name: Build and Push Teamspeak Images on Base Image Update

on:
  push:
    branches:
      - main
    paths-ignore:
      - '**/CHANGES.md'
      - '**/build-info.json'
  schedule:
    - cron: '30 */6 * * *'  # Every 6 hours

env:
  IMAGE_REGISTRY: gitea.fithwum.tech
  IMAGE_ORG: ${{ secrets.GIT_USERNAME }}
  IMAGE_REPO_TS: teamspeak-server
  IMAGE_REPO_DEBIAN: debian-base
  IMAGE_TAG_DEBIAN: bookworm
  ALPINE_IMAGE: alpine:latest
  CACHE_DIR: .cache

jobs:
  check-for-changes:
    runs-on: doc-docker-build
    outputs:
      should_build_alpine: ${{ steps.check.outputs.should_build_alpine }}
      should_build_debian: ${{ steps.check.outputs.should_build_debian }}
      alpine_digest: ${{ steps.get_digest.outputs.alpine_digest }}
      debian_digest: ${{ steps.get_digest.outputs.debian_digest }}

    steps:
      - name: Checkout code
        uses: actions/checkout@v3
        with:
          fetch-depth: 0

      - name: Pull latest base images
        run: |
          docker pull alpine:latest
          docker pull gitea.fithwum.tech/${{ secrets.GIT_USERNAME }}/debian-base:bookworm

      - name: Get base image digests
        id: get_digest
        run: |
          alpine_digest=$(docker inspect --format='{{index .RepoDigests 0}}' alpine:latest || echo "unknown")
          debian_digest=$(docker inspect --format='{{index .RepoDigests 0}}' gitea.fithwum.tech/${{ secrets.GIT_USERNAME }}/debian-base:bookworm || echo "unknown")

          echo "alpine_digest=$alpine_digest" >> $GITHUB_OUTPUT
          echo "debian_digest=$debian_digest" >> $GITHUB_OUTPUT

      - name: Compare digests and detect changes
        id: check
        run: |
          check_variant() {
            variant=$1
            new_digest=$2
            infofile="$variant/build-info.json"
            last_digest=""
            base_changed=false
            code_changed=false

            if [ -f "$infofile" ]; then
              last_digest=$(jq -r '.base_digest // empty' "$infofile")
            fi

            if [ "$last_digest" != "$new_digest" ]; then
              base_changed=true
            fi

            if git diff --name-only origin/main...HEAD | grep "^$variant/" > /dev/null; then
              code_changed=true
            fi

            should_build=false
            if [ "$base_changed" = true ] || [ "$code_changed" = true ]; then
              should_build=true
            fi

            echo "should_build_${variant}=$should_build" >> $GITHUB_OUTPUT
          }

          git fetch origin main

          check_variant "alpine" "${{ steps.get_digest.outputs.alpine_digest }}"
          check_variant "debian" "${{ steps.get_digest.outputs.debian_digest }}"

  build-alpine:
    needs: check-for-changes
    if: needs.check-for-changes.outputs.should_build_alpine == 'true'
    runs-on: doc-docker-build
    outputs:
      built: 'true'
    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: Build and Push Alpine Image
        if: steps.compare_digests.outputs.alpine_changed == 'true'
        run: |
          IMAGE="${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_ORG }}/${{ env.IMAGE_REPO_TS }}:alpine"
          echo "[INFO] Building $IMAGE"
          docker buildx build --platform linux/amd64 --push -t "$IMAGE" ./alpine

  build-debian:
    needs: check-for-changes
    if: needs.check-for-changes.outputs.should_build_debian == 'true'
    runs-on: doc-docker-build
    outputs:
      built: 'true'
    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: Build and Push Debian Image
        if: steps.compare_digests.outputs.debian-base_changed == 'true'
        run: |
          IMAGE="${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_ORG }}/${{ env.IMAGE_REPO_TS }}:debian"
          echo "[INFO] Building $IMAGE"
          docker buildx build --platform linux/amd64 --push -t "$IMAGE" ./debian

      - name: Build and Push Basic Image (depends on debian)
        if: steps.compare_digests.outputs.debian-base_changed == 'true'
        run: |
          IMAGE="${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_ORG }}/${{ env.IMAGE_REPO_TS }}:basic"
          echo "[INFO] Building $IMAGE"
          docker buildx build --platform linux/amd64 --push -t "$IMAGE" ./basic

  generate-changelogs:
    needs: check-for-changes
    if: |
      needs.check-for-changes.outputs.should_build_alpine == 'true' ||
      needs.check-for-changes.outputs.should_build_debian == 'true'
    runs-on: doc-docker-build
    steps:
      - name: Checkout source
        uses: actions/checkout@v3

      - name: Clone Teamspeak repo
        run: |
          git clone https://${{ secrets.GIT_USERNAME }}:${{ secrets.GIT_TOKEN }}@gitea.fithwum.tech/fithwum/teamspeak-server.git upload-repo

      - name: Generate changelogs only for updated variants
        run: |
          cd upload-repo

          if [[ "${{ needs.check-for-changes.outputs.should_build_alpine }}" == "true" ]]; then
            versions+=("alpine")
          fi
          if [[ "${{ needs.check-for-changes.outputs.should_build_debian }}" == "true" ]]; then
            versions+=("debian")
          fi

          for version in "${versions[@]}"; do
            echo "[INFO] Updating changelog for $version"

            changelog="$version/CHANGES.md"
            mkdir -p "$(dirname "$changelog")"
            touch "$changelog"

            infofile="$version/build-info.json"
            last_commit=""
            if [ -f "$infofile" ]; then
              last_commit=$(jq -r '.commit' "$infofile")
            fi

            echo -e "\n## $(date -u +'%Y-%m-%dT%H:%M:%SZ')" >> "$changelog"
            if [ -n "$last_commit" ]; then
              git log "${last_commit}..HEAD" --pretty=format:"- %s (%an)" | head -n 10 >> "$changelog"
            else
              git log -n 10 --pretty=format:"- %s (%an)" >> "$changelog"
            fi
          done

      - name: Commit and push changelogs
        run: |
          cd upload-repo
          git config user.name "${{ secrets.GIT_USERNAME }}"
          git config user.email "${{ secrets.GIT_EMAIL }}"

          if git status --porcelain | grep .; then
            git add */CHANGES.md
            git commit -m "Update changelogs on $(date -u +'%Y-%m-%dT%H:%M:%SZ')" --no-verify
            git push
          else
            echo "[INFO] No changelog changes to commit."
          fi

  generate-build-info:
    needs:
      - build-alpine
      - build-debian
    if: |
      needs.build-alpine.outputs.built == 'true' ||
      needs.build-debian.outputs.built == 'true'
    runs-on: doc-docker-build
    steps:
      - name: Checkout source
        uses: actions/checkout@v3

      - name: Clone Teamspeak repo
        run: |
          git clone https://${{ secrets.GIT_USERNAME }}:${{ secrets.GIT_TOKEN }}@gitea.fithwum.tech/fithwum/teamspeak-server.git upload-repo

      - name: Generate build-info.json only for updated variants
        env:
          IMAGE_REGISTRY: ${{ env.IMAGE_REGISTRY }}
          IMAGE_ORG: ${{ env.IMAGE_ORG }}
          IMAGE_REPO_TS: ${{ env.IMAGE_REPO_TS }}
          ALPINE_DIGEST: ${{ needs.check-for-changes.outputs.alpine_digest }}
          DEBIAN_DIGEST: ${{ needs.check-for-changes.outputs.debian_digest }}
        run: |
          human_size() {
            local b=$1
            local d=''
            local s=0
            local S=(B KB MB GB TB)
            while ((b >= 1024 && s < ${#S[@]}-1)); do
              d=$((b % 1024))
              b=$((b / 1024))
              s=$((s + 1))
            done
            printf "%s%s\n" "$b" "${S[$s]}"
          }

          cd upload-repo
          declare -A digests
          digests[alpine]="${ALPINE_DIGEST}"
          digests[debian]="${DEBIAN_DIGEST}"

          versions=()
          [[ "${{ needs.check-for-changes.outputs.should_build_alpine }}" == "true" ]] && versions+=("alpine")
          [[ "${{ needs.check-for-changes.outputs.should_build_debian }}" == "true" ]] && versions+=("debian")

          for version in "${versions[@]}"; do
            echo "[INFO] Generating build-info.json for $version"
            mkdir -p "$version"
            infofile="$version/build-info.json"
            image="${IMAGE_REGISTRY}/${IMAGE_ORG}/${IMAGE_REPO_TS}:$version"

            digest=$(docker inspect --format='{{if .RepoDigests}}{{index .RepoDigests 0}}{{else}}unknown{{end}}' "$image" 2>/dev/null || echo "unknown")
            size_bytes=$(docker image inspect "$image" --format='{{.Size}}' 2>/dev/null || echo "0")
            size_bytes=${size_bytes//[^0-9]/}
            size_human=$(human_size "$size_bytes")

            base_digest="${digests[$version]:-unknown}"

            jq -n \
              --arg version "$version" \
              --arg commit "$(git rev-parse HEAD)" \
              --arg build_time "$(date -u +'%Y-%m-%dT%H:%M:%SZ')" \
              --arg image_tag "$image" \
              --arg digest "$digest" \
              --arg image_size "$size_human" \
              --argjson image_size_bytes "$size_bytes" \
              --arg base_digest "$base_digest" \
              '{
                version: $version,
                commit: $commit,
                build_time: $build_time,
                image_tag: $image_tag,
                digest: $digest,
                image_size: $image_size,
                image_size_bytes: $image_size_bytes,
                base_digest: $base_digest
              }' > "$infofile"
          done

      - name: Commit and push build-info if changed
        run: |
          cd upload-repo
          git config user.name "${{ secrets.GIT_USERNAME }}"
          git config user.email "${{ secrets.GIT_EMAIL }}"

          if git status --porcelain | grep .; then
            git add */build-info.json
            git commit -m "Update build-info on $(date -u +'%Y-%m-%dT%H:%M:%SZ')"
            git push

            for version in alpine debian; do
              TAG="build-$version"
              git tag -d "$TAG" 2>/dev/null || true
              git tag "$TAG"
              git push origin "$TAG" --force
            done
          else
            echo "[INFO] No build-info changes to commit."
          fi