//
//  AutocompleteTextField.swift
//  WorkoutsPlus
//
//  Created by Felix Förtsch on 19.09.24.
//

import SwiftUI

struct AutocompleteTextField<Item: Nameable>: View {
		var placeholder: String
		
		@Binding var item: Item?
		var items: [Item]
		
		@State private var searchText = ""
		var filteredItems: [Item] {
				if searchText.isEmpty {
						return []
				} else {
						return items.filter { $0.name.localizedCaseInsensitiveContains(searchText) }
				}
		}
		
		@State private var isAutoCompleteShown: Bool = true
		
		var body: some View {
				Group {
						HStack {
								TextField(placeholder, text: $searchText)
								// TODO: Fix "List line" not extending to the full width
								if item == nil && !searchText.isEmpty {
										Text("NEW")
												.font(.caption)
												.foregroundStyle(.green)
								}
								if item != nil {
										Text("EDIT")
												.font(.caption)
												.foregroundStyle(.orange)
								}
						}
						.onAppear() {
								if item != nil {
										self.searchText = item!.name
								}
						}
						.onChange(of: searchText) {
								if filteredItems.count == 1 && filteredItems.first?.name == searchText {
										self.item = filteredItems.first
										isAutoCompleteShown = false
								} else {
										self.item = nil
										isAutoCompleteShown = true
								}
						}
						if isAutoCompleteShown {
								ForEach(filteredItems, id: \.self) { item in
										HStack {
												Text(item.name)
														.foregroundStyle(.gray)
												Spacer()
												Image(systemName: "arrow.up.left")
														.foregroundStyle(.blue)
										}
										// This .contentShape makes the whole row tappable
										.contentShape(Rectangle())
										.onTapGesture {
												self.item = item
												searchText = item.name
												isAutoCompleteShown = false
										}
								}
						}
				}
		}
}

private struct Item: Nameable {
		var id = UUID()
		var name: String
}

#Preview {
		@Previewable @State var item: Item? = nil
		VStack {
				Text("Preview only: ")
				Text(item?.name ?? "No item selected")
		}
		.background(.red)
		List {
				AutocompleteTextField<Item>(placeholder: "New Item", item: $item, items: [
						Item(name: "Item 1"),
						Item(name: "Item 2"),
						Item(name: "Item 3")
				])
		}
}