//
//  AsyncImageWithPlaceholder.swift
//  meterios
//
//  (c) 2025 Martin "maride" Dessauer
//

import Foundation
import SwiftUI
import OSLog

/// **AsyncImageWithPlaceholder** wraps AsyncImage, showing a Spinner while loading and a question mark in case of errors.
struct AsyncImageWithPlaceholder : View {
    private var url: URL?
    private var width: CGFloat
    private var height: CGFloat

    // Access the current color scheme (that is, e.g.: dark mode, light mode) environment value
    @Environment(\.colorScheme) var colorScheme

    // baseShape and baseShapeView resemble the "background" (while loading, and in case of errors, and for the image itself)
    private var baseShape : some Shape = RoundedRectangle(cornerRadius: 8.0)
    var baseShapeView : some View {
        baseShape
            .foregroundStyle(colorScheme == .dark ? .black : .white)
            .frame(width: width, height: height)
    }

    // Creates a new instance of AsyncImageWithPlaceholder, loading the image pointed to by url, with exact measures of width by height
    init(url: URL? = nil, width: CGFloat, height: CGFloat) {
        self.url = url
        self.width = width
        self.height = height
    }

    var body: some View {
        AsyncImage(url: self.url) { phase in
            if let image = phase.image {
                // Image loaded
                image
                    .resizable()
                    .aspectRatio(contentMode: .fit)
                    .frame(width: self.width, height: self.height)
                    .clipShape(baseShape)
            } else if phase.error != nil {
                // Error, log and display a dummy image (question mark)
                let _ = Logger().error("Error loading image: \(phase.error)")
                ZStack {
                    baseShapeView
                    Text("?")
                        .fontWeight(.bold)
                        .foregroundStyle(.gray)
                }
            } else {
                // Loading Placeholder
                ZStack {
                    baseShapeView
                    ProgressView()
                }
            }
        }.fixedSize()
    }
}