//
//  StarRating.swift
//  ReviewsUIKit
//
//  Created by Javier Cicchelli on 19/03/2024.
//  Copyright © 2024 Röck+Cöde. All rights reserved.
//

import SwiftUI

public struct StarRating: View {
    
    // MARK: Constants
    private let rating: Int
    private let total: Int

    // MARK: Initialisers
    public init(
        _ rating: Int,
        of total: Int
    ) {
        self.rating = rating
        self.total = total
    }

    // MARK: Body
    public var body: some View {
        HStack {
            ForEach(
                1...total,
                id: \.self
            ) { index in
                if #available(iOS 15.0, *) {
                    Image.Icon.star
                        .symbolVariant(symbolVariant(for: index))
                } else {
                    image(for: index)
                }
            }
        }
    }
    
}

// MARK: - Helpers
private extension StarRating {
    
    // MARK: Functions
    func image(for index: Int) -> Image {
        index <= rating
            ? .Icon.starFill
            : .Icon.star
    }

    @available(iOS 15.0, *)
    func symbolVariant(for index: Int) -> SymbolVariants {
        index <= rating
            ? .fill
            : .none
    }
    
}

// MARK: - Image+Constants
private extension Image {
    enum Icon {
        static let star: Image = .init(systemName: "star")
        static let starFill: Image = .init(systemName: "star.fill")
    }
}

// MARK: - Previews
#Preview("Star Rating") {
    VStack(spacing: 8) {
        StarRating(1, of: 5)
        StarRating(2, of: 5)
        StarRating(3, of: 5)
        StarRating(4, of: 5)
        StarRating(5, of: 5)
    }
}