name: Validate font processing

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  validate:
    runs-on: ubuntu-latest
    container:
      image: ghcr.io/nicoverbruggen/fntbld-oci:latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Download latest Readerly font
        run: |
          apt-get update && apt-get install -y curl jq
          LATEST_TAG=$(curl -s https://api.github.com/repos/nicoverbruggen/readerly/releases/latest | jq -r '.tag_name')
          curl -L -o Readerly.zip "https://github.com/nicoverbruggen/readerly/releases/download/${LATEST_TAG}/Readerly.zip"
          unzip Readerly.zip -d fonts

      - name: Dry run NV preset
        run: python3 kobofix.py --preset nv --dry-run fonts/*.ttf

      - name: Run NV preset
        run: python3 kobofix.py --preset nv fonts/*.ttf

      - name: Dry run KF preset on NV output
        run: python3 kobofix.py --preset kf --dry-run fonts/NV_*.ttf

      - name: Run KF preset on NV output
        run: python3 kobofix.py --preset kf fonts/NV_*.ttf

      - name: Validate KF fonts have kern table
        run: |
          python3 -c "
          from fontTools.ttLib import TTFont
          import glob, sys
          errors = 0
          for path in sorted(glob.glob('fonts/KF_*.ttf')):
              font = TTFont(path)
              has_kern = 'kern' in font
              pairs = 0
              if has_kern:
                  for st in font['kern'].kernTables:
                      pairs += len(st.kernTable)
              if not has_kern or pairs == 0:
                  print(f'FAIL: {path} — missing or empty kern table')
                  errors += 1
              else:
                  print(f'OK:   {path} — {pairs} kern pairs')
          sys.exit(1 if errors else 0)
          "