using bnhtrade.Core.Logic.Validate;
using bnhtrade.Core.Model.Account;
using FikaAmazonAPI.AmazonSpApiSDK.Models.FulfillmentInboundv20240320;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace bnhtrade.Core.Model.Stock
{
    public class StockJournal : IValidatableObject
    {
        public StockJournal(int stockJournalId, StockJournalType stockJournalType, int stockId, string stockNumber, DateTime entryDate, DateTime postDate, DateTime lastModified, bool isLocked, List<StockJournalPost> journalPosts)
        {
            StockJournalId = stockJournalId;
            StockJournalType = stockJournalType;
            StockId = stockId;
            StockNumber = stockNumber;
            EntryDate = entryDate;
            PostDate = postDate;
            LastModified = lastModified;
            IsLocked = isLocked;
            StockJournalPosts = journalPosts ?? throw new ArgumentNullException(nameof(journalPosts), "Journal posts cannot be null.");
        }

        [Required()]
        [Range(1, int.MaxValue, ErrorMessage = "StockJournalId must be greater than 0.")]
        public int StockJournalId { get; }

        public StockJournalType StockJournalType { get; }

        [Required()]
        [Range(1, int.MaxValue, ErrorMessage = "StockId must be greater than 0.")]
        public int StockId { get; }

        [Required(ErrorMessage = "Stock number is required.")]
        public string StockNumber { get; }

        public DateTime EntryDate { get; }

        public DateTime PostDate { get; }

        public DateTime LastModified { get; }

        public bool IsLocked { get; }

        public List<StockJournalPost> StockJournalPosts { get; }

        public class StockJournalPost : IValidatableObject
        {
            public StockJournalPost(int journalPostId, Status status, int quantity)
            {
                StockJournalPostId = journalPostId;
                Status = status;
                Quantity = quantity;
            }
            public int StockJournalPostId { get; }

            [Required()]
            public Status Status { get; }

            [Required()]
            public int Quantity { get; }

            public bool IsCredit
            {
                get
                {
                    if (Quantity < 0)
                    {
                        return true;
                    }
                    else if (Quantity > 0)
                    {
                        return false;
                    }
                    else
                    {
                        throw new InvalidOperationException("Quantity cannot be zero for a journal post.");
                    }
                }
            }

            public bool IsDebit
            {
                get
                {
                    return !IsCredit;
                }
            }

            public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
            {
                var validationResults = new List<ValidationResult>();

                if (Quantity == 0)
                {
                    validationResults.Add(new ValidationResult("Quantity cannot be zero for a journal post.", new[] { nameof(Quantity) }));
                }

                return validationResults;
            }
        }

        public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
        {
            var validationResults = new List<ValidationResult>();

            // dates are in UTC format
            if (EntryDate.Kind != DateTimeKind.Utc || EntryDate == default(DateTime))
            {
                validationResults.Add(new ValidationResult("Entry Date must be in UTC format and not a default value.", new[] { nameof(EntryDate) }));
            }
            if (PostDate.Kind != DateTimeKind.Utc || PostDate == default(DateTime))
            {
                validationResults.Add(new ValidationResult("PostDate must be in UTC format and not a default value.", new[] { nameof(PostDate) }));
            }
            if (LastModified.Kind != DateTimeKind.Utc || LastModified == default(DateTime))
            {
                validationResults.Add(new ValidationResult("LastModified must be in UTC format and not a default value.", new[] { nameof(LastModified) }));
            }

            if (Format.StockNumber(StockNumber) == false)
            {
                validationResults.Add(new ValidationResult("StockNumber must be in the format 'STK#000000'.", new[] { nameof(StockNumber) }));
            }

            // Validate each StockJournalPost using its own context and Validate method
            int sum = 0;
            for (int i = 0; i < StockJournalPosts.Count; i++)
            {
                sum += StockJournalPosts[i].Quantity;

                var post = StockJournalPosts[i];
                var postContext = new ValidationContext(post, validationContext, validationContext.Items);
                foreach (var result in post.Validate(postContext))
                {
                    // Prefix property name with the index for clarity
                    var memberNames = result.MemberNames.Select(name => $"StockJournalPosts[{i}].{name}");
                    validationResults.Add(new ValidationResult(result.ErrorMessage, memberNames));
                }
            }
            if (sum != 0)
            {
                validationResults.Add(new ValidationResult("The sum of all journal posts must equal zero.", new[] { nameof(StockJournalPosts) }));
            }

            return validationResults;
        }
    }
}