package templates

import (
	"bookhoard/internal/database"
	"fmt"
	"strings"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5/pgtype"
)

func activeClass(current, target string) string {
	base := "block px-4 py-2 rounded-lg "
	if current == target {
		return base + "bg-accent text-bg-primary"
	}
	return base + "hover:opacity-80"
}

func ContainsString(slice []string, item string) bool {
	for _, s := range slice {
		if s == item {
			return true
		}
	}
	return false
}

func uuidToString(id pgtype.UUID) string {
	if !id.Valid {
		return ""
	}
	u, err := uuid.FromBytes(id.Bytes[0:16])
	if err != nil {
		return ""
	}
	return u.String()
}

// renderStars converts rating (1-10 scale) to star display
// Always displays 5 stars total with filled stars in yellow
// and empty stars in grey (using theme variable)
// Rating scale: 1-10 where each 2 points = 1 full star, odd numbers = half stars
func renderStars(rating int32) string {
	const totalStars = 5
	fullStars := rating / 2
	hasHalf := rating%2 != 0

	var stars strings.Builder

	for i := int32(0); i < totalStars; i++ {
		if i < fullStars {
			// Filled star - accent color (theme-aware highlight)
			stars.WriteString(`<span style="color: var(--accent);">★</span>`)
		} else if i == fullStars && hasHalf {
			// Half star - gradient from accent (left) to grey (right)
			stars.WriteString(`<span style="background: linear-gradient(90deg, var(--accent) 50%, var(--text-secondary) 50%); -webkit-background-clip: text; -webkit-text-fill-color: transparent;">★</span>`)
		} else {
			// Empty star - grey using theme variable
			stars.WriteString(`<span style="color: var(--text-secondary);">★</span>`)
		}
	}

	return stars.String()
}

// formatFileSize converts bytes to human-readable format
func formatFileSize(bytes int64) string {
	const (
		KB = 1024
		MB = KB * 1024
		GB = MB * 1024
	)

	switch {
	case bytes >= GB:
		return fmt.Sprintf("%.2f GB", float64(bytes)/float64(GB))
	case bytes >= MB:
		return fmt.Sprintf("%.2f MB", float64(bytes)/float64(MB))
	case bytes >= KB:
		return fmt.Sprintf("%.2f KB", float64(bytes)/float64(KB))
	default:
		return fmt.Sprintf("%d B", bytes)
	}
}

// getExternalURL generates URL for external book services
// Priority: ID > ISBN > Title+Author search
func getExternalURL(service string, id string, isbn pgtype.Text, title string, author pgtype.Text) string {
	baseURL := ""
	searchTerm := ""

	// Determine search term: ID > ISBN > Title+Author
	if id != "" {
		searchTerm = id
	} else if isbn.Valid && isbn.String != "" {
		searchTerm = isbn.String
	} else {
		// Build title+author search query
		if author.Valid && author.String != "" {
			searchTerm = fmt.Sprintf("%s %s", title, author.String)
		} else {
			searchTerm = title
		}
	}

	// Build URL based on service
	switch service {
	case "goodreads":
		if id != "" {
			baseURL = "https://www.goodreads.com/book/show/"
		} else {
			baseURL = "https://www.goodreads.com/search?q="
		}
	case "openlibrary":
		if id != "" {
			baseURL = "https://openlibrary.org/books/"
		} else {
			baseURL = "https://openlibrary.org/search?q="
		}
	case "googlebooks":
		if id != "" {
			baseURL = "https://books.google.com/books?id="
		} else {
			baseURL = "https://www.google.com/search?tbm=bks&q="
		}
	case "amazon":
		// Amazon doesn't have direct book IDs, always search
		baseURL = "https://www.amazon.com/s?k="
		if isbn.Valid && isbn.String != "" {
			searchTerm = isbn.String
		}
	}

	return baseURL + searchTerm
}

// getBookRating returns the rating value or 0 if not rated
func getBookRating(rating *database.MediaRatings) int32 {
	if rating != nil {
		return rating.Rating
	}
	return 0
}