name: Linear ticket

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

permissions:
  pull-requests: read

jobs:
  linear-ticket:
    name: Check Linear ticket link
    runs-on: ubuntu-latest
    if: github.event.pull_request.user.type != 'Bot'
    steps:
      - name: Require a Linear ticket reference or an explicit opt-out
        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
        with:
          script: |
            const pr = context.payload.pull_request;
            const text = `${pr.title}\n${pr.body ?? ""}\n${pr.head.ref}`;
            const ticket = /\bres-\d+\b|linear\.app\/[\w-]+\/issue\/res-\d+/i;
            const optOut = /^\s*No-Ticket:\s*\S.*$/im;
            if (ticket.test(text)) {
              core.info("Linear ticket reference found.");
              return;
            }
            const match = (pr.body ?? "").match(optOut);
            if (match) {
              core.info(`No-ticket opt-out present: ${match[0].trim()}`);
              return;
            }
            core.setFailed(
              [
                "No Linear ticket is linked in this pull request.",
                "Prime Agent tickets should normally use the Research team and the Prime Agent: Long-Horizon research project.",
                "Add the ticket ID (e.g. RES-1234) or a linear.app issue link to the PR title or description,",
                "or use a branch named after the ticket (e.g. res-1234).",
                'If this change genuinely has no ticket, add a line to the PR description: "No-Ticket: <short reason>".',
              ].join(" "),
            );