//
//  TestHelpers.swift
//  iOS Foundations
//
//  Common test utilities and helpers
//

import XCTest

/// Common test helper functions
public enum TestHelpers {

    // MARK: - Async Testing

    /// Wait for an async condition to become true
    ///
    /// - Parameters:
    ///   - timeout: Maximum time to wait
    ///   - condition: The condition to check
    ///
    /// - Returns: true if condition became true within timeout
    ///
    @discardableResult
    public static func wait(
        timeout: TimeInterval = 5.0,
        for condition: @escaping () -> Bool
    ) -> Bool {
        let expectation = XCTNSPredicateExpectation(
            predicate: NSPredicate(block: { _, _ in condition() }),
            object: nil
        )

        let result = XCTWaiter().wait(for: [expectation], timeout: timeout)
        return result == .completed
    }

    /// Wait for an async operation with timeout
    ///
    /// - Parameters:
    ///   - timeout: Maximum time to wait
    ///   - operation: The async operation to perform
    ///
    public static func waitForAsync(
        timeout: TimeInterval = 5.0,
        operation: @escaping (@escaping () -> Void) -> Void
    ) async {
        await withCheckedContinuation { continuation in
            let timeoutTimer = Timer.scheduledTimer(withTimeInterval: timeout, repeats: false) { _ in
                continuation.resume()
            }

            operation {
                timeoutTimer.invalidate()
                continuation.resume()
            }
        }
    }

    // MARK: - Data Generation

    /// Generate a random string
    ///
    /// - Parameter length: Length of the string
    /// - Returns: Random alphanumeric string
    ///
    public static func randomString(length: Int) -> String {
        let letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
        return String((0..<length).map { _ in letters.randomElement()! })
    }

    /// Generate a random email address
    ///
    /// - Returns: Random email address
    ///
    public static func randomEmail() -> String {
        "\(randomString(length: 10))@test.com"
    }

    // MARK: - File Helpers

    /// Get path to a test resource file
    ///
    /// - Parameters:
    ///   - name: File name
    ///   - extension: File extension
    ///   - bundle: Bundle containing the file (defaults to test bundle)
    ///
    /// - Returns: Path to the file, or nil if not found
    ///
    public static func pathForTestResource(
        named name: String,
        withExtension extension: String,
        in bundle: Bundle = Bundle(for: BundleToken.self)
    ) -> String? {
        bundle.path(forResource: name, ofType: `extension`)
    }
}

/// Token class for bundle identification
public class BundleToken {}