package at.lockstep.player.ui

import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Pause
import androidx.compose.material.icons.filled.PlayArrow
import androidx.compose.material.icons.filled.SkipNext
import androidx.compose.material.icons.filled.SkipPrevious
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Slider
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableFloatStateOf
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.text.style.TextOverflow
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp

data class NowPlayingUiState(
    val title: String,
    val artist: String,
    /** 0f..1f until real timing is wired to Oboe / JNI. */
    val progress: Float,
    /** Total track length in seconds (placeholder for UI formatting). */
    val durationSeconds: Int,
    val isPlaying: Boolean,
)

@Composable
fun NowPlayingScreen(
    state: NowPlayingUiState,
    onProgressChange: (Float) -> Unit,
    onPrevious: () -> Unit,
    onTogglePlayPause: () -> Unit,
    onNext: () -> Unit,
    modifier: Modifier = Modifier,
) {
    val elapsed = (state.progress * state.durationSeconds).toInt().coerceIn(0, state.durationSeconds)

    Column(
        modifier = modifier
            .fillMaxSize()
            .padding(horizontal = 24.dp, vertical = 16.dp),
        verticalArrangement = Arrangement.spacedBy(24.dp),
    ) {
        Column(verticalArrangement = Arrangement.spacedBy(4.dp)) {
            Text(
                text = state.title,
                style = MaterialTheme.typography.headlineSmall,
                maxLines = 2,
                overflow = TextOverflow.Ellipsis,
            )
            Text(
                text = state.artist,
                style = MaterialTheme.typography.bodyLarge,
                color = MaterialTheme.colorScheme.onSurfaceVariant,
                maxLines = 1,
                overflow = TextOverflow.Ellipsis,
            )
        }

        Column(
            modifier = Modifier.fillMaxWidth(),
            verticalArrangement = Arrangement.spacedBy(12.dp),
        ) {
            Column(
                modifier = Modifier.fillMaxWidth(),
                verticalArrangement = Arrangement.spacedBy(4.dp),
            ) {
                Slider(
                    value = state.progress,
                    onValueChange = onProgressChange,
                    modifier = Modifier.fillMaxWidth(),
                )
                Row(
                    modifier = Modifier.fillMaxWidth(),
                    horizontalArrangement = Arrangement.SpaceBetween,
                ) {
                    Text(
                        text = formatMmSs(elapsed),
                        style = MaterialTheme.typography.labelMedium,
                        color = MaterialTheme.colorScheme.onSurfaceVariant,
                    )
                    Text(
                        text = formatMmSs(state.durationSeconds),
                        style = MaterialTheme.typography.labelMedium,
                        color = MaterialTheme.colorScheme.onSurfaceVariant,
                    )
                }
            }
            Row(
                modifier = Modifier.fillMaxWidth(),
                horizontalArrangement = Arrangement.SpaceEvenly,
                verticalAlignment = Alignment.CenterVertically,
            ) {
                IconButton(onClick = onPrevious, modifier = Modifier.size(80.dp)) {
                    Icon(Icons.Default.SkipPrevious, contentDescription = "Previous track")
                }
                IconButton(onClick = onTogglePlayPause, modifier = Modifier.size(104.dp)) {
                    Icon(
                        imageVector = if (state.isPlaying) Icons.Default.Pause else Icons.Default.PlayArrow,
                        contentDescription = if (state.isPlaying) "Pause" else "Play",
                        modifier = Modifier.size(56.dp),
                    )
                }
                IconButton(onClick = onNext, modifier = Modifier.size(80.dp)) {
                    Icon(Icons.Default.SkipNext, contentDescription = "Next track")
                }
            }
        }
    }
}

private fun formatMmSs(totalSeconds: Int): String {
    val s = totalSeconds.coerceAtLeast(0)
    val m = s / 60
    val r = s % 60
    return "%d:%02d".format(m, r)
}

@Preview(showBackground = true)
@Composable
private fun NowPlayingScreenPreview() {
    MaterialTheme {
        var progress by remember { mutableFloatStateOf(0.35f) }
        var playing by remember { mutableStateOf(true) }
        NowPlayingScreen(
            state = NowPlayingUiState(
                title = "Example Track Title",
                artist = "Example Artist",
                progress = progress,
                durationSeconds = 215,
                isPlaying = playing,
            ),
            onProgressChange = { progress = it },
            onPrevious = {},
            onTogglePlayPause = { playing = !playing },
            onNext = {},
        )
    }
}