//
//  Widget.swift
//  Meta
//
//  Created by david-swift on 26.05.24.
//

/// A widget is a view that know about its GTUI widget.
public protocol Widget: AnyView {

    /// The debug tree parameters.
    var debugTreeParameters: [(String, value: CustomStringConvertible)] { get }
    /// The debug tree's content.
    var debugTreeContent: [(String, body: Body)] { get }
    /// The view storage.
    /// - Parameters:
    ///     - modifiers: Modify views before being updated.
    ///     - type: The type of the widgets.
    func container<WidgetType>(modifiers: [(AnyView) -> AnyView], type: WidgetType.Type) -> ViewStorage
    /// Update the stored content.
    /// - Parameters:
    ///     - storage: The storage to update.
    ///     - modifiers: Modify views before being updated
    ///     - updateProperties: Whether to update the view's properties.
    ///     - type: The type of the widgets.
    func update<WidgetType>(
        _ storage: ViewStorage,
        modifiers: [(AnyView) -> AnyView],
        updateProperties: Bool,
        type: WidgetType.Type
    )

}

extension Widget {

    /// A widget's view is empty.
    public var viewContent: Body { [] }

    /// A description of the view.
    public func getViewDescription<WidgetType>(
        parameters: Bool,
        type: WidgetType.Type,
        modifiers: [(AnyView) -> AnyView]
    ) -> String {
        let oldValue = StateManager.saveState
        StateManager.saveState = false
        defer {
            StateManager.saveState = oldValue
        }
        var content = ""
        for element in debugTreeContent {
            if content.isEmpty {
                content += """
                 {
                    \(indented: element.body.getDebugTree(parameters: parameters, type: type, modifiers: modifiers))
                }
                """
            } else {
                content += """
                 \(element.0): {
                    \(indented: element.body.getDebugTree(parameters: parameters, type: type, modifiers: modifiers))
                }
                """
            }
        }
        if parameters {
            let parametersString = debugTreeParameters.map { "\($0.0): \($0.value)" }.joined(separator: ", ")
            return "\(Self.self)(\(parametersString))\(content)"
        }
        return "\(Self.self)\(content)"
    }

}