package com.rizoma.trazo

import android.inputmethodservice.InputMethodService
import android.text.InputType
import android.view.KeyEvent
import android.view.View
import android.view.inputmethod.EditorInfo
import androidx.compose.ui.platform.ComposeView
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleOwner
import androidx.lifecycle.LifecycleRegistry
import androidx.lifecycle.ViewModelStore
import androidx.lifecycle.ViewModelStoreOwner
import androidx.lifecycle.setViewTreeLifecycleOwner
import androidx.lifecycle.setViewTreeViewModelStoreOwner
import androidx.savedstate.SavedStateRegistry
import androidx.savedstate.SavedStateRegistryController
import androidx.savedstate.SavedStateRegistryOwner
import androidx.savedstate.setViewTreeSavedStateRegistryOwner
import com.rizoma.trazo.ime.ImeHost
import com.rizoma.trazo.ime.KeyboardController
import com.rizoma.trazo.ui.KeyboardScreen
import com.rizoma.trazo.ui.theme.TrazoTheme

/**
 * Trazo IME. Hospeda un teclado Compose dentro del InputMethodService, para lo cual
 * el servicio actúa como Lifecycle/ViewModelStore/SavedState owner del ComposeView.
 */
class TrazoImeService : InputMethodService(), LifecycleOwner, ViewModelStoreOwner, SavedStateRegistryOwner {

    private val lifecycleRegistry = LifecycleRegistry(this)
    override val lifecycle: Lifecycle get() = lifecycleRegistry

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

    private val savedStateController = SavedStateRegistryController.create(this)
    override val savedStateRegistry: SavedStateRegistry get() = savedStateController.savedStateRegistry

    private var editorInputType: Int = InputType.TYPE_CLASS_TEXT

    private val host = object : ImeHost {
        override fun commit(text: String) {
            currentInputConnection?.commitText(text, 1)
        }

        override fun backspace() {
            val ic = currentInputConnection ?: return
            val selected = ic.getSelectedText(0)
            if (selected.isNullOrEmpty()) ic.deleteSurroundingText(1, 0) else ic.commitText("", 1)
        }

        override fun newline() {
            val action = currentInputEditorInfo?.imeOptions ?: 0
            val opt = action and EditorInfo.IME_MASK_ACTION
            if (opt != EditorInfo.IME_ACTION_NONE && opt != EditorInfo.IME_ACTION_UNSPECIFIED &&
                (action and EditorInfo.IME_FLAG_NO_ENTER_ACTION) == 0
            ) {
                currentInputConnection?.performEditorAction(opt)
            } else {
                currentInputConnection?.sendKeyEvent(KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_ENTER))
                currentInputConnection?.sendKeyEvent(KeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_ENTER))
            }
        }

        override fun textBeforeCursor(n: Int): CharSequence =
            currentInputConnection?.getTextBeforeCursor(n, 0) ?: ""

        override fun cursorCapsMode(): Int =
            currentInputConnection?.getCursorCapsMode(editorInputType) ?: 0
    }

    private val controller = KeyboardController(host)

    override fun onCreate() {
        super.onCreate()
        savedStateController.performRestore(null)
        lifecycleRegistry.currentState = Lifecycle.State.CREATED
    }

    override fun onCreateInputView(): View {
        val view = ComposeView(this).apply {
            setViewTreeLifecycleOwner(this@TrazoImeService)
            setViewTreeViewModelStoreOwner(this@TrazoImeService)
            setViewTreeSavedStateRegistryOwner(this@TrazoImeService)
            setContent {
                TrazoTheme {
                    KeyboardScreen(controller)
                }
            }
        }
        return view
    }

    override fun onStartInputView(info: EditorInfo?, restarting: Boolean) {
        super.onStartInputView(info, restarting)
        editorInputType = info?.inputType ?: InputType.TYPE_CLASS_TEXT
        lifecycleRegistry.currentState = Lifecycle.State.RESUMED
        controller.syncAutoShift()
    }

    override fun onFinishInputView(finishingInput: Boolean) {
        super.onFinishInputView(finishingInput)
        lifecycleRegistry.currentState = Lifecycle.State.CREATED
    }

    override fun onDestroy() {
        lifecycleRegistry.currentState = Lifecycle.State.DESTROYED
        store.clear()
        super.onDestroy()
    }
}