//
//  ProfileViewModel.swift
//  suixinkan
//

import Foundation

/// 个人信息页 ViewModel，负责资料加载与账号相关操作。
final class ProfileViewModel {

    private(set) var userInfo: UserInfoResponse?
    private(set) var realNameInfo: RealNameInfo?
    private(set) var bankCardInfo: BankCardInfo?
    private(set) var isLoading = false
    private(set) var isSaving = false

    var onStateChange: (() -> Void)?

    var displayNickname: String {
        nonEmpty(userInfo?.nickname) ?? "未设置昵称"
    }

    var displayRealName: String {
        nonEmpty(userInfo?.realName) ?? "--"
    }

    var displayPhone: String {
        nonEmpty(userInfo?.phone) ?? AppStore.shared.phone.nonEmpty ?? "--"
    }

    var displayAvatarURL: String {
        nonEmpty(userInfo?.avatar) ?? AppStore.shared.avatar.nonEmpty ?? ""
    }

    var displayUID: String {
        let uid = AppStore.shared.userId.trimmingCharacters(in: .whitespacesAndNewlines)
        return uid.isEmpty ? "--" : uid
    }

    var accountDisplayName: String {
        let name = AppStore.shared.accountDisplayName.trimmingCharacters(in: .whitespacesAndNewlines)
        return name.isEmpty ? "--" : name
    }

    var currentScenicName: String {
        let name = AppStore.shared.currentScenicName.trimmingCharacters(in: .whitespacesAndNewlines)
        return name.isEmpty ? "--" : name
    }

    var accountStatusText: String {
        nonEmpty(userInfo?.statusName) ?? "--"
    }

    var showPhotographerFields: Bool {
        if AppStore.shared.isPhotographerRole {
            return true
        }
        if let roleName = nonEmpty(userInfo?.roleName) {
            return AppRoleCode.fromRoleName(roleName)?.isPhotographer == true || roleName == "摄影师"
        }
        return false
    }

    var realNameStatusText: String {
        guard let realNameInfo else { return "点击去实名认证" }
        switch realNameInfo.auditStatus {
        case 2: return "已实名认证"
        case 3: return "审核不通过"
        default: return "审核中"
        }
    }

    var bankCardDisplayText: String {
        guard let bankCardInfo else { return "点击绑定银行卡" }
        if bankCardInfo.auditStatus == 2 {
            let masked = Self.maskCardNumber(bankCardInfo.cardNumber)
            return "\(bankCardInfo.bankName) \(masked)"
        }
        let label = bankCardInfo.auditStatusLabel.trimmingCharacters(in: .whitespacesAndNewlines)
        return label.isEmpty ? "审核中" : label
    }

    func reload(api: ProfileAPI) async throws {
        guard !isLoading else { return }
        isLoading = true
        notifyStateChange()
        defer {
            isLoading = false
            notifyStateChange()
        }

        let info = try await api.userInfo()
        userInfo = info
        AppStore.shared.applyUserInfo(info)
        if !info.roleName.isEmpty {
            AppStore.shared.roleName = info.roleName
        }

        if showPhotographerFields {
            async let realName = api.realNameInfo()
            async let bankCard = api.bankCardInfo()
            let extra = try await (realName, bankCard)
            realNameInfo = extra.0.realNameInfo
            bankCardInfo = extra.1.bankCard
        } else {
            realNameInfo = nil
            bankCardInfo = nil
        }
    }

    /// 从 `AppStore` 同步头像与昵称，用于资料保存后的本地即时刷新。
    func applyLocalProfileUpdate(from store: AppStore = .shared) {
        let previous = userInfo ?? UserInfoResponse()
        let nextNickname = store.userName.trimmingCharacters(in: .whitespacesAndNewlines)
        let nextAvatar = store.avatar.trimmingCharacters(in: .whitespacesAndNewlines)
        userInfo = UserInfoResponse(
            avatar: nextAvatar.isEmpty ? previous.avatar : nextAvatar,
            realName: previous.realName,
            phone: previous.phone,
            nickname: nextNickname.isEmpty ? previous.nickname : nextNickname,
            roleName: previous.roleName,
            status: previous.status,
            statusName: previous.statusName
        )
        notifyStateChange()
    }

    func updatePassword(_ password: String, api: ProfileAPI) async throws {
        let nextPassword = password.trimmingCharacters(in: .whitespacesAndNewlines)
        guard nextPassword.count >= 6 else {
            throw ProfileValidationError.shortPassword
        }

        guard !isSaving else { return }
        isSaving = true
        notifyStateChange()
        defer {
            isSaving = false
            notifyStateChange()
        }

        try await api.updateUserInfo(password: nextPassword)
    }

    static func maskCardNumber(_ cardNumber: String) -> String {
        let digits = cardNumber.filter(\.isNumber)
        guard digits.count >= 4 else { return cardNumber }
        return "**** **** **** \(digits.suffix(4))"
    }

    private func nonEmpty(_ value: String?) -> String? {
        let text = value?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
        return text.isEmpty ? nil : text
    }

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

private extension String {
    var nonEmpty: String? {
        let text = trimmingCharacters(in: .whitespacesAndNewlines)
        return text.isEmpty ? nil : text
    }
}