/**
 * Bumps the patch version in Chart.yaml, updates appVersion and values.yaml image tag.
 * Must be called inside container('tools') block (needs sed + git).
 *
 * config keys:
 *   imageTag   (required) - new image tag to write into values.yaml
 *   chartFile  (optional) - path to Chart.yaml,   default: manifest/helm/Chart.yaml
 *   valuesFile (optional) - path to values.yaml,  default: manifest/helm/values.yaml
 */
def call(Map config) {
    def imageTag   = config.imageTag
    if (!imageTag) error('bumpHelmChart: imageTag is required')

    def chartFile  = config.chartFile  ?: 'manifest/helm/Chart.yaml'
    def valuesFile = config.valuesFile ?: 'manifest/helm/values.yaml'

    def content    = readFile(chartFile)
    def matcher    = content =~ /version:\s+(\d+)\.(\d+)\.(\d+)/
    if (!matcher) error("bumpHelmChart: could not parse version in ${chartFile}")

    def newVersion = "${matcher[0][1]}.${matcher[0][2]}.${(matcher[0][3] as int) + 1}"

    sh "sed -i 's/^version: .*/version: ${newVersion}/' ${chartFile}"
    sh "sed -i 's/^appVersion: .*/appVersion: \"${imageTag}\"/' ${chartFile}"
    sh "sed -i 's/^  tag: .*/  tag: ${imageTag}/' ${valuesFile}"
}