import _CJavaScriptKit

/// `JSValue` represents a value in JavaScript.

@dynamicMemberLookup

public struct JSValue: Equatable {

/// The internal storage of the JSValue, which is intentionally not public

/// to leave the flexibility to change the storage.

internal enum Storage: Equatable {

case boolean(Bool)

case string(JSString)

case number(Double)

case object(JSObject)

case null

case undefined

case symbol(JSSymbol)

case bigInt(JSBigInt)

}

internal var storage: Storage

internal init(storage: Storage) {

self.storage = storage

}

public static func boolean(_ value: Bool) -> JSValue {

.init(storage: .boolean(value))

}

public static func string(_ value: JSString) -> JSValue {

.init(storage: .string(value))

}

public static func number(_ value: Double) -> JSValue {

.init(storage: .number(value))

}

public static func object(_ value: JSObject) -> JSValue {

.init(storage: .object(value))

}

public static var null: JSValue {

.init(storage: .null)

}

public static var undefined: JSValue {

.init(storage: .undefined)

}

public static func symbol(_ value: JSSymbol) -> JSValue {

.init(storage: .symbol(value))

}

public static func bigInt(_ value: JSBigInt) -> JSValue {

.init(storage: .bigInt(value))

}

/// Returns the `Bool` value of this JS value if its type is boolean.

/// If not, returns `nil`.

public var boolean: Bool? {

switch storage {

case .boolean(let boolean): return boolean

default: return nil

}

}

/// Returns the `String` value of this JS value if the type is string.

/// If not, returns `nil`.

///

/// Note that this accessor may copy the JS string value into Swift side memory.

///

/// To avoid the copying, please consider the `jsString` instead.

public var string: String? {

jsString.map(String.init)

}

/// Returns the `JSString` value of this JS value if the type is string.

/// If not, returns `nil`.

///

public var jsString: JSString? {

switch storage {

case .string(let string): return string

default: return nil

}

}

/// Returns the `Double` value of this JS value if the type is number.

/// If not, returns `nil`.

public var number: Double? {

switch storage {

case .number(let number): return number

default: return nil

}

}

/// Returns the `JSObject` of this JS value if its type is object.

/// If not, returns `nil`.

public var object: JSObject? {

switch storage {

case .object(let object): return object

default: return nil

}

}

// @available(*, deprecated, renamed: "object", message: "Use the .object property instead")

public var function: JSObject? { object }

/// Returns the `JSSymbol` of this JS value if its type is function.

/// If not, returns `nil`.

public var symbol: JSSymbol? {

switch storage {

case .symbol(let symbol): return symbol

default: return nil

}

}

/// Returns the `JSBigInt` of this JS value if its type is function.

/// If not, returns `nil`.

public var bigInt: JSBigInt? {

switch storage {

case .bigInt(let bigInt): return bigInt

default: return nil

}

}

/// Returns the `true` if this JS value is null.

/// If not, returns `false`.

public var isNull: Bool {

return storage == .null

}

/// Returns the `true` if this JS value is undefined.

/// If not, returns `false`.

public var isUndefined: Bool {

return storage == .undefined

}

}

/// JSValue is intentionally not `Sendable` because accessing a JSValue living in a different

/// thread is invalid. Although there are some cases where Swift allows sending a non-Sendable

/// values to other isolation domains, not conforming `Sendable` is still useful to prevent

/// accidental misuse.

@available(*, unavailable)

extension JSValue: Sendable {}

extension JSValue {

#if !hasFeature(Embedded)

/// An unsafe convenience method of `JSObject.subscript(_ name: String) -> ((ConvertibleToJSValue...) -> JSValue)?`

/// - Precondition: `self` must be a JavaScript Object and specified member should be a callable object.

public subscript(dynamicMember name: String) -> ((ConvertibleToJSValue...) -> JSValue) {

object![dynamicMember: name]!

}

#endif

/// An unsafe convenience method of `JSObject.subscript(_ index: Int) -> JSValue`

/// - Precondition: `self` must be a JavaScript Object.

public subscript(dynamicMember name: String) -> JSValue {

get { self.object![name] }

nonmutating set { self.object![name] = newValue }

}

/// An unsafe convenience method of `JSObject.subscript(_ index: Int) -> JSValue`

/// - Precondition: `self` must be a JavaScript Object.

public subscript(_ index: Int) -> JSValue {

get { object![index] }

nonmutating set { object![index] = newValue }

}

}

extension JSValue {

public func fromJSValue<Type>() -> Type? where Type: ConstructibleFromJSValue {

return Type.construct(from: self)

}

}

extension JSValue {

public static func string(_ value: String) -> JSValue {

.init(storage: .string(JSString(value)))

}

/// Deprecated: Please create `JSClosure` directly and manage its lifetime manually.

///

/// Migrate this usage

///

/// ```swift

/// button.addEventListener!("click", JSValue.function { _ in

/// ...

/// return JSValue.undefined

/// })

/// ```

///

/// into below code.

///

/// ```swift

/// let eventListener = JSClosure { _ in

/// ...

/// return JSValue.undefined

/// }

///

/// button.addEventListener!("click", JSValue.function(eventListener))

/// ...

/// button.removeEventListener!("click", JSValue.function(eventListener))

/// eventListener.release()

/// ```

@available(*, deprecated, message: "Please create JSClosure directly and manage its lifetime manually.")

public static func function(_ body: @escaping ([JSValue]) -> JSValue) -> JSValue {

.init(storage: .object(JSClosure(body)))

}

@available(

*,

deprecated,

renamed: "object",

message: "JSClosure is no longer a subclass of JSFunction. Use .object(closure) instead."

)

public static func function(_ closure: JSClosure) -> JSValue {

.init(storage: .object(closure))

}

@available(*, deprecated, renamed: "object", message: "Use .object(function) instead")

public static func function(_ function: JSObject) -> JSValue { .init(storage: .object(function)) }

}

extension JSValue: ExpressibleByStringLiteral {

public init(stringLiteral value: String) {

self = .init(storage: .string(JSString(value)))

}

}

extension JSValue: ExpressibleByIntegerLiteral {

public init(integerLiteral value: Int32) {

self = .init(storage: .number(Double(value)))

}

}

extension JSValue: ExpressibleByFloatLiteral {

public init(floatLiteral value: Double) {

self = .init(storage: .number(value))

}

}

extension JSValue: ExpressibleByNilLiteral {

public init(nilLiteral _: ()) {

self = .init(storage: .null)

}

}

public func getJSValue(this: JSObject, name: JSString) -> JSValue {

var rawValue = RawJSValue()

let rawBitPattern = swjs_get_prop(

this.id,

name.asInternalJSRef(),

&rawValue.payload1,

&rawValue.payload2

)

rawValue.kind = unsafeBitCast(rawBitPattern, to: JavaScriptValueKind.self)

return rawValue.jsValue

}

public func setJSValue(this: JSObject, name: JSString, value: JSValue) {

value.withRawJSValue { rawValue in

swjs_set_prop(this.id, name.asInternalJSRef(), rawValue.kind, rawValue.payload1, rawValue.payload2)

}

}

public func getJSValue(this: JSObject, index: Int32) -> JSValue {

var rawValue = RawJSValue()

let rawBitPattern = swjs_get_subscript(

this.id,

index,

&rawValue.payload1,

&rawValue.payload2

)

rawValue.kind = unsafeBitCast(rawBitPattern, to: JavaScriptValueKind.self)

return rawValue.jsValue

}

public func setJSValue(this: JSObject, index: Int32, value: JSValue) {

value.withRawJSValue { rawValue in

swjs_set_subscript(

this.id,

index,

rawValue.kind,

rawValue.payload1,

rawValue.payload2

)

}

}

public func getJSValue(this: JSObject, symbol: JSSymbol) -> JSValue {

var rawValue = RawJSValue()

let rawBitPattern = swjs_get_prop(

this.id,

symbol.id,

&rawValue.payload1,

&rawValue.payload2

)

rawValue.kind = unsafeBitCast(rawBitPattern, to: JavaScriptValueKind.self)

return rawValue.jsValue

}

public func setJSValue(this: JSObject, symbol: JSSymbol, value: JSValue) {

value.withRawJSValue { rawValue in

swjs_set_prop(this.id, symbol.id, rawValue.kind, rawValue.payload1, rawValue.payload2)

}

}

extension JSValue {

/// Return `true` if this value is an instance of the passed `constructor` function.

/// Returns `false` for everything except objects and functions.

/// - Parameter constructor: The constructor function to check.

/// - Returns: The result of `instanceof` in the JavaScript environment.

public func isInstanceOf(_ constructor: JSObject) -> Bool {

switch storage {

case .boolean, .string, .number, .null, .undefined, .symbol, .bigInt:

return false

case .object(let ref):

return ref.isInstanceOf(constructor)

}

}

}

extension JSValue: CustomStringConvertible {

public var description: String {

// per https://tc39.es/ecma262/multipage/text-processing.html#sec-string-constructor-string-value

// this always returns a string

JSObject.global.String.object!(self).string!

}

}

#if hasFeature(Embedded)

// Overloads of `JSValue.subscript(dynamicMember name: String) -> ((ConvertibleToJSValue...) -> JSValue)`

// for 0 through 7 arguments for Embedded Swift.

//

// These are required because the `ConvertibleToJSValue...` subscript is not

// available in Embedded Swift due to lack of support for existentials.

//

// Note: Once Embedded Swift supports parameter packs/variadic generics, we can

// replace all of these with a single method that takes a generic pack.

extension JSValue {

@_disfavoredOverload

public subscript(dynamicMember name: String) -> (() -> JSValue) {

object![dynamicMember: name]!

}

@_disfavoredOverload

public subscript<A0: ConvertibleToJSValue>(dynamicMember name: String) -> ((A0) -> JSValue) {

object![dynamicMember: name]!

}

@_disfavoredOverload

public subscript<

A0: ConvertibleToJSValue,

A1: ConvertibleToJSValue

>(dynamicMember name: String) -> ((A0, A1) -> JSValue) {

object![dynamicMember: name]!

}

@_disfavoredOverload

public subscript<

A0: ConvertibleToJSValue,

A1: ConvertibleToJSValue,

A2: ConvertibleToJSValue

>(dynamicMember name: String) -> ((A0, A1, A2) -> JSValue) {

object![dynamicMember: name]!

}

@_disfavoredOverload

public subscript<

A0: ConvertibleToJSValue,

A1: ConvertibleToJSValue,

A2: ConvertibleToJSValue,

A3: ConvertibleToJSValue

>(dynamicMember name: String) -> ((A0, A1, A2, A3) -> JSValue) {

object![dynamicMember: name]!

}

@_disfavoredOverload

public subscript<

A0: ConvertibleToJSValue,

A1: ConvertibleToJSValue,

A2: ConvertibleToJSValue,

A3: ConvertibleToJSValue,

A4: ConvertibleToJSValue

>(dynamicMember name: String) -> ((A0, A1, A2, A3, A4) -> JSValue) {

object![dynamicMember: name]!

}

@_disfavoredOverload

public subscript<

A0: ConvertibleToJSValue,

A1: ConvertibleToJSValue,

A2: ConvertibleToJSValue,

A3: ConvertibleToJSValue,

A4: ConvertibleToJSValue,

A5: ConvertibleToJSValue

>(dynamicMember name: String) -> ((A0, A1, A2, A3, A4, A5) -> JSValue) {

object![dynamicMember: name]!

}

@_disfavoredOverload

public subscript<

A0: ConvertibleToJSValue,

A1: ConvertibleToJSValue,

A2: ConvertibleToJSValue,

A3: ConvertibleToJSValue,

A4: ConvertibleToJSValue,

A5: ConvertibleToJSValue,

A6: ConvertibleToJSValue

>(dynamicMember name: String) -> ((A0, A1, A2, A3, A4, A5, A6) -> JSValue) {

object![dynamicMember: name]!

}

}

#endif