action.yml

name: "Restore Nix store"
description: "Restore Nix store using GitHub Actions cache to speed up workflows."
author: "GitHub"
inputs:
  primary-key:
    description: |
      - When a non-empty string, the action uses this key for restoring a cache.
      - Otherwise, the action fails.
    required: true

  restore-prefixes-first-match:
    description: |
      - When a newline-separated non-empty list of non-empty key prefixes, when there's a miss on the `primary-key`, 
        the action searches in this list for the first prefix
        for which there exists a cache whose key has this prefix,
        and the action tries to restore that cache.
      - Otherwise, this input has no effect.
    default: ""

  restore-prefixes-all-matches:
    description: |
      - When a newline-separated non-empty list of non-empty key prefixes, when there's a miss on the `primary-key`,
        the action tries to restore all caches whose keys have these prefixes.
        - Tries caches across all refs to make use of caches created 
          on the current, base, and default branches 
          (see [docs](https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#restrictions-for-accessing-a-cache)).
      - Otherwise, this input has no effect.
    default: ""

  skip-restore-on-hit-primary-key:
    description: |
      - When `true`, when there's a hit on the `primary-key`, the action doesn't restore the found cache.
      - Otherwise, the action restores the cache.
    default: "false"

  fail-on:
    description: |
      - Input form: `<key type>.<result>`.
      - `<key type>` options: `primary-key`, `first-match`.
      - `<result>` options: `miss`, `not-restored`.
      - When the input satisfies the input form, when the event described in the input happens, the action fails.
        - Example:
          - Input: `primary-key.not-restored`.
          - Event: a cache could not be restored via the `primary-key`.
      - Otherwise, this input has no effect.
    default: ""

  nix:
    description: |
      - Can have an effect only when the action runs on a `Linux` or a `macOS` runner.
      - When `true`, the action can do Nix-specific things.
      - Otherwise, the action doesn't do them.
    default: "true"

  save:
    description: |
      - When `true`, the action can save a cache with the `primary-key`.
      - Otherwise, the action can't save a cache.
    default: "true"

  paths:
    description: |
      - When `nix: true`, the action uses `["/nix", "~/.cache/nix", "~root/.cache/nix"]` as default paths, as suggested [here](https://github.com/divnix/nix-cache-action/blob/b14ec98ae694c754f57f8619ea21b6ab44ccf6e7/action.yml#L7).
      - Otherwise, the action uses an empty list as default paths.
      - When a newline-separated non-empty list of non-empty path patterns (see [`@actions/glob`](https://github.com/actions/toolkit/tree/main/packages/glob) for supported patterns), the action appends it to default paths and uses the resulting list for restoring caches.
      - Otherwise, the action uses default paths for restoring caches.
    default: ""
  paths-macos:
    description: |
      - Overrides `paths`.
      - Can have an effect only when the action runs on a `macOS` runner.
    default: ""
  paths-linux:
    description: |
      - Overrides `paths`.
      - Can have an effect only when the action runs on a `Linux` runner.
    default: ""

  backend:
    description: |
      Choose an implementation of the `cache` package.
      - When `actions`, use the [actions version](https://github.com/actions/toolkit/tree/main/packages/cache) from [here](https://github.com/nix-community/cache-nix-action/tree/actions-toolkit/packages/cache).
      - When `buildjet`, use the [BuildJet version](https://github.com/BuildJet/toolkit/tree/main/packages/cache-buildjet) from [here](https://github.com/nix-community/cache-nix-action/tree/buildjet-toolkit/packages/cache).
    default: "actions"
    required: false

  token:
    description: |
      - The action uses it to communicate with GitHub API.
      - If you use a personal access token, it must have the `repo` scope ([link](https://docs.github.com/en/rest/actions/cache?apiVersion=2022-11-28#delete-github-actions-caches-for-a-repository-using-a-cache-key)).
    default: ${{ github.token }}
outputs:
  primary-key:
    description: |
      - A string.
      - The `primary-key`.

  hit:
    description: |
      - A boolean value.
      - `true` when `hit-primary-key` is `true` or `hit-first-match` is `true`.
      - `false` otherwise.
  hit-primary-key:
    description: |
      - A boolean value.
      - `true` when there was a hit on the `primary-key`.
      - `false` otherwise.
  hit-first-match:
    description: |
      - A boolean value.
      - `true` when there was a hit on a key matching `restore-prefixes-first-match`.
      - `false` otherwise.

  restored-key:
    description: |
      - A string.
      - The key of a cache restored via the `primary-key` or via the `restore-prefixes-first-match`.
      - An empty string otherwise.

  restored-keys:
    description: |
      - A possibly empty array of strings (JSON).
      - Keys of restored caches.
      - Example: `["key1", "key2"]`.
runs:
  using: "node20"
  main: "../dist/restore-only/index.js"

branding:
  icon: "archive"
  color: "gray-dark"