//
//  WriteOffListViewModel.swift
//  suixinkan
//
//  Created by Codex on 2026/6/29.
//

import Foundation
import Combine

@MainActor
/// 核销管理页 ViewModel，对齐 Android WriteOffListViewModel。
final class WriteOffListViewModel: ObservableObject {
    @Published var searchPhone = ""
    @Published var selectedStatus = 0
    @Published var filterStartDate: Date?
    @Published var filterEndDate: Date?
    @Published private(set) var orders: [WriteOffOrderItem] = []
    @Published private(set) var loading = false
    @Published private(set) var loadingMore = false
    @Published private(set) var isVerifying = false
    @Published private(set) var total = 0
    @Published private(set) var page = 1
    @Published private(set) var hasMore = false

    private let pageSize = 20

    /// 返回去除首尾空白后的手机号搜索值。
    var normalizedPhone: String? {
        let text = searchPhone.trimmingCharacters(in: .whitespacesAndNewlines)
        return text.isEmpty ? nil : text
    }

    /// 刷新核销列表。
    func reload(api: OrderServing, scenicId: Int?, storeId: Int? = nil, showLoading: Bool = true) async throws {
        guard let scenicId else {
            orders = []
            total = 0
            page = 1
            hasMore = false
            return
        }

        if showLoading { loading = true }
        defer { if showLoading { loading = false } }

        let result = try await api.writeOffList(
            scenicId: scenicId,
            storeId: storeId,
            page: 1,
            pageSize: pageSize,
            orderStatus: orderStatusQuery,
            orderVerifyStatus: verifyStatusQuery,
            startTime: OrderDateRangeFormatter.queryValue(from: filterStartDate),
            endTime: OrderDateRangeFormatter.queryValue(from: filterEndDate),
            userPhone: normalizedPhone
        )
        orders = result.list
        total = result.total
        page = 1
        hasMore = orders.count < result.total && !result.list.isEmpty
    }

    /// 加载下一页。
    func loadMore(api: OrderServing, scenicId: Int?, storeId: Int? = nil) async throws {
        guard !loadingMore, hasMore, let scenicId else { return }
        loadingMore = true
        defer { loadingMore = false }

        let nextPage = page + 1
        let result = try await api.writeOffList(
            scenicId: scenicId,
            storeId: storeId,
            page: nextPage,
            pageSize: pageSize,
            orderStatus: orderStatusQuery,
            orderVerifyStatus: verifyStatusQuery,
            startTime: OrderDateRangeFormatter.queryValue(from: filterStartDate),
            endTime: OrderDateRangeFormatter.queryValue(from: filterEndDate),
            userPhone: normalizedPhone
        )
        orders.append(contentsOf: result.list)
        total = result.total
        page = nextPage
        hasMore = orders.count < result.total && !result.list.isEmpty
    }

    /// 核销订单并刷新列表。
    func verify(api: OrderServing, scenicId: Int, storeId: Int? = nil, orderNumber: String) async throws {
        guard !isVerifying else { return }
        isVerifying = true
        defer { isVerifying = false }

        try await api.writeOff(orderNumber: orderNumber)
        try await reload(api: api, scenicId: scenicId, storeId: storeId, showLoading: false)
    }

    /// 解析扫码结果并返回当前列表中的匹配订单。
    func matchedWriteOffOrder(for rawCode: String) -> (orderNumber: String, matched: WriteOffOrderItem?)? {
        guard let orderNumber = OrderNumberParser.parse(rawCode) else { return nil }
        let matched = orders.first {
            $0.orderNumber.caseInsensitiveCompare(orderNumber) == .orderedSame
        }
        return (matched?.orderNumber ?? orderNumber, matched)
    }

    /// 根据订单号查找当前列表中的订单。
    func writeOffOrder(matching orderNumber: String) -> WriteOffOrderItem? {
        orders.first { $0.orderNumber.caseInsensitiveCompare(orderNumber) == .orderedSame }
    }

    /// 判断订单是否仍可核销。
    func canVerify(_ item: WriteOffOrderItem) -> Bool {
        let status = displayVerificationStatus(for: item)
        return !status.contains("已核销") && !status.contains("已退款") && !status.contains("已完成")
    }

    /// 返回核销状态展示文案。
    func displayVerificationStatus(for item: WriteOffOrderItem) -> String {
        let text = item.orderVerificationStatus.trimmingCharacters(in: .whitespacesAndNewlines)
        return text.isEmpty ? "待核销" : text
    }

    private var orderStatusQuery: Int? {
        switch selectedStatus {
        case 18, 30:
            return selectedStatus
        default:
            return nil
        }
    }

    private var verifyStatusQuery: Int? {
        switch selectedStatus {
        case 1, 2:
            return selectedStatus
        default:
            return nil
        }
    }
}