name: Links

on:
  workflow_dispatch:
  schedule:
    - cron: '0 0 * * *'

concurrency:
  group: links
  cancel-in-progress: false

jobs:
  links:
    name: Links
    runs-on: ubuntu-latest
    permissions:
      actions: read
      packages: read
      contents: read
    steps:
      -
        name: Checkout
        uses: actions/checkout@v7
        with:
          fetch-depth: 0
      -
        name: Install aria2
        run: |
          if ! command -v aria2c > /dev/null; then
            sudo apt-get update -qq
            sudo apt-get install -qq --no-install-recommends -y aria2
          fi
      -
        name: Validate all download mirrors
        id: validate
        run: |
          errors=0
          tested=0
          host=""
          failed_links=""
          failed_links_html=""
          declare -A seen

          ignored_domains=(
            files.dog
          )

          check() {
            local url="$1"
            local agent="Mozilla/5.0 (X11; Linux x86_64; rv:154.0) Gecko/20100101 Firefox/154.0"
            local tmp output pid blocks bytes rc
            local start=$SECONDS

            tmp=$(mktemp -d)
            output="$tmp/aria2.log"

            aria2c \
              --no-conf=true \
              --connect-timeout=30 \
              --timeout=30 \
              --max-tries=2 \
              --retry-wait=2 \
              --async-dns=false \
              --follow-metalink=false \
              --follow-torrent=false \
              --user-agent="$agent" \
              --split=4 \
              --max-connection-per-server=4 \
              --file-allocation=none \
              --allow-overwrite=true \
              --auto-file-renaming=false \
              --continue=false \
              --dir="$tmp" \
              --out=probe \
              --console-log-level=error \
              --summary-interval=0 \
              --download-result=hide \
              --show-console-readout=false \
              --enable-color=false \
              -- "$url" > "$output" 2>&1 &
            pid=$!

            while kill -0 "$pid" 2>/dev/null; do
              if [[ -f "$tmp/probe" ]]; then
                blocks=$(stat -c '%b' "$tmp/probe" 2>/dev/null || echo 0)
                bytes=$((blocks * 512))

                if (( bytes >= 1048576 )); then
                  kill "$pid" 2>/dev/null || true
                  wait "$pid" 2>/dev/null || true
                  rm -rf -- "$tmp"
                  return 0
                fi
              fi

              if (( SECONDS - start >= 60 )); then
                kill "$pid" 2>/dev/null || true
                break
              fi

              sleep 0.2
            done

            if wait "$pid"; then
              rc=0
            else
              rc=$?
            fi

            blocks=0

            if [[ -f "$tmp/probe" ]]; then
              blocks=$(stat -c '%b' "$tmp/probe" 2>/dev/null || echo 0)
            fi

            bytes=$((blocks * 512))

            if (( bytes >= 1048576 || (rc == 0 && bytes > 0) )); then
              rm -rf -- "$tmp"
              return 0
            fi

            sed 's/^/      /' "$output" >&2
            echo "      Downloaded bytes: $bytes" >&2
            echo "      aria2c exit status: $rc" >&2
            rm -rf -- "$tmp"
            return 1
          }

          isIgnoredDomain() {
            local url="$1"
            local domain ignored

            domain="${url#*://}"
            domain="${domain%%/*}"
            domain="${domain%%:*}"
            domain="${domain,,}"

            for ignored in "${ignored_domains[@]}"; do
              if [[ "$domain" == "$ignored" || "$domain" == *."$ignored" ]]; then
                return 0
              fi
            done

            return 1
          }

          while IFS= read -r line; do
            if [[ "$line" =~ ^[[:space:]]*local[[:space:]]+host=\"(https://[^\"]+)\" ]]; then
              host="${BASH_REMATCH[1]%/}"
              continue
            fi

            [[ "$line" =~ ^[[:space:]]*url=\"(.+)\" ]] || continue
            val="${BASH_REMATCH[1]#/}"

            if [[ "$val" == https://* ]]; then
              url="$val"
            elif [[ -n "$host" ]]; then
              url="$host/$val"
            else
              continue
            fi

            [[ -v seen[$url] ]] && continue
            seen[$url]=1

            if isIgnoredDomain "$url"; then
              echo "SKIP: $url"
              continue
            fi

            tested=$((tested + 1))

            if check "$url"; then
              echo "  OK: $url"
            else
              echo "FAIL: $url"
              errors=$((errors + 1))
              failed_links+="$url"$'\n'
              failed_links_html+="<li><a href=\"$url\">$url</a></li>"$'\n'
            fi
          done < "src/define.sh"

          echo ""
          printf '%d/%d tested links valid\n' "$((tested - errors))" "$tested"

          if (( errors > 0 )); then
            printf '%d blocking failure(s)\n' "$errors"

            {
              echo "failed=true"
              echo "links<<EOF"
              printf '%s' "$failed_links"
              echo "EOF"
              echo "html_links<<EOF"
              printf '%s' "$failed_links_html"
              echo "EOF"
            } >> "$GITHUB_OUTPUT"
          else
            echo "failed=false" >> "$GITHUB_OUTPUT"
          fi
      -
        name: Send mail
        if: steps.validate.outputs.failed == 'true'
        uses: action-pack/send-mail@v1
        with:
          to: ${{secrets.MAILTO}}
          from: Github Actions <${{secrets.MAILTO}}>
          connection_url: ${{secrets.MAIL_CONNECTION}}
          subject: Mirror verification failed!
          body: |
            Mirror verification failed!

            The following links failed:

            ${{ steps.validate.outputs.links }}

            See https://github.com/${{ github.repository }}/actions for more information.
          html_body: |
            <p>Mirror verification failed!</p>

            <p>The following links failed:</p>

            <ul>
            ${{ steps.validate.outputs.html_links }}
            </ul>

            <p>
              See
              <a href="https://github.com/${{ github.repository }}/actions">GitHub Actions</a>
              for more information.
            </p>
      -
        name: Fail workflow
        if: always() && steps.validate.outputs.failed == 'true'
        run: exit 1