pages.yml

name: Publish web app

# Deploys the Flutter web build to GitHub Pages:
#   /      web build of the newest release (falls back to the newest dev build
#          while there is no release with a web build)
#   /dev/  web build of the newest dev build (dev-<n>)
# The web build is the *-web.zip asset of each release. Runs when a release is
# published or changed, and by hand. The dev build workflow also calls it
# with its fresh web build (dev_web_artifact), so /dev/ is live before the
# slower app builds and the dev-<n> release are done.
#
# Requires Settings -> Pages -> Source: "GitHub Actions".

on:
  release:
    types: [published, edited, deleted, released, prereleased]
  workflow_dispatch:
  workflow_call:
    inputs:
      dev_web_artifact:
        description: Artifact of the calling run with the dev *-web.zip; replaces the newest dev release's
        type: string
        default: ""

permissions:
  contents: read

jobs:
  build:
    name: Assemble site
    runs-on: ubuntu-latest
    concurrency:
      group: pages-build
      cancel-in-progress: true
    env:
      GH_TOKEN: ${{ github.token }}
      GH_REPO: ${{ github.repository }}
    steps:
      - id: pages
        uses: actions/configure-pages@v5
      - if: inputs.dev_web_artifact != ''
        uses: actions/download-artifact@v4
        with:
          name: ${{ inputs.dev_web_artifact }}
          path: fresh
      - name: Download newest web builds
        env:
          BASE_PATH: ${{ steps.pages.outputs.base_path }}
          FRESH: ${{ inputs.dev_web_artifact != '' }}
        run: |
          gh api --paginate --slurp "repos/${GH_REPO}/releases?per_page=100" | jq 'add' > releases.json
          # newest published release of a kind that has a web build attached
          newest() {
            jq -r --arg kind "$1" '
              map(select(.draft | not)
                  | select(any(.assets[]; .name | endswith("-web.zip")))
                  | select(if $kind == "dev"
                           then .prerelease and (.tag_name | startswith("dev-"))
                           else (.prerelease | not) end))
              | sort_by(.published_at) | last | .tag_name // empty' releases.json
          }
          stable="$(newest stable)"
          dev="$(newest dev)"
          [ "$FRESH" = true ] && dev=fresh
          echo "stable: ${stable:-none}, dev: ${dev:-none}"
          if [ -z "$dev" ] && [ -z "$stable" ]; then
            echo "::error::No release has a *-web.zip asset yet"
            exit 1
          fi

          # unpack <tag> into <dir> and point its base href at <href>
          unpack() {
            mkdir -p "$2" dl
            if [ "$1" = fresh ]; then
              cp fresh/*-web.zip dl/
            else
              gh release download "$1" --pattern '*-web.zip' --dir dl --clobber
            fi
            unzip -qo dl/*-web.zip -d "$2"
            rm -f dl/*
            sed -i "s|<base href=\"/\">|<base href=\"$3\">|" "$2/index.html"
            grep -q "<base href=\"$3\">" "$2/index.html"
          }
          unpack "${stable:-$dev}" site "${BASE_PATH}/"
          [ -n "$dev" ] && unpack "$dev" site/dev "${BASE_PATH}/dev/"
          ls site
      - uses: actions/upload-pages-artifact@v3
        with:
          path: site

  deploy:
    name: Deploy to GitHub Pages
    needs: build
    runs-on: ubuntu-latest
    concurrency:
      group: pages-deploy
      cancel-in-progress: false
    permissions:
      pages: write
      id-token: write
    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}
    steps:
      - id: deployment
        uses: actions/deploy-pages@v4