import Foundation

// Mirrors the Kotlin MibContactsClient exactly.
// Endpoint: POST https://faisamobilex-wv.mib.com.mv/ajaxBeneficiary/main
// Auth: Cookie header with xxid, IBSID, mbnonce, mbmodel (same session established by MibLoginFlow).
actor MibContactsClient {

    private let wvBase = "https://faisamobilex-wv.mib.com.mv"

    private let urlSession: URLSession = {
        let cfg = URLSessionConfiguration.ephemeral
        cfg.timeoutIntervalForRequest = 30
        cfg.timeoutIntervalForResource = 60
        cfg.httpCookieAcceptPolicy = .never
        cfg.httpShouldSetCookies = false
        return URLSession(configuration: cfg)
    }()

    private let session: MibSession

    init(session: MibSession) {
        self.session = session
    }

    // MARK: - Public

    func fetchContacts(loginTag: String) async throws -> [BankContact] {
        var all: [BankContact] = []
        var page = 1
        let pageSize = 100

        while true {
            let start = (page - 1) * pageSize + 1
            let end   = page * pageSize

            let formFields: [(String, String)] = [
                ("page",             String(page)),
                ("search",           ""),
                ("searchCategoryId", "0"),
                ("benefType",        "A"),
                ("sortBenef",        "name"),
                ("sortDir",          "asc"),
                ("start",            String(start)),
                ("end",              String(end)),
                ("includeCount",     "1"),
            ]

            let (contacts, totalCount) = try await fetchPage(formFields: formFields, loginTag: loginTag)
            all.append(contentsOf: contacts)
            if all.count >= totalCount || contacts.isEmpty { break }
            page += 1
        }
        return all
    }

    // MARK: - Private

    private func fetchPage(formFields: [(String, String)], loginTag: String) async throws -> ([BankContact], Int) {
        let url = URL(string: "\(wvBase)/ajaxBeneficiary/main")!

        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
        request.setValue(cookieHeader, forHTTPHeaderField: "Cookie")
        request.setValue(
            "Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148",
            forHTTPHeaderField: "User-Agent"
        )
        request.setValue("XMLHttpRequest", forHTTPHeaderField: "X-Requested-With")
        request.setValue("*/*",            forHTTPHeaderField: "Accept")
        request.setValue(wvBase,           forHTTPHeaderField: "Origin")
        request.setValue("\(wvBase)/beneficiary?dashurl=1", forHTTPHeaderField: "Referer")

        var allowed = CharacterSet.alphanumerics
        allowed.insert(charactersIn: "-._~")
        let body = formFields.map { k, v in
            "\(k.addingPercentEncoding(withAllowedCharacters: allowed) ?? k)=\(v.addingPercentEncoding(withAllowedCharacters: allowed) ?? v)"
        }.joined(separator: "&")
        request.httpBody = Data(body.utf8)

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

        guard let obj = try? JSONSerialization.jsonObject(with: data) as? [String: Any] else {
            throw MibError.invalidResponse
        }

        let totalCount = obj["total_count"] as? Int
            ?? Int(obj["total_count"] as? String ?? "") ?? 0

        guard let arr = obj["data"] as? [[String: Any]] else {
            return ([], totalCount)
        }

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

            let benefNo = d["benefNo"] as? String ?? account
            // Android: benefType "I"=Internal(MIB), "L"=Local(IPS), "S"=Swift
            let rawType = d["benefType"] as? String ?? "I"
            let benefType: String
            switch rawType {
            case "I": benefType = "MIB"
            case "L": benefType = "LOCAL"
            case "S": benefType = "SWIFT"
            default:  benefType = rawType
            }

            return BankContact(
                id:              "MIB_\(benefNo)_\(loginTag)",
                benefNo:         benefNo,
                benefName:       d["benefName"] as? String ?? "",
                benefNickName:   (d["benefNickName"] as? String).flatMap { $0.isEmpty ? nil : $0 },
                benefAccount:    account,
                benefType:       benefType,
                bankColor:       d["bankColor"] as? String,
                benefBankName:   d["benefBankName"] as? String,
                bankCode:        d["bankCode"] as? String,
                benefStatus:     d["benefStatus"] as? String ?? "Active",
                transferCyDesc:  d["transferCyDesc"] as? String ?? "MVR",
                customerImgHash: (d["customerImgHash"] as? String).flatMap { $0.isEmpty || $0 == "null" ? nil : $0 },
                benefCategoryId: d["benefCategoryID"] as? String,
                profileId:       nil,
                source:          "MIB"
            )
        }

        return (contacts, totalCount)
    }

    private var cookieHeader: String {
        "mbmodel=IOS-1.0; xxid=\(session.xxid); IBSID=\(session.xxid); mbnonce=\(session.nonceGenerator); time-tracker=597"
    }
}