import DivKit
import DivKitTestsSupport
import VGSL
import XCTest

final class DivVariableStorageWithOuterStorageTest: XCTestCase {
  private let outerStorage = DivVariableStorage()
  private var storage: DivVariableStorage!
  private let disposePool = AutodisposePool()

  private var event: DivVariableStorage.ChangeEvent?

  override func setUp() {
    storage = DivVariableStorage(outerStorage: outerStorage)
    storage.addObserver { [unowned self] in self.event = $0 }
      .dispose(in: disposePool)
  }

  func test_getValue_ReturnsValueFromOuterStorage() {
    storage.put(variables)
    outerStorage.put(outerVariables)

    XCTAssertEqual("outer value", storage.getValue("outer_string_var"))
  }

  func test_getValue_ReturnsLocalValue_ForShadowedVariable() {
    storage.put(variables)
    outerStorage.put(name: "string_var", value: .string("outer value"))

    XCTAssertEqual("value", storage.getValue("string_var"))
  }

  func test_hasValue_ReturnsTrueIfOuterStorageContainsVariable() {
    storage.put(variables)
    outerStorage.put(outerVariables)

    XCTAssertTrue(storage.hasValue("outer_string_var"))
  }

  func test_update_UpdatesOuterVariable() {
    storage.put(variables)
    outerStorage.put(outerVariables)

    storage.update(name: "outer_string_var", value: .string("new value"))

    XCTAssertEqual("new value", outerStorage.getValue("outer_string_var"))
  }

  func test_update_DoesNotUpdateShadowedVariable() {
    storage.put(variables)
    outerStorage.put(name: "string_var", value: .string("outer value"))

    storage.update(name: "string_var", value: .string("new value"))

    XCTAssertEqual("outer value", outerStorage.getValue("string_var"))
  }

  func test_update_InOuterStorage_TriggersEventInLocalStorage() {
    storage.put(variables)
    outerStorage.put(outerVariables)

    outerStorage.update(name: "outer_string_var", value: .string("new value"))

    XCTAssertEqual(["outer_string_var"], event?.changedVariables)
  }

  func test_clear_DoesNotClearOuterStorage() {
    storage.put(variables)
    outerStorage.put(outerVariables)

    storage.clear()

    XCTAssertEqual(outerVariables, storage.allValues)
  }

  func test_remove_DoesNotAffectOuterStorage() {
    storage.put(variables)
    outerStorage.put(outerVariables)

    storage.remove(variableNames: Set(variables.keys))
    storage.remove(variableNames: Set(outerVariables.keys))

    XCTAssertEqual(outerVariables, storage.allValues)
  }
}

private let variables: DivVariables = [
  "string_var": .string("value"),
  "int_var": .integer(100),
  "number_var": .number(123.34),
  "bool_var": .bool(true),
  "url_var": .url(url("https://test.url")),
]

private let outerVariables: DivVariables = [
  "outer_string_var": .string("outer value"),
  "outer_int_var": .integer(200),
]