import SwiftUI
import CoreModel
import CoreUI
import DesignSystem

public struct ProfileScreen: View {
    private let viewModel: ProfileViewModel
    private let onNavigateToAuth: () -> Void

    @State private var showLogoutConfirm = false

    public init(viewModel: ProfileViewModel, onNavigateToAuth: @escaping () -> Void) {
        self.viewModel = viewModel
        self.onNavigateToAuth = onNavigateToAuth
    }

    public var body: some View {
        content
            .navigationTitle("我的")
            .task { viewModel.load() }
    }

    @ViewBuilder
    private var content: some View {
        switch viewModel.uiState {
        case .loading:
            LoadingView()
        case .loggedOut:
            LoggedOutView(onNavigateToAuth: onNavigateToAuth)
        case .error(let message):
            ErrorView(message: message) { viewModel.load() }
        case .success(let profile):
            successContent(profile)
        }
    }

    private func successContent(_ profile: UserProfile) -> some View {
        ScrollView {
            VStack(spacing: DS.Spacing.md) {
                ProfileHeaderCard(profile: profile)
                InfoCard(profile: profile)
                if !profile.classGroups.isEmpty {
                    ClassGroupCard(groups: profile.classGroups)
                }
                Button("退出登录", role: .destructive) {
                    showLogoutConfirm = true
                }
                .frame(maxWidth: .infinity)
                .buttonStyle(.bordered)
            }
            .padding(DS.Spacing.md)
        }
        .background(DS.Color.brandPaper)
        .alert("退出登录", isPresented: $showLogoutConfirm) {
            Button("取消", role: .cancel) {}
            Button("确定", role: .destructive) { viewModel.logout() }
        } message: {
            Text("确定要退出登录吗？退出后需要重新登录。")
        }
    }
}

// MARK: - 头像卡

private struct ProfileHeaderCard: View {
    let profile: UserProfile

    var body: some View {
        HStack(spacing: DS.Spacing.md) {
            ZStack(alignment: .bottomTrailing) {
                Text(String(profile.displayName.prefix(1)))
                    .font(.title.bold())
                    .foregroundStyle(.white)
                    .frame(width: 56, height: 56)
                    .background(DS.Color.brandGold)
                    .clipShape(Circle())
                Text("📷")
                    .font(.caption2)
                    .frame(width: 20, height: 20)
                    .background(DS.Color.brandGold)
                    .clipShape(Circle())
                    .overlay(Circle().stroke(DS.Color.brandPaper, lineWidth: 2))
            }
            VStack(alignment: .leading, spacing: 2) {
                HStack(spacing: DS.Spacing.xs) {
                    Text(profile.displayName)
                        .font(.title3.bold())
                        .foregroundStyle(DS.Color.brandDark)
                    Text(profile.role)
                        .font(.caption.bold())
                        .foregroundStyle(DS.Color.brandGold)
                        .padding(.horizontal, DS.Spacing.sm)
                        .padding(.vertical, 2)
                        .background(DS.Color.brandChip)
                        .clipShape(Capsule())
                }
                Text(profile.studentId)
                    .font(.caption)
                    .foregroundStyle(DS.Color.brandMuted)
            }
            Spacer()
        }
        .padding(DS.Spacing.md)
        .background(Color.white)
        .clipShape(RoundedRectangle(cornerRadius: 16, style: .continuous))
    }
}

// MARK: - 信息卡

private struct InfoCard: View {
    let profile: UserProfile

    var body: some View {
        VStack(alignment: .leading, spacing: DS.Spacing.sm) {
            Text("个人信息")
                .font(.subheadline.bold())
                .foregroundStyle(DS.Color.brandDark)
            LabeledRow(label: "姓名", value: profile.name)
            LabeledRow(label: "学号", value: profile.studentId)
            LabeledRow(label: "手机号", value: profile.phone ?? "未绑定")
            LabeledRow(label: "角色", value: profile.role)
            LabeledRow(label: "小组", value: profile.group ?? "未分组")
            LabeledRow(label: "登录方式", value: profile.loginType)
        }
        .padding(DS.Spacing.md)
        .frame(maxWidth: .infinity, alignment: .leading)
        .background(Color.white)
        .clipShape(RoundedRectangle(cornerRadius: 16, style: .continuous))
    }
}

private struct ClassGroupCard: View {
    let groups: [ClassGroup]

    var body: some View {
        VStack(alignment: .leading, spacing: DS.Spacing.sm) {
            Text("小组分组")
                .font(.subheadline.bold())
                .foregroundStyle(DS.Color.brandDark)
            ForEach(groups) { group in
                LabeledRow(label: group.period, value: "\(group.group) · \(group.role)")
            }
        }
        .padding(DS.Spacing.md)
        .frame(maxWidth: .infinity, alignment: .leading)
        .background(Color.white)
        .clipShape(RoundedRectangle(cornerRadius: 16, style: .continuous))
    }
}

private struct LabeledRow: View {
    let label: String
    let value: String

    var body: some View {
        HStack {
            Text(label)
                .font(.subheadline)
                .foregroundStyle(DS.Color.brandMuted)
            Spacer()
            Text(value)
                .font(.subheadline)
                .foregroundStyle(DS.Color.brandDark)
        }
        .padding(.vertical, DS.Spacing.xs)
    }
}