package quality

import (
	"fmt"
	"time"
)

// Scorer calculates quality scores and generates scorecards
type Scorer struct {
	targetScore int
}

// NewScorer creates a new scorer with the given target score
func NewScorer(targetScore int) *Scorer {
	if targetScore <= 0 {
		targetScore = 95 // Default target
	}
	return &Scorer{
		targetScore: targetScore,
	}
}

// CalculateScore calculates the quality score from findings
func (s *Scorer) CalculateScore(findings []Finding) (int, int) {
	totalScore := 0
	strictScore := 0

	for _, finding := range findings {
		weight := int(finding.Severity)
		score := finding.Score * weight
		totalScore += score

		// Strict score includes open and wontfix findings
		if finding.Status == StatusOpen || finding.Status == StatusWontfix {
			strictScore += score
		}
	}

	return totalScore, strictScore
}

// GenerateScorecard creates a scorecard from scan results
func (s *Scorer) GenerateScorecard(findings []Finding, lastScan time.Time) *Scorecard {
	totalScore, strictScore := s.CalculateScore(findings)

	// Group findings by type and tier
	findingsByType := make(map[string]int)
	findingsByTier := make(map[Severity]int)
	statusByType := make(map[string]int)

	for _, finding := range findings {
		findingsByType[finding.Type]++
		findingsByTier[finding.Severity]++
		statusByType[string(finding.Status)]++
	}

	return &Scorecard{
		TotalScore:     totalScore,
		StrictScore:    strictScore,
		TargetScore:    s.targetScore,
		FindingsByType: findingsByType,
		FindingsByTier: findingsByTier,
		StatusByType:   statusByType,
		LastScan:       lastScan,
	}
}

// GetHealthGrade returns a health grade based on score
func (s *Scorer) GetHealthGrade(score int) string {
	percentage := s.getScorePercentage(score)

	switch {
	case percentage >= 90:
		return "A"
	case percentage >= 80:
		return "B"
	case percentage >= 70:
		return "C"
	case percentage >= 60:
		return "D"
	default:
		return "F"
	}
}

// getScorePercentage converts score to percentage (inverted - lower is better)
func (s *Scorer) getScorePercentage(score int) int {
	// Invert score so lower debt = higher percentage
	maxPossibleScore := 1000 // Arbitrary high value for normalization
	percentage := 100 - (score * 100 / maxPossibleScore)
	if percentage < 0 {
		percentage = 0
	}
	return percentage
}

// FormatScorecard formats the scorecard for display
func (s *Scorer) FormatScorecard(card *Scorecard) string {
	grade := s.GetHealthGrade(card.StrictScore)
	percentage := s.getScorePercentage(card.StrictScore)

	output := fmt.Sprintf(`
Code Quality Scorecard
=======================================

Overall Health: %s (%d%%)
Target Score: %d
Current Score: %d (strict: %d)

Findings by Type:
`, grade, percentage, card.TargetScore, card.TotalScore, card.StrictScore)

	for ftype, count := range card.FindingsByType {
		output += fmt.Sprintf("  - %s: %d\n", ftype, count)
	}

	output += "\nFindings by Severity:\n"
	tierNames := map[Severity]string{
		SeverityT1: "T1 (Auto-fixable)",
		SeverityT2: "T2 (Quick manual)",
		SeverityT3: "T3 (Needs judgment)",
		SeverityT4: "T4 (Major refactor)",
	}

	for severity, count := range card.FindingsByTier {
		if name, ok := tierNames[severity]; ok {
			output += fmt.Sprintf("  - %s: %d\n", name, count)
		}
	}

	output += "\nStatus Breakdown:\n"
	for status, count := range card.StatusByType {
		output += fmt.Sprintf("  - %s: %d\n", status, count)
	}

	output += fmt.Sprintf("\nLast Scan: %s\n", card.LastScan.Format("2006-01-02 15:04:05"))

	return output
}

// GetNextPriority returns the next highest priority finding to fix
func (s *Scorer) GetNextPriority(findings []Finding) *Finding {
	if len(findings) == 0 {
		return nil
	}

	var highest *Finding
	highestWeight := 0

	for _, finding := range findings {
		if finding.Status != StatusOpen {
			continue
		}

		weight := int(finding.Severity) * finding.Score
		if weight > highestWeight {
			highestWeight = weight
			highest = &finding
		}
	}

	return highest
}

// GetFindingsByTier returns findings grouped by severity tier
func (s *Scorer) GetFindingsByTier(findings []Finding) map[Severity][]Finding {
	result := make(map[Severity][]Finding)

	for _, finding := range findings {
		if finding.Status == StatusOpen {
			result[finding.Severity] = append(result[finding.Severity], finding)
		}
	}

	return result
}

// GetProgressMetrics returns progress metrics for the scan
func (s *Scorer) GetProgressMetrics(findings []Finding) map[string]interface{} {
	total := len(findings)
	open := 0
	fixed := 0
	wontfix := 0

	for _, finding := range findings {
		switch finding.Status {
		case StatusOpen:
			open++
		case StatusFixed:
			fixed++
		case StatusWontfix:
			wontfix++
		}
	}

	return map[string]interface{}{
		"total":    total,
		"open":     open,
		"fixed":    fixed,
		"wontfix":  wontfix,
		"progress": float64(fixed) / float64(total) * 100,
	}
}