########################################################################################
# "yarn install" composite action for yarn 2/3/4+ and "nodeLinker: node-modules"       #
#--------------------------------------------------------------------------------------#
# Cache:                                                                               #
#   - Downloaded zip archive (multi-arch, preserved across yarn.lock changes)          #
#   - Yarn install state (discarded on yarn.lock changes)                              #
# References:                                                                          #
#   - bench: https://gist.github.com/belgattitude/0ecd26155b47e7be1be6163ecfbb0f0b     #
#   - vs @setup/node: https://github.com/actions/setup-node/issues/325                 #
########################################################################################

name: "Yarn install"
description: "Run yarn install with node_modules linker and cache enabled"
inputs:
  node_version:
    required: false
    default: v20.x
  skip-install-if-cache-hit:
    description: "Skip yarn install if node_modules cache is hit. Use this for jobs that only need to check that cache exists."
    required: false
    default: "false"

runs:
  using: "composite"
  steps:
    - name: Use Node ${{ inputs.node_version }}
      uses: actions/setup-node@v4
      with:
        node-version: ${{ inputs.node_version }}
    - name: Expose yarn config as "$GITHUB_OUTPUT"
      id: yarn-config
      shell: bash
      run: |
        echo "CACHE_FOLDER=$(yarn config get cacheFolder)" >> $GITHUB_OUTPUT

    # When skip-install-if-cache-hit is true, first check if all caches exist without downloading (lookup-only mode)
    # This avoids downloading ~1.2GB of cache data when we just want to verify caches exist
    - name: Check yarn cache (lookup-only)
      if: ${{ inputs.skip-install-if-cache-hit == 'true' }}
      uses: actions/cache/restore@v4
      id: yarn-download-cache-check
      with:
        path: ${{ steps.yarn-config.outputs.CACHE_FOLDER }}
        key: yarn-download-cache-${{ hashFiles('yarn.lock') }}
        lookup-only: true

    - name: Check node_modules cache (lookup-only)
      if: ${{ inputs.skip-install-if-cache-hit == 'true' }}
      uses: actions/cache/restore@v4
      id: yarn-nm-cache-check
      with:
        path: |
          **/node_modules/
          !**/.next/node_modules/
        key: ${{ runner.os }}-yarn-nm-cache-${{ hashFiles('yarn.lock', '.yarnrc.yml') }}
        lookup-only: true

    - name: Check yarn install state cache (lookup-only)
      if: ${{ inputs.skip-install-if-cache-hit == 'true' }}
      uses: actions/cache/restore@v4
      id: yarn-install-state-cache-check
      with:
        path: .yarn/ci-cache/
        key: ${{ runner.os }}-yarn-install-state-cache-${{ hashFiles('yarn.lock', '.yarnrc.yml') }}
        lookup-only: true

    # Compute whether all caches hit (only in skip mode)
    - name: Check if all caches hit
      if: ${{ inputs.skip-install-if-cache-hit == 'true' }}
      id: all-caches-check
      shell: bash
      run: |
        if [[ "${{ steps.yarn-download-cache-check.outputs.cache-hit }}" == "true" && \
              "${{ steps.yarn-nm-cache-check.outputs.cache-hit }}" == "true" && \
              "${{ steps.yarn-install-state-cache-check.outputs.cache-hit }}" == "true" ]]; then
          echo "all-hit=true" >> $GITHUB_OUTPUT
        else
          echo "all-hit=false" >> $GITHUB_OUTPUT
        fi

    # Yarn rotates the downloaded cache archives, @see https://github.com/actions/setup-node/issues/325
    # Yarn cache is also reusable between arch and os.
    # Only restore if not in skip mode, or if skip mode but any cache check missed
    - name: Restore yarn cache
      if: ${{ inputs.skip-install-if-cache-hit != 'true' || steps.all-caches-check.outputs.all-hit != 'true' }}
      uses: actions/cache@v4
      id: yarn-download-cache
      with:
        path: ${{ steps.yarn-config.outputs.CACHE_FOLDER }}
        key: yarn-download-cache-${{ hashFiles('yarn.lock') }}

    # Invalidated on yarn.lock changes
    - name: Restore node_modules
      if: ${{ inputs.skip-install-if-cache-hit != 'true' || steps.all-caches-check.outputs.all-hit != 'true' }}
      id: yarn-nm-cache
      uses: actions/cache@v4
      with:
        path: |
          **/node_modules/
          !**/.next/node_modules/
        key: ${{ runner.os }}-yarn-nm-cache-${{ hashFiles('yarn.lock', '.yarnrc.yml') }}

    # Invalidated on yarn.lock changes
    - name: Restore yarn install state
      if: ${{ inputs.skip-install-if-cache-hit != 'true' || steps.all-caches-check.outputs.all-hit != 'true' }}
      id: yarn-install-state-cache
      uses: actions/cache@v4
      with:
        path: .yarn/ci-cache/
        key: ${{ runner.os }}-yarn-install-state-cache-${{ hashFiles('yarn.lock', '.yarnrc.yml') }}

    - name: Install dependencies
      if: ${{ inputs.skip-install-if-cache-hit != 'true' || steps.all-caches-check.outputs.all-hit != 'true' }}
      shell: bash
      run: yarn install --inline-builds
      env:
        # CI optimizations. Overrides yarnrc.yml options (or their defaults) in the CI action.
        YARN_ENABLE_IMMUTABLE_INSTALLS: "false" # So it doesn't try to remove our private submodule deps
        YARN_ENABLE_GLOBAL_CACHE: "false" # Use local cache folder to keep downloaded archives
        YARN_INSTALL_STATE_PATH: .yarn/ci-cache/install-state.gz # Very small speedup when lock does not change
        YARN_NM_MODE: "hardlinks-local" # Reduce node_modules size
        # Other environment variables
        HUSKY: "0" # By default do not run HUSKY install