package com.example.compose_anim_01

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.compose.animation.animateColor
import androidx.compose.animation.core.LinearEasing
import androidx.compose.animation.core.RepeatMode
import androidx.compose.animation.core.animateFloat
import androidx.compose.animation.core.infiniteRepeatable
import androidx.compose.animation.core.rememberInfiniteTransition
import androidx.compose.animation.core.tween
import androidx.compose.foundation.Canvas
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.offset
import androidx.compose.foundation.layout.padding
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import com.example.compose_anim_01.ui.theme.ComposeAnim01Theme

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContent {
            ComposeAnim01Theme {
                Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding ->

                    //SingleSnowflakeDemo(Modifier.padding(innerPadding))

                    Greeting(
                        name = "Android",
                        modifier = Modifier.padding(innerPadding)
                    )
                }
            }
        }
    }
}

@Composable
fun Greeting(name: String, modifier: Modifier = Modifier) {

    val infiniteTransition = rememberInfiniteTransition(label = "infinite")
    // 1) Barva textu
    val color by infiniteTransition.animateColor(
        initialValue = Color.Red,
        targetValue = Color.Green,
        animationSpec = infiniteRepeatable(
            animation = tween(1000, easing = LinearEasing),
            repeatMode = RepeatMode.Reverse
        ),
        label = "color"
    )

    // 2) Velikost textu
    val fontSize by infiniteTransition.animateFloat(
        initialValue = 24f,
        targetValue = 40f,
        animationSpec = infiniteRepeatable(
            animation = tween(1000, easing = LinearEasing),
            repeatMode = RepeatMode.Reverse
        ),
        label = "fontSize"
    )

    // 3) Pozice textu (letí doprava a zpět)
    val offsetX by infiniteTransition.animateFloat(
        initialValue = 0f,
        targetValue = 200f,
        animationSpec = infiniteRepeatable(
            animation = tween(2000, easing = LinearEasing),
            repeatMode = RepeatMode.Reverse
        ),
        label = "offsetX"
    )


    Text(
        text = "Hello $name!",
        modifier = modifier.offset(x = offsetX.dp, y = 0.dp),
        color = color,
        fontSize = fontSize.sp
    )
}

@Composable
fun SingleSnowflakeDemo(modifier: Modifier = Modifier) {

    val infiniteTransition = rememberInfiniteTransition(label = "snow")

    // Animovaná hodnota progress od 0f do 1f, která se pořád dokola opakuje.
    // Můžeme ji používat jako „čas“ pádu vločky z horního okraje dolů.
    val progress by infiniteTransition.animateFloat(
        initialValue = 0f,   // start animace (0 % dráhy)
        targetValue = 1f,    // konec animace (100 % dráhy)
        animationSpec = infiniteRepeatable(
            // Jedno „spuštění“ pádu trvá 4000 ms, průběh je lineární.
            animation = tween(durationMillis = 4000, easing = LinearEasing),
            // Po dosažení targetValue se animace znovu restartuje od initialValue.
            repeatMode = RepeatMode.Restart
        ),
        label = "progress"
    )

    // Zde může být Canvas + drawCircle pro nízkoúrovňové vykreslování navázané na animovanou hodnotu progress.
    // Nápověda:
    // 1. Použijt je možné Canvas(modifier = modifier.fillMaxSize()) { ... }
    // 2. Uvnitř spočítejte y = size.height * progress
    // 3. Vykreslete kruh pomocí drawCircle()    
}

@Preview(showBackground = true)
@Composable
fun GreetingPreview() {
    ComposeAnim01Theme {
        Greeting("Android")
    }
}