# Warms the Cypress deps cache (node_modules + the Cypress binary) from master.
# This workflow is the only writer of the key, so PR and merge runs never write
# to the Actions cache; they restore it read-only via
# .github/actions/restore-cypress-deps.
#
# Until this workflow has warmed a given key, runs on that tree fall back to the
# run-scoped artifact built by prep-deps in e2e-tests-cypress-template.yml.
name: "E2E Cache Warm: Cypress deps"

on:
  schedule:
    - cron: "0 3 * * *" # Daily 3am UTC — after the webapp node_modules and E2E npm registry caches warm at 1am
  # Warm as soon as the key's only input lands on master, so the merge run and
  # subsequent PRs hit the cache instead of paying for the artifact fallback all
  # day. The schedule is the backstop.
  push:
    branches:
      - master
    paths:
      - "e2e-tests/cypress/package-lock.json"
  workflow_dispatch:

# Keep manual, scheduled and push-triggered runs from racing to save the same key.
concurrency:
  group: e2e-ci-cache-warm-cypress-deps
  cancel-in-progress: false

permissions:
  contents: read
  actions: write # required to save the Actions cache

jobs:
  warm:
    name: Warm Cypress deps cache
    runs-on: ubuntu-24.04
    # workflow_dispatch can target any branch. Warming from one would write a
    # branch-scoped entry keyed on that branch's lockfile — quota spent on a key
    # no other branch can read, which is the churn this workflow exists to avoid.
    if: github.ref == 'refs/heads/master'
    # Bound a hung run so it can't hold the concurrency group for the default
    # 6-hour timeout and block subsequent warm runs.
    timeout-minutes: 30
    steps:
      - name: Checkout mattermost project
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          persist-credentials: false
      - name: ci/probe-cypress-deps
        id: deps
        uses: ./.github/actions/restore-cypress-deps
        with:
          lookup-only: "true"
      # Ahead of webapp-setup so its install benefits too, and so cache/restore
      # never untars ~/.npm on top of entries npm has already written this job.
      - name: ci/restore-npm-cache
        if: steps.deps.outputs.cache-hit != 'true'
        uses: ./.github/actions/restore-e2e-npm-cache
      # Provides the @mattermost/eslint-plugin target the cypress install
      # symlinks to.
      - name: ci/setup-webapp-node-modules
        if: steps.deps.outputs.cache-hit != 'true'
        uses: ./.github/actions/webapp-setup
        with:
          read-only: "true"
      # The postinstall downloads the Cypress binary to ~/.cache/Cypress rather
      # than into node_modules, which is why the save below covers both.
      - name: ci/install-cypress-deps
        if: steps.deps.outputs.cache-hit != 'true'
        working-directory: e2e-tests/cypress
        run: npm ci
      # Must stay in sync with restore-cypress-deps and pack-cypress-deps.
      - name: ci/save-cypress-deps
        if: steps.deps.outputs.cache-hit != 'true'
        uses: actions/cache/save@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
        with:
          path: |
            e2e-tests/cypress/node_modules
            ~/.cache/Cypress
          key: ${{ steps.deps.outputs.key }}
      # This job is the sole writer of the key, so its summary is where "is
      # warming actually working?" gets answered.
      - name: ci/report-warm-outcome
        env:
          CACHE_HIT: ${{ steps.deps.outputs.cache-hit }}
          CACHE_KEY: ${{ steps.deps.outputs.key }}
        run: |
          if [ "${CACHE_HIT}" = "true" ]; then
            echo "Cypress deps: \`${CACHE_KEY}\` already warm; nothing new to save." >> "${GITHUB_STEP_SUMMARY}"
          else
            echo "Cypress deps: saved \`${CACHE_KEY}\`." >> "${GITHUB_STEP_SUMMARY}"
          fi