name: Run the performance journeys
description: >-
    Runs `pnpm run perf:journeys` under xvfb on an Ubuntu runner, writes the
    measurements to the job summary and returns the path of the summary.json
    it wrote. Callers check out, set up pnpm and Node, install dependencies
    and upload what they need. Contract: docs/architecture/performance-journeys.md.

outputs:
    summary:
        description: Path of the journey summary.json this run wrote.
        value: ${{ steps.summary.outputs.path }}

runs:
    using: composite
    steps:
        # The journeys drive Electron through Playwright's _electron API
        # and never launch a Playwright browser, so no `playwright
        # install`. The runner image ships Electron's shared libraries and
        # xvfb; fail fast with a clear message if an image update drops one.
        # pnpm skips Electron's postinstall, so download the binary first;
        # otherwise ldd sees no file and the check passes vacuously.
        - name: Check Electron runtime dependencies
          shell: bash
          run: |
              command -v xvfb-run || { echo "::error::xvfb-run is missing on the runner"; exit 1; }
              node tools/testing/ensure-electron-binary.mjs || { echo "::error::Electron binary download failed"; exit 1; }
              missing="$(ldd node_modules/electron/dist/electron | grep 'not found' || true)"
              if [ -n "$missing" ]; then
                  echo "::error::Electron is missing shared libraries:"
                  echo "$missing"
                  exit 1
              fi

        # The Nx target builds electron-backend:build-performance first
        # and playwright.journeys.config.ts starts the Xtream mock server.
        - name: Run the performance journeys
          shell: bash
          run: xvfb-run --auto-servernum --server-args="-screen 0 1280x960x24" pnpm run perf:journeys
          env:
              CI: 'true'
              NX_TASKS_RUNNER_DYNAMIC_OUTPUT: 'false'

        # Every run writes a fresh timestamped directory, so a clean
        # checkout must hold exactly one summary.
        - name: Locate the journey summary
          id: summary
          shell: bash
          run: |
              set -euo pipefail
              mapfile -t summaries < <(find dist/performance/journeys -mindepth 2 -maxdepth 2 -name summary.json)
              if [ "${#summaries[@]}" -ne 1 ]; then
                  echo "::error::Expected one journey summary, found ${#summaries[@]}"
                  exit 1
              fi
              echo "path=${summaries[0]}" >> "$GITHUB_OUTPUT"

        - name: Report journey measurements
          shell: bash
          env:
              SUMMARY: ${{ steps.summary.outputs.path }}
          run: |
              set -euo pipefail
              jq -r '
                  "## Performance journeys (\(.harness.platform), \(.harness.measuredIterations) measured iterations)", "",
                  (.journeys | to_entries[] | .key as $journey | .value as $j |
                      "### `\($journey)`", "",
                      "| Measurement | Value | Iterations |",
                      "| --- | ---: | --- |",
                      (($j.counters // {}) | to_entries[] |
                          ($j.counterStability[.key] // {}) as $s |
                          "| `\(.key)` | \(.value) | \(($s.values // []) | map(tostring) | join(", "))\(if $s.stable == false then " (unstable)" else "" end) |"),
                      (($j.wallClock // {}) | to_entries[] | "| `\(.key)` | \(.value) | |"),
                      "",
                      ([($j.iterations // [])[] | select(.warmup | not) | .evidence.ipcSerialDepth // empty][0] // empty |
                          "Serial IPC chain (first measured iteration): \(.chain | map("`\(.)`") | join(" → "))", ""))
              ' "$SUMMARY" | tee -a "$GITHUB_STEP_SUMMARY"