import SwiftUI

struct BoardView: View {
    @EnvironmentObject private var store: TaskStore
    @State private var newTaskTitle = ""

    var body: some View {
        VStack(alignment: .leading, spacing: 20) {
            Text("My board")
                .font(.largeTitle.bold())

            HStack(spacing: 12) {
                TextField("Add a task", text: $newTaskTitle)
                    .textFieldStyle(.roundedBorder)
                    .onSubmit(addTask)
                Button("Add", action: addTask)
                    .keyboardShortcut(.defaultAction)
            }

            HStack(alignment: .top, spacing: 16) {
                ForEach(TaskList.allCases) { list in
                    TaskColumn(list: list, tasks: tasks(in: list))
                }
            }
        }
        .padding(24)
        .frame(minWidth: 780, minHeight: 460)
    }

    private func tasks(in list: TaskList) -> [TaskItem] {
        store.tasks.filter { $0.list == list }
    }

    private func addTask() {
        store.add(title: newTaskTitle)
        newTaskTitle = ""
    }
}

private struct TaskColumn: View {
    @EnvironmentObject private var store: TaskStore
    let list: TaskList
    let tasks: [TaskItem]

    var body: some View {
        VStack(alignment: .leading, spacing: 10) {
            Text(list.title)
                .font(.headline)
            ScrollView {
                LazyVStack(spacing: 8) {
                    ForEach(tasks) { task in
                        TaskCard(task: task)
                    }
                }
            }
        }
        .padding(12)
        .frame(maxWidth: .infinity, minHeight: 320, alignment: .topLeading)
        .background(.quaternary, in: RoundedRectangle(cornerRadius: 12))
    }
}

private struct TaskCard: View {
    @EnvironmentObject private var store: TaskStore
    let task: TaskItem

    var body: some View {
        HStack(alignment: .top, spacing: 8) {
            Text(task.title)
                .frame(maxWidth: .infinity, alignment: .leading)
            Menu {
                ForEach(TaskList.allCases.filter { $0 != task.list }) { list in
                    Button("Move to \(list.title)") { store.move(task, to: list) }
                }
                Divider()
                Button("Delete", role: .destructive) { store.delete(task) }
            } label: {
                Image(systemName: "ellipsis")
            }
            .menuStyle(.borderlessButton)
            .fixedSize()
        }
        .padding(10)
        .background(.background, in: RoundedRectangle(cornerRadius: 8))
    }
}