name: Rust Setup + Cache
description: Install Rust toolchain and cache cargo/rustup dependencies for Gitea Actions
author: eric

inputs:
  toolchain:
    description: Rust toolchain to install (e.g., stable, 1.75.0, nightly)
    default: stable
    required: false
  cache-prefix:
    description: Prefix for cache keys.
    default: rust
    required: false
  cache-version:
    description: Cache format version. Bump this to avoid reusing stale or partial cache entries.
    default: v2
    required: false

outputs:
  cache-hit:
    description: "Whether a cache entry was found"
    value: ${{ steps.cache-restore.outputs.cache-hit }}

runs:
  using: composite
  steps:
    - name: Compute cache key
      id: cache-key
      shell: bash
      run: |
        OS=$(printf '%s' '${{ runner.os }}' | tr '[:upper:]' '[:lower:]')
        ARCH=$(printf '%s' '${{ runner.arch }}' | tr '[:upper:]' '[:lower:]')
        {
          printf 'toolchain=%s\n' '${{ inputs.toolchain }}'
          find . \
            \( -path './.git' -o -path './target' \) -prune -o \
            \( -name Cargo.toml -o -name Cargo.lock -o -name rust-toolchain -o -name rust-toolchain.toml \) \
            -type f -print0 \
            | sort -z \
            | xargs -0 sha256sum 2>/dev/null || true
        } > /tmp/rust-cache-fingerprint
        HASH=$(sha256sum /tmp/rust-cache-fingerprint | cut -d' ' -f1)
        echo "hash=$HASH" >> $GITHUB_OUTPUT
        echo "key=${{ inputs.cache-prefix }}-${{ inputs.cache-version }}-$OS-$ARCH-${{ inputs.toolchain }}-$HASH" >> $GITHUB_OUTPUT
        echo "restore-prefix=${{ inputs.cache-prefix }}-${{ inputs.cache-version }}-$OS-$ARCH-${{ inputs.toolchain }}-" >> $GITHUB_OUTPUT

    - name: Restore Rust cache
      id: cache-restore
      env:
        ACTIONS_CACHE_SERVICE_V2: "0"
      uses: https://gitea.com/actions/cache@v3
      with:
        path: |
          ~/.cargo/registry
          ~/.cargo/git
          ~/.rustup/toolchains
          ~/.rustup/settings.toml
          target
        key: ${{ steps.cache-key.outputs.key }}
        restore-keys: |
          ${{ steps.cache-key.outputs.restore-prefix }}

    - name: Show Rust cache status
      shell: bash
      run: |
        echo "Rust cache key: ${{ steps.cache-key.outputs.key }}"
        echo "Rust cache hit: ${{ steps.cache-restore.outputs.cache-hit }}"

    - name: Setup Rust
      shell: bash
      run: |
        curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
          | sh -s -- -y --profile minimal --default-toolchain ${{ inputs.toolchain }}
        echo "$HOME/.cargo/bin" >> $GITHUB_PATH