CleverClass/app/src/main/java/com/schoolapp/cleverclass/DSBActivity.kt

package com.schoolapp.cleverclass

import android.content.Context
import android.content.Intent
import android.graphics.BitmapFactory
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.Image
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
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.size
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.verticalScroll
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.ArrowBack
import androidx.compose.material.icons.filled.Refresh
import androidx.compose.material3.CircularProgressIndicator
import androidx.compose.material3.Divider
import androidx.compose.material3.ExperimentalMaterial3Api
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.material3.TopAppBar
import androidx.compose.material3.TopAppBarDefaults
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.asImageBitmap
import androidx.compose.ui.unit.dp
import com.schoolapp.cleverclass.ui.theme.CleverClassTheme
import com.schoolapp.cleverclass.ui.theme.MiddleColor
import kotlinx.coroutines.DelicateCoroutinesApi
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.launch
import org.json.JSONObject
import java.io.File


class DSBActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContent {
            CleverClassTheme {
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    DSBContent(activity = this)
                }
            }
        }
    }
}

// Content of DSBmobile
@OptIn(ExperimentalMaterial3Api::class, DelicateCoroutinesApi::class)
@Composable
fun DSBContent(activity: ComponentActivity){
    var loadingState by remember {
        mutableStateOf(1)
    }

    LaunchedEffect(Unit) {
        GlobalScope.launch(Dispatchers.IO) {
            loadingState = downloadDSB(activity)
        }
    }

    Column {
        TopAppBar(
            colors = TopAppBarDefaults.centerAlignedTopAppBarColors(MaterialTheme.colorScheme.primaryContainer),
            title = {
                Text(text = "DSBmobile",
                    style = MaterialTheme.typography.headlineSmall,
                    color = MaterialTheme.colorScheme.onPrimaryContainer
                )},
            navigationIcon = {
                IconButton(onClick = { activity.finish() }) {
                    Icon(
                        imageVector = Icons.Filled.ArrowBack,
                        contentDescription = null,
                        modifier = Modifier.size(28.dp),
                        tint = MaterialTheme.colorScheme.onPrimaryContainer
                    )
                }
            },
            actions = {
                if(loadingState != 1) {
                    IconButton(
                        onClick = {
                            loadingState = 1
                            GlobalScope.launch(Dispatchers.IO) {
                                loadingState = downloadDSB(activity)
                            }
                        }
                    ) {
                        Icon(
                            imageVector = Icons.Filled.Refresh,
                            contentDescription = null,
                            modifier = Modifier.size(28.dp),
                            tint = MaterialTheme.colorScheme.onPrimaryContainer
                        )
                    }
                }
            },
            modifier = Modifier.fillMaxWidth()
        )

        when (loadingState) {
            1 -> {
                DSBLoading()
            }
            -1 -> {
                DSBNoInternet()
            }
            else -> {
                Column(
                    horizontalAlignment = Alignment.CenterHorizontally,
                    modifier = Modifier
                        .verticalScroll(rememberScrollState())
                        .fillMaxWidth()
                ) {
                    Spacer(modifier = Modifier.height(32.dp))

                    val mainFolder = File(activity.filesDir, "dataDSB")

                    mainFolder.listFiles()?.forEach { folder ->
                        DayPrefab(folder, activity)
                        Spacer(modifier = Modifier.height(32.dp))
                        Divider()
                        Spacer(modifier = Modifier.height(32.dp))
                    }
                }
            }
        }
    }
}

@Composable
fun DSBLoading(){
    Box(
        modifier = Modifier.fillMaxSize(),
        contentAlignment = Alignment.Center
    ){
        CircularProgressIndicator()
    }
}

@Composable
fun DSBNoInternet(){
    Box(
        modifier = Modifier.fillMaxSize(),
        contentAlignment = Alignment.Center
    ){
        Text(
            text = "Keine Internetverbindung",
            style = MaterialTheme.typography.bodySmall,
            color = MaterialTheme.colorScheme.onBackground
        )
    }
}

@Composable
fun DayPrefab(folder: File, activity: Context){
    Box(
        contentAlignment = Alignment.Center,
        modifier = Modifier
            .fillMaxWidth()
            .height(300.dp)
            .clickable {
                val intent = Intent(activity, DSBDayViewActivity::class.java).apply {
                    putExtra(DSBDayViewActivity.FOLDER_KEY, folder.absolutePath)
                }
                activity.startActivity(intent)
            }
    ) {
        val information = JSONObject(File(folder, "info.json").readText())
        val previewImageBitmap = BitmapFactory.decodeFile(File(folder, "0.jpg").absolutePath)

        Column(horizontalAlignment = Alignment.CenterHorizontally) {
            Text(
                text = "${information.get("FormatInfo")} - ${information.get("PlanInfo").toString().removeSuffix(".pdf")}",
                style = MaterialTheme.typography.bodySmall,
                color = MaterialTheme.colorScheme.onBackground
            )

            Spacer(modifier = Modifier.height(8.dp))

            Text(
                text = information.get("Date").toString(),
                style = MaterialTheme.typography.bodySmall,
                color = MiddleColor
            )

            Spacer(modifier = Modifier.height(8.dp))

            Image(
                bitmap = previewImageBitmap.asImageBitmap(),
                contentDescription = null
            )
        }
    }
}