name: Build and Push Minecraft Docker Images on Debian-base update

on:
  push:
    branches:
      - master
    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_DEBIAN: debian-base
  IMAGE_REPO_MINECRAFT: minecraft
  IMAGE_TAG_DEBIAN: bookworm
  DIGEST_FILE: .cache/debian-base.digest

jobs:
  poll-debian-base-and-build:
    runs-on: docker-build

    steps:
      - name: Checkout repo
        uses: actions/checkout@v3

      - name: Ensure .cache exists with .gitkeep
        run: |
          mkdir -p .cache
          touch .cache/.gitkeep

      - name: Log in to Gitea Registry
        run: echo "${{ secrets.DOCKER_PASSWORD }}" | docker login ${{ env.IMAGE_REGISTRY }} -u "${{ secrets.DOCKER_USERNAME }}" --password-stdin

      - name: Get current digest of debian-base image
        id: get_digest
        run: |
          IMAGE="${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_ORG }}/${{ env.IMAGE_REPO_DEBIAN }}:${{ env.IMAGE_TAG_DEBIAN }}"
          echo "Checking image: $IMAGE"
          docker pull "$IMAGE" > /dev/null
          DIGEST=$(docker inspect --format='{{index .RepoDigests 0}}' "$IMAGE" 2>/dev/null || echo "")
          if [ -z "$DIGEST" ]; then
            echo "Failed to get digest for $IMAGE"
            exit 1
          fi
          echo "digest=$DIGEST" >> $GITHUB_OUTPUT
          echo "$DIGEST" > .cache/debian-base.digest.new

      - name: Compare with stored digest
        id: compare_digest
        run: |
          CURRENT_DIGEST="${{ steps.get_digest.outputs.digest }}"
          LAST_DIGEST=""

          if [ -f "${{ env.DIGEST_FILE }}" ]; then
            LAST_DIGEST=$(cat "${{ env.DIGEST_FILE }}")
          fi

          echo "Current digest: $CURRENT_DIGEST"
          echo "Last digest: $LAST_DIGEST"

          if [ "$CURRENT_DIGEST" = "$LAST_DIGEST" ]; then
            echo "Digest unchanged. Skipping build."
            echo "changed=false" >> $GITHUB_OUTPUT
          else
            echo "Digest changed or first run."
            echo "$CURRENT_DIGEST" > "${{ env.DIGEST_FILE }}"
            git config user.name "${{ secrets.GIT_USERNAME }}"
            git config user.email "${{ secrets.GIT_EMAIL }}"
            git add "${{ env.DIGEST_FILE }}"
            git commit -m "Update debian-base image digest to $CURRENT_DIGEST" || echo "No changes to commit"
            git push
            echo "changed=true" >> $GITHUB_OUTPUT
          fi

      - name: Build and Push Minecraft Docker Images
        if: steps.compare_digest.outputs.changed == 'true'
        env:
          IMAGE_TAG_VANILLA: vanilla
          IMAGE_TAG_TESTING: testing
          IMAGE_TAG_FABRIC: fabric
          DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
          DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
        run: |
          echo "${DOCKER_PASSWORD}" | docker login $IMAGE_REGISTRY -u "${DOCKER_USERNAME}" --password-stdin

          for TAG in $IMAGE_TAG_VANILLA $IMAGE_TAG_TESTING $IMAGE_TAG_FABRIC; do
            IMAGE="$IMAGE_REGISTRY/$IMAGE_ORG/$IMAGE_REPO_MINECRAFT:$TAG"
            echo "[INFO] Building and pushing $IMAGE"
            docker buildx build --platform linux/amd64 --push -t "$IMAGE" "./$TAG"
          done

  generate-changelogs:
    needs: build-minecraft-images
    runs-on: docker-build

    steps:
      - name: Checkout source
        uses: actions/checkout@v3

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

      - name: Generate per-version changelogs
        run: |
          cd upload-repo
          for version in vanilla testing fabric; 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 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 */CHANGES.md
            git commit -m "Update changelogs on $(date -u +'%Y-%m-%dT%H:%M:%SZ') [skip ci]" --no-verify
            git push
          else
            echo "[INFO] No changelog changes to commit."
          fi

  generate-build-info:
    needs: generate-changelogs
    runs-on: docker-build

    steps:
      - name: Checkout source
        uses: actions/checkout@v3

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

      - name: Generate build-info.json per version
        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
          for version in vanilla testing fabric; do
            echo "[INFO] Generating build-info.json for $version"
            mkdir -p "$version"
            infofile="$version/build-info.json"
            image="${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_ORG }}/${{ env.IMAGE_REPO_MINECRAFT }}:$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=${size_bytes//[^0-9]/}
            if [[ -z "$size_bytes" ]]; then size_bytes=0; fi

            size_human=$(human_size "$size_bytes")

            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" \
              '{
                version: $version,
                commit: $commit,
                build_time: $build_time,
                image_tag: $image_tag,
                digest: $digest,
                image_size: $image_size,
                image_size_bytes: $image_size_bytes
              }' > "$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') [skip ci]"
            git push

            for version in vanilla testing fabric; 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