ScriptMessage.swift

import WebKit

struct ScriptMessage {
    let name: Name
    let data: [String: Any]

    var identifier: String? {
        data["identifier"] as? String
    }

    /// Milliseconds since unix epoch as provided by JavaScript Date.now()
    var timestamp: TimeInterval {
        data["timestamp"] as? TimeInterval ?? 0
    }

    var date: Date {
        Date(timeIntervalSince1970: timestamp / 1000.0)
    }

    var restorationIdentifier: String? {
        data["restorationIdentifier"] as? String
    }

    var location: URL? {
        guard let locationString = data["location"] as? String else { return nil }
        return URL(string: locationString)
    }

    var options: VisitOptions? {
        guard let options = data["options"] as? [String: Any] else { return nil }
        return VisitOptions(json: options)
    }
}

extension ScriptMessage {
    init?(message: WKScriptMessage) {
        guard let body = message.body as? [String: Any],
              let rawName = body["name"] as? String,
              let name = Name(rawValue: rawName),
              let data = body["data"] as? [String: Any]
        else {
            return nil
        }

        self.init(name: name, data: data)
    }
}

extension ScriptMessage {
    enum Name: String {
        case pageLoaded
        case pageLoadFailed
        case errorRaised
        case visitProposed
        case visitProposalScrollingToAnchor
        case visitProposalRefreshingPage
        case visitStarted
        case visitRequestStarted
        case visitRequestCompleted
        case visitRequestFailed
        case visitRequestFailedWithNonHttpStatusCode
        case visitRequestFinished
        case visitRendered
        case visitCompleted
        case formSubmissionStarted
        case formSubmissionFinished
        case pageInvalidated
        case log
    }
}