package chunking

// Summary provides a concise overview of chunking results for reports
type Summary struct {
	ChunkCount           int  `json:"chunk_count"`
	MinEstimatedTokens   int  `json:"min_estimated_chunk_tokens"`
	MaxEstimatedTokens   int  `json:"max_estimated_chunk_tokens"`
	TotalEstimatedTokens int  `json:"total_estimated_transcript_tokens"`
	TargetSections       *int `json:"target_sections,omitempty"`
	MaxSectionTokens     int  `json:"max_section_tokens"`
	MinSectionTokens     int  `json:"min_section_tokens"`
}

// ChunkSummary represents a single chunk's metadata for diagnostics
type ChunkSummary struct {
	Index           int `json:"index"`
	StartSegmentID  int `json:"start_segment_id"`
	EndSegmentID    int `json:"end_segment_id"`
	EstimatedTokens int `json:"estimated_tokens"`
	SegmentCount    int `json:"segment_count"`
}

// DetailedSummary provides per-chunk details for diagnostics
type DetailedSummary struct {
	Summary `json:",inline"`
	Chunks  []ChunkSummary `json:"chunks"`
}

// ComputeSummary creates a Summary from sections and config
func ComputeSummary(sections []Section, config ChunkingConfig) Summary {
	if len(sections) == 0 {
		return Summary{
			ChunkCount:       0,
			MaxSectionTokens: config.MaxSectionTokens,
			MinSectionTokens: config.MinSectionTokens,
			TargetSections:   config.TargetSections,
		}
	}

	minTokens := sections[0].EstimatedTokens
	maxTokens := sections[0].EstimatedTokens
	totalTokens := 0

	for _, sec := range sections {
		if sec.EstimatedTokens < minTokens {
			minTokens = sec.EstimatedTokens
		}
		if sec.EstimatedTokens > maxTokens {
			maxTokens = sec.EstimatedTokens
		}
		totalTokens += sec.EstimatedTokens
	}

	return Summary{
		ChunkCount:           len(sections),
		MinEstimatedTokens:   minTokens,
		MaxEstimatedTokens:   maxTokens,
		TotalEstimatedTokens: totalTokens,
		TargetSections:       config.TargetSections,
		MaxSectionTokens:     config.MaxSectionTokens,
		MinSectionTokens:     config.MinSectionTokens,
	}
}

// ComputeDetailedSummary creates a DetailedSummary from sections and config
func ComputeDetailedSummary(sections []Section, config ChunkingConfig) DetailedSummary {
	summary := ComputeSummary(sections, config)

	chunks := make([]ChunkSummary, len(sections))
	for i, sec := range sections {
		chunks[i] = ChunkSummary{
			Index:           sec.Index,
			StartSegmentID:  sec.StartSegmentID,
			EndSegmentID:    sec.EndSegmentID,
			EstimatedTokens: sec.EstimatedTokens,
			SegmentCount:    len(sec.Segments),
		}
	}

	return DetailedSummary{
		Summary: summary,
		Chunks:  chunks,
	}
}