name: 'Nix Flake Outputs Size Report'
author: Jalil David Salamé Messina
description: |
  Use `nix path-info` to query the size of flake outputs and produce a markdown
  report.

  You can post this report as a comment to the PR associated with the current
  branch and/or export the report as a markdown artifact.

  Requires `nix`, `jq`, `curl`, `sed` and `coreutils` to be in path.

  Usage:

  ```yaml
  - name: Generate size report
    uses: https://git.salame.cl/jalil/nix-flake-outputs-size@main
    with: # Default values
      comment-on-pr: 'true'
      generate-artifact: 'false'
      artifact-name: 'size-report.md'
  ```
inputs:
  comment-on-pr:
    description: Comment the report on the PR associated with the current branch.
    default: 'true'
  generate-artifact:
    description: Export the generated markdown document as an artifact.
    default: 'false'
  artifact-name:
    description: The name of the generated artifact.
    default: 'size-report.md'
outputs:
runs:
  using: 'composite'
  steps:
    - name: Create report
      run: |
        "$GITHUB_ACTION_PATH/create-report.sh"
    - name: Upload Artifact
      uses: https://code.forgejo.org/forgejo/upload-artifact@v4
      if: inputs.generate-artifact == 'true'
      with:
        path: size-report.md
        name: ${{ inputs.artifact-name }}
    - name: Upload Report
      if: inputs.comment-on-pr == 'true'
      run: |
        set -eu

        # For push & tag events it'll bet GITHUB_REF_NAME, for pull_request events it'll be GITHUB_HEAD_REF
        head_ref=${GITHUB_REF_NAME-$GITHUB_HEAD_REF}

        pr_number=$(curl -X 'GET' \
                "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/pulls?state=open&sort=recentupdate" \
                -H 'accept: application/json' |
                jq --arg head_ref "$head_ref" '.[] | select(.head.ref == $head_ref) | .number')

        # Protect against running before a PR is made or if it is triggered on the main branch
        if [ -z "$pr_number" ]; then
                echo "No PR created for this commit"
                exit 0
        fi

        echo "Retrieved index: $pr_number" >&2
        echo "Expected PR URL: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/pulls/$pr_number" >&2

        echo 'Generating comment body' >&2
        comment=$(cat size-report.md)

        echo 'Posting comment:' >&2
        echo "$comment" >&2

        echo 'Request data:' >&2
        data=$(echo '{}' | jq --arg comment "$comment" '.body=$comment')
        echo "$data" >&2
        curl -o - -X 'POST' \
                "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/issues/$pr_number/comments" \
                -H 'accept: application/json' \
                -H "Authorization: token $GITHUB_TOKEN" \
                -H 'Content-Type: application/json' \
                -d "$data"