action.yml

name: 'Deploy mdbook docs'
description: 'GitHub Action to automatically build, test and deploy a versioned mdBook project to GitHub Pages.'
branding:
  icon: 'book'
  color: 'blue'

inputs:
  github-token:
    description: 'GitHub token for deployment.'
    required: true
  version:
    type: string
    description: "Version of the documentation to deploy"
    required: false
    default: "latest"
  docs-dir:
    type: string
    description: "Directory containing the mdbook documentation"
    required: false
    default: "docs"
  mdbook-version:
    type: string
    description: "Version of mdbook to use"
    required: false
    default: "latest"
  enable-tests:
    type: boolean
    description: "Disable mdbook tests"
    required: false
    default: true
  publish-branch:
    type: string
    description: "Branch to publish the documentation"
    required: false
    default: "gh-pages"
  project:
    type: string
    description: "Name of the project to deploy"
    required: false
    default: ""
  deploy:
    type: boolean
    description: "Enable or disable the deployment"
    required: false
    default: true

runs:
  using: composite
  steps:

    - name: Check runner OS
      if: runner.os != 'Linux'
      shell: 'bash -ex {0}'
      run: |
        echo "::error title=⛔ error hint::Only Linux is supported for this action."
        exit 1

    - name: Install latest mdbook
      shell: 'bash -ex {0}'
      env:
        MDBOOK_LATEST_API: "https://api.github.com/repos/rust-lang/mdbook/releases/${{ inputs.mdbook-version || 'latest' }}"
        MDBOOK_DOWNLOAD_URL: "https://github.com/rust-lang/mdbook/releases/download"
      run: |
        echo "::group::Install mdbook"
        TAG=$(curl "${MDBOOK_LATEST_API}" | jq -r .tag_name)
        URL="${MDBOOK_DOWNLOAD_URL}/${TAG}/mdbook-${TAG}-x86_64-unknown-linux-gnu.tar.gz"
        MDBOOK_INSTALL_DIR="${PWD}/.mdbook_$(date +%s)"
        mkdir -p "${MDBOOK_INSTALL_DIR}"
        curl -sSL "${URL}" | tar -xz --directory="${MDBOOK_INSTALL_DIR}"
        echo "${MDBOOK_INSTALL_DIR}" >> "${GITHUB_PATH}"
        echo "::endgroup::"

    - name: Build Book
      shell: 'bash -ex {0}'
      working-directory: ${{ inputs.docs-dir }}
      id: build-book
      run: |
        echo "::group::Building the book"
        if [ ${{ inputs.version }} == ${{ github.event.repository.default_branch }} ] || [ ${{ inputs.version }} == 'latest' ]; then
          VERSION=latest
        else
          VERSION=${{ inputs.version }}
        fi
        mdbook build --dest-dir=${VERSION}
        echo version=${VERSION} >> "${GITHUB_OUTPUT}"
        echo "::endgroup::"

    - name: Test Book
      if: ${{ inputs.enable-tests == 'true' || inputs.enable-tests == true }}
      shell: 'bash -ex {0}'
      working-directory: ${{ inputs.docs-dir }}
      run: |
        echo "::group::Testing the book"
        mdbook test
        echo "::endgroup::"

    - name: Init publishing branch
      if: ${{ inputs.deploy == 'true' || inputs.deploy == true }}
      shell: 'bash -ex {0}'
      env:
        GH_TOKEN: ${{ inputs.github-token }}
      run: |
        echo "::group::Initizalizing or updating publishing branch"
        # Configure git
        git config user.name "Deploy from CI"
        git config user.email ""
        # Check if the deploy branch exists
        if [ $(gh api "/repos/${GITHUB_REPOSITORY}/branches/${{ inputs.publish-branch }}" > /dev/null 2>&1; echo $?) -eq 1 ]; then
          git checkout --orphan ${{ inputs.publish-branch }}
          git rm -rf .
          git commit --allow-empty -m "Initialize ${{ inputs.publish-branch }} branch"
        else
          git fetch origin ${{ inputs.publish-branch }}
          git checkout ${{ inputs.publish-branch }}
        fi
        echo "::endgroup::"

    - name: Update versions file
      if: ${{ inputs.deploy == 'true' || inputs.deploy == true }}
      shell: 'bash -ex {0}'
      env:
        VERSION: ${{ steps.build-book.outputs.version }}
      run: |
        echo "::group::Updating versions file"
        if [ ! -z "${{ inputs.project }}" ]; then
          mkdir -p "${{ inputs.project }}"
          cd "${{ inputs.project }}"
        fi
        JSON_FILE="versions.json"
        # Check if the JSON file exists
        if [ ! -f "${JSON_FILE}" ]; then
          echo "${JSON_FILE} not found, creating..."
          echo "{}" > "${JSON_FILE}"
        fi
        # Read the current JSON content
        CURRENT_JSON=$(<"$JSON_FILE")
        # Check if the new version already exists
        if echo "${CURRENT_JSON}" | grep -q "\"${VERSION}\":"; then
          echo "Updating docs for the existing version ${VERSION} in ${JSON_FILE}."
          exit 0
        fi
        # Use jq to update the JSON file
        UPDATED_JSON=$(echo "${CURRENT_JSON}" | jq --arg version "${VERSION}" --arg url "/${VERSION}" '. + {($version): $url}')
        # Write the updated JSON back to the file
        echo "${UPDATED_JSON}" > "${JSON_FILE}"
        echo "Version ${VERSION} added successfully to ${JSON_FILE}."
        cat "${JSON_FILE}"
        echo "::endgroup::"

    - name: Deploy book
      if: ${{ inputs.deploy == 'true' || inputs.deploy == true }}
      shell: 'bash -ex {0}'
      env:
        VERSION: ${{ steps.build-book.outputs.version }}
      run: |
        echo "::group::Deploying the book"
        BOOK_DIR=$(readlink -f "${{ inputs.docs-dir }}/${VERSION}")
        [ ! -z "${{ inputs.project }}" ] && cd "${{ inputs.project }}"
        # Remove the previous version of the book
        rm -rf ${VERSION}
        # Move the new version of the book
        mv "${BOOK_DIR}" "${VERSION}"
        # Add the new version of the book
        git add "${VERSION}" versions.json
        git commit --amend -m "Deploy ${GITHUB_SHA::7}"
        git push --force --set-upstream origin ${{ inputs.publish-branch }}
        echo "::endgroup::"