using System;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using System.Linq;
using AyaNova.Util;
using AyaNova.Api.ControllerHelpers;
using AyaNova.Models;
using Newtonsoft.Json.Linq;
using System.Collections.Generic;
using Newtonsoft.Json;

namespace AyaNova.Biz
{
    internal class MemoBiz : BizObject, IJobObject, ISearchAbleObject, IReportAbleObject, IExportAbleObject, IImportAbleObject, INotifiableObject
    {
        internal MemoBiz(AyContext dbcontext, long currentUserId, long userTranslationId, AuthorizationRoles UserRoles)
        {
            ct = dbcontext;
            UserId = currentUserId;
            UserTranslationId = userTranslationId;
            CurrentUserRoles = UserRoles;
            BizType = AyaType.Memo;
        }

        internal static MemoBiz GetBiz(AyContext ct, Microsoft.AspNetCore.Http.HttpContext httpContext = null)
        {
            if (httpContext != null)
                return new MemoBiz(ct, UserIdFromContext.Id(httpContext.Items), UserTranslationIdFromContext.Id(httpContext.Items), UserRolesFromContext.Roles(httpContext.Items));
            else
                return new MemoBiz(ct, 1, ServerBootConfig.AYANOVA_DEFAULT_TRANSLATION_ID, AuthorizationRoles.BizAdminFull);
        }

        ////////////////////////////////////////////////////////////////////////////////////////////////
        //EXISTS 
        internal async Task<bool> ExistsAsync(long id)
        {
            return await ct.Memo.AnyAsync(z => z.Id == id);
        }

        ////////////////////////////////////////////////////////////////////////////////////////////////
        //CREATE   
        //
        internal async Task<Memo> CreateAsync(Memo newObject)
        {

            await ValidateAsync(newObject);//a bit different, can't update a memo so only need to worry about new objects
            if (HasErrors)
                return null;
            else
            {
                newObject.Tags = TagBiz.NormalizeTags(newObject.Tags);
                newObject.CustomFields = JsonUtil.CompactJson(newObject.CustomFields);
                await ct.Memo.AddAsync(newObject);
                await ct.SaveChangesAsync();
                await EventLogProcessor.LogEventToDatabaseAsync(new Event(UserId, newObject.Id, BizType, AyaEvent.Created), ct);
                await SearchIndexAsync(newObject, true);
                await TagBiz.ProcessUpdateTagsInRepositoryAsync(ct, newObject.Tags, null);
                await HandlePotentialNotificationEvent(AyaEvent.Created, newObject);
                return newObject;
            }
        }


        ////////////////////////////////////////////////////////////////////////////////////////////////
        //GET 
        //      
        internal async Task<Memo> GetAsync(long id, bool logTheGetEvent = true)
        {
            var ret = await ct.Memo.AsNoTracking().SingleOrDefaultAsync(m => m.Id == id && m.ToId == UserId);//## SECURITY, if need general purpose then make new method
            if (logTheGetEvent && ret != null)
            {
                //Hijack this method to also flag as read
                //batch ops will get but will set logthegetevent as false which is helpful for also setting read or not
                if (!ret.Viewed)
                {
                    //FLAG VIEWED
                    ret.Viewed = true;
                    await ct.SaveChangesAsync();
                }
                await EventLogProcessor.LogEventToDatabaseAsync(new Event(UserId, id, BizType, AyaEvent.Retrieved), ct);
            }
            return ret;
        }



        ////////////////////////////////////////////////////////////////////////////////////////////////
        //UPDATE  - ## NOTE: only internally, not exposed to controller route only here for batch ops
        // 
        //
        internal async Task<Memo> PutAsync(Memo putObject)
        {
            var dbObject = await GetAsync(putObject.Id, false);
            if (dbObject == null)
            {
                AddError(ApiErrorCode.NOT_FOUND, "id");
                return null;
            }
            if (dbObject.Concurrency != putObject.Concurrency)
            {
                AddError(ApiErrorCode.CONCURRENCY_CONFLICT);
                return null;
            }

            putObject.Tags = TagBiz.NormalizeTags(putObject.Tags);
            putObject.CustomFields = JsonUtil.CompactJson(putObject.CustomFields);


            ct.Replace(dbObject, putObject);
            try
            {
                await ct.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!await ExistsAsync(putObject.Id))
                    AddError(ApiErrorCode.NOT_FOUND);
                else
                    AddError(ApiErrorCode.CONCURRENCY_CONFLICT);
                return null;
            }
            await EventLogProcessor.LogEventToDatabaseAsync(new Event(UserId, dbObject.Id, BizType, AyaEvent.Modified), ct);
            await SearchIndexAsync(putObject, false);
            await TagBiz.ProcessUpdateTagsInRepositoryAsync(ct, putObject.Tags, dbObject.Tags);
            await HandlePotentialNotificationEvent(AyaEvent.Modified, putObject, dbObject);
            return putObject;
        }

        ////////////////////////////////////////////////////////////////////////////////////////////////
        //DELETE
        //
        internal async Task<bool> DeleteAsync(long id)
        {
            using (var transaction = await ct.Database.BeginTransactionAsync())
            {
                try
                {
                    var dbObject = await GetAsync(id, false);
                    if (dbObject == null)
                    {
                        AddError(ApiErrorCode.NOT_FOUND);
                        return false;
                    }
                    ValidateCanDelete(dbObject);
                    if (HasErrors)
                        return false;
                    if (HasErrors)
                        return false;
                    ct.Memo.Remove(dbObject);
                    await ct.SaveChangesAsync();

                    //Log event 
                    await EventLogProcessor.DeleteObjectLogAsync(UserId, BizType, dbObject.Id, dbObject.Name, ct);
                    await Search.ProcessDeletedObjectKeywordsAsync(dbObject.Id, BizType, ct);
                    await TagBiz.ProcessDeleteTagsInRepositoryAsync(ct, dbObject.Tags);
                    await FileUtil.DeleteAttachmentsForObjectAsync(BizType, dbObject.Id, ct);
                    await transaction.CommitAsync();
                    await HandlePotentialNotificationEvent(AyaEvent.Deleted, dbObject);
                }
                catch
                {
                    //Just re-throw for now, let exception handler deal, but in future may want to deal with this more here
                    throw;
                }
                return true;
            }
        }

        ////////////////////////////////////////////////////////////////////////////////////////////////
        //SEARCH
        //
        private async Task SearchIndexAsync(Memo obj, bool isNew)
        {
            var SearchParams = new Search.SearchIndexProcessObjectParameters(UserTranslationId, obj.Id, BizType);
            DigestSearchText(obj, SearchParams);
            if (isNew)
                await Search.ProcessNewObjectKeywordsAsync(SearchParams);
            else
                await Search.ProcessUpdatedObjectKeywordsAsync(SearchParams);
        }

        public async Task<Search.SearchIndexProcessObjectParameters> GetSearchResultSummary(long id)
        {
            var obj = await GetAsync(id, false);
            var SearchParams = new Search.SearchIndexProcessObjectParameters();
            DigestSearchText(obj, SearchParams);
            return SearchParams;
        }

        public void DigestSearchText(Memo obj, Search.SearchIndexProcessObjectParameters searchParams)
        {
            if (obj != null)
                searchParams.AddText(obj.Notes)
                            .AddText(obj.Name)
                            .AddText(obj.Wiki)
                            .AddText(obj.Tags)
                            .AddCustomFields(obj.CustomFields);
        }


        ////////////////////////////////////////////////////////////////////////////////////////////////
        //VALIDATION
        //

        private async Task ValidateAsync(Memo proposedObj)
        {

            //skip validation if seeding
            if (ServerBootConfig.SEEDING) return;

            //Only can send a memo from your own account 
            //with bypass for import if superuser 
            if (proposedObj.FromId != UserId && UserId != 1)
            {
                AddError(ApiErrorCode.NOT_AUTHORIZED, "FromId", "No impersonation");
                return;//no need to bother with any other validation, this is not allowed
            }

            //valid TO ID?
            if (!await ct.User.AnyAsync(m => m.Id == proposedObj.ToId))
            {
                AddError(ApiErrorCode.VALIDATION_INVALID_VALUE, "ToId");
                return;//no need to bother with any other validation
            }

            //Name ("subject") is still required for a memo, empty subject not valid
            //also, subject was required by biz rule in v7 so no need to worry about that on migrate
            if (string.IsNullOrWhiteSpace(proposedObj.Name))
                AddError(ApiErrorCode.VALIDATION_REQUIRED, "Name");



            //Name does *NOT* need to be unique because for memo it's actually the subject line
            //just kept internal naming the same to make coding easier with less workarounds

            // //If name is otherwise OK, check that name is unique
            // if (!PropertyHasErrors("Name"))
            // {
            //     //Use Any command is efficient way to check existance, it doesn't return the record, just a true or false
            //     if (await ct.Memo.AnyAsync(m => m.Name == proposedObj.Name && m.Id != proposedObj.Id))
            //     {
            //         AddError(ApiErrorCode.VALIDATION_NOT_UNIQUE, "Name");
            //     }
            // }


            //Any form customizations to validate?
            var FormCustomization = await ct.FormCustom.AsNoTracking().SingleOrDefaultAsync(x => x.FormKey == AyaType.Memo.ToString());
            if (FormCustomization != null)
            {
                //Yeppers, do the validation, there are two, the custom fields and the regular fields that might be set to required

                //validate users choices for required non custom fields
                RequiredFieldsValidator.Validate(this, FormCustomization, proposedObj);

                //validate custom fields
                CustomFieldsValidator.Validate(this, FormCustomization, proposedObj.CustomFields);
            }

        }

        private void ValidateCanDelete(Memo inObj)
        {
            //whatever needs to be check to delete this object
        }



        ////////////////////////////////////////////////////////////////////////////////////////////////
        //REPORTING
        //
        public async Task<JArray> GetReportData(long[] idList)
        {
            JArray ReportData = new JArray();
            while (idList.Any())
            {
                var batch = idList.Take(IReportAbleObject.REPORT_DATA_BATCH_SIZE);
                idList = idList.Skip(IReportAbleObject.REPORT_DATA_BATCH_SIZE).ToArray();
                //query for this batch, comes back in db natural order unfortunately
                var batchResults = await ct.Memo.AsNoTracking().Where(z => batch.Contains(z.Id)).ToArrayAsync();
                //order the results back into original
                var orderedList = from id in batch join z in batchResults on id equals z.Id select z;
                foreach (Memo w in orderedList)
                {
                    await PopulateVizFields(w);
                    var jo = JObject.FromObject(w);
                    if (!JsonUtil.JTokenIsNullOrEmpty(jo["CustomFields"]))
                        jo["CustomFields"] = JObject.Parse((string)jo["CustomFields"]);
                    ReportData.Add(jo);
                }
            }
            return ReportData;
        }


        //populate viz fields from provided object
        private async Task PopulateVizFields(Memo o)
        {
            if (o.ToId != null)
                o.ToViz = await ct.User.AsNoTracking().Where(x => x.Id == o.ToId).Select(x => x.Name).FirstOrDefaultAsync();
            if (o.FromId != null)
                o.FromViz = await ct.User.AsNoTracking().Where(x => x.Id == o.FromId).Select(x => x.Name).FirstOrDefaultAsync();
        }

        ////////////////////////////////////////////////////////////////////////////////////////////////       
        // IMPORT EXPORT
        //

        public async Task<JArray> GetExportData(long[] idList)
        {
            //for now just re-use the report data code
            //this may turn out to be the pattern for most biz object types but keeping it seperate allows for custom usage from time to time
            return await GetReportData(idList);
        }

        public async Task<List<string>> ImportData(JArray ja)
        {
            List<string> ImportResult = new List<string>();
            string ImportTag = $"imported-{FileUtil.GetSafeDateFileName()}";

            var jsset = JsonSerializer.CreateDefault(new JsonSerializerSettings { ContractResolver = new AyaNova.Util.JsonUtil.ShouldSerializeContractResolver(new string[] { "Concurrency", "Id", "CustomFields" }) });
            foreach (JObject j in ja)
            {
                var w = j.ToObject<Memo>(jsset);
                if (j["CustomFields"] != null)
                    w.CustomFields = j["CustomFields"].ToString();
                w.Tags.Add(ImportTag);//so user can find them all and revert later if necessary
                var res = await CreateAsync(w);
                if (res == null)
                {
                    ImportResult.Add($"* {w.Name} - {this.GetErrorsAsString()}");
                    this.ClearErrors();
                }
                else
                {
                    ImportResult.Add($"{w.Name} - ok");
                }
            }
            return ImportResult;
        }




        ////////////////////////////////////////////////////////////////////////////////////////////////
        //JOB / OPERATIONS
        //
        public async Task HandleJobAsync(OpsJob job)
        {
            //Hand off the particular job to the corresponding processing code
            //NOTE: If this code throws an exception the caller (JobsBiz::ProcessJobsAsync) will automatically set the job to failed and log the exeption so 
            //basically any error condition during job processing should throw up an exception if it can't be handled
            switch (job.JobType)
            {
                case JobType.BatchCoreObjectOperation:
                    await ProcessBatchJobAsync(job);
                    break;
                default:
                    throw new System.ArgumentOutOfRangeException($"MemoBiz.HandleJob-> Invalid job type{job.JobType.ToString()}");
            }
        }



        private async Task ProcessBatchJobAsync(OpsJob job)
        {
            await JobsBiz.UpdateJobStatusAsync(job.GId, JobStatus.Running);
            await JobsBiz.LogJobAsync(job.GId, $"LT:StartJob {job.SubType}");
            List<long> idList = new List<long>();
            long FailedObjectCount = 0;
            JObject jobData = JObject.Parse(job.JobInfo);
            if (jobData.ContainsKey("idList"))
                idList = ((JArray)jobData["idList"]).ToObject<List<long>>();
            else
                idList = await ct.Memo.AsNoTracking().Select(z => z.Id).ToListAsync();
            bool SaveIt = false;
            foreach (long id in idList)
            {
                try
                {
                    SaveIt = false;
                    ClearErrors();
                    Memo o = null;
                    //save a fetch if it's a delete
                    if (job.SubType != JobSubType.Delete)
                        o = await GetAsync(id, false);
                    switch (job.SubType)
                    {
                        case JobSubType.TagAddAny:
                        case JobSubType.TagAdd:
                        case JobSubType.TagRemoveAny:
                        case JobSubType.TagRemove:
                        case JobSubType.TagReplaceAny:
                        case JobSubType.TagReplace:
                            SaveIt = TagBiz.ProcessBatchTagOperation(o.Tags, (string)jobData["tag"], jobData.ContainsKey("toTag") ? (string)jobData["toTag"] : null, job.SubType);
                            break;
                        case JobSubType.Delete:
                            if (!await DeleteAsync(id))
                            {
                                await JobsBiz.LogJobAsync(job.GId, $"LT:Errors {GetErrorsAsString()} id {id}");
                                FailedObjectCount++;
                            }
                            break;
                        default:
                            throw new System.ArgumentOutOfRangeException($"ProcessBatchJobAsync -> Invalid job Subtype{job.SubType}");
                    }
                    if (SaveIt)
                    {
                        o = await PutAsync(o);
                        if (o == null)
                        {
                            await JobsBiz.LogJobAsync(job.GId, $"LT:Errors {GetErrorsAsString()} id {id}");
                            FailedObjectCount++;
                        }
                    }
                }
                catch (Exception ex)
                {
                    await JobsBiz.LogJobAsync(job.GId, $"LT:Errors id({id})");
                    await JobsBiz.LogJobAsync(job.GId, ExceptionUtil.ExtractAllExceptionMessages(ex));
                }
            }
            await JobsBiz.LogJobAsync(job.GId, $"LT:BatchJob {job.SubType} {idList.Count}{(FailedObjectCount > 0 ? " - LT:Failed " + FailedObjectCount : "")}");
            await JobsBiz.UpdateJobStatusAsync(job.GId, JobStatus.Completed);
        }








        ////////////////////////////////////////////////////////////////////////////////////////////////
        // NOTIFICATION PROCESSING
        //
        public async Task HandlePotentialNotificationEvent(AyaEvent ayaEvent, ICoreBizObjectModel proposedObj, ICoreBizObjectModel currentObj = null)
        {
            ILogger log = AyaNova.Util.ApplicationLogging.CreateLogger<MemoBiz>();
            if (ServerBootConfig.SEEDING) return;
            log.LogDebug($"HandlePotentialNotificationEvent processing:  [AyaType:{this.BizType}, AyaEvent:{ayaEvent}]");

            bool isNew = currentObj == null;


            //STANDARD EVENTS FOR ALL OBJECTS
            await NotifyEventHelper.ProcessStandardObjectEvents(ayaEvent, proposedObj, ct);

            //SPECIFIC EVENTS FOR THIS OBJECT

        }//end of process notifications




        /////////////////////////////////////////////////////////////////////

    }//eoc


}//eons