versionUtil.mill

package build

import mill._, scalalib._
import os.Path

/* Utilities to manage versions for the application */

/** A version in our system */
case class Version(major: Int, minor: Int, point: Int, isRC: Boolean) {
  override def toString = s"""$major.$minor.$point${if (isRC) "-RC" else ""}"""
  def next: Version = this.copy(point = point + 1)
  def asRelease = this.copy(isRC = false)
  def asRC = this.copy(isRC = true)
}

def versionFileName = "version.txt"

def vFile(rootPath: Path) = rootPath / versionFileName

/**
  * Read the current version from the version file
  *
  * @param rootPath Path to the directory where the version file is located
  * @return `Version` instance read from the file
  */
def currentVersion(rootPath: Path): Version = {
  val current = os.read(vFile(rootPath)).trim
  parseVersion(current)
}

/** Reads a version string and parses it */
def parseVersion(vString: String): Version = {
  val r = """([0-9]*)\.([0-9]*)\.([0-9]*)(-RC)?""".r
  val r(major, minor, point, rc) = vString
  Version(major.toInt, minor.toInt, point.toInt, rc != null)
}

/** Write a new version into the version file */
def write(v: Version, rootPath: Path): Unit = {
  os.write.over(vFile(rootPath), v.toString)
}