name: Build & Push Docker Image

on:
  push:
    branches: [main]
    paths-ignore:
      - 'docs/**'
      - '**/*.md'
  workflow_dispatch:
    inputs:
      bump:
        description: 'Force bump line (auto = patch/finalize as today)'
        type: choice
        options: [auto, patch, minor, major]
        default: auto
      confirm_major:
        description: "Type MAJOR (all caps) to confirm a major release"
        type: string
        default: ''

permissions:
  contents: write

concurrency:
  group: stable-build
  cancel-in-progress: false

jobs:
  version-bump:
    runs-on: ubuntu-latest
    outputs:
      version: ${{ steps.bump.outputs.VERSION }}
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
          fetch-tags: true
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Determine bump type and update version
        id: bump
        run: |
          git fetch --tags

          # Derive version from git tags — no package.json dependency
          STABLE_TAG=$(git tag -l 'v[0-9]*.[0-9]*.[0-9]*' | grep -v '\-pre\.' | sort -V | tail -1)
          STABLE="${STABLE_TAG#v}"
          STABLE="${STABLE:-0.0.0}"

          PRE_TAG=$(git tag -l 'v*-pre.*' | sort -V | tail -1)

          BUMP_INPUT="${{ github.event.inputs.bump || 'auto' }}"
          IFS='.' read -r MAJOR MINOR PATCH <<< "$STABLE"

          if [ "$BUMP_INPUT" = "major" ]; then
            if [ "${{ github.event.inputs.confirm_major }}" != "MAJOR" ]; then
              echo "::error::confirm_major must equal 'MAJOR' to cut a major release"
              exit 1
            fi
            NEW_VERSION="$((MAJOR + 1)).0.0"
            BUMP="major"
          elif [ "$BUMP_INPUT" = "minor" ]; then
            NEW_VERSION="${MAJOR}.$((MINOR + 1)).0"
            BUMP="minor"
          elif [ "$BUMP_INPUT" = "patch" ]; then
            NEW_VERSION="${MAJOR}.${MINOR}.$((PATCH + 1))"
            BUMP="patch"
          else
            # auto: finalize in-flight prerelease if one exists, else patch
            if [ -n "$PRE_TAG" ]; then
              PRE_BASE="${PRE_TAG#v}"
              PRE_BASE="${PRE_BASE%-pre.*}"
              PRE_MAJOR="$(echo "$PRE_BASE" | cut -d. -f1)"
              # Refuse to auto-finalize a major bump — it bypasses confirm_major
              if [ "$PRE_MAJOR" -gt "$MAJOR" ]; then
                echo "::error::In-flight prerelease $PRE_TAG is a major bump ($STABLE → $PRE_BASE). Use bump=major with confirm_major=MAJOR to finalize."
                exit 1
              fi
              # If prerelease base is strictly greater than stable, finalize it
              HIGHEST=$(printf '%s\n' "$PRE_BASE" "$STABLE" | sort -V | tail -1)
              if [ "$HIGHEST" = "$PRE_BASE" ] && [ "$PRE_BASE" != "$STABLE" ]; then
                NEW_VERSION="$PRE_BASE"
                BUMP="finalize"
              else
                PATCH=$((PATCH + 1))
                NEW_VERSION="${MAJOR}.${MINOR}.${PATCH}"
                BUMP="patch"
              fi
            else
              PATCH=$((PATCH + 1))
              NEW_VERSION="${MAJOR}.${MINOR}.${PATCH}"
              BUMP="patch"
            fi
          fi

          echo "Bump type: $BUMP"
          echo "VERSION=$NEW_VERSION" >> $GITHUB_OUTPUT
          echo "$STABLE → $NEW_VERSION ($BUMP)"

          # Update package.json files and Helm chart
          cd server && npm version "$NEW_VERSION" --no-git-tag-version && cd ..
          cd client && npm version "$NEW_VERSION" --no-git-tag-version && cd ..
          sed -i "s/^version: .*/version: $NEW_VERSION/" charts/trek/Chart.yaml
          sed -i "s/^appVersion: .*/appVersion: \"$NEW_VERSION\"/" charts/trek/Chart.yaml

          # Commit and tag
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git add server/package.json server/package-lock.json client/package.json client/package-lock.json charts/trek/Chart.yaml
          git commit -m "chore: bump version to $NEW_VERSION [skip ci]"
          git tag "v$NEW_VERSION"
          git push origin main --follow-tags

  build:
    runs-on: ${{ matrix.runner }}
    needs: version-bump
    strategy:
      fail-fast: false
      matrix:
        include:
          - platform: linux/amd64
            runner: ubuntu-latest
          - platform: linux/arm64
            runner: ubuntu-24.04-arm
    steps:
      - name: Prepare platform tag-safe name
        run: echo "PLATFORM_PAIR=$(echo ${{ matrix.platform }} | sed 's|/|-|g')" >> $GITHUB_ENV

      - uses: actions/checkout@v4
        with:
          ref: main

      - uses: docker/setup-buildx-action@v3

      - uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Build and push by digest
        id: build
        uses: docker/build-push-action@v6
        with:
          context: .
          platforms: ${{ matrix.platform }}
          outputs: type=image,name=mauriceboe/trek,push-by-digest=true,name-canonical=true,push=true
          no-cache: true
          build-args: |
            APP_VERSION=${{ needs.version-bump.outputs.version }}

      - name: Export digest
        run: |
          mkdir -p /tmp/digests
          digest="${{ steps.build.outputs.digest }}"
          touch "/tmp/digests/${digest#sha256:}"

      - name: Upload digest artifact
        uses: actions/upload-artifact@v4
        with:
          name: digests-${{ env.PLATFORM_PAIR }}
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1

  merge:
    runs-on: ubuntu-latest
    needs: [version-bump, build]
    steps:
      - uses: actions/checkout@v4
        with:
          ref: main

      - name: Download build digests
        uses: actions/download-artifact@v4
        with:
          path: /tmp/digests
          pattern: digests-*
          merge-multiple: true

      - uses: docker/setup-buildx-action@v3

      - uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Create and push multi-arch manifest
        working-directory: /tmp/digests
        run: |
          VERSION="${{ needs.version-bump.outputs.version }}"
          mapfile -t digests < <(printf 'mauriceboe/trek@sha256:%s\n' *)
          MAJOR_TAG="$(echo "$VERSION" | cut -d. -f1)"
          docker buildx imagetools create \
            -t "mauriceboe/trek:latest" \
            -t "mauriceboe/trek:$MAJOR_TAG" \
            -t "mauriceboe/trek:$VERSION" \
            "${digests[@]}"

      - name: Inspect manifest
        run: docker buildx imagetools inspect mauriceboe/trek:latest

  release-helm:
    runs-on: ubuntu-latest
    needs: version-bump
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          ref: main

      - name: Publish Helm chart
        uses: stefanprodan/helm-gh-pages@v1.7.0
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          charts_dir: charts
