using CampusErrand.Data;
using CampusErrand.Models;
using CampusErrand.Models.Dtos;
using CampusErrand.Helpers;
using Microsoft.EntityFrameworkCore;

namespace CampusErrand.Endpoints;

public static class BannerEndpoints
{
    public static void MapBannerEndpoints(this WebApplication app)
    {
        // 前端获取 Banner 列表（仅启用+按排序权重排列）
        app.MapGet("/api/banners", async (AppDbContext db) =>
        {
            var banners = await db.Banners
                .Where(b => b.IsEnabled)
                .OrderBy(b => b.SortOrder)
                .Select(b => new BannerResponse
                {
                    Id = b.Id,
                    ImageUrl = b.ImageUrl,
                    LinkType = b.LinkType.ToString(),
                    LinkUrl = b.LinkUrl,
                    SortOrder = b.SortOrder,
                    IsEnabled = b.IsEnabled,
                    CreatedAt = b.CreatedAt
                })
                .ToListAsync();
            return Results.Ok(banners);
        });

        // 管理端获取全部 Banner 列表
        app.MapGet("/api/admin/banners", async (AppDbContext db) =>
        {
            var banners = await db.Banners
                .OrderBy(b => b.SortOrder)
                .Select(b => new BannerResponse
                {
                    Id = b.Id,
                    ImageUrl = b.ImageUrl,
                    LinkType = b.LinkType.ToString(),
                    LinkUrl = b.LinkUrl,
                    SortOrder = b.SortOrder,
                    IsEnabled = b.IsEnabled,
                    CreatedAt = b.CreatedAt
                })
                .ToListAsync();
            return Results.Ok(banners);
        }).RequireAuthorization("AdminOnly");

        // 创建 Banner
        app.MapPost("/api/admin/banners", async (BannerRequest request, AppDbContext db) =>
        {
            // 校验
            var errors = BusinessHelpers.ValidateBannerRequest(request);
            if (errors.Count > 0)
            {
                return Results.BadRequest(new { code = 400, message = "校验失败", errors });
            }

            if (!Enum.TryParse<LinkType>(request.LinkType, true, out var linkType) || !Enum.IsDefined(linkType))
            {
                return Results.BadRequest(new { code = 400, message = "校验失败", errors = new[] { new { field = "linkType", message = "链接类型不合法" } } });
            }

            var banner = new Banner
            {
                ImageUrl = request.ImageUrl,
                LinkType = linkType,
                LinkUrl = request.LinkUrl,
                SortOrder = request.SortOrder,
                IsEnabled = request.IsEnabled,
                CreatedAt = DateTime.UtcNow
            };

            db.Banners.Add(banner);
            await db.SaveChangesAsync();

            return Results.Created($"/api/admin/banners/{banner.Id}", new BannerResponse
            {
                Id = banner.Id,
                ImageUrl = banner.ImageUrl,
                LinkType = banner.LinkType.ToString(),
                LinkUrl = banner.LinkUrl,
                SortOrder = banner.SortOrder,
                IsEnabled = banner.IsEnabled,
                CreatedAt = banner.CreatedAt
            });
        }).RequireAuthorization("AdminOnly");

        // 更新 Banner
        app.MapPut("/api/admin/banners/{id}", async (int id, BannerRequest request, AppDbContext db) =>
        {
            var banner = await db.Banners.FindAsync(id);
            if (banner == null)
            {
                return Results.NotFound(new { code = 404, message = "Banner 不存在" });
            }

            var errors = BusinessHelpers.ValidateBannerRequest(request);
            if (errors.Count > 0)
            {
                return Results.BadRequest(new { code = 400, message = "校验失败", errors });
            }

            if (!Enum.TryParse<LinkType>(request.LinkType, true, out var linkType) || !Enum.IsDefined(linkType))
            {
                return Results.BadRequest(new { code = 400, message = "校验失败", errors = new[] { new { field = "linkType", message = "链接类型不合法" } } });
            }

            banner.ImageUrl = request.ImageUrl;
            banner.LinkType = linkType;
            banner.LinkUrl = request.LinkUrl;
            banner.SortOrder = request.SortOrder;
            banner.IsEnabled = request.IsEnabled;

            await db.SaveChangesAsync();

            return Results.Ok(new BannerResponse
            {
                Id = banner.Id,
                ImageUrl = banner.ImageUrl,
                LinkType = banner.LinkType.ToString(),
                LinkUrl = banner.LinkUrl,
                SortOrder = banner.SortOrder,
                IsEnabled = banner.IsEnabled,
                CreatedAt = banner.CreatedAt
            });
        }).RequireAuthorization("AdminOnly");

        // 删除 Banner
        app.MapDelete("/api/admin/banners/{id}", async (int id, AppDbContext db) =>
        {
            var banner = await db.Banners.FindAsync(id);
            if (banner == null)
            {
                return Results.NotFound(new { code = 404, message = "Banner 不存在" });
            }

            db.Banners.Remove(banner);
            await db.SaveChangesAsync();

            return Results.NoContent();
        }).RequireAuthorization("AdminOnly");
    }
}