using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using SharedKernel.Results;
using Domain.Entities.Donations;
using Domain.Entities.Donations.ValueObject;
using Microsoft.EntityFrameworkCore;

namespace Application.Features.Api.DonationGoal.SaveConfig;

internal sealed class Handler(IAppDbContext db) : ICommandHandler<Command, Result>
{
    public async Task<Result> Handle(Command r, CancellationToken ct)
    {
        var period = (RankPeriodType)r.Period;

        // Custom 시 StartAt/EndAt 필수
        if (period == RankPeriodType.Custom && (!r.StartAt.HasValue || !r.EndAt.HasValue))
        {
            return Result.Failure(Error.Problem("DonationGoal.CustomPeriodRequired", "사용자 지정 기간은 시작일/종료일이 필요합니다."));
        }

        // 기간 중복 검증: 활성 + Custom 끼리만
        if (r.IsActive && period == RankPeriodType.Custom && r.StartAt.HasValue && r.EndAt.HasValue)
        {
            var overlap = await db.DonationGoalConfig
                .AnyAsync(c => c.ChannelID == r.ChannelID
                    && c.IsActive
                    && c.Period == RankPeriodType.Custom
                    && c.ID != (r.ID ?? 0)
                    && c.StartAt != null && c.EndAt != null
                    && c.StartAt < r.EndAt && c.EndAt > r.StartAt, ct
                );

            if (overlap)
            {
                return Result.Failure(Error.Conflict("DonationGoal.PeriodOverlap", "해당 기간에 이미 활성화된 목표가 존재합니다."));
            }
        }

        if (r.ID.HasValue)
        {
            var config = await db.DonationGoalConfig.FirstOrDefaultAsync(c => c.ID == r.ID.Value && c.ChannelID == r.ChannelID, ct);
            if (config is null)
            {
                return Result.Failure(Error.NotFound("DonationGoal.NotFound", "설정을 찾을 수 없습니다."));
            }

            config.Update(
                r.Title, (GoalWidgetStyle)r.Style, r.StartAmount, r.TargetAmount,
                r.StartAt, r.EndAt, r.IsShowPercent,
                r.BarColor, r.BarBackgroundColor, r.BarHeightPx,
                r.TitleFontSizePx, r.TitleFontColor,
                r.AmountFontSizePx, r.AmountFontColor,
                r.TitleFontFamily, r.AmountFontFamily,
                period,
                r.IsActive
            );
        }
        else
        {
            var config = DonationGoalConfig.Create(r.ChannelID, r.MemberID, r.Title, r.TargetAmount);
            config.Update(
                r.Title, (GoalWidgetStyle)r.Style, r.StartAmount, r.TargetAmount,
                r.StartAt, r.EndAt, r.IsShowPercent,
                r.BarColor, r.BarBackgroundColor, r.BarHeightPx,
                r.TitleFontSizePx, r.TitleFontColor,
                r.AmountFontSizePx, r.AmountFontColor,
                r.TitleFontFamily, r.AmountFontFamily,
                period,
                r.IsActive
            );
            db.DonationGoalConfig.Add(config);
        }

        await db.SaveChangesAsync(ct);

        return Result.Success();
    }
}