using System.Collections.Generic;
using System.Linq;
using TakeoutSaaS.Application.Identity.Contracts;

namespace TakeoutSaaS.Application.Identity.Services;

/// <summary>
/// 管理端菜单生成器（基于权限过滤）。
/// </summary>
public static class AdminMenuProvider
{
    /// <summary>
    /// 按权限生成可见菜单树。
    /// </summary>
    /// <param name="permissions">当前用户拥有的权限集合。</param>
    /// <returns>过滤后的菜单树。</returns>
    public static IReadOnlyList<MenuNodeDto> BuildMenuTree(IEnumerable<string> permissions)
    {
        // 1. 归一化权限集合
        var permissionSet = new HashSet<string>(permissions ?? [], System.StringComparer.OrdinalIgnoreCase);
        // 2. 过滤菜单
        var definitions = GetMenuDefinitions();
        return Filter(definitions, permissionSet);
    }

    private static IReadOnlyList<MenuNodeDto> Filter(IEnumerable<MenuNodeDto> nodes, HashSet<string> permissionSet)
    {
        // 1. 遍历节点并过滤子节点
        var result = new List<MenuNodeDto>();
        foreach (var node in nodes)
        {
            // 1.1 递归过滤子节点
            var filteredChildren = Filter(node.Children, permissionSet);

            // 1.2 判断当前节点是否可见
            var visible = node.RequiredPermissions.Length == 0 || node.RequiredPermissions.Any(permissionSet.Contains);
            if (visible || filteredChildren.Count > 0)
            {
                result.Add(node with { Children = filteredChildren });
            }
        }

        // 2. 返回过滤结果
        return result;
    }

    private static IReadOnlyList<MenuNodeDto> GetMenuDefinitions()
    {
        // 1. 顶部菜单定义（按需求自定义排序）
        return
        [
            new MenuNodeDto
            {
                Name = "Dashboard",
                Path = "/dashboard",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "仪表盘",
                    Icon = "ri:pie-chart-line",
                    Permissions = System.Array.Empty<string>()
                },
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "Console",
                        Path = "console",
                        Component = "/dashboard/console",
                        Meta = new MenuMetaDto
                        {
                            Title = "工作台",
                            Icon = "ri:dashboard-line",
                            KeepAlive = false,
                            Permissions = System.Array.Empty<string>()
                        },
                        RequiredPermissions = System.Array.Empty<string>()
                    }
                ]
            },
            new MenuNodeDto
            {
                Name = "Tenant",
                Path = "/tenant",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "租户管理",
                    Icon = "ri:building-3-line",
                    Permissions = ["tenant:read"]
                },
                RequiredPermissions = ["tenant:read"],
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "TenantList",
                        Path = "list",
                        Component = "/system/tenant",
                        Meta = new MenuMetaDto
                        {
                            Title = "租户列表",
                            Icon = "ri:community-line",
                            KeepAlive = true,
                            Permissions = ["tenant:read"],
                            AuthList =
                            [
                                new MenuAuthItemDto { Title = "新增", AuthMark = "add" },
                                new MenuAuthItemDto { Title = "编辑", AuthMark = "edit" },
                                new MenuAuthItemDto { Title = "删除", AuthMark = "delete" },
                                new MenuAuthItemDto { Title = "审核", AuthMark = "review" }
                            ]
                        },
                        RequiredPermissions = ["tenant:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "TenantReview",
                        Path = "review",
                        Component = "/tenant/review",
                        Meta = new MenuMetaDto
                        {
                            Title = "入驻审核",
                            Icon = "ri:checkbox-line",
                            KeepAlive = true,
                            Permissions = ["tenant:review"]
                        },
                        RequiredPermissions = ["tenant:review"]
                    },
                    new MenuNodeDto
                    {
                        Name = "TenantPackage",
                        Path = "package",
                        Component = "/tenant/package",
                        Meta = new MenuMetaDto
                        {
                            Title = "套餐管理",
                            Icon = "ri:vip-crown-2-line",
                            KeepAlive = true,
                            Permissions = ["tenant-package:read"]
                        },
                        RequiredPermissions = ["tenant-package:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "TenantSubscription",
                        Path = "subscription",
                        Component = "/tenant/subscription",
                        Meta = new MenuMetaDto
                        {
                            Title = "订阅管理",
                            Icon = "ri:hand-coin-line",
                            KeepAlive = true,
                            Permissions = ["tenant:subscription"]
                        },
                        RequiredPermissions = ["tenant:subscription"]
                    },
                    new MenuNodeDto
                    {
                        Name = "TenantBill",
                        Path = "bill",
                        Component = "/tenant/bill",
                        Meta = new MenuMetaDto
                        {
                            Title = "账单管理",
                            Icon = "ri:bill-line",
                            KeepAlive = true,
                            Permissions = ["tenant-bill:read"]
                        },
                        RequiredPermissions = ["tenant-bill:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "TenantAnnouncement",
                        Path = "announcement",
                        Component = "/tenant/announcement",
                        Meta = new MenuMetaDto
                        {
                            Title = "公告管理",
                            Icon = "ri:notification-3-line",
                            KeepAlive = true,
                            Permissions = ["tenant-announcement:read"]
                        },
                        RequiredPermissions = ["tenant-announcement:read"]
                    }
                ]
            },
            new MenuNodeDto
            {
                Name = "Merchant",
                Path = "/merchant",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "商户中心",
                    Icon = "ri:store-2-line",
                    Permissions = ["merchant:read"]
                },
                RequiredPermissions = ["merchant:read"],
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "MerchantList",
                        Path = "list",
                        Component = "/merchant/list",
                        Meta = new MenuMetaDto
                        {
                            Title = "商户列表",
                            Icon = "ri:community-line",
                            KeepAlive = true,
                            Permissions = ["merchant:read"]
                        },
                        RequiredPermissions = ["merchant:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "Store",
                        Path = "store",
                        Component = "/merchant/store",
                        Meta = new MenuMetaDto
                        {
                            Title = "门店管理",
                            Icon = "ri:store-line",
                            KeepAlive = true,
                            Permissions = ["store:read"]
                        },
                        RequiredPermissions = ["store:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "Staff",
                        Path = "staff",
                        Component = "/merchant/staff",
                        Meta = new MenuMetaDto
                        {
                            Title = "员工管理",
                            Icon = "ri:team-line",
                            KeepAlive = true,
                            Permissions = ["store-staff:read"]
                        },
                        RequiredPermissions = ["store-staff:read"]
                    }
                ]
            },
            new MenuNodeDto
            {
                Name = "Dictionary",
                Path = "/dictionary",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "字典管理",
                    Icon = "ri:book-open-line",
                    Permissions = ["dictionary:group:read", "dictionary:item:read"]
                },
                RequiredPermissions = ["dictionary:group:read", "dictionary:item:read"],
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "DictionaryGroup",
                        Path = "group",
                        Component = "/dictionary/group",
                        Meta = new MenuMetaDto
                        {
                            Title = "字典分组",
                            Icon = "ri:booklet-line",
                            KeepAlive = true,
                            Permissions = ["dictionary:group:read"]
                        },
                        RequiredPermissions = ["dictionary:group:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "DictionaryItem",
                        Path = "item",
                        Component = "/dictionary/item",
                        Meta = new MenuMetaDto
                        {
                            Title = "字典条目",
                            Icon = "ri:links-line",
                            KeepAlive = true,
                            Permissions = ["dictionary:item:read"]
                        },
                        RequiredPermissions = ["dictionary:item:read"]
                    }
                ]
            },
            new MenuNodeDto
            {
                Name = "Product",
                Path = "/product",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "商品中心",
                    Icon = "ri:shopping-basket-line",
                    Permissions = ["product:read"]
                },
                RequiredPermissions = ["product:read"],
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "ProductList",
                        Path = "list",
                        Component = "/product/list",
                        Meta = new MenuMetaDto
                        {
                            Title = "商品列表",
                            Icon = "ri:shopping-cart-2-line",
                            KeepAlive = true,
                            Permissions = ["product:read"]
                        },
                        RequiredPermissions = ["product:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "Category",
                        Path = "category",
                        Component = "/product/category",
                        Meta = new MenuMetaDto
                        {
                            Title = "类目管理",
                            Icon = "ri:folder-settings-line",
                            KeepAlive = true,
                            Permissions = ["merchant_category:read"]
                        },
                        RequiredPermissions = ["merchant_category:read"]
                    }
                ]
            },
            new MenuNodeDto
            {
                Name = "Order",
                Path = "/order",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "订单中心",
                    Icon = "ri:bill-line",
                    Permissions = ["order:read"]
                },
                RequiredPermissions = ["order:read"],
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "OrderList",
                        Path = "list",
                        Component = "/order/list",
                        Meta = new MenuMetaDto
                        {
                            Title = "订单列表",
                            Icon = "ri:file-list-3-line",
                            KeepAlive = true,
                            Permissions = ["order:read"]
                        },
                        RequiredPermissions = ["order:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "Delivery",
                        Path = "delivery",
                        Component = "/order/delivery",
                        Meta = new MenuMetaDto
                        {
                            Title = "配送管理",
                            Icon = "ri:route-line",
                            KeepAlive = true,
                            Permissions = ["delivery:read"]
                        },
                        RequiredPermissions = ["delivery:read"]
                    }
                ]
            },
            new MenuNodeDto
            {
                Name = "Payment",
                Path = "/payment",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "支付结算",
                    Icon = "ri:wallet-3-line",
                    Permissions = ["payment:read"]
                },
                RequiredPermissions = ["payment:read"],
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "PaymentList",
                        Path = "list",
                        Component = "/payment/list",
                        Meta = new MenuMetaDto
                        {
                            Title = "收支明细",
                            Icon = "ri:money-cny-circle-line",
                            KeepAlive = true,
                            Permissions = ["payment:read"]
                        },
                        RequiredPermissions = ["payment:read"]
                    }
                ]
            },
            new MenuNodeDto
            {
                Name = "Inventory",
                Path = "/inventory",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "库存中心",
                    Icon = "ri:archive-stack-line",
                    Permissions = ["inventory:read"]
                },
                RequiredPermissions = ["inventory:read"],
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "InventoryList",
                        Path = "list",
                        Component = "/inventory/list",
                        Meta = new MenuMetaDto
                        {
                            Title = "库存明细",
                            Icon = "ri:stock-line",
                            KeepAlive = true,
                            Permissions = ["inventory:read"]
                        },
                        RequiredPermissions = ["inventory:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "InventoryBatch",
                        Path = "batch",
                        Component = "/inventory/batch",
                        Meta = new MenuMetaDto
                        {
                            Title = "批次管理",
                            Icon = "ri:layout-grid-line",
                            KeepAlive = true,
                            Permissions = ["inventory:batch:read"]
                        },
                        RequiredPermissions = ["inventory:batch:read"]
                    }
                ]
            },
            new MenuNodeDto
            {
                Name = "System",
                Path = "/system",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "系统设置",
                    Icon = "ri:settings-3-line",
                    Permissions = ["identity:permission:read", "identity:role:read"]
                },
                RequiredPermissions = ["identity:permission:read", "identity:role:read"],
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "User",
                        Path = "user",
                        Component = "/system/user",
                        Meta = new MenuMetaDto
                        {
                            Title = "用户管理",
                            Icon = "ri:user-3-line",
                            KeepAlive = true,
                            Permissions = ["identity:permission:read"]
                        },
                        RequiredPermissions = ["identity:permission:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "Role",
                        Path = "role",
                        Component = "/system/role",
                        Meta = new MenuMetaDto
                        {
                            Title = "角色管理",
                            Icon = "ri:shield-user-line",
                            KeepAlive = true,
                            Permissions = ["identity:role:read"]
                        },
                        RequiredPermissions = ["identity:role:read"]
                    },
                    new MenuNodeDto
                    {
                        Name = "Menus",
                        Path = "menu",
                        Component = "/system/menu",
                        Meta = new MenuMetaDto
                        {
                            Title = "菜单管理",
                            Icon = "ri:menu-fold-line",
                            KeepAlive = true,
                            Permissions = ["identity:permission:read"],
                            AuthList =
                            [
                                new MenuAuthItemDto { Title = "新增", AuthMark = "add" },
                                new MenuAuthItemDto { Title = "编辑", AuthMark = "edit" },
                                new MenuAuthItemDto { Title = "删除", AuthMark = "delete" }
                            ]
                        },
                        RequiredPermissions = ["identity:permission:read"]
                    }
                ]
            },
            new MenuNodeDto
            {
                Name = "Docs",
                Path = "/docs",
                Component = "/index/index",
                Meta = new MenuMetaDto
                {
                    Title = "帮助文档",
                    Icon = "ri:book-2-line",
                    Permissions = System.Array.Empty<string>()
                },
                Children =
                [
                    new MenuNodeDto
                    {
                        Name = "GuideIframe",
                        Path = "guide",
                        Component = "",
                        Meta = new MenuMetaDto
                        {
                            Title = "操作指南",
                            IsIframe = true,
                            Link = "https://example.com/guide",
                            Icon = "ri:article-line",
                            Permissions = System.Array.Empty<string>()
                        }
                    },
                    new MenuNodeDto
                    {
                        Name = "ExternalLink",
                        Path = "official",
                        Component = "",
                        Meta = new MenuMetaDto
                        {
                            Title = "官网链接",
                            Link = "https://example.com",
                            Icon = "ri:external-link-line",
                            Permissions = System.Array.Empty<string>()
                        }
                    }
                ]
            }
        ];
    }
}