swift-forms/Sources/LilithForms/SearchInput.swift

// SearchInput.swift
// iOS UI Components - Form Components
//
// Search input field with magnifying glass icon and clear button

import SwiftUI
#if canImport(UIKit)
import UIKit
#endif
import LilithDesignTokens

/// Search input field
///
/// Specialized text input for search functionality with debouncing support.
///
/// Example:
/// ```swift
/// @State private var searchQuery = ""
///
/// SearchInput(
///     text: $searchQuery,
///     placeholder: "Search...",
///     onSearch: { query in
///         performSearch(query)
///     }
/// )
/// ```
public struct SearchInput: View {
    // MARK: - Properties

    @Binding private var text: String
    private let placeholder: String
    private let onSearch: ((String) -> Void)?
    private let debounceDelay: TimeInterval
    private let isDisabled: Bool

    // MARK: - Focus State

    @FocusState private var isFocused: Bool

    // MARK: - State

    @State private var debounceTask: Task<Void, Never>?

    // MARK: - Initialization

    /// Create a search input
    /// - Parameters:
    ///   - text: Binding to search query
    ///   - placeholder: Placeholder text
    ///   - onSearch: Debounced search callback
    ///   - debounceDelay: Delay before triggering search (default: 0.3s)
    ///   - isDisabled: Disable input
    public init(
        text: Binding<String>,
        placeholder: String = "Search...",
        onSearch: ((String) -> Void)? = nil,
        debounceDelay: TimeInterval = 0.3,
        isDisabled: Bool = false
    ) {
        self._text = text
        self.placeholder = placeholder
        self.onSearch = onSearch
        self.debounceDelay = debounceDelay
        self.isDisabled = isDisabled
    }

    // MARK: - Body

    public var body: some View {
        HStack(spacing: AppSpacing.sm) {
            // Leading search icon
            Image(systemName: "magnifyingglass")
                .font(.system(size: AppTypography.FontSize.base))
                .foregroundColor(iconColor)

            TextField(placeholder, text: $text)
                .font(AppTypography.body())
                .foregroundColor(AppColors.textPrimary)
                #if os(iOS) || os(tvOS) || os(watchOS) || os(visionOS)
                .textInputAutocapitalization(.never)
                #endif
                .autocorrectionDisabled()
                .disabled(isDisabled)
                .focused($isFocused)
                .onChange(of: text) { _, newValue in
                    handleTextChange(newValue)
                }

            // Clear button
            if !text.isEmpty {
                Button(action: clearSearch) {
                    Image(systemName: "xmark.circle.fill")
                        .font(.system(size: AppTypography.FontSize.base))
                        .foregroundColor(AppColors.textTertiary)
                }
                .accessibilityLabel("Clear search")
            }
        }
        .padding(.horizontal, AppSpacing.md)
        .padding(.vertical, AppSpacing.sm)
        .background(backgroundColor)
        .overlay(
            RoundedRectangle(cornerRadius: AppRadius.input)
                .stroke(borderColor, lineWidth: isFocused ? 2 : 1)
        )
        .clipShape(RoundedRectangle(cornerRadius: AppRadius.input))
        .animation(AppAnimations.fast, value: isFocused)
        .animation(AppAnimations.fast, value: text.isEmpty)
    }

    // MARK: - Computed Properties

    private var borderColor: Color {
        if isDisabled {
            return AppColors.Gray.gray700
        }
        if isFocused {
            return AppColors.primary
        }
        return AppColors.border
    }

    private var backgroundColor: Color {
        isDisabled ? AppColors.Gray.gray800 : AppColors.surface
    }

    private var iconColor: Color {
        if isDisabled {
            return AppColors.textTertiary
        }
        if isFocused {
            return AppColors.primary
        }
        return AppColors.textSecondary
    }

    // MARK: - Methods

    private func handleTextChange(_ newValue: String) {
        // Cancel previous debounce task
        debounceTask?.cancel()

        // Create new debounced task
        debounceTask = Task {
            try? await Task.sleep(nanoseconds: UInt64(debounceDelay * 1_000_000_000))

            guard !Task.isCancelled else { return }

            await MainActor.run {
                onSearch?(newValue)
            }
        }
    }

    private func clearSearch() {
        text = ""

        #if canImport(UIKit)
        let generator = UIImpactFeedbackGenerator(style: .light)
        generator.impactOccurred()
        #endif

        onSearch?("")
    }
}

// MARK: - Preview Provider

#if DEBUG
struct SearchInput_Previews: PreviewProvider {
    static var previews: some View {
        VStack(spacing: AppSpacing.xl) {
            // Default state
            SearchInput(text: .constant(""))

            // With placeholder
            SearchInput(text: .constant(""), placeholder: "Search products...")

            // With value
            SearchInput(text: .constant("SwiftUI"))

            // Focused with text
            SearchInput(text: .constant("Search query"))

            // Disabled
            SearchInput(text: .constant("Cannot search"), isDisabled: true)

            // In context - Search bar
            VStack(spacing: 0) {
                SearchInput(
                    text: .constant(""),
                    placeholder: "Search messages...",
                    onSearch: { query in
                        print("Searching for: \(query)")
                    }
                )
                .padding()
                .background(AppColors.surface)

                List(0..<10) { index in
                    Text("Result \(index)")
                }
            }
        }
        .padding()
        .background(AppColors.background)
        .previewDisplayName("Search Input States")
    }
}
#endif