import Foundation

// Mirrors Kotlin BmlContactsClient exactly.
// Endpoint: GET /api/mobile/contacts
// Response: { success: true, payload: [ { id, name, alias, account, status, currency }, ... ] }
final class BmlContactsClient {

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

    private let bmlSession: BmlSession
    private let urlSession: URLSession

    init(bmlSession: BmlSession) {
        self.bmlSession = bmlSession
        let cfg = URLSessionConfiguration.ephemeral
        cfg.timeoutIntervalForRequest = 30
        self.urlSession = URLSession(configuration: cfg)
    }

    func fetchContacts(loginTag: String) async throws -> [BankContact] {
        var req = URLRequest(url: URL(string: "\(base)/api/mobile/contacts")!)
        req.setValue("Bearer \(bmlSession.accessToken)", forHTTPHeaderField: "Authorization")
        req.setValue(ua,  forHTTPHeaderField: "User-Agent")
        req.setValue(ver, forHTTPHeaderField: "x-app-version")

        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.compactMap { item -> BankContact? in
            let account = item["account"] as? String ?? ""
            guard !account.isEmpty else { return nil }

            let id      = item["id"] as? Int ?? 0
            let name    = item["name"] as? String ?? ""
            let alias   = (item["alias"] as? String).flatMap { $0.isEmpty ? nil : $0 } ?? name
            let status  = item["status"] as? String ?? "S"
            let currency = item["currency"] as? String ?? "MVR"

            return BankContact(
                id:              "BML_bml_\(id)_\(loginTag)",
                benefNo:         "bml_\(id)",
                benefName:       name,
                benefNickName:   alias == name ? nil : alias,
                benefAccount:    account,
                benefType:       "I",
                bankColor:       "#0066A1",
                benefBankName:   "Bank of Maldives",
                bankCode:        "",
                benefStatus:     status,
                transferCyDesc:  currency,
                customerImgHash: nil,
                benefCategoryId: "BML",
                profileId:       loginTag,
                source:          "BML"
            )
        }
    }
}