Coverage Summary for Class: SurferNetTrendColumn (com.georgeci.moneysurfer.uikit.components.chart)

 package com.georgeci.moneysurfer.uikit.components.chart
 
 import androidx.compose.foundation.background
 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.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 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.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import com.georgeci.moneysurfer.uikit.atom.SurferCard
 import com.georgeci.moneysurfer.uikit.preview.SurferComponentPreview
 import com.georgeci.moneysurfer.uikit.theme.AppTheme
 
 /**
  * One month of [SurferNetTrendCard]. [income] and [expense] are magnitudes, so the taller bar is the
  * bigger number whichever way the month went.
  *
  * [contentDescription] is the whole column as a screen reader should read it — the card draws no
  * per-bar numerals, so this is the only place the figures are spoken.
  */
 data class SurferNetTrendColumn(
     val label: String,
     val income: Long,
     val expense: Long,
     val contentDescription: String,
 )
 
 /**
  * Income against expense, month by month, as paired bar columns.
  *
  * Built on [SurferBarColumns] — the same treatment the category trend uses — rather than on a
  * charting library, so the app's one chart dependency stays confined to `SurferBalanceChartCard`.
  * Both series share one scale, which is the whole point of the card: two independently scaled rows
  * would make every month look break-even.
  *
  * The last column is the one the selection is anchored in and is drawn solid; the earlier months sit
  * behind an outline. Values are not printed on the bars — twelve numerals over six columns is
  * unreadable at phone width — so the legend and [SurferNetTrendColumn.contentDescription] carry the
  * naming instead.
  */
 @Composable
 fun SurferNetTrendCard(
     title: String,
     columns: List<SurferNetTrendColumn>,
     incomeLabel: String,
     expenseLabel: String,
     modifier: Modifier = Modifier,
     trailingLabel: String? = null,
 ) {
     val incomeTint = AppTheme.semanticColors.income
     val expenseTint = AppTheme.semanticColors.expense
     SurferCard(modifier = modifier.fillMaxWidth()) {
         Column(modifier = Modifier.padding(16.dp)) {
             SurferChartCardHeader(title = title, trailingLabel = trailingLabel)
 
             Spacer(Modifier.height(ChartHeaderSpacing))
 
             SurferBarColumns(
                 columns = columns.mapIndexed { index, column ->
                     SurferBarColumn(
                         label = column.label,
                         bars = listOf(
                             SurferBar(value = column.income, tint = incomeTint),
                             SurferBar(value = column.expense, tint = expenseTint),
                         ),
                         contentDescription = column.contentDescription,
                         emphasised = index == columns.lastIndex,
                     )
                 },
             )
 
             Spacer(Modifier.height(LegendSpacing))
 
             Row(horizontalArrangement = Arrangement.spacedBy(16.dp)) {
                 LegendEntry(label = incomeLabel, tint = incomeTint)
                 LegendEntry(label = expenseLabel, tint = expenseTint)
             }
         }
     }
 }
 
 @Composable
 private fun LegendEntry(label: String, tint: Color) {
     Row(
         verticalAlignment = Alignment.CenterVertically,
         horizontalArrangement = Arrangement.spacedBy(6.dp),
     ) {
         // A plain painted Box: it publishes no semantics of its own, so the label beside it is the
         // only thing a screen reader reads — which is what names the series.
         Box(
             modifier = Modifier
                 .size(LegendDotSize)
                 .clip(CircleShape)
                 .background(tint),
         )
         Text(
             text = label,
             style = AppTheme.typography.labelMedium,
             color = AppTheme.materialColors.onSurfaceVariant,
             maxLines = 1,
         )
     }
 }
 
 private val LegendDotSize = 10.dp
 private val LegendSpacing = 12.dp
 
 @Preview
 @Composable
 private fun SurferNetTrendCardPreview() {
     SurferComponentPreview {
         Column(modifier = Modifier.padding(16.dp)) {
             SurferNetTrendCard(
                 title = "Income vs expense",
                 trailingLabel = "Last 6 months",
                 incomeLabel = "Income",
                 expenseLabel = "Expense",
                 columns = listOf(
                     SurferNetTrendColumn("Nov", 320_000, 285_000, "Nov: income €3,200, expense €2,850"),
                     SurferNetTrendColumn("Dec", 320_000, 410_000, "Dec: income €3,200, expense €4,100"),
                     SurferNetTrendColumn("Jan", 340_000, 260_000, "Jan: income €3,400, expense €2,600"),
                     SurferNetTrendColumn("Feb", 340_000, 275_000, "Feb: income €3,400, expense €2,750"),
                     SurferNetTrendColumn("Mar", 0, 190_000, "Mar: income €0, expense €1,900"),
                     SurferNetTrendColumn("Apr", 340_000, 301_500, "Apr: income €3,400, expense €3,015"),
                 ),
             )
         }
     }
 }