package birdfmt

import (
	"strings"
)

// ProtocolsSummary is a lightweight parse of `birdc show protocols all` (BIRD 2).
type ProtocolsSummary struct {
	BGPSessionsTotal int
	BGPEstablished   int
	RawLineCount     int
}

// isBGPProtocolSummaryRow is true for BIRD "show protocols" summary rows where the
// second column (Proto) is BGP. Substring checks are unsafe: names like evobgp_* contain "bgp".
func isBGPProtocolSummaryRow(line string) bool {
	line = strings.TrimSpace(line)
	if line == "" {
		return false
	}
	low := strings.ToLower(line)
	if strings.HasPrefix(low, "name") || strings.HasPrefix(low, "table") {
		return false
	}
	fields := strings.Fields(line)
	if len(fields) < 2 {
		return false
	}
	return strings.EqualFold(fields[1], "BGP")
}

// SummarizeProtocolsOutput extracts BGP session heuristics from birdc output.
func SummarizeProtocolsOutput(output string) ProtocolsSummary {
	var s ProtocolsSummary
	lines := strings.Split(output, "\n")
	s.RawLineCount = len(lines)
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line == "" {
			continue
		}
		low := strings.ToLower(line)
		if !isBGPProtocolSummaryRow(line) {
			continue
		}
		s.BGPSessionsTotal++
		if strings.Contains(low, "established") {
			s.BGPEstablished++
		}
	}
	return s
}