using CMSMicroservice.Protobuf.Protos.NetworkMembership;

namespace FrontOffice.BFF.Application.NetworkMembershipCQ.Queries.GetMyNetworkStatistics;

public class GetMyNetworkStatisticsQueryHandler : IRequestHandler<GetMyNetworkStatisticsQuery, GetMyNetworkStatisticsResponseDto>
{
    private readonly IApplicationContractContext _context;
    private readonly ICurrentUserService _currentUserService;

    public GetMyNetworkStatisticsQueryHandler(
        IApplicationContractContext context,
        ICurrentUserService currentUserService)
    {
        _context = context;
        _currentUserService = currentUserService;
    }

    public async Task<GetMyNetworkStatisticsResponseDto> Handle(GetMyNetworkStatisticsQuery request, CancellationToken cancellationToken)
    {
        var userId = _currentUserService.UserId ?? throw new UnauthorizedAccessException("User not authenticated");

        // Get user's own network info which contains personal stats AND subtree stats
        var userNetworkRequest = new GetUserNetworkRequest { UserId = userId };
        var userNetwork = await _context.NetworkMemberships.GetUserNetworkAsync(userNetworkRequest, cancellationToken: cancellationToken);

        // Calculate percentages from user's subtree stats
        var totalSubtreeMembers = userNetwork.TotalLeftLegMembers + userNetwork.TotalRightLegMembers;
        var leftPercentage = totalSubtreeMembers > 0 ? (double)userNetwork.TotalLeftLegMembers / totalSubtreeMembers * 100 : 0;
        var rightPercentage = totalSubtreeMembers > 0 ? (double)userNetwork.TotalRightLegMembers / totalSubtreeMembers * 100 : 0;

        var weakerLeg = userNetwork.TotalLeftLegMembers < userNetwork.TotalRightLegMembers ? "Left" : "Right";

        // Get tree to find last member and calculate depth
        var treeRequest = new GetNetworkTreeRequest
        {
            UserId = userId,
            MaxDepth = 20 // Get deep enough to find last member
        };
        var treeResponse = await _context.NetworkMemberships.GetNetworkTreeAsync(treeRequest, cancellationToken: cancellationToken);
        
        // Find the last joined member in user's subtree
        var lastMember = treeResponse.Nodes
            .Where(n => n.UserId != userId && n.JoinedAt != null)
            .OrderByDescending(n => n.JoinedAt)
            .FirstOrDefault();

        // Calculate max depth from tree nodes
        var maxDepth = treeResponse.Nodes.Count > 0 
            ? treeResponse.Nodes.Max(n => n.NetworkLevel) - userNetwork.NetworkLevel 
            : 0;

        // Calculate active members in user's subtree
        var activeMembers = treeResponse.Nodes.Count(n => n.IsActive);

        return new GetMyNetworkStatisticsResponseDto
        {
            // User's subtree stats from GetUserNetwork
            TotalMembers = userNetwork.TotalNetworkSize,
            ActiveMembers = activeMembers,
            LeftLegCount = userNetwork.TotalLeftLegMembers,
            RightLegCount = userNetwork.TotalRightLegMembers,
            LeftPercentage = Math.Round(leftPercentage, 2),
            RightPercentage = Math.Round(rightPercentage, 2),
            AverageDepth = 0, // Not available from current API
            MaxDepth = Math.Max(maxDepth, userNetwork.MaxNetworkDepth),
            WeakerLeg = weakerLeg,

            // User's personal info
            MyNetworkLevel = userNetwork.NetworkLevel,
            MyNetworkLeg = userNetwork.NetworkLeg == 0 ? "Left" : "Right",
            MyReferralCode = userNetwork.ReferralCode,

            // Last member info from tree
            LastMember = lastMember != null ? new LastMemberDto
            {
                UserId = lastMember.UserId,
                FullName = lastMember.UserName ?? string.Empty,
                Position = lastMember.NetworkLeg == 0 ? "Left" : "Right",
                TotalChildren = 0 // Would need another call to get this
            } : null
        };
    }
}