foundry.gradle.util.charting.ChartProperty.kt Maven / Gradle / Ivy

Go to download
/*
 * Copyright (C) 2022 Slack Technologies, LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package foundry.gradle.util.charting

/**
 * Represents a configurable property of the chart. All properties end up in a URL, using the [key]
 * as the query parameter name and the [value] as the query parameter value.
 *
 * Currently only certain features of line charts are supported, so the reference at
 * https://developers.google.com/chart/image/docs/gallery/line_charts is a good place to start.
 */
internal interface ChartProperty {
  val key: String
  val value: String

  /**
   * Combines both [ChartProperty]s into a one, with their values combined as [multiline] values.
   * The keys of both properties must be the same.
   */
  operator fun plus(other: ChartProperty): ChartProperty {
    require(key == other.key) {
      "This property's key '$key' does not match the other property's key '${other.key}'"
    }

    return MultilineChartProperty(this, other)
  }
}

/**
 * Combines all of the given [ChartProperty]s into a single one, with their values combined as
 * [multiline] values. The keys of all properties must be the same.
 *
 * This is useful for combining repeated values like [ColorRange]s.
 */
internal fun Collection.collapse(): ChartProperty = reduce(ChartProperty::plus)

internal fun multiline(vararg lines: String): String = multiline(lines.toList())

internal fun multiline(lines: Collection): String = lines.joinToString(separator = "|")

private data class MultilineChartProperty(val lines: Collection) : ChartProperty {
  override val key: String
    get() = lines.first().key

  override val value: String
    get() = multiline(lines.map { it.value })

  constructor(vararg lines: ChartProperty) : this(lines.toList())

  override operator fun plus(other: ChartProperty): ChartProperty {
    require(key == other.key) {
      "This property's key '$key' does not match the other property's key '${other.key}'"
    }

    return MultilineChartProperty(lines + other)
  }
}