package helpers

import (
	"fmt"
	"math"
)

// EngagementHelpers provides utility functions for engagement system

// ComputeLevelProgress returns the progress percentage within current level
func ComputeLevelProgress(xp int64, level int) (int, int64, int64) {
	if level < 1 {
		level = 1
	}
	// Total XP needed to reach level L: 50 * (L-1) * L
	totalToLevel := int64(50 * (level - 1) * level)
	nextIncrement := int64(100 * level)
	
	inLevel := xp - totalToLevel
	if inLevel < 0 {
		inLevel = 0
	}
	
	percentage := 0
	if nextIncrement > 0 {
		percentage = int(math.Floor(float64(inLevel) / float64(nextIncrement) * 100))
		if percentage > 100 {
			percentage = 100
		}
		if percentage < 0 {
			percentage = 0
		}
	}
	
	return percentage, inLevel, nextIncrement
}

// GetLevelTitle returns a descriptive title for a level
func GetLevelTitle(level int) string {
	switch {
	case level >= 100:
		return "Legenda"
	case level >= 80:
		return "Mistr"
	case level >= 60:
		return "Expert"
	case level >= 40:
		return "Veterán"
	case level >= 25:
		return "Zkušený fanoušek"
	case level >= 15:
		return "Oddaný příznivec"
	case level >= 10:
		return "Aktivní člen"
	case level >= 5:
		return "Nováček"
	default:
		return "Začátečník"
	}
}

// GetLevelColor returns a color scheme for level badge
func GetLevelColor(level int) string {
	switch {
	case level >= 80:
		return "gold"
	case level >= 60:
		return "purple"
	case level >= 40:
		return "blue"
	case level >= 20:
		return "cyan"
	case level >= 10:
		return "green"
	default:
		return "gray"
	}
}

// FormatPoints formats points with thousands separator
func FormatPoints(points int64) string {
	if points < 1000 {
		return fmt.Sprintf("%d", points)
	}
	if points < 1000000 {
		return fmt.Sprintf("%.1fk", float64(points)/1000)
	}
	return fmt.Sprintf("%.1fM", float64(points)/1000000)
}

// GetNextLevelXP returns XP needed for next level
func GetNextLevelXP(currentXP int64, currentLevel int) int64 {
	totalToLevel := int64(50 * (currentLevel - 1) * currentLevel)
	nextIncrement := int64(100 * currentLevel)
	return (totalToLevel + nextIncrement) - currentXP
}

// GetRewardTypeDisplayName returns localized display name for reward type
func GetRewardTypeDisplayName(rewardType string) string {
	names := map[string]string{
		"avatar_static":        "Avatar (statický)",
		"avatar_animated":      "Avatar (animovaný)",
		"avatar_upload_unlock": "Odemknutí vlastního avataru",
		"merch_coupon":         "Slevový kupon",
		"merch_physical":       "Fyzické zboží",
		"merch_digital":        "Digitální odměna",
		"custom":               "Vlastní",
	}
	if name, ok := names[rewardType]; ok {
		return name
	}
	return rewardType
}

// GetPointsReasonDisplayName returns localized display name for transaction reason
func GetPointsReasonDisplayName(reason string) string {
	names := map[string]string{
		"comment_create":       "Nový komentář",
		"comment_reacted":      "Reakce na komentář",
		"poll_vote":            "Hlasování v anketě",
		"newsletter_subscribe": "Odběr newsletteru",
		"redeem":               "Uplatnění odměny",
		"redeem_refund":        "Vrácení bodů",
		"admin_adjust":         "Manuální úprava",
	}
	if name, ok := names[reason]; ok {
		return name
	}
	// Achievement reasons start with "achievement:"
	if len(reason) > 12 && reason[:12] == "achievement:" {
		return "Úspěch odemknut"
	}
	return reason
}

// GetRedemptionStatusDisplayName returns localized display name for redemption status
func GetRedemptionStatusDisplayName(status string) string {
	names := map[string]string{
		"pending":   "Čeká na vyřízení",
		"approved":  "Schváleno",
		"rejected":  "Zamítnuto",
		"fulfilled": "Vydáno",
	}
	if name, ok := names[status]; ok {
		return name
	}
	return status
}

// GetRedemptionStatusColor returns color scheme for redemption status
func GetRedemptionStatusColor(status string) string {
	colors := map[string]string{
		"pending":   "yellow",
		"approved":  "blue",
		"rejected":  "red",
		"fulfilled": "green",
	}
	if color, ok := colors[status]; ok {
		return color
	}
	return "gray"
}

// CalculateBadgeLevel returns badge tier based on points/level
func CalculateBadgeLevel(level int) string {
	switch {
	case level >= 80:
		return "diamond"
	case level >= 60:
		return "platinum"
	case level >= 40:
		return "gold"
	case level >= 20:
		return "silver"
	case level >= 10:
		return "bronze"
	default:
		return "none"
	}
}