import Foundation

/// Creates a temporary directory containing `entries` (a trailing slash marks
/// a subdirectory, like an `.xcodeproj` bundle) and removes it after `body`
/// runs.
func withTemporaryProjectDirectory(
  entries: [String],
  contents: [String: Data] = [:],
  body: (URL) throws -> Void
) throws {
  let directory = try makeTemporaryProjectDirectory(entries: entries, contents: contents)
  defer { try? FileManager.default.removeItem(at: directory) }
  try body(directory)
}

func withTemporaryProjectDirectory(
  entries: [String],
  contents: [String: Data] = [:],
  body: (URL) async throws -> Void
) async throws {
  let directory = try makeTemporaryProjectDirectory(entries: entries, contents: contents)
  defer { try? FileManager.default.removeItem(at: directory) }
  try await body(directory)
}

private func makeTemporaryProjectDirectory(
  entries: [String],
  contents: [String: Data]
) throws -> URL {
  let fileManager = FileManager.default
  let directory = fileManager.temporaryDirectory
    .appending(path: "project-fixture-\(UUID().uuidString)")
  try fileManager.createDirectory(at: directory, withIntermediateDirectories: true)
  do {
    for entry in entries {
      if entry.hasSuffix("/") {
        try fileManager.createDirectory(
          at: directory.appending(path: String(entry.dropLast())),
          withIntermediateDirectories: true
        )
      } else {
        try Data().write(to: directory.appending(path: entry))
      }
    }
    for (path, data) in contents {
      let fileURL = directory.appending(path: path)
      try fileManager.createDirectory(
        at: fileURL.deletingLastPathComponent(),
        withIntermediateDirectories: true
      )
      try data.write(to: fileURL)
    }
  } catch {
    try? fileManager.removeItem(at: directory)
    throw error
  }
  return directory
}