name: Gemini Automated PR Triage 🛳️

on:
  pull_request:
    types: [opened, edited, synchronize, reopened]

jobs:
  triage-pr:
    timeout-minutes: 5
    permissions:
      contents: read
      id-token: write
      issues: write
      pull-requests: write
    concurrency:
      group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
      cancel-in-progress: true
    runs-on: ubuntu-latest
    steps:
      - name: Generate GitHub App Token
        id: generate_token
        uses: actions/create-github-app-token@v1
        with:
          app-id: ${{ secrets.APP_ID }}
          private-key: ${{ secrets.PRIVATE_KEY }}

      - name: Run Gemini PR Triage
        uses: google-gemini/gemini-cli-action@41c0f1b3cbd1a0b284251bd1aac034edd07a3a2f
        env:
          GITHUB_TOKEN: ${{ steps.generate_token.outputs.token }}
        with:
          version: 0.1.8-rc.0
          GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
          OTLP_GCP_WIF_PROVIDER: ${{ secrets.OTLP_GCP_WIF_PROVIDER }}
          OTLP_GCP_SERVICE_ACCOUNT: ${{ secrets.OTLP_GCP_SERVICE_ACCOUNT }}
          OTLP_GOOGLE_CLOUD_PROJECT: ${{ secrets.OTLP_GOOGLE_CLOUD_PROJECT }}
          settings_json: |
            {
              "coreTools": [
                "run_shell_command(gh pr list)",
                "run_shell_command(gh pr view)",
                "run_shell_command(gh pr edit)",
                "run_shell_command(gh issue view)"
              ]
            }
          prompt: |
            You are a PR triage assistant. Your task is to ensure every pull request is linked to an issue and to perform a full synchronization of labels from the issue to the PR.

            The current pull request is #${{ github.event.pull_request.number }} in the repository ${{ github.repository }}.

            Follow these steps:
            1.  **Check for a linked issue in the PR body.**
                `gh pr view ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --json body -q .body`

            2.  **Scan the body for an issue reference** (e.g., `#123`, `Closes #456`).

            3.  **Process the result:**
                - If **no issue reference is found**, add the `status/need-issue` label to the PR:
                  `gh pr edit ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --add-label "status/need-issue"`

                - If **an issue reference is found**, perform a full label synchronization:
                  a. **Remove the `status/need-issue` label** (if present):
                     `gh pr edit ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --remove-label "status/need-issue"`

                  b. **Extract the issue number** from the reference.

                  c. **Fetch all labels for the issue** and store them.
                     `gh issue view <ISSUE_NUMBER> --repo ${{ github.repository }} --json labels`

                  d. **Fetch all labels for the PR** and store them.
                     `gh pr view ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --json labels`

                  e. **Compare the two sets of labels.**
                     - Identify labels to **add**: those on the issue but not on the PR.
                     - Identify labels to **remove**: those on the PR but not on the issue.

                  f. **Execute the synchronization.**
                     - If there are labels to add, run: `gh pr edit ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --add-label "label1,label2,..."`
                     - If there are labels to remove, run: `gh pr edit ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --remove-label "label3,label4,..."`

            **Strictly follow these rules:**
            - Only use the `gh` commands provided.
            - Do not add any comments to the PR.
            - The final set of labels on the PR must exactly match the labels on the linked issue.