import XCTest

struct DemoReaderState {
    let rawValue: String
    let fields: [String: String]

    init(rawValue: String) {
        self.rawValue = rawValue
        var parsed: [String: String] = [:]
        let separators = CharacterSet.whitespacesAndNewlines.union(CharacterSet(charactersIn: ";"))
        for token in rawValue.components(separatedBy: separators) where !token.isEmpty {
            guard let delimiterIndex = token.firstIndex(of: "=") else { continue }
            let key = String(token[..<delimiterIndex])
            let value = String(token[token.index(after: delimiterIndex)...])
            parsed[key] = value
        }
        fields = parsed
    }

    subscript(key: String) -> String? {
        fields[key]
    }

    private func decodedField(_ key: String) -> String? {
        guard let rawValue = fields[key], rawValue != "nil" else { return nil }
        return rawValue.removingPercentEncoding ?? rawValue
    }

    var isOpened: Bool { fields["reader"] == "opened" }
    var page: Int? { fields["page"].flatMap(Int.init) }
    var display: String? { fields["display"] }
    var toolbar: String? { fields["toolbar"] }
    var highlights: Int? { fields["highlights"].flatMap(Int.init) }
    var bookmarks: Int? { fields["bookmarks"].flatMap(Int.init) }
    var selection: Int? { fields["selection"].flatMap(Int.init) }
    var href: String? { decodedField("href") }
    var progression: Double? { fields["progression"].flatMap(Double.init) }
    var cfi: String? { decodedField("cfi") }
    var lastCFI: String? { decodedField("lastCFI") }
    var rangeCFI: String? { decodedField("rangeCFI") }
    var mode: String? { fields["mode"] }
    var pagination: String? { fields["pagination"] }
    var knownPages: Int? { fields["knownPages"].flatMap(Int.init) }
    var knownChapters: Int? { fields["knownChapters"].flatMap(Int.init) }
    var buildableChapters: Int? { fields["buildableChapters"].flatMap(Int.init) }
    var avoidWidows: Int? { fields["avoidWidows"].flatMap(Int.init) }
    var avoidOrphans: Int? { fields["avoidOrphans"].flatMap(Int.init) }
    var windowSize: Int? { fields["windowSize"].flatMap(Int.init) }
    var parseMs: Int? { fields["parseMs"].flatMap(Int.init) }
    var parseConcurrency: Int? { fields["parseConcurrency"].flatMap(Int.init) }
    var inspectable: Int? { fields["inspectable"].flatMap(Int.init) }
    var streamedResources: Int? { fields["streamedResources"].flatMap(Int.init) }
    var inMemoryResources: Int? { fields["inMemoryResources"].flatMap(Int.init) }
    var resourceFailures: Int? { fields["resourceFailures"].flatMap(Int.init) }
    var cacheFiles: Int? { fields["cacheFiles"].flatMap(Int.init) }
    var cacheBytes: Int? { fields["cacheBytes"].flatMap(Int.init) }
    var externalLinks: Int? { fields["externalLinks"].flatMap(Int.init) }
    var lastExternalURL: String? { decodedField("lastExternalURL") }
    var lastError: String? { decodedField("lastError") }
    var searchMatchText: String? { decodedField("searchMatchText") }
    var footprintMB: Double? { fields["footprintMB"].flatMap(Double.init) }
}

extension XCUIApplication {
    func currentDemoReaderState() -> DemoReaderState? {
        let state = staticTexts[IDs.demoReaderState]
        guard state.exists else { return nil }
        return DemoReaderState(rawValue: state.label)
    }

    @discardableResult
    func waitForDemoReaderState(
        timeout: TimeInterval = 8,
        description: String,
        where predicate: (DemoReaderState) -> Bool
    ) -> DemoReaderState {
        let stateElement = staticTexts[IDs.demoReaderState]
        let deadline = Date().addingTimeInterval(timeout)
        var lastState = DemoReaderState(rawValue: "<missing>")

        while Date() < deadline {
            if stateElement.exists {
                lastState = DemoReaderState(rawValue: stateElement.label)
                if predicate(lastState) {
                    return lastState
                }
            }
            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
        }

        XCTFail("阅读器状态未满足条件: \(description)，当前：\(lastState.rawValue)")
        return lastState
    }
}