import Foundation

// Mirrors Kotlin BmlForeignLimitsClient exactly.
// Endpoint: GET https://app.bankofmaldives.com.mv/api/v2/foreign-limits
final class BmlForeignLimitsClient {

    private let base = "https://app.bankofmaldives.com.mv/api/v2"
    private let ua   = "bml-mobile-banking/348 (Apple; iOS 17.0; iPhone)"
    private let ver  = "2.1.44.348"

    private let urlSession: URLSession = {
        let cfg = URLSessionConfiguration.ephemeral
        cfg.timeoutIntervalForRequest = 30
        return URLSession(configuration: cfg)
    }()

    func fetchForeignLimits(session: BmlSession) async throws -> [BmlForeignLimit] {
        var req = URLRequest(url: URL(string: "\(base)/foreign-limits")!)
        req.setValue("Bearer \(session.accessToken)", forHTTPHeaderField: "Authorization")
        req.setValue(ua,                "User-Agent")
        req.setValue(ver,               "x-app-version")
        req.setValue("application/json","Accept")

        let (data, response) = try await urlSession.data(for: req)
        let code = (response as? HTTPURLResponse)?.statusCode ?? 0
        if code == 401 || code == 419 { throw BmlError.sessionExpired }
        if code >= 500 { throw BmlError.networkError("HTTP \(code)") }

        guard let root = try? JSONSerialization.jsonObject(with: data) as? [String: Any],
              root["success"] as? Bool == true,
              let payload = root["payload"] as? [[String: Any]] else {
            return []
        }

        return payload.map { item in
            let usage = item["usageByCategory"] as? [String: Any] ?? [:]
            let atm   = usage["ATM"]  as? [String: Any] ?? [:]
            let ecom  = usage["ECOM"] as? [String: Any] ?? [:]
            let pos   = usage["POS"]  as? [String: Any] ?? [:]
            return BmlForeignLimit(
                type:             item["type"]             as? String ?? "Debit",
                used:             item["used"]             as? Double ?? 0,
                totalLimit:       item["totalLimit"]       as? Double ?? 0,
                generalCap:       item["generalCap"]       as? Double ?? 0,
                generalRemaining: item["generalRemaining"] as? Double ?? 0,
                medicalRemaining: item["medicalRemaining"] as? Double ?? 0,
                isAtmEnabled:     item["isAtmEnabled"]     as? Bool   ?? false,
                isPosEnabled:     item["isPosEnabled"]     as? Bool   ?? false,
                atmRemaining:     atm["remaining"]         as? Double ?? 0,
                atmLimit:         atm["limit"]             as? Double ?? 0,
                ecomRemaining:    ecom["remaining"]        as? Double ?? 0,
                ecomLimit:        ecom["limit"]            as? Double ?? 0,
                posRemaining:     pos["remaining"]         as? Double ?? 0,
                posLimit:         pos["limit"]             as? Double ?? 0
            )
        }
    }
}

private extension URLRequest {
    mutating func setValue(_ value: String, _ field: String) {
        setValue(value, forHTTPHeaderField: field)
    }
}