package memory

// Confidence gate for a recall. Two checks, both must pass before Maven says a
// note back:
//
//   - minScore — an absolute cosine floor.
//   - minMargin — the top hit must beat the runner-up by more than this.
//
// The margin is the one that carries the weight. The e5 embedder packs every
// score into a narrow high band (0.79-0.89 on the recall fixture), so an
// absolute floor cannot tell a real hit from a confident-looking miss: every
// value under the band admits everything, every value above it answers nothing.
// A margin asks a different question — "is this note clearly the best one, or
// is the whole shelf equally close?" — and a made-up question has no clear best.
//
// With one hit and no runner-up there is nothing to compare, so only the floor
// applies.

// ConfidentScores reports whether the top score clears both gates. scores must
// be sorted highest first. minMargin <= 0 turns the margin check off.
func ConfidentScores(scores []float64, minScore, minMargin float64) bool {
	if len(scores) == 0 || scores[0] < minScore {
		return false
	}
	if minMargin > 0 && len(scores) > 1 && scores[0]-scores[1] <= minMargin {
		return false
	}
	return true
}

// Confident is ConfidentScores for search results.
func Confident(results []Result, minScore, minMargin float64) bool {
	scores := make([]float64, len(results))
	for i, r := range results {
		scores[i] = r.Score
	}
	return ConfidentScores(scores, minScore, minMargin)
}