name: Validate Collection URLs

on:
  push:
    paths:
      - 'collections/**.json'
  pull_request:
    paths:
      - 'collections/**.json'

jobs:
  validate-urls:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6

      - name: Extract and validate URLs
        run: |
          FAILED=0
          CHECKED=0
          FAILED_URLS=""

          # Recursively extract all non-null string URLs from every JSON file in collections/
          URLS=$(jq -r '.. | .url? | select(type == "string")' collections/*.json | sort -u)

          while IFS= read -r url; do
            [ -z "$url" ] && continue
            CHECKED=$((CHECKED + 1))
            printf "Checking: %s ... " "$url"

            # HEAD transfers no body at all, so nothing is downloaded even when a
            # server ignores Range headers. curl can still exit non-zero (DNS,
            # TLS, timeout), so capture the status without letting `set -e`
            # (bash -e) kill the whole step mid-loop.
            METHOD="HEAD"
            CURL_EXIT=0
            HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" \
              --head \
              --max-time 30 \
              --retry 2 \
              --retry-delay 2 \
              --location \
              "$url") || CURL_EXIT=$?

            # Some servers refuse HEAD outright. Fall back to a single-byte
            # ranged GET for those. --max-filesize caps the damage if the server
            # ignores the Range header, but has to stay comfortably above a
            # redirect body: --location applies the limit to the 3xx body too,
            # and a cap below that aborts on the redirect itself.
            case "$HTTP_CODE" in
              403|405|501)
                METHOD="GET"
                CURL_EXIT=0
                HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" \
                  --range 0-0 \
                  --max-filesize 8192 \
                  --max-time 30 \
                  --retry 2 \
                  --retry-delay 2 \
                  --location \
                  "$url") || CURL_EXIT=$?
                ;;
            esac

            if [ "$HTTP_CODE" = "200" ] || [ "$HTTP_CODE" = "206" ]; then
              echo "OK ($HTTP_CODE via $METHOD)"
            else
              echo "FAILED (HTTP $HTTP_CODE via $METHOD, curl exit $CURL_EXIT)"
              FAILED=$((FAILED + 1))
              FAILED_URLS="$FAILED_URLS\n  - $url (HTTP $HTTP_CODE via $METHOD, curl exit $CURL_EXIT)"
            fi
          done <<< "$URLS"

          echo ""
          echo "Checked $CHECKED URLs, $FAILED failed."

          if [ "$FAILED" -gt 0 ]; then
            echo ""
            echo "Broken URLs:"
            printf "%b\n" "$FAILED_URLS"
            exit 1
          fi