# This workflow is triggered on any PR comment, and tries to find a `@rerun-bot` mention in it.
# If the mention is a command, such as `@rerun-bot full-check`, then it runs the command.
#
# Available commands:
#   full-check    Triggers a run of `on_push_main.yml` on the PR.

name: "PR Comment"

on:
  issue_comment:
    types: [created]

defaults:
  run:
    shell: bash --noprofile --norc -euo pipefail {0}

permissions:
  contents: "read"
  id-token: "write"
  pull-requests: "write"

jobs:
  parse-command:
    if: |
      contains(github.event.comment.html_url, '/pull/') &&
      contains(github.event.comment.body, '@rerun-bot') &&
      contains(
        fromJSON('["COLLABORATOR","MEMBER","OWNER"]'),
        github.event.comment.author_association
      )
    runs-on: ubuntu-latest
    outputs:
      command: ${{ steps.parse.outputs.command }}
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Parse comment
        id: parse
        env:
          GITHUB_COMMENT_BODY: "${{ github.event.comment.body }}"
        run: python ./scripts/ci/parse_bot_pr_comment.py

  full-check:
    needs: [parse-command]
    if: needs.parse-command.outputs.command == 'full-check'
    runs-on: ubuntu-latest
    steps:
      - name: Acknowledge command (eyes reaction)
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          gh api -X POST \
            /repos/${{ github.repository }}/issues/comments/${{ github.event.comment.id }}/reactions \
            -f content=eyes

      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Dispatch main workflow
        id: dispatch
        env:
          # NOTE: This uses `RERUN_BOT_TOKEN` instead of `GITHUB_TOKEN`,
          # otherwise the recursive workflow protection prevents us from
          # starting the `on_push_main` run.
          # https://docs.github.com/en/actions/using-workflows/triggering-a-workflow#triggering-a-workflow-from-a-workflow
          GH_TOKEN: ${{ secrets.RERUN_BOT_TOKEN }}
        run: |
          get_latest_workflow_run () {
            local workflow_name=$1
            local ref_name=$2
            local created_after=$3
            echo $(
              # https://cli.github.com/manual/gh_run_list
              # https://docs.github.com/en/search-github/getting-started-with-searching-on-github/understanding-the-search-syntax#query-for-dates
              gh run list \
                --workflow $workflow_name \
                --event workflow_dispatch \
                --branch $ref_name \
                --created ">$created_after" \
                --json databaseId
            )
          }

          dispatch_workflow () {
            local workflow_name=$1
            local ref_name=$2
            local inputs=$3
            # https://cli.github.com/manual/gh_workflow_run
            echo $inputs | gh workflow run $workflow_name --ref "refs/heads/$ref_name" --json
          }

          workflow_name='on_push_main.yml'
          ref_name=$(gh pr view ${{ github.event.issue.number }} --json headRefName | jq -r '.headRefName')
          inputs='{"CONCURRENCY":"pr-${{ github.event.issue.number }}-full-check"}'
          now=$(date --utc --iso-8601=seconds)

          echo "Dispatching workflow $workflow_name on branch $ref_name"
          dispatch_workflow $workflow_name $ref_name $inputs

          # `gh workflow run` does NOT return the ID.
          # In fact, it returns absolutely nothing: https://github.com/cli/cli/issues/4001
          # Instead, we have to wait for the workflow to start, and hope that nobody has
          # started a workflow in parallel with us on the same branch.

          echo "Fetching workflow run id…"
          run_info=$(get_latest_workflow_run $workflow_name $ref_name $now)
          echo $run_info
          run_id=$(echo $run_info | jq -r '.[0].databaseId')
          while [ $run_id == 'null' ]
          do
            run_info=$(get_latest_workflow_run $workflow_name $ref_name $now)
            echo $run_info
            run_id=$(echo $run_info | jq -r '.[0].databaseId')
            sleep 1
          done
          echo "Workflow run: https://github.com/rerun-io/rerun/actions/runs/$run_id"

          echo "workflow_run_url=https://github.com/rerun-io/rerun/actions/runs/$run_id" >> "$GITHUB_OUTPUT"

      - name: Create PR comment
        # https://github.com/mshick/add-pr-comment
        uses: mshick/add-pr-comment@v3.9.1
        with:
          # We use `GITHUB_TOKEN` here so there is no chance that we'll trigger another run of this workflow.
          # https://docs.github.com/en/actions/using-workflows/triggering-a-workflow#triggering-a-workflow-from-a-workflow
          repo-token: ${{ secrets.GITHUB_TOKEN }}
          message-id: "pr-${{ github.event.issue.number }}-${{ github.run_id }}"
          message: |
            Started a full build: ${{ steps.dispatch.outputs.workflow_run_url }}