import SwiftUI

struct SearchSuggestions: View {
    @EnvironmentObject<NavigationModel> private var navigation
    @EnvironmentObject<RecentsModel> private var recents
    @EnvironmentObject<SearchModel> private var state

    var body: some View {
        List {
            Button {
                runQueryAction()
            } label: {
                HStack {
                    Image(systemName: "magnifyingglass")
                    Text(state.queryText)
                        .lineLimit(1)
                }
            }
            .padding(.vertical, 5)

            #if os(macOS)
                .onHover(perform: onHover(_:))
            #endif

            ForEach(visibleSuggestions, id: \.self) { suggestion in
                HStack {
                    Button {
                        state.queryText = suggestion
                        runQueryAction()
                    } label: {
                        HStack {
                            Image(systemName: "magnifyingglass")
                            HStack(spacing: 0) {
                                if suggestion.hasPrefix(state.suggestionsText.lowercased()) {
                                    Text(state.suggestionsText.lowercased())
                                        .lineLimit(1)
                                        .layoutPriority(2)
                                        .foregroundColor(.secondary)
                                }

                                Text(querySuffix(suggestion))
                                    .lineLimit(1)
                                    .layoutPriority(1)
                                    .frame(minWidth: 0, maxWidth: .infinity, alignment: .leading)
                                    .contentShape(Rectangle())
                            }
                        }
                    }
                    .frame(minWidth: 0, maxWidth: .infinity, alignment: .leading)
                    .buttonStyle(.plain)

                    Spacer()

                    Button {
                        state.queryText = suggestion
                    } label: {
                        Image(systemName: "arrow.up.left.circle")
                            .foregroundColor(.secondary)
                    }
                    .padding(.horizontal, 10)
                    .padding(.vertical, 5)
                    .buttonStyle(.plain)
                }
                #if os(macOS)
                .onHover(perform: onHover(_:))
                #endif
            }
        }
        .id(UUID())
        #if os(macOS)
            .buttonStyle(.link)
        #endif
    }

    private func runQueryAction() {
        state.changeQuery { query in
            query.query = state.queryText
            state.fieldIsFocused = false
            navigation.hideKeyboard()
        }

        recents.addQuery(state.queryText, navigation: navigation)
    }

    private var visibleSuggestions: [String] {
        state.querySuggestions.collection.filter {
            $0.compare(state.queryText, options: .caseInsensitive) != .orderedSame
        }
    }

    private func querySuffix(_ suggestion: String) -> String {
        suggestion.replacingFirstOccurrence(of: state.suggestionsText.lowercased(), with: "")
    }

    #if os(macOS)
        private func onHover(_ inside: Bool) {
            if inside {
                NSCursor.pointingHand.push()
            } else {
                NSCursor.pop()
            }
        }
    #endif
}

struct SearchSuggestions_Previews: PreviewProvider {
    static var previews: some View {
        SearchSuggestions()
            .injectFixtureEnvironmentObjects()
    }
}