name: Build Documentation

on:
  workflow_dispatch:
    inputs:
      pr_number:
        description: 'Pull request number for which the documentation should be built'
        type: number
        required: true
      doc_version:
        description: 'Version number of the documentation build'
        type: string
        required: true
      force_build:
        description: 'Force the build of the documentation'
        type: boolean
        required: false
        default: false

  issue_comment:
    types: [created]

env:
  author_association: ${{ github.event.comment.author_association }}
  comment_body: ${{ github.event.comment.body }}

permissions:
  contents: read # to fetch code (actions/checkout)

jobs:
  pre_build_checks:
    if: ${{ inputs.pr_number || startsWith(github.event.comment.body, '/build:') || startsWith(github.event.comment.body, '/force-build:') }}
    runs-on: ubuntu-latest
    name: Trigger the build?
    outputs:
      trigger_build: ${{ steps.get_doc_version.outputs.result && steps.get_doc_version.outputs.result != '' }}
      force_build: ${{ steps.check_comment_body.outputs.force_build }}
      pr_number: ${{ steps.get_pr_number.outputs.pr_number }}
      doc_version: ${{ steps.get_doc_version.outputs.result }}
    steps:
      - name: Display inputs
        run: |
          echo "pr_number=${{ inputs.pr_number || github.event.issue.number }}"
          echo "doc_version=${{ inputs.doc_version }}"
          echo "force_build=${{ inputs.force_build || startsWith(env.comment_body, '/force-build:') }}"
      - name: Check comment body
        id: check_comment_body
        env:
          trigger_build: ${{ inputs && inputs.pr_number || startsWith(env.comment_body, '/build:') || startsWith(env.comment_body, '/force-build:') }}
          force_build: ${{ inputs && inputs.force_build || startsWith(env.comment_body, '/force-build:') }}
        if: inputs.pr_number || startsWith(env.comment_body, '/build:') || startsWith(env.comment_body, '/force-build:')
        run: |
          if [ "${trigger_build}" = "false" ]; then
            echo "No build requested"
            exit 1
          fi
          echo "force_build=${force_build}" >> $GITHUB_OUTPUT
          echo "trigger_build=${trigger_build}" >> $GITHUB_OUTPUT

      - name: Check permissions
        if: ( steps.check_comment_body.outputs.trigger_build || false ) && (inputs.pr_number || env.author_association == 'OWNER' || env.author_association == 'MEMBER')
        run: echo "Authorized"

      - name: No permissions
        if: ( steps.check_comment_body.outputs.trigger_build || false ) && (! inputs.pr_number && env.author_association != 'OWNER' && env.author_association != 'MEMBER' )
        run: |
          echo 'ERROR: User ${{ github.actor }} is not allowed to trigger the build of the documentation with /build:* or /force-build:*'
          exit 1

      - name: Get PR number
        if: ( steps.check_comment_body.outputs.trigger_build || false )
        id: get_pr_number
        env:
          pr_number: ${{ inputs.pr_number || github.event.issue.number }}
        run: echo "pr_number=$pr_number" >> $GITHUB_OUTPUT

      - name: Get doc version
        if: ( steps.check_comment_body.outputs.trigger_build || false )
        uses: actions/github-script@v7
        id: get_doc_version
        with:
          result-encoding: string
          script: |
            if ( context.payload.input && context.payload.inputs.doc_version ) {
              return context.payload.inputs.doc_version
            }
            const body = context.payload.comment.body
            const re = /\/(force-)?build:(\w+)\s*/;
            if(re.test(body)) {
              const res = re.exec(body)
              return res[2]
            }
            throw new Error('No version found')

  build_doc:
    name: |
      ${{ format('{0}: Build Documentation version "{1}"', github.actor, needs.pre_build_checks.outputs.doc_version) }}
    needs: pre_build_checks
    permissions:
      contents: read # to fetch code (actions/checkout)
      pull-requests: write # to create comment
    runs-on: ubuntu-latest
    env:
      force_build: ${{ needs.pre_build_checks.outputs.force_build }}
      pr_number: ${{ needs.pre_build_checks.outputs.pr_number }}
      doc_version: ${{ needs.pre_build_checks.outputs.doc_version }}
    if: ${{ fromJSON(needs.pre_build_checks.outputs.trigger_build || false) }}
    steps:

      - name: Emoji-comment
        if: github.event_name == 'issue_comment'
        continue-on-error: true
        uses: actions/github-script@v7
        with:
          script: |
            github.rest.reactions.createForIssueComment({
              comment_id: ${{ github.event.comment.id }},
              owner: context.repo.owner,
              repo: context.repo.repo,
              content: 'rocket'
            })

      - uses: actions/checkout@v4
        name: "checkout branch"
        with:
          repository: ${{ github.repository }}
          ref: refs/pull/${{ env.pr_number }}/head
          fetch-depth: 0

      - name: Install dependencies
        run: |
          set -x

          # Install Github CLI `gh`
          (type -p wget >/dev/null || (sudo apt update && sudo apt-get install wget -y))
          sudo mkdir -p -m 755 /etc/apt/keyrings
          wget -qO- https://cli.github.com/packages/githubcli-archive-keyring.gpg | sudo tee /etc/apt/keyrings/githubcli-archive-keyring.gpg > /dev/null
          sudo chmod go+r /etc/apt/keyrings/githubcli-archive-keyring.gpg
          echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/githubcli-archive-keyring.gpg] https://cli.github.com/packages stable main" | sudo tee /etc/apt/sources.list.d/github-cli.list > /dev/null

          sudo apt-get update && sudo apt-get install -y gh cmake graphviz ssh bibtex2html
          sudo pip install lxml
          sudo pip install pyquery
          wget --no-verbose -O doxygen_exe https://cgal.geometryfactory.com/~cgaltest/doxygen_1_9_6_patched/doxygen
          sudo mv doxygen_exe /usr/bin/doxygen
          sudo chmod +x /usr/bin/doxygen
          git config --global user.email "cgal@geometryfactory.com"
          git config --global user.name "cgaltest"

      - name: CMake configuration of Documentation/doc
        run: |
          set -ex
          mkdir -p build_doc && cd build_doc && cmake ../Documentation/doc

      - name: Build and upload Doc
        id: build_and_run
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          set -ex
          PR_NUMBER=$pr_number
          ROUND=$doc_version
          force=$force_build
          wget --no-verbose cgal.github.io -O index.html
          if ! egrep -qF "/$PR_NUMBER/$ROUND" index.html || [ "$force" = "yes" ]; then
            #list impacted packages
            LIST_OF_PKGS=$(git diff --name-only origin/master...HEAD |cut -s -d/ -f1 |sort -u | xargs -I {} echo {} && ls -d {}/package_info 2>/dev/null  |cut -d/ -f1 |egrep -v Installation||true)
            if [ "$LIST_OF_PKGS" = "" ]; then
              echo "DoxygenError=No package affected." >> $GITHUB_OUTPUT
              exit 1
            fi
            for p in $LIST_OF_PKGS; do
              if [ -f $p/doc/$p/dependencies ]; then
                LIST_OF_PKGS="$LIST_OF_PKGS $(cat $p/doc/$p/dependencies)"
              fi
            done
            LIST_OF_PKGS=$(echo $LIST_OF_PKGS | tr ' ' '\n' | sort -u)
            cd build_doc && make -j$(nproc) doc
            make -j$(nproc) doc_with_postprocessing 2>build.log
            if [ -s build.log ]; then
              delimiter="$(openssl rand -hex 8)"
              echo "DoxygenError<<${delimiter}" >> "${GITHUB_OUTPUT}"
              cat build.log >> "${GITHUB_OUTPUT}"
              echo "${delimiter}" >> "${GITHUB_OUTPUT}"
              exit 1
            fi
            cd ..
            git clone https://CGAL:${{ secrets.PUSH_TO_CGAL_GITHUB_IO_TOKEN }}@github.com/CGAL/cgal.github.io.git
            mkdir -p cgal.github.io/${PR_NUMBER}/$ROUND
            rm cgal.github.io/${PR_NUMBER}/$ROUND/* -rf
            for f in $LIST_OF_PKGS Manual
            do
              if [ -d ./build_doc/doc_output/$f ]; then
                cp -r ./build_doc/doc_output/$f ./cgal.github.io/${PR_NUMBER}/$ROUND
              fi
            done
            cd ./cgal.github.io
            echo "<li><a href=https://cgal.github.io/${PR_NUMBER}/$ROUND/Manual/index.html>Manual for PR ${PR_NUMBER} ($ROUND).</a></li>" >> ./index.html
            ./cleanup.bash
            git add ${PR_NUMBER}/$ROUND index.html && git commit -q --amend -m "sole commit" && git push -q -f -u origin master
          else
            echo "DoxygenError=This round already exists. Overwrite it with /force-build." >> $GITHUB_OUTPUT
            exit 1
          fi

      - name: Post address
        uses: actions/github-script@v7
        if: ${{ success() }}
        with:
          script: |
            const round = "${{ env.doc_version }}"
            const address = "The documentation is built. It will be available, after a few minutes, here: https://cgal.github.io/${{ env.pr_number }}/"+round+"/Manual/index.html"
            github.rest.issues.createComment({
              owner: "CGAL",
              repo: "cgal",
              issue_number: ${{ github.event.issue.number }},
              body: address
            });

      - name: Post error
        env:
          ERRORMSG: ${{steps.build_and_run.outputs.DoxygenError}}
        uses: actions/github-script@v7
        if: ${{ failure() }}
        with:
          script: |
            const error = process.env.ERRORMSG
            const job_url = `${context.serverUrl}/CGAL/cgal/actions/runs/${context.runId}`
            const msg = "There was an error while building the doc: \n```\n"+error + "\n```\n" + job_url
            github.rest.issues.createComment({
              owner: "CGAL",
              repo: "cgal",
              issue_number: ${{ github.event.issue.number }},
              body: msg
            });