name: Auto set milestone on PR

on:
  pull_request:
    types: opened

env:
  QGIS_MAJOR_VERSION: 3

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      # obfuscate the github token so it can be used on jobs triggered from forks
      - name: Clear GH Token
        id: token
        uses: opengisch/clear-token@v1.0.12
        with:
          bot_token_encrypted: ddbdec32940df79f1adf2369b4b10f10b5a66f65
          bot_token_xor_key: a1b2c3d47311f8e29e204f85a81b4df4a44e252c

      # list the tags and milestones
      - uses: octokit/graphql-action@v2.x
        id: list_tags_milestones
        with:
          query: |
            query list_tags_milestones($owner: String!, $repo: String!) {
              repository(owner: $owner, name: $repo) {
                refs(refPrefix: "refs/tags/", orderBy: {field: TAG_COMMIT_DATE, direction: DESC}, first: 30) {
                  edges {
                    node {
                      name
                    }
                  }
                }
                milestones(orderBy: {field: CREATED_AT, direction: DESC}, first: 30) {
                  edges {
                    node {
                      title
                      number
                    }
                  }
                }
              }
            }
          owner: ${{ github.event.pull_request.base.repo.owner.login }}
          repo: ${{ github.event.pull_request.base.repo.name }}
        env:
          GITHUB_TOKEN: ${{ steps.token.outputs.token }}

      # calculate the milestone and determine if it exists
      - name: Get the latest release
        id: calculate_milestone
        env:
          JSON_DATA: ${{ steps.list_tags_milestones.outputs.data }}
          BASE_BRANCH: ${{ github.event.pull_request.base.ref }}
        run: |
          # master => NOTHING, release_3-10 => _10
          MINOR_VERSION=$(echo ${BASE_BRANCH} | sed -r -e 's/^release-[0-9]_([0-9]+)/_\1/;t;d')
          echo "MINOR_VERSION: ${MINOR_VERSION}"
          # get the max release from the tags
          MAX_RELEASE=$(echo "${JSON_DATA}" | jq ".repository.refs.edges[].node.name | select( . | test(\"^final-${QGIS_MAJOR_VERSION}${MINOR_VERSION}\") ) | sub(\"^final-${QGIS_MAJOR_VERSION}_(?<m>[0-9]+)_(?<p>.)\"; .m+\".\"+.p) | tonumber" | jq -s '. | max')
          echo "MAX_RELEASE: ${MAX_RELEASE}"
          MILESTONE_TITLE="${QGIS_MAJOR_VERSION}."$(echo "${MAX_RELEASE} + 0.1 " | bc)
          echo "MILESTONE_TITLE: ${MILESTONE_TITLE}"
          echo "::set-output name=milestone_title::${MILESTONE_TITLE}"
          MILESTONE_NUMBER=$(echo "${JSON_DATA}" | jq ".repository.milestones.edges[] | select( .node.title == \"${MILESTONE_TITLE}\" ) | .node.number")
          echo "MILESTONE_NUMBER: ${MILESTONE_NUMBER}"
          echo "::set-output name=milestone_number::${MILESTONE_NUMBER}"
          MILESTONE_EXISTS=$([[ -n $(echo "${JSON_DATA}" | jq ".repository.refs.edges[].node.name | select( . | test(\"^${MILESTONE_TITLE}\") ) ") ]] && echo "true" || echo "false" )
          echo "MILESTONE_EXISTS: ${MILESTONE_EXISTS}"
          echo "::set-output name=milestone_exists::${MILESTONE_EXISTS}"

      # create the milestone if needed
      - name: Create milestone
        id: create_milestone
        if: steps.calculate_milestone.outputs.milestone_exists == false
        uses: octokit/request-action@v2.x
        with:
          route: POST /repos/:owner/:repo/milestones
          title: ${{ steps.calculate_milestone.outputs.milestone_title }}
          owner: ${{ github.event.pull_request.base.repo.owner.login }}
          repo: ${{ github.event.pull_request.base.repo.name }}
        env:
          GITHUB_TOKEN: ${{ steps.token.outputs.token }}

      - id: compute_milestone
        name: compute the milestone number
        env:
          MILESTONE_NUMBER_EXISTING: ${{ steps.calculate_milestone.outputs.milestone_number }}
          MILESTONE_NUMBER_CREATED_JSON: ${{ steps.create_milestone.outputs.data }}
        run: |
          FINAL_MILESTONE_NUMBER=$([[ -n ${MILESTONE_NUMBER_EXISTING} ]] && echo "${MILESTONE_NUMBER_EXISTING}" || $(echo "${MILESTONE_NUMBER_CREATED_JSON}" | jq '.number' ))
          echo "FINAL_MILESTONE_NUMBER: ${FINAL_MILESTONE_NUMBER}"
          echo "::set-output name=milestone_number::${FINAL_MILESTONE_NUMBER}"

      # update PR with milestone
      - name: update PR milestone
        uses: octokit/request-action@v2.x
        env:
          GITHUB_TOKEN: ${{ steps.token.outputs.token }}
        with:
          route: PATCH /repos/:owner/:repo/issues/:pull_number
          pull_number: ${{ github.event.pull_request.number }}
          milestone: ${{ steps.compute_milestone.outputs.milestone_number }}
          owner: ${{ github.event.pull_request.base.repo.owner.login }}
          repo: ${{ github.event.pull_request.base.repo.name }}

      # if the PR author could not set the milestone due to missing rights, add a comment
      - name: leave comment for milestone
        if: failure()
        uses: octokit/request-action@v2.x
        env:
          GITHUB_TOKEN: ${{ steps.token.outputs.token }}
        with:
          route: POST /repos/:owner/:repo/issues/:pull_number/comments
          pull_number: ${{ github.event.pull_request.number }}
          body: format('**Calculated milestone for the PR: {0}**', ${{ steps.compute_milestone.outputs.milestone_number }})
          owner: ${{ github.event.pull_request.base.repo.owner.login }}
          repo: ${{ github.event.pull_request.base.repo.name }}