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 also rebuild
# the matching major-version path from a specified branch, tag, or commit.
# Triggers on release publish and manual dispatch.

on:
  release:
    types: [published]
  workflow_dispatch:
    inputs:
      docs_ref:
        description: Branch, tag, or commit whose docs should refresh its matching major version
        required: false
        type: string

# 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@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      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@c2fa09f4bde5ebb9d1777cf28262a3eb3db3ced7 # v5.2.0
      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:
        CONTENT_REF: ${{ inputs.docs_ref }}
      run: |
        set -euo pipefail
        ROOT="$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 docs_ref replaces the matching major's
        # HTML with content built from that ref, allowing content-only refreshes
        # without minting a product release.
        git fetch --tags --force origin
        CONTENT_REF="${CONTENT_REF:-}"
        CONTENT_WORKTREE=""
        CONTENT_SLUG=""
        if [[ -n "$CONTENT_REF" ]]; then
          CONTENT_WORKTREE="$ROOT/../work-content"
          git worktree add --force --detach "$CONTENT_WORKTREE" "$CONTENT_REF"
          CONTENT_SLUG="$(node "$ROOT/scripts/get-docs-version-slug.mjs" "$CONTENT_WORKTREE/src/Directory.Build.props")"
          if ! node "$ROOT/scripts/list-versions.mjs" | cut -f1 | grep -Fxq "$CONTENT_SLUG"; then
            echo "::error::The docs ref '$CONTENT_REF' has major '$CONTENT_SLUG', which has no published release."
            exit 1
          fi
          echo "Refreshing $CONTENT_SLUG docs from $CONTENT_REF"
        fi

        while IFS=$'\t' read -r slug ref; do
          if [[ "$slug" == "$CONTENT_SLUG" ]]; then
            echo "::group::Build $slug (from ref $CONTENT_REF)"
            wt="$CONTENT_WORKTREE"
          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 /

          if [[ "$wt" != "$CONTENT_WORKTREE" ]]; then
            git worktree remove --force "$wt"
          fi
          echo "::endgroup::"
        done < <(node "$ROOT/scripts/list-versions.mjs")

        if [[ -n "$CONTENT_WORKTREE" ]]; then
          git worktree remove --force "$CONTENT_WORKTREE"
        fi

        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