package diarization

import (
	"transcribe/internal/whisper"
)

// AlignSpeakers maps speaker segments to transcription segments by timestamp overlap
func AlignSpeakers(transcription *whisper.TranscriptionResult, diarization *DiarizationResult) {
	if diarization == nil || len(diarization.Speakers) == 0 {
		return
	}

	for i := range transcription.Segments {
		seg := &transcription.Segments[i]
		speaker := findSpeakerForSegment(seg.Start, seg.End, diarization.Speakers)
		seg.Speaker = speaker
	}
}

// findSpeakerForSegment finds the speaker with the most overlap with the given time range
func findSpeakerForSegment(start, end float64, speakers []SpeakerSegment) string {
	var bestSpeaker string
	var maxOverlap float64

	for _, spk := range speakers {
		overlap := calculateOverlap(start, end, spk.Start, spk.End)
		if overlap > maxOverlap {
			maxOverlap = overlap
			bestSpeaker = spk.Speaker
		}
	}

	return bestSpeaker
}

// calculateOverlap returns the duration of overlap between two time ranges
func calculateOverlap(start1, end1, start2, end2 float64) float64 {
	overlapStart := max(start1, start2)
	overlapEnd := min(end1, end2)

	if overlapEnd > overlapStart {
		return overlapEnd - overlapStart
	}
	return 0
}

func max(a, b float64) float64 {
	if a > b {
		return a
	}
	return b
}

func min(a, b float64) float64 {
	if a < b {
		return a
	}
	return b
}