import Foundation
import WebKit

enum RDEPUBWebViewDebug {

    static var isEnabled: Bool = {
        if let configured = UserDefaults.standard.object(forKey: "RDEPUBWebViewDebugEnabled") as? Bool {
            return configured
        }
#if DEBUG
        return true
#else
        return false
#endif
    }()

    static var isVerboseEnabled: Bool = {
        if let configured = UserDefaults.standard.object(forKey: "RDEPUBWebViewVerboseEnabled") as? Bool {
            return configured
        }
        return false
    }()

    static var isInspectableEnabled: Bool = {
        if let configured = UserDefaults.standard.object(forKey: "RDEPUBInspectableWebViewsEnabled") as? Bool {
            return configured
        }
        return false
    }()

    static func applyDebugPolicy(inspectableEnabled: Bool, verboseLoggingEnabled: Bool) {
        isInspectableEnabled = inspectableEnabled
        isVerboseEnabled = verboseLoggingEnabled
    }

    static func webViewID(_ webView: WKWebView?) -> String {
        guard let webView else { return "nil-webview" }
        return String(ObjectIdentifier(webView).hashValue, radix: 16)
    }

    static func log(_ scope: String, message: String) {
        guard isEnabled else { return }
        print("[RDReaderWK][\(scope)] \(message)")
    }

    static func logNavigationEvent(_ scope: String, webView: WKWebView?, event: String, url: URL? = nil, error: Error? = nil) {
        guard isEnabled else { return }
        let webViewToken = webViewID(webView)
        let urlText = summarizedURL(url)
        if let error {
            log(scope, message: "webView=\(webViewToken) event=\(event) url=\(urlText) error=\(error.localizedDescription)")
        } else {
            log(scope, message: "webView=\(webViewToken) event=\(event) url=\(urlText)")
        }
    }

    static func logJavaScript(_ scope: String, webView: WKWebView?, action: String, details: String) {
        guard isEnabled else { return }
        log(scope, message: "webView=\(webViewID(webView)) js=\(action) \(details)")
    }

    static func logMessage(_ scope: String, webView: WKWebView?, name: String, body: Any) {
        guard isEnabled else { return }
        if isVerboseEnabled {
            log(scope, message: "webView=\(webViewID(webView)) message=\(name) body=\(String(describing: body))")
            return
        }
        if let dict = body as? [String: Any] {
            let keys = dict.keys.sorted().joined(separator: ",")
            var meta = "keys=[\(keys)]"
            if let text = dict["text"] as? String {
                meta += " textLen=\(text.count)"
            }
            if let urlString = dict["url"] as? String ?? dict["href"] as? String {
                meta += " url=\(summarizedURL(URL(string: urlString)))"
            }
            log(scope, message: "webView=\(webViewID(webView)) message=\(name) \(meta)")
        } else {
            log(scope, message: "webView=\(webViewID(webView)) message=\(name) type=\(Swift.type(of: body))")
        }
    }

    static func logSchemeTask(_ scope: String, requestURL: URL?, fileURL: URL? = nil, event: String, error: Error? = nil) {
        guard isEnabled else { return }
        let requestText = summarizedURL(requestURL)
        let fileText = summarizedURL(fileURL)
        if let error {
            log(scope, message: "scheme=\(event) request=\(requestText) file=\(fileText) error=\(error.localizedDescription)")
        } else {
            log(scope, message: "scheme=\(event) request=\(requestText) file=\(fileText)")
        }
    }

    static func summarizedURL(_ url: URL?) -> String {
        guard let url else { return "nil" }
        if let scheme = url.scheme, scheme == RDEPUBResourceURLSchemeHandler.scheme {
            return url.absoluteString
        }
        let path = url.path
        if path.isEmpty {
            return url.absoluteString
        }
        return url.lastPathComponent.isEmpty ? path : url.lastPathComponent
    }
}