check if azure artifact exists before download

trigger: none

pool:
  vmImage: 'ubuntu-latest'

steps:
- script: |
    set -e
    # Variables
    FEED_NAME="MyFeed"
    PACKAGE_NAME="MyUniversalPackage"
    PACKAGE_VERSION="1.0.0"
    ORGANIZATION_URL="$(System.TeamFoundationCollectionUri)"
    PROJECT_NAME="$(System.TeamProject)"

    echo "Checking if package '$PACKAGE_NAME' (version $PACKAGE_VERSION) exists in feed '$FEED_NAME'..."

    # List all universal packages in the feed and filter by package name and version.
    # The command below retrieves all packages and their versions in the feed.
    packages_json=$(az artifacts universal list \
      --feed "$FEED_NAME" \
      --organization "$ORGANIZATION_URL" \
      --project "$PROJECT_NAME" \
      -o json)

    # Using 'jq' to check if the desired package and version exist.
    # If you do not have jq installed on the agent, you can parse using grep or another method.
    if echo "$packages_json" | jq -e --arg name "$PACKAGE_NAME" --arg version "$PACKAGE_VERSION" \
      '.[] | select(.name == $name) | .versions[] | select(. == $version)' > /dev/null; then
        echo "Package found!"
        echo "##vso[task.setvariable variable=PackageExists]true"
    else
        echo "Package not found."
        echo "##vso[task.setvariable variable=PackageExists]false"
    fi
  displayName: "Check if Universal Package exists"

- task: UniversalPackages@0
  displayName: "Download Universal Package"
  condition: eq(variables['PackageExists'], 'true')
  inputs:
    command: download
    feed: "MyFeed"
    packageName: "MyUniversalPackage"
    packageVersion: "1.0.0"
    downloadDirectory: "$(Build.SourcesDirectory)/downloaded_package"