//
//  PermissionApplyStatusView.swift
//  suixinkan
//
//  Created by Codex on 2026/6/23.
//

import SwiftUI

/// 权限申请状态页面，展示审核中、通过或驳回的角色景区权限申请。
struct PermissionApplyStatusView: View {
    @Environment(ScenicPermissionAPI.self) private var scenicPermissionAPI
    @State private var viewModel = PermissionApplyStatusViewModel()
    @State private var editingPending: RoleApplyPendingResponse?
    let applyCode: String?

    /// 初始化权限申请状态页面，可传入指定申请编号。
    init(applyCode: String? = nil) {
        self.applyCode = applyCode
    }

    var body: some View {
        ScrollView {
            VStack(spacing: AppMetrics.Spacing.small) {
                if let pending = viewModel.pending {
                    statusCard(pending)
                    roleCard(pending)
                    scenicCard(pending)
                } else if viewModel.loadFailed {
                    ContentUnavailableView(
                        "申请状态加载失败",
                        systemImage: "exclamationmark.triangle",
                        description: Text(viewModel.loadFailureReason ?? "请检查网络后重试")
                    )
                    Button("重新加载") {
                        Task { await viewModel.load(api: scenicPermissionAPI, applyCode: applyCode) }
                    }
                    .font(.system(size: AppMetrics.FontSize.footnote, weight: .semibold))
                    .buttonStyle(.plain)
                } else {
                    ContentUnavailableView("暂无审核中的申请", systemImage: "doc.text.magnifyingglass")
                }
            }
            .padding(AppMetrics.Spacing.medium)
        }
        .background(Color(hex: 0xF5F7FA).ignoresSafeArea())
        .navigationTitle("权限申请")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            if let pending = viewModel.pending, pending.status == 3 {
                ToolbarItem(placement: .topBarTrailing) {
                    Button {
                        editingPending = pending
                    } label: {
                        Label("去编辑", systemImage: "pencil")
                    }
                }
            }
        }
        .navigationDestination(item: $editingPending) { pending in
            PermissionApplyView(initialPending: pending)
        }
        .task {
            await viewModel.load(api: scenicPermissionAPI, applyCode: applyCode)
        }
    }

    /// 构建审核状态卡片。
    private func statusCard(_ pending: RoleApplyPendingResponse) -> some View {
        VStack(alignment: .leading, spacing: AppMetrics.Spacing.xSmall) {
            HStack {
                Label(statusLabel(pending), systemImage: statusIcon(pending.status))
                    .font(.system(size: AppMetrics.FontSize.subheadline, weight: .semibold))
                    .foregroundStyle(statusColor(pending.status))
                    .padding(.horizontal, AppMetrics.Spacing.small)
                    .frame(height: 28)
                    .background(statusColor(pending.status).opacity(0.12), in: Capsule())
                Spacer()
            }
            row("申请编号", pending.code)
            row("提交时间", pending.createdAt)
            row("审核时间", pending.auditedAt ?? "--")
            row("审核人", pending.auditedBy ?? "--")
            row("审核备注", pending.auditNote ?? "--")
        }
        .padding(AppMetrics.Spacing.small)
        .background(statusColor(pending.status).opacity(0.08), in: RoundedRectangle(cornerRadius: 12))
        .overlay {
            RoundedRectangle(cornerRadius: 12).stroke(statusColor(pending.status).opacity(0.35), lineWidth: 1)
        }
    }

    /// 构建角色卡片。
    private func roleCard(_ pending: RoleApplyPendingResponse) -> some View {
        VStack(alignment: .leading, spacing: AppMetrics.Spacing.xSmall) {
            Text("新增角色")
                .font(.system(size: AppMetrics.FontSize.subheadline, weight: .semibold))
            Text(pending.roleName)
                .font(.system(size: AppMetrics.FontSize.footnote, weight: .medium))
                .foregroundStyle(AppDesign.primary)
                .padding(.horizontal, AppMetrics.Spacing.small)
                .padding(.vertical, AppMetrics.Spacing.xSmall)
                .background(AppDesign.primarySoft, in: Capsule())
        }
        .frame(maxWidth: .infinity, alignment: .leading)
        .padding(AppMetrics.Spacing.small)
        .background(.white, in: RoundedRectangle(cornerRadius: 12))
    }

    /// 构建景区卡片。
    private func scenicCard(_ pending: RoleApplyPendingResponse) -> some View {
        VStack(alignment: .leading, spacing: AppMetrics.Spacing.xSmall) {
            HStack {
                Text("新增景区")
                    .font(.system(size: AppMetrics.FontSize.subheadline, weight: .semibold))
                Spacer()
                Text("\(pending.scenicList.count) 个")
                    .font(.system(size: AppMetrics.FontSize.caption))
                    .foregroundStyle(AppDesign.textSecondary)
            }
            if pending.scenicList.isEmpty {
                Text("未选择景区")
                    .font(.system(size: AppMetrics.FontSize.caption))
                    .foregroundStyle(AppDesign.textSecondary)
            } else {
                LazyVGrid(columns: [GridItem(.adaptive(minimum: 90), spacing: AppMetrics.Spacing.xSmall)], alignment: .leading, spacing: AppMetrics.Spacing.xSmall) {
                    ForEach(pending.scenicList) { scenic in
                        Text(scenic.name)
                            .font(.system(size: AppMetrics.FontSize.footnote))
                            .foregroundStyle(AppDesign.primary)
                            .padding(.horizontal, AppMetrics.Spacing.small)
                            .padding(.vertical, AppMetrics.Spacing.xSmall)
                            .background(AppDesign.primarySoft, in: Capsule())
                    }
                }
            }
        }
        .frame(maxWidth: .infinity, alignment: .leading)
        .padding(AppMetrics.Spacing.small)
        .background(.white, in: RoundedRectangle(cornerRadius: 12))
    }

    private func row(_ title: String, _ value: String?) -> some View {
        HStack(spacing: AppMetrics.Spacing.xSmall) {
            Text("\(title)：")
                .foregroundStyle(AppDesign.textSecondary)
            Spacer()
            Text(nonEmpty(value) ?? "--")
                .foregroundStyle(AppDesign.textPrimary)
                .multilineTextAlignment(.trailing)
        }
        .font(.system(size: AppMetrics.FontSize.footnote))
    }

    private func statusLabel(_ pending: RoleApplyPendingResponse) -> String {
        nonEmpty(pending.statusLabel) ?? {
            switch pending.status {
            case 2: return "已通过"
            case 3: return "已驳回"
            case 1: return "审核中"
            default: return "未知状态"
            }
        }()
    }

    private func statusIcon(_ status: Int) -> String {
        switch status {
        case 2: return "checkmark.circle.fill"
        case 3: return "xmark.octagon.fill"
        case 1: return "clock.badge.exclamationmark.fill"
        default: return "questionmark.circle.fill"
        }
    }

    private func statusColor(_ status: Int) -> Color {
        switch status {
        case 2: return AppDesign.success
        case 3: return Color(hex: 0xDC2626)
        case 1: return AppDesign.warning
        default: return AppDesign.textSecondary
        }
    }

    /// 去除空白字符后返回非空字符串。
    private func nonEmpty(_ value: String?) -> String? {
        let trimmed = value?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
        return trimmed.isEmpty ? nil : trimmed
    }
}