import Foundation
import CoreGraphics

/// Pure schema-diagram operations shared by the UI and XCTest suite.
enum DiagramLogic {
    static func selectedObjects(_ requested: Set<String>, available: [String]) -> Set<String> {
        requested.intersection(Set(available))
    }

    static func arrangedPositions(_ names: [String]) -> [String: CGPoint] {
        let countPerRow = max(1, Int(ceil(sqrt(Double(max(1, names.count))))))
        var positions: [String: CGPoint] = [:]
        for (index, name) in names.enumerated() {
            positions[name] = CGPoint(x: CGFloat(index % countPerRow) * 290 + 30,
                                      y: CGFloat(index / countPerRow) * 300 + 30)
        }
        return positions
    }

    static func translatedPosition(_ origin: CGPoint, translation: CGSize, zoom: CGFloat) -> CGPoint {
        let scale = max(zoom, 0.1)
        return CGPoint(x: origin.x + translation.width / scale,
                       y: origin.y + translation.height / scale)
    }
}