using System.Linq;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using AyaNova.Models;


namespace AyaNova.Biz
{
    internal static class EventLogProcessor
    {

        /// <summary>
        /// Add an entry to the log
        /// 
        /// </summary>      
        /// <param name="newEvent"></param>
        /// <param name="ct"></param>
        /// <returns></returns>
        internal static async Task LogEventToDatabaseAsync(Event newEvent, AyContext ct)
        {
            await ct.Event.AddAsync(newEvent);
            await ct.SaveChangesAsync();
        }



        /// <summary>
        /// Handle delete
        /// remove all prior entries for object, add one deleted entry
        /// </summary>             
        /// <param name="userId"></param>
        /// <param name="ayType"></param>
        /// <param name="ayId"></param>
        /// <param name="textra"></param>
        /// <param name="ct"></param>
        internal static async Task DeleteObjectLogAsync(long userId, AyaType ayType, long ayId, string textra, AyContext ct)
        {
            await ct.Database.ExecuteSqlInterpolatedAsync($"delete from aevent where aytype = {ayType} and ayid={ayId}");
            await ct.Event.AddAsync(new Event(userId, ayId, ayType, AyaEvent.Deleted, textra));
            await ct.SaveChangesAsync();
        }

        /// <summary>
        /// Get the event log for a specified object
        /// Presentation is the client's responsibility (localization internationalization etc)
        /// </summary>
        internal static async Task<AyaNova.Api.Controllers.EventLogController.ObjectEventLogItem[]> GetLogForObjectAsync(AyaNova.Api.Controllers.EventLogController.EventLogOptions opt, AyContext ct)
        {
            //This is also an example of conditional where statements 

            //Set up the query
            var q = ct.Event.Select(m => m).AsNoTracking();

            q = q.Where(m => m.AyId == opt.AyId);

            if (opt.StartDate != null)
                q = q.Where(m => m.Created > opt.StartDate);

            if (opt.EndDate != null)
                q = q.Where(m => m.Created < opt.EndDate);

            q = q.OrderBy(m => m.Created);

            //Execute the query
            var EventItems = await q.ToArrayAsync();

            //convert the Event array to the correct return type array
            var ret = EventItems.Select(m => new AyaNova.Api.Controllers.EventLogController.ObjectEventLogItem()
            {
                Date = m.Created,
                UserId = m.UserId,
                Event = m.AyEvent,
                Textra = m.Textra
            }).ToArray();

            return ret;
        }



        /// <summary>
        /// Get the event log for a specified User
        /// Presentation is the client's responsibility (localization internationalization etc)
        /// </summary>
        internal static async Task<AyaNova.Api.Controllers.EventLogController.UserEventLogItem[]> GetLogForUserAsync(AyaNova.Api.Controllers.EventLogController.EventLogOptions opt, AyContext ct)
        {
            //Set up the query
            var q = ct.Event.Select(m => m);

            q = q.Where(m => m.UserId == opt.AyId);

            if (opt.StartDate != null)
                q = q.Where(m => m.Created > opt.StartDate);

            if (opt.EndDate != null)
                q = q.Where(m => m.Created < opt.EndDate);

            q = q.OrderBy(m => m.Created);

            //Execute the query
            var EventItems = await q.ToArrayAsync();

            //convert the Event array to the correct return type array
            var ret = EventItems.Select(m => new AyaNova.Api.Controllers.EventLogController.UserEventLogItem()
            {
                Date = m.Created,
                ObjectType = m.AyType,
                ObjectId = m.AyId,
                Event = m.AyEvent,
                Textra = m.Textra
            }).ToArray();

            return ret;
        }



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


    }//eoc

}//eons