import Foundation

#if os(macOS)
import SweetCookieKit

public enum KimiCookieImporter {
    public static func desktopAuthToken() -> String? {
        KimiDesktopAuthToken.load()
    }

    private static let log = CodexBarLog.logger(LogCategories.provider(.kimi, scope: "cookie"))
    private static let cookieClient = BrowserCookieClient()
    private static let cookieDomains = ["www.kimi.com", "kimi.com"]
    private static let cookieImportOrder: BrowserCookieImportOrder =
        ProviderDefaults.metadata[.kimi]?.browserCookieOrder ?? Browser.defaultImportOrder

    public struct SessionInfo: Sendable {
        public let cookies: [HTTPCookie]
        public let sourceLabel: String

        public init(cookies: [HTTPCookie], sourceLabel: String) {
            self.cookies = cookies
            self.sourceLabel = sourceLabel
        }

        public var authToken: String? {
            self.cookies.first(where: { $0.name == "kimi-auth" })?.value
        }
    }

    public static func importSessions(
        browserDetection: BrowserDetection = BrowserDetection(),
        logger: ((String) -> Void)? = nil) throws -> [SessionInfo]
    {
        var sessions: [SessionInfo] = []
        let candidates = self.cookieImportOrder.cookieImportCandidates(using: browserDetection)
        for browserSource in candidates {
            do {
                let perSource = try self.importSessions(from: browserSource, logger: logger)
                sessions.append(contentsOf: perSource)
            } catch {
                BrowserCookieAccessGate.recordIfNeeded(error)
                self.emit(
                    "\(browserSource.displayName) cookie import failed: \(error.localizedDescription)",
                    logger: logger)
            }
        }

        guard !sessions.isEmpty else {
            throw KimiCookieImportError.noCookies
        }
        return sessions
    }

    public static func importSessions(
        from browserSource: Browser,
        logger: ((String) -> Void)? = nil) throws -> [SessionInfo]
    {
        let query = BrowserCookieQuery(domains: self.cookieDomains)
        let log: (String) -> Void = { msg in self.emit(msg, logger: logger) }
        let sources = try Self.cookieClient.codexBarRecords(
            matching: query,
            in: browserSource,
            logger: log)

        var sessions: [SessionInfo] = []
        let grouped = Dictionary(grouping: sources, by: { $0.store.profile.id })
        let sortedGroups = grouped.values.sorted { lhs, rhs in
            self.mergedLabel(for: lhs) < self.mergedLabel(for: rhs)
        }

        for group in sortedGroups where !group.isEmpty {
            let label = self.mergedLabel(for: group)
            let mergedRecords = self.mergeRecords(group)
            guard !mergedRecords.isEmpty else { continue }
            let httpCookies = BrowserCookieClient.makeHTTPCookies(mergedRecords, origin: query.origin)
            guard !httpCookies.isEmpty else { continue }

            // Only include sessions that have the kimi-auth cookie
            guard httpCookies.contains(where: { $0.name == "kimi-auth" }) else {
                continue
            }

            log("Found kimi-auth cookie in \(label)")
            sessions.append(SessionInfo(cookies: httpCookies, sourceLabel: label))
        }
        return sessions
    }

    public static func importSession(
        browserDetection: BrowserDetection = BrowserDetection(),
        logger: ((String) -> Void)? = nil) throws -> SessionInfo
    {
        let sessions = try self.importSessions(browserDetection: browserDetection, logger: logger)
        guard let first = sessions.first else {
            throw KimiCookieImportError.noCookies
        }
        return first
    }

    public static func hasSession(
        browserDetection: BrowserDetection = BrowserDetection(),
        logger: ((String) -> Void)? = nil) -> Bool
    {
        do {
            return try !self.importSessions(browserDetection: browserDetection, logger: logger).isEmpty
        } catch {
            return false
        }
    }

    private static func cookieNames(from cookies: [HTTPCookie]) -> String {
        let names = Set(cookies.map { "\($0.name)@\($0.domain)" }).sorted()
        return names.joined(separator: ", ")
    }

    private static func emit(_ message: String, logger: ((String) -> Void)?) {
        logger?("[kimi-cookie] \(message)")
        self.log.debug(message)
    }

    private static func mergedLabel(for sources: [BrowserCookieStoreRecords]) -> String {
        guard let base = sources.map(\.label).min() else {
            return "Unknown"
        }
        if base.hasSuffix(" (Network)") {
            return String(base.dropLast(" (Network)".count))
        }
        return base
    }

    private static func mergeRecords(_ sources: [BrowserCookieStoreRecords]) -> [BrowserCookieRecord] {
        let sortedSources = sources.sorted { lhs, rhs in
            self.storePriority(lhs.store.kind) < self.storePriority(rhs.store.kind)
        }
        var mergedByKey: [String: BrowserCookieRecord] = [:]
        for source in sortedSources {
            for record in source.records {
                let key = self.recordKey(record)
                if let existing = mergedByKey[key] {
                    if self.shouldReplace(existing: existing, candidate: record) {
                        mergedByKey[key] = record
                    }
                } else {
                    mergedByKey[key] = record
                }
            }
        }
        return Array(mergedByKey.values)
    }

    private static func storePriority(_ kind: BrowserCookieStoreKind) -> Int {
        switch kind {
        case .network: 0
        case .primary: 1
        case .safari: 2
        }
    }

    private static func recordKey(_ record: BrowserCookieRecord) -> String {
        "\(record.name)|\(record.domain)|\(record.path)"
    }

    private static func shouldReplace(existing: BrowserCookieRecord, candidate: BrowserCookieRecord) -> Bool {
        switch (existing.expires, candidate.expires) {
        case let (lhs?, rhs?):
            rhs > lhs
        case (nil, .some):
            true
        case (.some, nil):
            false
        case (nil, nil):
            false
        }
    }
}

enum KimiCookieImportError: LocalizedError {
    case noCookies

    var errorDescription: String? {
        switch self {
        case .noCookies:
            "No Kimi session cookies found in browsers."
        }
    }
}
#endif
