import Foundation
import SwiftData
import SwiftUI

@Model
final class Exercise {
    var name: String = ""
    var descr: String = ""
    
    @Relationship(deleteRule: .nullify, inverse: \ExerciseType.exercises)
    var type: ExerciseType?
    
    @Relationship(deleteRule: .nullify, inverse: \Muscle.exercises)
    var muscles: [Muscle]? = []
    
    @Relationship(deleteRule: .nullify, inverse: \SplitExerciseAssignment.exercise)
    var splits: [SplitExerciseAssignment]? = []
    
    @Relationship(deleteRule: .nullify, inverse: \WorkoutLog.exercise)
    var logs: [WorkoutLog]? = []
    
    init(name: String, descr: String) {
        self.name = name
        self.descr = descr
    }
    
    static let unnamed = "Unnamed Exercise"
}

extension Exercise: EditableEntity {
    static func createNew() -> Exercise {
        return Exercise(name: "", descr: "")
    }
    
    static var navigationTitle: String {
        return "Exercises"
    }
    
    @ViewBuilder
    static func formView(for model: Exercise) -> some View {
        EntityAddEditView(model: model) { $model in
            // This internal view is necessary to use @Query within the form.
            ExerciseFormView(model: $model)
        }
    }
}

fileprivate struct ExerciseFormView: View {
    @Binding var model: Exercise
    @Query(sort: [SortDescriptor(\ExerciseType.name)]) var exerciseTypes: [ExerciseType]

    var body: some View {
        Section(header: Text("Name")) {
            TextField("Name", text: $model.name)
                .bold()
        }
        
        Section(header: Text("Exercise Type")) {
            Picker("Type", selection: $model.type) {
                Text("Select a type").tag(nil as ExerciseType?)
                ForEach(exerciseTypes) { type in
                    Text(type.name).tag(type as ExerciseType?)
                }
            }
        }
        
        Section(header: Text("Description")) {
            TextEditor(text: $model.descr)
                .frame(minHeight: 100)
        }
    }
}