name: Preview Docs Image — Build

on:
  pull_request:
    paths:
      - 'document/**'
    types: [opened, synchronize, reopened]

# Only one build per PR branch at a time
concurrency:
  group: 'preview-docs-build-${{ github.head_ref }}'
  cancel-in-progress: true

permissions:
  contents: read

jobs:
  build:
    runs-on: ubuntu-24.04

    steps:
      - name: Checkout PR code
        uses: actions/checkout@v4
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          repository: ${{ github.event.pull_request.head.repo.full_name }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Build Docker image (no push)
        uses: docker/build-push-action@v6
        with:
          context: ./document
          file: ./document/Dockerfile
          platforms: linux/amd64
          push: false
          tags: fastgpt-docs-pr:${{ github.event.pull_request.head.sha }}
          labels: |
            org.opencontainers.image.source=https://github.com/${{ github.repository_owner }}/FastGPT
            org.opencontainers.image.description=FastGPT Docs Preview
          build-args: |
            FASTGPT_HOME_DOMAIN=https://fastgpt.io
          outputs: type=docker,dest=/tmp/docs-image.tar
          cache-from: type=gha,scope=docs
          cache-to: type=gha,mode=max,scope=docs

      - name: Save PR metadata
        run: |
          echo "${{ github.event.pull_request.number }}" > /tmp/pr-number.txt
          echo "${{ github.event.pull_request.head.sha }}" > /tmp/pr-sha.txt

      - name: Upload Docker image artifact
        uses: actions/upload-artifact@v4
        with:
          name: preview-docs-image
          path: |
            /tmp/docs-image.tar
            /tmp/pr-number.txt
            /tmp/pr-sha.txt
          retention-days: 1