# example:
#       - uses: ./.github/actions/get-llvm
#         with:
#           target: x86_64-unknown-linux-gnu

name: "Download LLVM"
description: "Downloads a prebuilt LLVM release for a specific target."

inputs:
  target:
    description: "Target triple (e.g., x86_64-unknown-linux-musl)"
    required: true

runs:
  using: "composite"
  steps:
    - name: check override version
      id: override
      shell: bash
      env:
        # To test a draft LLVM release across every CI workflow, set this to the full
        # draft name (e.g. "llvm-21.1.8-revive.0f80912") and revert to "" before merging.
        OVERRIDE_VERSION: ""
      run: echo "version=${OVERRIDE_VERSION}" | tee -a "$GITHUB_OUTPUT"

    - name: resolve llvm version
      id: resolve-version
      if: ${{ steps.override.outputs.version == '' }}
      shell: bash
      run: |
        set -euo pipefail

        if [ ! -s .llvm-version ]; then
          echo "::error file=.llvm-version::Missing or empty .llvm-version. It must contain the version matching the llvm submodule pin."
          exit 1
        fi
        echo "version_prefix=$(cat .llvm-version)" | tee -a "$GITHUB_OUTPUT"

    - name: find asset
      id: find
      uses: actions/github-script@v7
      env:
        target: ${{ inputs.target }}
        version_prefix: ${{ steps.override.outputs.version || steps.resolve-version.outputs.version_prefix }}
      with:
        result-encoding: string
        script: |
          let page = 1;
          let allReleases = [];

          let target = process.env.target
          let versionPrefix = process.env.version_prefix

          if (!versionPrefix) {
            core.setFailed("version_prefix env is missing");
            return;
          }

          // Fetch all releases from all pages
          core.info('Fetching releases from revive repository...');
          let hasMorePages = true;
          while (hasMorePages) {
            const res = await github.rest.repos.listReleases({
              owner: context.repo.owner,
              repo: context.repo.repo,
              per_page: 50,
              page,
            });

            if (res.data.length > 0) {
              core.info(`Page ${page}: Fetched ${res.data.length} releases`);
              allReleases.push(...res.data);
              page++;
            } else {
              hasMorePages = false;
            }
          }

          core.info(`Total releases fetched: ${allReleases.length}`);

          // Sort all releases by publication date (newest first)
          allReleases.sort((a, b) => new Date(b.published_at) - new Date(a.published_at));

          // Debug: Print all LLVM releases
          const llvmReleases = allReleases.filter(r => r.tag_name.startsWith('llvm-') && !r.prerelease);
          core.info(`Found ${llvmReleases.length} LLVM releases in total:`);
          llvmReleases.forEach(r => {
            core.info(`  - ${r.tag_name} (published: ${r.published_at})`);
          });

          // Find the latest LLVM release matching the version prefix.
          const llvmRelease = llvmReleases.find(release => release.tag_name.startsWith(versionPrefix));
          if (!llvmRelease) {
            core.setFailed(`No LLVM releases matching prefix '${versionPrefix}' found! Please check the version, or first release LLVM`);
            return;
          }

          core.info(`Selected LLVM release matching prefix '${versionPrefix}': ${llvmRelease.tag_name}`);

          const asset = llvmRelease.assets.find(asset => asset.name.includes(target));
          if (!asset) {
            core.setFailed(`Artifact for '${target}' not found in release ${llvmRelease.tag_name} (${llvmRelease.html_url})`);
            return;
          }

          // Use the API URL (rather than `browser_download_url`) so that
          // the authorization header is respected for draft releases.
          return asset.url;

    - name: download
      shell: bash
      run: |
        # Pass the authorization token to allow downloading draft release assets.
        curl -sSLo llvm.tar.gz -H "Authorization: Bearer ${{ github.token }}" -H "Accept: application/octet-stream" ${{ steps.find.outputs.result }}

    - name: unpack
      shell: bash
      run: |
        tar -xf llvm.tar.gz
        rm llvm.tar.gz