package webapp

import (
	"net/http"
	"strconv"
)

// handleLogs tails the in-memory worker log buffer. The handler
// reads ?tail=200|500|1000|5000 (default 200) per section 6.6.
func (s *Server) handleLogs(w http.ResponseWriter, r *http.Request) {
	writeNoStore(w)
	sess, _ := sessionFromContext(r.Context())
	tail := parseTail(r.URL.Query().Get("tail"))
	lines := s.logBuffer.Tail(tail)
	data := logsPageData{
		basePageData: s.newBasePage(r, "Worker logs", sess),
		Tail:         tail,
		Lines:        lines,
		BufferSize:   s.logBuffer.Size(),
		BufferCap:    s.logBuffer.Cap(),
	}
	if err := s.templates.Execute(w, "logs.html", data); err != nil {
		s.deps.Logger.Printf("render logs: %v", err)
		http.Error(w, "template error", http.StatusInternalServerError)
	}
}

// parseTail clamps the requested tail count to one of the
// doc-prescribed buckets (200/500/1000/5000) and falls back to 200.
func parseTail(raw string) int {
	n, err := strconv.Atoi(raw)
	if err != nil {
		return 200
	}
	for _, allowed := range []int{200, 500, 1000, 5000} {
		if n == allowed {
			return allowed
		}
	}
	return 200
}

type logsPageData struct {
	basePageData
	Tail       int
	Lines      []string
	BufferSize int
	BufferCap  int
}