using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;
using MoShiro.Backend.Application;
using MoShiro.Protocol;

namespace MoShiro.Backend.Api;

/// <summary>审计日志：管理接口里每个写操作、登录都会记一行，这里只读。</summary>
public static class AuditEndpoints
{
    private const string Tag = "admin-audit";

    /// <summary>handler 往这里放一句「这次具体做了什么」（例如新建令牌的名字），守卫记审计时一起写进去。</summary>
    public const string DetailItem = "moshiro.audit.detail";

    public static void Map(RouteGroupBuilder guarded) =>
        guarded.MapGet("/audit", ListAsync)
            .Api("audit_list", "Audit log of admin actions, newest first", Tag).Returns<PageDto<AuditDto>>().ProducesProblems(400, 401, 403)
            .Requires(Capability.AuditRead);

    public static void SetDetail(this HttpContext http, string detail) => http.Items[DetailItem] = detail;

    private static async Task<IResult> ListAsync(HttpContext http, AuditService audit, string? actor, string? action, int? limit, string? cursor)
    {
        long? before = null;
        if (cursor is not null)
        {
            if (!long.TryParse(cursor, out long parsed))
            {
                return Problems.From(http, ValidationError.Single("cursor", "is not a valid cursor"));
            }

            before = parsed;
        }

        int size = Math.Clamp(limit ?? 50, 1, 500);
        IReadOnlyList<AuditRecord> rows = await audit.ListAsync(new AuditQuery(before, size + 1, string.IsNullOrEmpty(actor) ? null : actor, string.IsNullOrEmpty(action) ? null : action), http.RequestAborted);
        bool more = rows.Count > size;
        IReadOnlyList<AuditRecord> page = [.. rows.Take(size)];
        string? next = more ? page[^1].Id.ToString(System.Globalization.CultureInfo.InvariantCulture) : null;
        return TypedResults.Json(new PageDto<AuditDto>([.. page.Select(Mappers.ToDto)], next), ApiJsonContext.Default.PageDtoAuditDto);
    }
}