using Disco.Data.Repository;
using Disco.Models.Repository;
using Disco.Plugins.ServiceTracker.Models;
using System;
using System.Collections.Generic;
using System.Linq;

namespace Disco.Plugins.ServiceTracker.Services
{
    public class ServiceTrackerService
    {
        private readonly DiscoDataContext _database;
        private readonly ServiceTrackerDataStore _dataStore;
        private readonly ServiceTrackerConfig _config;

        public ServiceTrackerService(DiscoDataContext database, ServiceTrackerDataStore dataStore)
        {
            _database = database;
            _dataStore = dataStore;
            _config = dataStore.LoadConfig();
        }

        public DashboardViewModel BuildDashboard(string filterPriority = null, string filterLocation = null,
            string filterStatus = null, string filterTech = null, string sortBy = "due")
        {
            var openJobs = _database.Jobs
                .Include("Device").Include("Device.DeviceModel")
                .Include("User").Include("OpenedTechUser")
                .Include("JobType").Include("JobSubTypes")
                .Where(j => j.ClosedDate == null)
                .ToList();

            var allTickets = _dataStore.LoadAllTickets();
            var ticketLookup = allTickets.ToDictionary(t => t.JobId, t => t);

            if (_config.AutoCreateTicketsForNewJobs)
            {
                foreach (var job in openJobs)
                {
                    if (!ticketLookup.ContainsKey(job.Id))
                    {
                        var newTicket = CreateDefaultTicket(job);
                        _dataStore.SaveTicket(newTicket);
                        ticketLookup[job.Id] = newTicket;
                    }
                }
            }

            var tiles = new List<DashboardTile>();
            foreach (var job in openJobs)
            {
                ServiceTicket ticket;
                ticketLookup.TryGetValue(job.Id, out ticket);
                tiles.Add(BuildTile(job, ticket));
            }

            if (!string.IsNullOrEmpty(filterPriority))
                tiles = tiles.Where(t => t.PriorityId == filterPriority).ToList();
            if (!string.IsNullOrEmpty(filterLocation))
                tiles = tiles.Where(t => t.LocationId == filterLocation).ToList();
            if (!string.IsNullOrEmpty(filterStatus))
                tiles = tiles.Where(t => t.StatusOverride == filterStatus).ToList();
            if (!string.IsNullOrEmpty(filterTech))
                tiles = tiles.Where(t => t.AssignedTechId == filterTech).ToList();

            switch (sortBy)
            {
                case "priority":
                    tiles = tiles.OrderBy(t => t.PrioritySortOrder).ThenBy(t => t.SortDate).ToList();
                    break;
                case "age":
                    tiles = tiles.OrderByDescending(t => t.AgeDays).ToList();
                    break;
                case "modified":
                    tiles = tiles.OrderByDescending(t => t.LastModifiedDate).ToList();
                    break;
                case "sla":
                    tiles = tiles.OrderBy(t => t.IsSlaBreached ? 0 : t.IsSlaWarning ? 1 : 2)
                                .ThenBy(t => t.SlaDeadline.HasValue ? t.SlaDeadline.Value : DateTime.MaxValue).ToList();
                    break;
                case "due":
                default:
                    tiles = tiles.OrderBy(t => t.SortDate).ToList();
                    break;
            }

            return new DashboardViewModel
            {
                Tiles = tiles,
                Stats = BuildStats(tiles),
                Config = _config,
                CurrentFilter = filterPriority ?? filterLocation ?? filterStatus ?? "",
                SortBy = sortBy
            };
        }

        private DashboardTile BuildTile(Job job, ServiceTicket ticket)
        {
            var now = DateTime.Now;
            var priorityId = (ticket != null ? ticket.PriorityId : null) ?? _config.DefaultPriorityId;
            var priority = _config.Priorities.FirstOrDefault(p => p.Id == priorityId) ?? _config.Priorities.FirstOrDefault();
            var locationId = (ticket != null ? ticket.LocationId : null) ?? _config.DefaultLocationId;
            var location = _config.Locations.FirstOrDefault(l => l.Id == locationId) ?? _config.Locations.FirstOrDefault();

            var slaDeadline = ticket != null ? ticket.SlaDeadline : (DateTime?)null;
            if (!slaDeadline.HasValue && priority != null && priority.SlaHours > 0)
                slaDeadline = job.OpenedDate.AddHours(priority.SlaHours);
            bool slaBreached = slaDeadline.HasValue && now > slaDeadline.Value;
            bool slaWarning = !slaBreached && slaDeadline.HasValue && priority != null && priority.SlaHours > 0
                              && now > slaDeadline.Value.AddHours(-priority.SlaHours * 0.25);

            int ageDays = (int)(now - job.OpenedDate).TotalDays;
            string ageBadge;
            if (ageDays == 0) ageBadge = "Today";
            else if (ageDays == 1) ageBadge = "1 day";
            else if (ageDays < 7) ageBadge = ageDays + " days";
            else if (ageDays < 30) ageBadge = (ageDays / 7) + " wk" + (ageDays / 7 > 1 ? "s" : "");
            else ageBadge = (ageDays / 30) + " mo" + (ageDays / 30 > 1 ? "s" : "");

            var eta = (ticket != null ? ticket.EstimatedCompletion : null) ?? job.ExpectedClosedDate;
            string etaDisplay = "—";
            if (eta.HasValue)
            {
                var etaDays = (int)(eta.Value - now).TotalDays;
                if (etaDays < 0) etaDisplay = Math.Abs(etaDays) + "d overdue";
                else if (etaDays == 0) etaDisplay = "Today";
                else if (etaDays == 1) etaDisplay = "Tomorrow";
                else etaDisplay = eta.Value.ToString("dd MMM");
            }

            DateTime sortDate = slaBreached && slaDeadline.HasValue ? slaDeadline.Value
                              : eta.HasValue ? eta.Value
                              : job.ExpectedClosedDate.HasValue ? job.ExpectedClosedDate.Value : job.OpenedDate;

            string discoStatus = "Open";
            if (job.WaitingForUserAction.HasValue) discoStatus = "Awaiting User Action";
            else if (job.DeviceHeld.HasValue && !job.DeviceReadyForReturn.HasValue) discoStatus = "Device Held";
            else if (job.DeviceReadyForReturn.HasValue && !job.DeviceReturnedDate.HasValue) discoStatus = "Ready for Return";

            string latestNote = null;
            int noteCount = 0;
            if (ticket != null && ticket.Notes != null && ticket.Notes.Count > 0)
            {
                noteCount = ticket.Notes.Count;
                var latest = ticket.Notes.OrderByDescending(n => n.Timestamp).First();
                latestNote = latest.Content;
                if (latestNote != null && latestNote.Length > 80)
                    latestNote = latestNote.Substring(0, 77) + "...";
            }

            return new DashboardTile
            {
                JobId = job.Id,
                JobTypeDescription = job.JobType != null ? job.JobType.Description : job.JobTypeId,
                DeviceSerialNumber = job.DeviceSerialNumber ?? "—",
                DeviceModelDescription = job.Device != null && job.Device.DeviceModel != null ? job.Device.DeviceModel.Description : null,
                DeviceComputerName = job.Device != null ? job.Device.DeviceDomainId : null,
                UserId = job.UserId,
                UserDisplayName = job.User != null ? job.User.DisplayName : job.UserId,
                OpenedByTechId = job.OpenedTechUserId,
                OpenedByTechName = job.OpenedTechUser != null ? job.OpenedTechUser.DisplayName : job.OpenedTechUserId,
                OpenedDate = job.OpenedDate,
                ExpectedClosedDate = job.ExpectedClosedDate,
                DiscoStatus = discoStatus,
                PriorityId = priorityId,
                PriorityName = priority != null ? priority.Name : "Unknown",
                PriorityColor = priority != null ? priority.Color : "#999",
                PrioritySortOrder = priority != null ? priority.SortOrder : 99,
                LocationId = locationId,
                LocationName = location != null ? location.Name : "Unknown",
                LocationIcon = location != null ? location.Icon : "",
                LocationColor = location != null ? location.Color : "#999",
                AssignedTechId = ticket != null ? ticket.AssignedTechId : null,
                AssignedTechName = ResolveUserName(ticket != null ? ticket.AssignedTechId : null),
                EstimatedCompletion = eta,
                SlaDeadline = slaDeadline,
                StatusOverride = ticket != null && ticket.StatusOverride != null ? ticket.StatusOverride : discoStatus,
                Summary = ticket != null ? ticket.Summary : null,
                NoteCount = noteCount,
                LatestNote = latestNote,
                LastModifiedDate = ticket != null ? ticket.LastModifiedDate : job.OpenedDate,
                IsSlaBreached = slaBreached,
                IsSlaWarning = slaWarning,
                AgeBadge = ageBadge,
                AgeDays = ageDays,
                EtaDisplay = etaDisplay,
                SortDate = sortDate
            };
        }

        private DashboardStats BuildStats(List<DashboardTile> tiles)
        {
            var stats = new DashboardStats
            {
                TotalOpen = tiles.Count,
                SlaBreached = tiles.Count(t => t.IsSlaBreached),
                SlaWarning = tiles.Count(t => t.IsSlaWarning),
                AvgAgeDays = tiles.Count > 0 ? Math.Round(tiles.Average(t => (double)t.AgeDays), 1) : 0,
                OldestJobDays = tiles.Count > 0 ? tiles.Max(t => t.AgeDays) : 0
            };
            foreach (var p in _config.Priorities)
                stats.ByPriority[p.Id] = tiles.Count(t => t.PriorityId == p.Id);
            stats.Critical = tiles.Count(t => t.PriorityId == "critical");
            stats.High = tiles.Count(t => t.PriorityId == "high");
            stats.Medium = tiles.Count(t => t.PriorityId == "medium");
            stats.Low = tiles.Count(t => t.PriorityId == "low");
            stats.Scheduled = tiles.Count(t => t.PriorityId == "scheduled");
            foreach (var l in _config.Locations)
                stats.ByLocation[l.Id] = tiles.Count(t => t.LocationId == l.Id);
            stats.InItOffice = tiles.Count(t => t.LocationId == "it-office");
            stats.WithUser = tiles.Count(t => t.LocationId == "with-user");
            stats.AtRepairer = tiles.Count(t => t.LocationId == "at-repairer");
            foreach (var tile in tiles)
            {
                var status = tile.StatusOverride ?? "Open";
                if (!stats.ByStatus.ContainsKey(status)) stats.ByStatus[status] = 0;
                stats.ByStatus[status]++;
            }
            foreach (var tile in tiles.Where(t => !string.IsNullOrEmpty(t.AssignedTechId)))
            {
                var tech = tile.AssignedTechName ?? tile.AssignedTechId;
                if (!stats.ByTech.ContainsKey(tech)) stats.ByTech[tech] = 0;
                stats.ByTech[tech]++;
            }
            return stats;
        }

        private ServiceTicket CreateDefaultTicket(Job job)
        {
            var priority = _config.Priorities.FirstOrDefault(p => p.Id == _config.DefaultPriorityId);
            DateTime? sla = null;
            if (priority != null && priority.SlaHours > 0)
                sla = job.OpenedDate.AddHours(priority.SlaHours);
            string locationId = _config.DefaultLocationId;
            if (job.DeviceHeld.HasValue && !string.IsNullOrEmpty(job.DeviceHeldLocation))
            {
                var matchedLoc = _config.Locations.FirstOrDefault(
                    l => l.Name.Equals(job.DeviceHeldLocation, StringComparison.OrdinalIgnoreCase));
                if (matchedLoc != null) locationId = matchedLoc.Id;
            }
            return new ServiceTicket
            {
                JobId = job.Id, PriorityId = _config.DefaultPriorityId, LocationId = locationId,
                AssignedTechId = job.OpenedTechUserId, EstimatedCompletion = job.ExpectedClosedDate,
                SlaDeadline = sla, CreatedDate = DateTime.Now, LastModifiedDate = DateTime.Now
            };
        }

        private string ResolveUserName(string userId)
        {
            if (string.IsNullOrEmpty(userId)) return null;
            try
            {
                var user = _database.Users.FirstOrDefault(u => u.UserId == userId);
                return user != null ? user.DisplayName : userId;
            }
            catch { return userId; }
        }

        public void UpdateTicket(int jobId, string priorityId, string locationId,
            string assignedTechId, DateTime? eta, string status, string summary, string modifiedBy)
        {
            var ticket = _dataStore.GetTicket(jobId);
            if (ticket == null) ticket = new ServiceTicket { JobId = jobId };
            if (priorityId != null) ticket.PriorityId = priorityId;
            if (locationId != null) ticket.LocationId = locationId;
            if (assignedTechId != null) ticket.AssignedTechId = assignedTechId;
            if (eta.HasValue) ticket.EstimatedCompletion = eta;
            if (status != null) ticket.StatusOverride = status;
            if (summary != null) ticket.Summary = summary;
            ticket.LastModifiedBy = modifiedBy;
            if (priorityId != null)
            {
                var priority = _config.Priorities.FirstOrDefault(p => p.Id == priorityId);
                if (priority != null && priority.SlaHours > 0)
                    ticket.SlaDeadline = ticket.CreatedDate.AddHours(priority.SlaHours);
                else
                    ticket.SlaDeadline = null;
            }
            _dataStore.SaveTicket(ticket);
        }

        public void AddNote(int jobId, string authorId, string authorName, string content, string noteType)
        {
            _dataStore.AddNote(jobId, new TicketNote
            {
                AuthorId = authorId, AuthorName = authorName,
                Content = content, NoteType = noteType ?? "general"
            });
        }

        public ServiceTicket GetTicketDetail(int jobId) { return _dataStore.GetTicket(jobId); }
    }
}