import SwiftUI

struct DocumentThumbnailData: Decodable, Sendable {
    let bars: [Bar]?
    let width: Double
    let height: Double
    enum CodingKeys: String, CodingKey { case bars = "Bars", width = "W", height = "H" }
    struct Bar: Decodable, Sendable {
        let x: Double; let y: Double; let width: Double; let height: Double
        enum CodingKeys: String, CodingKey { case x = "X", y = "Y", width = "W", height = "H" }
    }
}

struct DocumentThumbnail: View {
    let data: DocumentThumbnailData?
    var width: CGFloat = 34
    var height: CGFloat = 44
    var body: some View {
        Canvas { context, size in
            guard let data, data.width > 0, data.height > 0 else { return }
            let scale = min(size.width / data.width, size.height / data.height)
            let x = (size.width - data.width * scale) / 2
            let y = (size.height - data.height * scale) / 2
            for bar in data.bars ?? [] {
                context.fill(Path(CGRect(x: x + bar.x * scale, y: y + bar.y * scale,
                                         width: max(0, bar.width * scale), height: max(0, bar.height * scale))), with: .foreground)
            }
        }
        .foregroundStyle(.secondary)
        .frame(width: width, height: height)
        .background(.background)
        .clipShape(.rect(cornerRadius: 3))
        .overlay { RoundedRectangle(cornerRadius: 3).strokeBorder(.quaternary) }
        .accessibilityHidden(true)
    }
}