using F9WebAiTest.Application.Common;
using F9WebAiTest.Application.Dtos.SYS.Zq;
using F9WebAiTest.Application.Interfaces.Repositories.SYS.Zq;
using F9WebAiTest.Application.Interfaces.SnowflakeID;
using F9WebAiTest.Domain.Entities.SYS.Zq;
using F9WebAiTest.Domain.Interfaces.SYS.Zq;
using MediatR;

namespace F9WebAiTest.Application.CQRS.SYS.Zq.Queries;

/// <summary>账期分页查询（按年度筛选）</summary>
public record GetZhangqiPagedQuery(int? Year = null, string Keyword = "", int PageIndex = 1, int PageSize = 20)
    : IRequest<PageResult<ZhangqiReadDto_View>>;

public class GetZhangqiPagedQueryHandler(IZhangqiReadRepository readRepository)
    : IRequestHandler<GetZhangqiPagedQuery, PageResult<ZhangqiReadDto_View>>
{
    public async Task<PageResult<ZhangqiReadDto_View>> Handle(GetZhangqiPagedQuery query, CancellationToken ct)
        => await readRepository.GetPagedAsync(query.Year, query.Keyword, query.PageIndex, query.PageSize);
}

/// <summary>按 Id 查询账期（编辑回显）</summary>
public record GetZhangqiByIdQuery(long Id) : IRequest<ZhangqiReadDto_Edit>;

public class GetZhangqiByIdQueryHandler(IZhangqiReadRepository readRepository)
    : IRequestHandler<GetZhangqiByIdQuery, ZhangqiReadDto_Edit>
{
    public async Task<ZhangqiReadDto_Edit> Handle(GetZhangqiByIdQuery query, CancellationToken ct)
        => await readRepository.GetByIdForEditAsync(query.Id);
}

/// <summary>
/// 按日期取所属账期：不存在时按"每月 28 日"划分规则自动创建
/// （日期 ≤ 28 号：上月 29 日 ~ 本月 28 日；日期 &gt; 28 号：本月 29 日 ~ 下月 28 日）。
/// </summary>
public record GetZhangqiByDateQuery(DateTime Date) : IRequest<ZhangqiReadDto_Edit>;

public class GetZhangqiByDateQueryHandler(
    IZhangqiReadRepository readRepository,
    IZhangqiWriteRepository writeRepository,
    ISnowflakeIdGenerator snowflakeIdGenerator) : IRequestHandler<GetZhangqiByDateQuery, ZhangqiReadDto_Edit>
{
    public async Task<ZhangqiReadDto_Edit> Handle(GetZhangqiByDateQuery query, CancellationToken ct)
    {
        var exist = await readRepository.GetByDateAsync(query.Date);
        if (exist != null) return exist;

        var (startDate, endDate) = CalcRange(query.Date);

        var entity = new Zhangqi(snowflakeIdGenerator.CreateId(), endDate.Year, endDate.Month, startDate, endDate);
        await writeRepository.AddAsync(entity);

        return new ZhangqiReadDto_Edit(entity.Id, entity.Year, entity.Month, entity.StartDate, entity.EndDate, entity.IsZhaZhang);
    }

    /// <summary>按 28 日边界推算账期区间（截止日期取当天 23:59:59）</summary>
    private static (DateTime StartDate, DateTime EndDate) CalcRange(DateTime date)
    {
        DateTime startDate;
        DateTime endDay;

        if (date.Day <= 28)
        {
            var lastMonth = date.AddMonths(-1);
            startDate = new DateTime(lastMonth.Year, lastMonth.Month, 28).AddDays(1);
            endDay = new DateTime(date.Year, date.Month, 28);
        }
        else
        {
            var nextMonth = date.AddMonths(1);
            startDate = new DateTime(date.Year, date.Month, 28).AddDays(1);
            endDay = new DateTime(nextMonth.Year, nextMonth.Month, 28);
        }

        return (startDate, endDay.Date.AddDays(1).AddSeconds(-1));
    }
}

/// <summary>指定年月是否已扎帐</summary>
public record GetZhangqiIsZhaZhangQuery(int Year, int Month) : IRequest<bool>;

public class GetZhangqiIsZhaZhangQueryHandler(IZhangqiReadRepository readRepository)
    : IRequestHandler<GetZhangqiIsZhaZhangQuery, bool>
{
    public async Task<bool> Handle(GetZhangqiIsZhaZhangQuery query, CancellationToken ct)
        => await readRepository.GetIsZhaZhangAsync(query.Year, query.Month);
}

/// <summary>指定日期所属账期是否已扎帐</summary>
public record GetZhangqiIsZhaZhangByDateQuery(DateTime Date) : IRequest<bool>;

public class GetZhangqiIsZhaZhangByDateQueryHandler(IZhangqiReadRepository readRepository)
    : IRequestHandler<GetZhangqiIsZhaZhangByDateQuery, bool>
{
    public async Task<bool> Handle(GetZhangqiIsZhaZhangByDateQuery query, CancellationToken ct)
        => await readRepository.GetIsZhaZhangByDateAsync(query.Date);
}