package com.example.ui.screens

import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
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.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.layout.statusBarsPadding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.CheckCircle
import androidx.compose.material.icons.filled.ClearAll
import androidx.compose.material.icons.filled.History
import androidx.compose.material.icons.filled.MusicNote
import androidx.compose.material.icons.filled.PlayArrow
import androidx.compose.material.icons.filled.Replay
import androidx.compose.material.icons.filled.Videocam
import androidx.compose.material3.AlertDialog
import androidx.compose.material3.Button
import androidx.compose.material3.ButtonDefaults
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.LinearProgressIndicator
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Surface
import androidx.compose.material3.Text
import androidx.compose.material3.TextButton
import androidx.compose.runtime.Composable
import androidx.compose.runtime.collectAsState
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.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.platform.testTag
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import androidx.media3.common.util.UnstableApi
import com.example.playback.PlaybackManager
import com.example.ui.components.formatTime
import com.example.ui.theme.AccentViolet
import com.example.ui.theme.AmoledBlack
import com.example.ui.theme.DividerSubtle
import com.example.ui.theme.ErrorRed
import com.example.ui.theme.SurfaceElevated
import com.example.ui.theme.SurfaceSecondary
import com.example.ui.theme.TextPrimary
import com.example.ui.theme.TextSecondary
import com.example.ui.viewmodel.MainViewModel

@OptIn(UnstableApi::class)
@Composable
fun HistoryScreen(
  viewModel: MainViewModel,
  modifier: Modifier = Modifier
) {
  val historyList by viewModel.history.collectAsState()
  var showClearConfirm by remember { mutableStateOf(false) }

  Column(
    modifier = modifier
      .fillMaxSize()
      .background(AmoledBlack)
      .statusBarsPadding()
      .testTag("history_screen")
  ) {
    // Header
    Row(
      modifier = Modifier
        .fillMaxWidth()
        .padding(horizontal = 16.dp, vertical = 12.dp),
      verticalAlignment = Alignment.CenterVertically,
      horizontalArrangement = Arrangement.SpaceBetween
    ) {
      Text(
        text = "Playback History",
        color = TextPrimary,
        style = MaterialTheme.typography.headlineMedium,
        fontWeight = FontWeight.Bold
      )

      if (historyList.isNotEmpty()) {
        IconButton(
          onClick = { showClearConfirm = true },
          modifier = Modifier.testTag("history_clear_btn")
        ) {
          Icon(imageVector = Icons.Default.ClearAll, contentDescription = "Clear History", tint = TextSecondary)
        }
      }
    }

    if (historyList.isEmpty()) {
      Box(
        modifier = Modifier
          .fillMaxSize()
          .padding(32.dp),
        contentAlignment = Alignment.Center
      ) {
        Column(horizontalAlignment = Alignment.CenterHorizontally) {
          Icon(imageVector = Icons.Default.History, contentDescription = null, tint = AccentViolet, modifier = Modifier.size(56.dp))
          Spacer(modifier = Modifier.height(12.dp))
          Text("No playback history yet.", color = TextSecondary)
          Text("Played audio and videos will appear here with saved progress.", color = TextSecondary, fontSize = 12.sp)
        }
      }
    } else {
      LazyColumn(
        modifier = Modifier
          .fillMaxSize()
          .padding(horizontal = 16.dp),
        verticalArrangement = Arrangement.spacedBy(10.dp)
      ) {
        items(historyList, key = { it.id }) { item ->
          val progress = if (item.durationMs > 0) {
            (item.lastPositionMs.toFloat() / item.durationMs.toFloat()).coerceIn(0f, 1f)
          } else 0f

          Surface(
            modifier = Modifier
              .fillMaxWidth()
              .clip(RoundedCornerShape(12.dp))
              .clickable { viewModel.resumeFromHistory(item) }
              .testTag("history_item_${item.id}"),
            color = SurfaceSecondary
          ) {
            Column(modifier = Modifier.padding(14.dp)) {
              Row(verticalAlignment = Alignment.CenterVertically) {
                Box(
                  modifier = Modifier
                    .size(42.dp)
                    .clip(RoundedCornerShape(8.dp))
                    .background(SurfaceElevated),
                  contentAlignment = Alignment.Center
                ) {
                  Icon(
                    imageVector = if (item.isVideo) Icons.Default.Videocam else Icons.Default.MusicNote,
                    contentDescription = null,
                    tint = AccentViolet,
                    modifier = Modifier.size(22.dp)
                  )
                }

                Spacer(modifier = Modifier.width(12.dp))

                Column(modifier = Modifier.weight(1f)) {
                  Text(
                    text = item.title,
                    color = TextPrimary,
                    fontSize = 14.sp,
                    fontWeight = FontWeight.SemiBold,
                    maxLines = 1,
                    overflow = TextOverflow.Ellipsis
                  )
                  Text(
                    text = "${item.artist} • ${if (item.completed) "Completed" else "At ${formatTime(item.lastPositionMs)}"}",
                    color = TextSecondary,
                    fontSize = 12.sp
                  )
                }

                // Resume or Restart Button
                Surface(
                  onClick = { viewModel.resumeFromHistory(item) },
                  shape = RoundedCornerShape(8.dp),
                  color = if (item.completed) SurfaceElevated else AccentViolet
                ) {
                  Row(
                    modifier = Modifier.padding(horizontal = 10.dp, vertical = 6.dp),
                    verticalAlignment = Alignment.CenterVertically
                  ) {
                    Icon(
                      imageVector = if (item.completed) Icons.Default.Replay else Icons.Default.PlayArrow,
                      contentDescription = null,
                      tint = if (item.completed) TextPrimary else AmoledBlack,
                      modifier = Modifier.size(16.dp)
                    )
                    Spacer(modifier = Modifier.width(4.dp))
                    Text(
                      text = if (item.completed) "Replay" else "Resume",
                      color = if (item.completed) TextPrimary else AmoledBlack,
                      fontWeight = FontWeight.Bold,
                      fontSize = 12.sp
                    )
                  }
                }
              }

              // Progress bar
              if (!item.completed && progress > 0.02f) {
                Spacer(modifier = Modifier.height(10.dp))
                LinearProgressIndicator(
                  progress = { progress },
                  modifier = Modifier
                    .fillMaxWidth()
                    .height(3.dp)
                    .clip(RoundedCornerShape(2.dp)),
                  color = AccentViolet,
                  trackColor = DividerSubtle
                )
              }
            }
          }
        }
      }
    }
  }

  // Clear History Dialog
  if (showClearConfirm) {
    AlertDialog(
      onDismissRequest = { showClearConfirm = false },
      confirmButton = {
        Button(
          onClick = {
            viewModel.clearHistory()
            showClearConfirm = false
          },
          colors = ButtonDefaults.buttonColors(containerColor = ErrorRed)
        ) {
          Text("Clear", color = Color.White)
        }
      },
      dismissButton = {
        TextButton(onClick = { showClearConfirm = false }) {
          Text("Cancel", color = TextSecondary)
        }
      },
      title = { Text("Clear Playback History?", color = TextPrimary) },
      text = {
        Text(
          "This will reset all saved playback timestamps and history entries. Original media files will not be modified.",
          color = TextSecondary
        )
      },
      containerColor = SurfaceElevated
    )
  }
}