Coverage Summary for Class: ArcSpan (com.georgeci.moneysurfer.uikit.components.budget)

 package com.georgeci.moneysurfer.uikit.components.budget
 
 import androidx.compose.foundation.Canvas
 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.fillMaxSize
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.StrokeCap
 import androidx.compose.ui.graphics.drawscope.Stroke
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 import com.georgeci.moneysurfer.uikit.preview.SurferComponentPreview
 import com.georgeci.moneysurfer.uikit.theme.AppTheme
 
 /**
  * Donut version of [SurferBudgetProgressBar] — the hero on Budget details. Sweeps clockwise
  * from twelve o'clock, capped at a full turn so an overspent budget shows a closed ring in the
  * error colour rather than lapping itself.
  *
  * [content] is stacked in the hole (percent, spent, "of limit"); the caller owns that text so
  * the ring stays free of formatting concerns.
  *
  * [color] defaults to the colour [status] maps to, which is what a budget screen wants. A caller
  * whose shape is not primarily about a budget overrides it — the dashboard's spent-by-category card
  * paints a category in its own tint until its cap has something to report, and passes that decision
  * here so its ring cannot disagree with the legend beside it.
  */
 @Composable
 fun SurferBudgetRing(
     progress: Float,
     status: SurferBudgetStatus,
     modifier: Modifier = Modifier,
     size: Dp = 176.dp,
     strokeWidth: Dp = 14.dp,
     color: Color = status.color,
     content: @Composable () -> Unit = {},
 ) {
     ArcMeter(
         progress = progress,
         color = color,
         span = ArcSpan.FullTurn,
         modifier = modifier,
         width = size,
         strokeWidth = strokeWidth,
         content = content,
     )
 }
 
 /**
  * Half-turn sibling of [SurferBudgetRing] — the dial the dashboard's spent-by-category card draws
  * for a single category. Sweeps clockwise from nine o'clock through twelve to three, so [content]
  * sits under the arc rather than inside a hole, and the card only pays for the height the dial
  * actually uses.
  *
  * Shares [ArcMeter] with the ring on purpose: the two differ in the arc they span and nothing else,
  * and a second copy of the geometry is how a status colour or a cap ends up fixed in one shape and
  * not the other. [color] overrides the status colour exactly as it does on [SurferBudgetRing].
  */
 @Composable
 fun SurferBudgetGauge(
     progress: Float,
     status: SurferBudgetStatus,
     modifier: Modifier = Modifier,
     width: Dp = 176.dp,
     strokeWidth: Dp = 12.dp,
     color: Color = status.color,
     content: @Composable () -> Unit = {},
 ) {
     ArcMeter(
         progress = progress,
         color = color,
         span = ArcSpan.TopHalf,
         modifier = modifier,
         width = width,
         strokeWidth = strokeWidth,
         content = content,
     )
 }
 
 /**
  * How much of the circle a meter draws, and what that leaves for its content.
  *
  * [heightRatio] is the share of the meter's width the box keeps: a full turn needs a square, a top
  * half only needs enough for the arc plus the line under it.
  */
 private data class ArcSpan(
     val startDegrees: Float,
     val sweepDegrees: Float,
     val heightRatio: Float,
     val contentAlignment: Alignment,
 ) {
     companion object {
         /** Twelve o'clock all the way round — Compose measures arc angles from three o'clock. */
         val FullTurn = ArcSpan(
             startDegrees = -90f,
             sweepDegrees = 360f,
             heightRatio = 1f,
             contentAlignment = Alignment.Center,
         )
 
         /** Nine o'clock to three o'clock over the top. */
         val TopHalf = ArcSpan(
             startDegrees = 180f,
             sweepDegrees = 180f,
             heightRatio = 0.62f,
             contentAlignment = Alignment.BottomCenter,
         )
     }
 }
 
 @Composable
 private fun ArcMeter(
     progress: Float,
     color: Color,
     span: ArcSpan,
     modifier: Modifier,
     width: Dp,
     strokeWidth: Dp,
     content: @Composable () -> Unit,
 ) {
     val track = AppTheme.materialColors.surfaceContainerHighest
     val capped = progress.coerceIn(0f, 1f)
 
     Box(
         modifier = modifier
             .width(width)
             .height(width * span.heightRatio),
         contentAlignment = span.contentAlignment,
     ) {
         Canvas(modifier = Modifier.fillMaxSize()) {
             // The arc always lives in a square the width of the box, anchored at its top — a
             // partial span simply leaves the rest of that square outside the box, unpainted.
             val stroke = strokeWidth.toPx()
             val inset = stroke / 2f
             val arcSize = Size(size.width - stroke, size.width - stroke)
             drawArc(
                 color = track,
                 startAngle = span.startDegrees,
                 sweepAngle = span.sweepDegrees,
                 useCenter = false,
                 topLeft = Offset(inset, inset),
                 size = arcSize,
                 style = Stroke(width = stroke),
             )
             if (capped > 0f) {
                 drawArc(
                     color = color,
                     startAngle = span.startDegrees,
                     sweepAngle = span.sweepDegrees * capped,
                     useCenter = false,
                     topLeft = Offset(inset, inset),
                     size = arcSize,
                     style = Stroke(width = stroke, cap = StrokeCap.Round),
                 )
             }
         }
         content()
     }
 }
 
 private val previewSamples = listOf(
     0.42f to SurferBudgetStatus.Ok,
     0.86f to SurferBudgetStatus.Warn,
     1.2f to SurferBudgetStatus.Over,
 )
 
 @Preview
 @Composable
 private fun SurferBudgetRingPreview() {
     SurferComponentPreview {
         Row(
             modifier = Modifier.padding(16.dp),
             horizontalArrangement = Arrangement.spacedBy(16.dp),
         ) {
             previewSamples.forEach { (progress, status) ->
                 SurferBudgetRing(progress = progress, status = status, size = 120.dp) {
                     Column(horizontalAlignment = Alignment.CenterHorizontally) {
                         Text(
                             text = "${(progress * 100).toInt()}%",
                             style = AppTheme.typography.headlineSmall,
                             color = AppTheme.materialColors.onSurface,
                         )
                         Text(
                             text = "of €400",
                             style = AppTheme.typography.bodySmall,
                             color = AppTheme.materialColors.onSurfaceVariant,
                         )
                     }
                 }
             }
         }
     }
 }
 
 @Preview
 @Composable
 private fun SurferBudgetGaugePreview() {
     SurferComponentPreview {
         Row(
             modifier = Modifier.padding(16.dp),
             horizontalArrangement = Arrangement.spacedBy(16.dp),
         ) {
             previewSamples.forEach { (progress, status) ->
                 SurferBudgetGauge(progress = progress, status = status, width = 120.dp) {
                     Text(
                         text = "${(progress * 100).toInt()}%",
                         style = AppTheme.typography.titleMedium,
                         color = AppTheme.materialColors.onSurface,
                     )
                 }
             }
         }
     }
 }