name: Publish Docs

# Publishes the versioned docs site to GitHub Pages.
#
# Discovers the versions to publish from the repository's GitHub releases (the
# latest release, by date, for each major >= 1), builds each release tag into
# its own sub-path (e.g. /v1/ and /v2/) with make generate-docs, injects a
# version-picker widget into each page, adds a root redirect to the default
# version, and deploys the combined site. A manual dispatch can build every
# major-version path from release tags or current source branches.
# Triggers on release publish and manual dispatch.

on:
  release:
    types: [published]
  workflow_dispatch:
    inputs:
      docs_source:
        description: Source for every published major-version path
        required: true
        default: release-tags
        type: choice
        options:
        - release-tags
        - latest-branches

# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
permissions:
  contents: read
  pages: write
  id-token: write # Required for actions/deploy-pages

# Allow only one concurrent deployment. Cancel any in-progress run when a newer one
# starts: every run rediscovers the current releases and rebuilds the whole site from
# scratch, so a newer run fully supersedes the work of the one it cancels.
concurrency:
  group: "pages"
  cancel-in-progress: true

jobs:
  publish-docs:
    # Only publish from the modelcontextprotocol/csharp-sdk repository
    if: ${{ github.repository == 'modelcontextprotocol/csharp-sdk' }}
    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}
    runs-on: ubuntu-latest
    steps:
    - name: Checkout docs orchestration
      uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
      with:
        # A release event otherwise checks out the released tag. Keep the
        # orchestration scripts and picker assets current with main.
        ref: main
        # Full history + tags so we can add a worktree for each version's release tag.
        fetch-depth: 0

    - name: .NET Setup
      uses: actions/setup-dotnet@a98b56852c35b8e3190ac28c8c2271da59106c68 # v6.0.0
      with:
        dotnet-version: |
          10.0.x
          9.0.x

    - name: Discover versions from GitHub releases
      shell: bash
      env:
        GH_TOKEN: ${{ github.token }}
      # For every major version >= 1, take the most recently published (by date)
      # non-draft release tagged v{major}.*. The vN prefix becomes the URL slug;
      # the site root redirects to the newest release, including prereleases.
      run: |
        set -euo pipefail
        gh release list --repo "${{ github.repository }}" --limit 200 \
          --json tagName,isPrerelease,isDraft,publishedAt \
          --jq '
            [ .[]
              | select((.isDraft | not) and (.tagName | test("^v[1-9][0-9]*\\.")))
              | { slug: (.tagName | match("^v[0-9]+").string),
                  ref: .tagName, label: .tagName,
                  prerelease: .isPrerelease, published: .publishedAt }
            ]
            | group_by(.slug)
            | map(max_by(.published))
            | sort_by(.published) | reverse
            | { default: .[0].slug,
                versions: map({ slug, ref, label, prerelease }) }
          ' | tee "$RUNNER_TEMP/docs-versions.json"

    - name: Build all versions
      shell: bash
      env:
        USE_SOURCE_BRANCHES: ${{ inputs.docs_source == 'latest-branches' }}
      run: |
        set -euo pipefail
        ROOT="$PWD"
        COMBINED="$ROOT/combined"
        rm -rf "$COMBINED"
        mkdir -p "$COMBINED"

        # Orchestration (discovered docs-versions.json, scripts, picker assets)
        # always comes from THIS branch. Normally each version's HTML is produced
        # by its release tag. A manual dispatch can instead build every major from
        # its current source branch.
        git fetch --tags --force --prune origin "+refs/heads/*:refs/remotes/origin/*"
        USE_SOURCE_BRANCHES="${USE_SOURCE_BRANCHES:-false}"

        MAIN_SLUG=""
        if [[ "$USE_SOURCE_BRANCHES" == "true" ]]; then
          MAIN_PROPS="$(mktemp)"
          git show refs/remotes/origin/main:src/Directory.Build.props > "$MAIN_PROPS"
          MAIN_SLUG="$(node "$ROOT/scripts/get-docs-version-slug.mjs" "$MAIN_PROPS")"
          rm -f "$MAIN_PROPS"
          echo "Refreshing all published docs from source branches (main serves $MAIN_SLUG)"
        else
          echo "Refreshing all published docs from release tags"
        fi

        while IFS=$'\t' read -r slug ref; do
          if [[ "$USE_SOURCE_BRANCHES" == "true" ]]; then
            source_branch="release/${slug#v}.x"
            if ! git show-ref --verify --quiet "refs/remotes/origin/$source_branch"; then
              if [[ "$slug" == "$MAIN_SLUG" ]]; then
                source_branch="main"
              else
                echo "::error::No source branch found for $slug. Expected release/${slug#v}.x, or main with VersionPrefix for $slug."
                exit 1
              fi
            fi

            echo "::group::Build $slug (from branch $source_branch)"
            wt="$ROOT/../work-$slug"
            git worktree add --force --detach "$wt" "refs/remotes/origin/$source_branch"
            source_slug="$(node "$ROOT/scripts/get-docs-version-slug.mjs" "$wt/src/Directory.Build.props")"
            if [[ "$source_slug" != "$slug" ]]; then
              git worktree remove --force "$wt"
              echo "::error::Source branch '$source_branch' has major '$source_slug', not '$slug'."
              exit 1
            fi
          else
            echo "::group::Build $slug (from tag $ref)"
            wt="$ROOT/../work-$slug"
            git worktree add --force --detach "$wt" "refs/tags/$ref"
          fi

          make -C "$wt" generate-docs

          mkdir -p "$COMBINED/$slug"
          cp -a "$wt/artifacts/_site/." "$COMBINED/$slug/"
          node "$ROOT/scripts/inject-version-picker.mjs" "$COMBINED/$slug" "$slug" --base /

          git worktree remove --force "$wt"
          echo "::endgroup::"
        done < <(node "$ROOT/scripts/list-versions.mjs")

        node "$ROOT/scripts/finalize-docs-site.mjs" "$COMBINED"

        echo "Combined site contents:"
        ls -la "$COMBINED"

    - name: Upload Pages artifact
      uses: actions/upload-pages-artifact@fc324d3547104276b827a68afc52ff2a11cc49c9 # v5.0.0
      with:
        path: 'combined'

    - name: Deploy to GitHub Pages
      id: deployment
      uses: actions/deploy-pages@cd2ce8fcbc39b97be8ca5fce6e763baed58fa128 # v5.0.0