using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using LCU.API.Collections.RepoApi.Models.Responses;
using LCU.Shared.Collections.RepoApiLib.Models;
using LCU.Shared.Collections.RepoApiLib.Repositories;
using Serilog;

namespace LCU.API.Collections.RepoApi.Services
{
    public class FactoidService : IFactoidService
    {
        private readonly IReportingRepository _reportingRepository;
        private readonly IRepoAccountRepository _repoAccountRepository;
        private readonly IImsAutoFileDataRepository _imsAutoFileDataRepository;
        private const string O4RStatus = "O4R";
        private const string RepoStatus = "REPO";
        private const string RedeemedStatus = "REDEEMED";
        
        public FactoidService(
            IReportingRepository reportingRepository,
            IRepoAccountRepository repoAccountRepository,
            IImsAutoFileDataRepository imsAutoFileDataRepository)
        {
            _reportingRepository = reportingRepository;
            _repoAccountRepository = repoAccountRepository;
            _imsAutoFileDataRepository = imsAutoFileDataRepository;
        }

        public int FindAuctionIndex(IReadOnlyCollection<string> auctionHouses, string auctionId)
        {
            if (auctionId != null)
            {
                foreach (var item in auctionHouses.Select((value, index) => new {index, value}))
                {
                    if (item.value == auctionId.Trim().ToLower())
                    {
                        return item.index;
                    }
                }
            }

            return auctionHouses.Count - 1;
        }
        

        public async Task<FactoidResponse> GetCurrentInventory()
        {
            var accountsInRepo = await _repoAccountRepository.FindByCurrentStatus(RepoStatus);

            var numCollateral = accountsInRepo.Aggregate(0, (total, curAccount) =>
                total += curAccount.Collaterals.Count());

            return new FactoidResponse
            {
                CumulativeValue = numCollateral.ToString(),
                Name = "Vehicles",
                Description = "Current Inventory (REPO)",
                FontAwesomeIcon = "fa-car",
                Records = accountsInRepo
            };
        }

        public async Task<FactoidResponse> GetAllAccountsO4R()
        {
            var filteredRepoAccounts = await _reportingRepository.GetAllAccountsInO4R();
            return new FactoidResponse
            {
                CumulativeValue = filteredRepoAccounts.Count().ToString(),
                Name = "Accounts",
                Description = "Total Accounts in O4R",
                FontAwesomeIcon = "fa-car",
                Records = filteredRepoAccounts
            };
        }

        public async Task<FactoidResponse> GetPercentFloorPrice(DateTime lowDateTime,
            DateTime highDateTime)
        {
            var soldImsAccounts = await _imsAutoFileDataRepository.GetImsSoldRecordsForPeriod(lowDateTime, highDateTime);

            decimal? percentFloor = 0m;
            if (soldImsAccounts.Count() != 0)
            {
                percentFloor = soldImsAccounts.Select(x => x.GrossPercentFloor).Sum() / soldImsAccounts.Count;
            }

            var records = await _repoAccountRepository.FindByRepoIdAsync(soldImsAccounts.Select(x => x.RepoId.ToString()).ToList());
            return new FactoidResponse
            {
                CumulativeValue = percentFloor?.ToString("#.#") + "%",
                Name = "Percentage of Floor",
                Description = "Last 30 Days",
                FontAwesomeIcon = "fa-money",
                Records = records
            };
        }

        public async Task<FactoidResponse> GetRecentlyRedeemed(DateTime lowDate, DateTime highDate)
        {
            var filteredRepoAccounts = await _repoAccountRepository.FindByStatusChangeInPeriod(RedeemedStatus, lowDate, highDate);
            return new FactoidResponse
            {
                CumulativeValue = filteredRepoAccounts.Count().ToString(),
                Name = "Recently Redeemed",
                Description = "Last 30 Days",
                FontAwesomeIcon = "fa-calendar",
                Records = filteredRepoAccounts
            };
        }

        public async Task<FactoidResponse> GetAvgDaysO4RToREPO(DateTime lowDate, DateTime highDate)
        {
            var recentAccountsInREPO = await _repoAccountRepository.FindByStatusChangeInPeriod(RepoStatus, lowDate, highDate);
            var avgDaysO4RtoRepo = GetAverageDaysBetweenStatuses(recentAccountsInREPO, RepoStatus, O4RStatus);
            return new FactoidResponse
            {
                CumulativeValue = avgDaysO4RtoRepo != null ? avgDaysO4RtoRepo.ToString() : "N/A",
                Name = "Avg. Days O4R to Repo",
                Description = "Last 30 Days",
                FontAwesomeIcon = "fa-calendar",
                Records = recentAccountsInREPO
            };
        }

        public async Task<FactoidResponse> GetGetAvgDaysDelqToO4R(DateTime lowDate, DateTime highDate)
        {
            IEnumerable<RepoAccount> recentAccountsInO4R = await _repoAccountRepository.FindByStatusChangeInPeriod(O4RStatus, lowDate, highDate);

            var accountsWithoutDateDelinquent = recentAccountsInO4R.Where(account => account.DaysDelinquent == null);
            if (accountsWithoutDateDelinquent.Count() > 0)
            {
                Log.Error($"Accounts found without DaysDelinquent when added: {accountsWithoutDateDelinquent} ", accountsWithoutDateDelinquent);
                recentAccountsInO4R = recentAccountsInO4R.Except(accountsWithoutDateDelinquent);
            }

            var totalAccounts = recentAccountsInO4R.Count();
            var avgDaysDelqToO4R = 0;
            if (totalAccounts > 0)
            {
                var delqToO4RSum = recentAccountsInO4R.Aggregate(0, (sum, repoAccount) => sum += repoAccount.DaysDelinquent ?? 0);
                avgDaysDelqToO4R = delqToO4RSum / totalAccounts;
            }

            return new FactoidResponse()
            {
                CumulativeValue = avgDaysDelqToO4R.ToString(),
                Name = "Avg. Days Dlqt To O4R",
                Description = "Last 30 Days",
                FontAwesomeIcon = "fa-calendar",
                Records = recentAccountsInO4R.ToList()
            };
        }

        public async Task<FactoidResponse> GetGetAvgDaysRepoToSold(DateTime lowDate, DateTime highDate)
        {
            var recentAccountsSold = await _repoAccountRepository.FindByStatusChangeInPeriod("SOLD", lowDate, highDate);
            var avgDaysRepoToSold = GetAverageDaysBetweenStatuses(recentAccountsSold, "SOLD", RepoStatus);
            return new FactoidResponse
            {
                CumulativeValue = avgDaysRepoToSold != null ? avgDaysRepoToSold.ToString() : "N/A",
                Name = "Avg. Days Repo to Sold",
                Description = "Last 30 Days",
                FontAwesomeIcon = "fa-calendar",
                Records = recentAccountsSold
            };
        }

        public async Task<FactoidResponse> GetCurrentlyOnHold()
        {
            var accountsOnHold = await _repoAccountRepository.GetCurrentAccountsOnHoldAtAuction();

            return new FactoidResponse
            {
                CumulativeValue = accountsOnHold.Count().ToString(),
                Name = "On Hold at Auction",
                Description = "Accounts",
                FontAwesomeIcon = "fa-car",
                Records = accountsOnHold
            };
        }

        public async Task<FactoidResponse> GetRecentlyRepoed(DateTime lowDate, DateTime highDate)
        {
            var accountsRecentlyRepoed = await _repoAccountRepository.FindByStatusChangeInPeriod(RepoStatus, lowDate, highDate);

            return new FactoidResponse
            {
                CumulativeValue = accountsRecentlyRepoed.Count().ToString(),
                Name = "Recently Repoed",
                Description = "Last 30 Days",
                FontAwesomeIcon = "fa-car",
                Records = accountsRecentlyRepoed
            };
        }

        public async Task<FactoidResponse> GetRecentlySold(DateTime lowDate, DateTime highDate)
        {
            var accountsRecentlySold = await _repoAccountRepository.FindByStatusChangeInPeriod("SOLD", lowDate, highDate);

            return new FactoidResponse
            {
                CumulativeValue = accountsRecentlySold.Count().ToString(),
                Name = "Recently Sold",
                Description = "Last 30 Days",
                FontAwesomeIcon = "fa-car",
                Records = accountsRecentlySold
            };
        }

        // Get the average day difference between two status changes.
        // If the accounts given don't have valid to and from status, those accounts are ignored from the calulcation.
        // However, if calling this array, the accounts SHOULD have valid status changes.
        private int? GetAverageDaysBetweenStatuses(IEnumerable<RepoAccount> repoAccount, string statusTo, string statusFrom)
        {
            IEnumerable<int?> daysBetweenStatuses = repoAccount.Select(
                (account) => GetDaysBetweenStatuses(account, statusTo, statusFrom));

            var validRepos = daysBetweenStatuses.Aggregate(0, (sum, days) => sum += days != null ? 1 : 0);
            var sumOfDays = daysBetweenStatuses.Aggregate(0, (sum, days) => sum += days != null ? days.Value : 0);

            if (validRepos == 0)
            {
                return null;
            }
            return sumOfDays / validRepos;
        }

        // If either status cannot be found, return null, indicating an that days could not be calculated.
        // If both the from status and to status are found, floor their difference of dates.
        private int? GetDaysBetweenStatuses(RepoAccount repoAccount, string newStatus, string oldStatus)
        {
            var fromStatusDate = GetLatestStatusChange(repoAccount, oldStatus)?.ChangedDate;
            var toStatusDate = GetLatestStatusChange(repoAccount, newStatus)?.ChangedDate;

            if (toStatusDate != null && fromStatusDate != null)
            {
                return (int) Math.Floor(toStatusDate.Value.Subtract(fromStatusDate.Value).TotalDays);
            }

            return null;
        }

        private RepoStatusChange GetLatestStatusChange(RepoAccount repoAccount, string status)
        {
            return (
                from statusChange in repoAccount.RepoStatusChanges
                where string.Equals(statusChange.StatusTo, status, StringComparison.CurrentCultureIgnoreCase)
                select statusChange).LastOrDefault();
        }
    }
}