//
//  CooperationAcquirerViewModel.swift
//  suixinkan
//

import Foundation

/// 合作获客员 ViewModel，对齐 Android `CooperationAcquirerViewModel`。
final class CooperationAcquirerViewModel {

    private(set) var acquirers: [CooperativeSalerEntity] = []
    private(set) var isRefreshing = false
    private(set) var remarkEditingAcquirer: CooperativeSalerEntity?
    private(set) var remarkDraft = ""
    private(set) var commissionEditingAcquirer: CooperativeSalerEntity?
    private(set) var commissionRateDraft = ""
    private(set) var commissionSmsCodeDraft = ""
    private(set) var commissionSmsCountdown = 0

    var onStateChange: (() -> Void)?
    var onShowMessage: ((String) -> Void)?
    var onNavigateBindAcquirer: ((Int) -> Void)?

    private let appStore: AppStore
    private var commissionSmsTimerTask: Task<Void, Never>?

    init(appStore: AppStore = .shared) {
        self.appStore = appStore
    }

    deinit {
        commissionSmsTimerTask?.cancel()
    }

    func loadAcquirers(api: OrderAPI, initial: Bool = false) async {
        let storeId = appStore.session.currentStoreId
        let storeIdParam = storeId > 0 ? String(storeId) : nil
        do {
            let response = try await api.cooperativeSalers(storeId: storeIdParam, pageSize: "20")
            acquirers = response.list
        } catch {
            onShowMessage?(error.localizedDescription)
        }
        isRefreshing = false
        notifyStateChange()
    }

    func refresh(api: OrderAPI) async {
        isRefreshing = true
        notifyStateChange()
        await loadAcquirers(api: api, initial: false)
    }

    func startEditRemark(_ acquirer: CooperativeSalerEntity) {
        remarkEditingAcquirer = acquirer
        remarkDraft = acquirer.photogRemarkName
        notifyStateChange()
    }

    func updateRemarkDraft(_ text: String) {
        remarkDraft = String(text.prefix(CooperationOrderFeature.remarkNameMaxLength))
        notifyStateChange()
    }

    func dismissRemarkDialog() {
        remarkEditingAcquirer = nil
        remarkDraft = ""
        notifyStateChange()
    }

    func saveRemark(api: OrderAPI) async {
        guard let acquirer = remarkEditingAcquirer else { return }
        let saleUserId = acquirer.saleUserId
        guard saleUserId > 0 else { return }
        let trimmedRemark = remarkDraft.trimmingCharacters(in: .whitespacesAndNewlines)
        if let message = CooperationOrderFeature.remarkNameValidationMessage(remarkDraft) {
            onShowMessage?(message)
            return
        }
        dismissRemarkDialog()
        do {
            try await api.saleUserUpdateRemark(saleUserId: saleUserId, photogRemarkName: trimmedRemark)
            acquirers = acquirers.map { item in
                item.saleUserId == saleUserId ? item.withRemarkName(trimmedRemark) : item
            }
            onShowMessage?("备注已保存")
            notifyStateChange()
        } catch {
            onShowMessage?(error.localizedDescription)
        }
    }

    func startEditCommissionRate(_ acquirer: CooperativeSalerEntity) {
        stopCommissionSmsTimer()
        commissionEditingAcquirer = acquirer
        commissionRateDraft = String(acquirer.commissionRate)
        commissionSmsCodeDraft = ""
        notifyStateChange()
    }

    func updateCommissionRateDraft(_ text: String) {
        commissionRateDraft = String(text.filter(\.isNumber).prefix(3))
        notifyStateChange()
    }

    func updateCommissionSmsCodeDraft(_ text: String) {
        commissionSmsCodeDraft = String(text.filter(\.isNumber).prefix(6))
        notifyStateChange()
    }

    func dismissCommissionRateDialog() {
        commissionEditingAcquirer = nil
        commissionRateDraft = ""
        commissionSmsCodeDraft = ""
        stopCommissionSmsTimer()
        notifyStateChange()
    }

    func requestCommissionSmsCode(api: OrderAPI) async {
        guard let acquirer = commissionEditingAcquirer else { return }
        if commissionSmsCountdown > 0 {
            onShowMessage?("请在倒计时结束后重新获取")
            return
        }
        let phone = acquirer.salerPhone.isEmpty ? acquirer.displayPhone : acquirer.salerPhone
        let trimmedPhone = phone.trimmingCharacters(in: .whitespacesAndNewlines)
        guard !trimmedPhone.isEmpty else {
            onShowMessage?("获客员手机号为空")
            return
        }
        do {
            try await api.saleUserCommissionRateSendSmsCode(phone: trimmedPhone)
            startCommissionSmsTimer()
            onShowMessage?("验证码已发送")
        } catch {
            onShowMessage?(error.localizedDescription)
        }
    }

    func saveCommissionRate(api: OrderAPI) async {
        guard let acquirer = commissionEditingAcquirer else { return }
        let saleUserId = acquirer.saleUserId
        guard saleUserId > 0 else { return }
        guard let commissionRate = Int(commissionRateDraft.trimmingCharacters(in: .whitespacesAndNewlines)) else {
            onShowMessage?("请输入分成比例")
            return
        }
        guard (0...100).contains(commissionRate) else {
            onShowMessage?("分成比例需在0到100之间")
            return
        }
        let smsCode = commissionSmsCodeDraft.trimmingCharacters(in: .whitespacesAndNewlines)
        guard !smsCode.isEmpty else {
            onShowMessage?("请输入验证码")
            return
        }
        do {
            let updated = try await api.saleUserUpdateCommissionRate(
                saleUserId: saleUserId,
                commissionRate: commissionRate,
                smsCode: smsCode
            )
            dismissCommissionRateDialog()
            if updated.saleUserId > 0 {
                acquirers = acquirers.map { item in
                    item.saleUserId == updated.saleUserId ? updated : item
                }
            } else {
                await loadAcquirers(api: api, initial: false)
            }
            onShowMessage?("分成比例已修改")
            notifyStateChange()
        } catch {
            onShowMessage?(error.localizedDescription)
        }
    }

    func processScanResult(_ scanResult: String) {
        guard let saleUserId = SaleUserQrParser.parseSaleUserId(scanResult), saleUserId > 0 else {
            onShowMessage?("请扫描正确的获客员二维码")
            return
        }
        onNavigateBindAcquirer?(saleUserId)
    }

    private func startCommissionSmsTimer() {
        commissionSmsTimerTask?.cancel()
        commissionSmsCountdown = 60
        notifyStateChange()
        commissionSmsTimerTask = Task { [weak self] in
            guard let self else { return }
            try? await Task.sleep(nanoseconds: 1_000_000_000)
            for second in stride(from: 59, through: 1, by: -1) {
                if Task.isCancelled { return }
                commissionSmsCountdown = second
                notifyStateChange()
                try? await Task.sleep(nanoseconds: 1_000_000_000)
            }
            if !Task.isCancelled {
                commissionSmsCountdown = 0
                notifyStateChange()
            }
        }
    }

    private func stopCommissionSmsTimer() {
        commissionSmsTimerTask?.cancel()
        commissionSmsTimerTask = nil
        commissionSmsCountdown = 0
    }

    private func notifyStateChange() {
        onStateChange?()
    }
}