//
//  AccountSelectionView.swift
//  suixinkan
//
//  Created by Codex on 2026/6/20.
//

import SwiftUI

/// 账号选择视图，展示 v9 登录返回的多个景区/门店账号并提交用户选择。
struct AccountSelectionView: View {
    let payload: AccountSelectionPayload
    let isLoading: Bool
    let onCancel: () -> Void
    let onConfirm: (AccountSwitchAccount) -> Void

    @State private var selectedAccountId: String?

    private var selectedAccount: AccountSwitchAccount? {
        payload.accounts.first { $0.id == selectedAccountId }
    }

    var body: some View {
        NavigationStack {
            VStack(spacing: 0) {
                accountList
                bottomBar
            }
            .background(Color(hex: 0xF5F7FB).ignoresSafeArea())
            .navigationTitle("选择账号")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("取消", action: onCancel)
                }
            }
            .onAppear {
                selectedAccountId = selectedAccountId ?? payload.accounts.first?.id
            }
        }
        .interactiveDismissDisabled(isLoading)
    }

    @ViewBuilder
    private var accountList: some View {
        if payload.accounts.isEmpty {
            AppContentUnavailableView(
                "暂无可用账号",
                systemImage: "person.crop.circle.badge.exclamationmark",
                description: Text("当前账号没有可用的景区账号或门店账号，请联系管理员。")
            )
            .frame(maxWidth: .infinity, maxHeight: .infinity)
            .padding(AppMetrics.Spacing.xLarge)
        } else {
            ScrollView {
                LazyVStack(spacing: AppMetrics.Spacing.small) {
                    ForEach(payload.accounts) { account in
                        accountCard(account)
                    }
                }
                .padding(AppMetrics.Spacing.medium)
                .padding(.bottom, 90)
            }
        }
    }

    private var bottomBar: some View {
        VStack(spacing: 0) {
            Divider()
            Button {
                guard let selectedAccount else { return }
                onConfirm(selectedAccount)
            } label: {
                Text("进入系统")
                    .font(.system(size: AppMetrics.FontSize.body, weight: .semibold))
                    .foregroundStyle(.white)
                .frame(maxWidth: .infinity)
                .frame(height: AppMetrics.ControlSize.primaryButtonHeight)
                .background(canConfirm ? AppDesign.primary : Color(hex: 0xC9CED6), in: RoundedRectangle(cornerRadius: AppMetrics.CornerRadius.button))
                .padding(.horizontal, AppMetrics.Spacing.medium)
                .padding(.vertical, AppMetrics.FontSize.subheadline)
            }
            .buttonStyle(.plain)
            .disabled(!canConfirm)
        }
        .background(.white)
    }

    private var canConfirm: Bool {
        selectedAccount != nil && !isLoading
    }

    /// 渲染单个账号卡片，并处理选中状态。
    private func accountCard(_ account: AccountSwitchAccount) -> some View {
        let selected = selectedAccountId == account.id
        return Button {
            selectedAccountId = account.id
        } label: {
            HStack(spacing: AppMetrics.FontSize.footnote) {
                avatarFallback(account)
                    .frame(width: AppMetrics.ControlSize.primaryButtonHeight, height: AppMetrics.ControlSize.primaryButtonHeight)

                VStack(alignment: .leading, spacing: AppMetrics.Spacing.xxSmall) {
                    HStack(spacing: AppMetrics.Spacing.xSmall) {
                        Text(account.title.isEmpty ? account.accountTypeLabel : account.title)
                            .font(.system(size: AppMetrics.FontSize.body, weight: .semibold))
                            .foregroundStyle(AppDesign.textPrimary)
                            .lineLimit(1)
                        if account.isCurrent {
                            tag("当前", foreground: AppDesign.primary, background: AppDesign.primarySoft)
                        }
                    }

                    if !account.subtitle.isEmpty {
                        Text(account.subtitle)
                            .font(.system(size: AppMetrics.FontSize.footnote))
                            .foregroundStyle(AppDesign.textSecondary)
                            .lineLimit(1)
                    }

                    if !account.phone.isEmpty {
                        Text(account.phone)
                            .font(.system(size: AppMetrics.FontSize.caption))
                            .foregroundStyle(Color(hex: 0x9AA1AA))
                    }
                }
                .frame(maxWidth: .infinity, alignment: .leading)

                VStack(alignment: .trailing, spacing: AppMetrics.Spacing.xSmall) {
                    tag(
                        account.isStoreUser ? "门店" : "景区",
                        foreground: account.isStoreUser ? Color(hex: 0x0F9F6E) : Color(hex: 0x7C3AED),
                        background: account.isStoreUser ? Color(hex: 0xE8F8F1) : Color(hex: 0xF3ECFF)
                    )
                    Image(systemName: selected ? "checkmark.circle.fill" : "circle")
                        .font(.system(size: AppMetrics.ControlSize.passwordIcon, weight: .semibold))
                        .foregroundStyle(selected ? AppDesign.primary : Color(hex: 0xB6BECA))
                }
            }
            .padding(AppMetrics.FontSize.subheadline)
            .background(.white, in: RoundedRectangle(cornerRadius: AppMetrics.CornerRadius.button))
            .overlay {
                RoundedRectangle(cornerRadius: AppMetrics.CornerRadius.button)
                    .stroke(selected ? AppDesign.primary : Color(hex: 0xE6ECF4), lineWidth: selected ? 1.4 : 1)
            }
            .shadow(color: Color(hex: 0xC8D7EA, alpha: selected ? 0.24 : 0.12), radius: selected ? 10 : 6, x: 0, y: 5)
        }
        .buttonStyle(.plain)
    }

    /// 构造账号头像占位视图，按景区或门店账号展示不同标识。
    private func avatarFallback(_ account: AccountSwitchAccount) -> some View {
        ZStack {
            Circle()
                .fill(account.isStoreUser ? Color(hex: 0xE8F8F1) : Color(hex: 0xF3ECFF))
            Text(account.isStoreUser ? "店" : "景")
                .font(.system(size: AppMetrics.FontSize.callout, weight: .semibold))
                .foregroundStyle(account.isStoreUser ? Color(hex: 0x0F9F6E) : Color(hex: 0x7C3AED))
        }
    }

    /// 构造账号类型和当前账号标记使用的胶囊标签。
    private func tag(_ text: String, foreground: Color, background: Color) -> some View {
        Text(text)
            .font(.system(size: 11, weight: .semibold))
            .foregroundStyle(foreground)
            .padding(.horizontal, 7)
            .frame(height: AppMetrics.Spacing.sheet)
            .background(background, in: RoundedRectangle(cornerRadius: AppMetrics.Spacing.xxSmall))
    }
}

#Preview {
    AccountSelectionView(
        payload: AccountSelectionPayload(
            tempToken: "token",
            accounts: [
                AccountSwitchAccount(
                    accountType: V9ScenicUser.accountTypeValue,
                    businessUserId: 1,
                    title: "西湖景区",
                    subtitle: "摄影师",
                    phone: "13800000000",
                    avatar: "",
                    scenicName: "西湖景区",
                    storeId: nil,
                    storeName: "",
                    scenicId: 100,
                    isCurrent: false
                ),
                AccountSwitchAccount(
                    accountType: V9StoreUser.accountTypeValue,
                    businessUserId: 2,
                    title: "东门门店",
                    subtitle: "西湖景区 · 店长",
                    phone: "13900000000",
                    avatar: "",
                    scenicName: "西湖景区",
                    storeId: 200,
                    storeName: "东门门店",
                    scenicId: 100,
                    isCurrent: true
                )
            ]
        ),
        isLoading: false,
        onCancel: {},
        onConfirm: { _ in }
    )
}