWords?, rtlSubtype: Boolean) {
        this.suggestedWords = suggestedWords
        setContent()
    }

    override fun maybeShowImportantNoticeTitle(): Boolean {
        return false
    }

    override fun triggerSystemVoiceInput() {
        latinIMELegacy.onCodeInput(
            Constants.CODE_SHORTCUT,
            Constants.SUGGESTION_STRIP_COORDINATE,
            Constants.SUGGESTION_STRIP_COORDINATE,
            false
        );
    }

    override fun updateTheme(newTheme: ThemeOption) {
        assert(newTheme.available(this))
        activeThemeOption = newTheme
        updateDrawableProvider(newTheme.obtainColors(this))

        deferSetSetting(THEME_KEY, newTheme.key)
    }

    @RequiresApi(Build.VERSION_CODES.R)
    override fun onCreateInlineSuggestionsRequest(uiExtras: Bundle): InlineSuggestionsRequest {
        return createInlineSuggestionsRequest(this, this.activeColorScheme)
    }

    @RequiresApi(Build.VERSION_CODES.R)
    override fun onInlineSuggestionsResponse(response: InlineSuggestionsResponse): Boolean {
        inlineSuggestions = response.inlineSuggestions.map {
            inflateInlineSuggestion(it)
        }
        setContent()

        return true
    }
}