using InABox.Core;
using InABox.Database;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace PRS.Shared
{
    public static class FormUpdater
    {
        public static void UpdateAllForms(
            Func<DigitalForm, IList<DigitalFormVariable>, bool> skip,
            Func<Type, IDigitalFormInstance, DigitalForm, IList<DigitalFormVariable>, bool> convert, int step = 100)
        {
            var forms = DbFactory.NewProvider(Logger.Main).Query<DigitalForm>(
                null,
                Columns.None<DigitalForm>().Add(x => x.ID)
                    .Add(x => x.Code)
                    .Add(x => x.Description)
                    .Add(x => x.AppliesTo));
            foreach(var form in forms.ToObjects<DigitalForm>())
            {
                Logger.Send(LogType.Information, "", $"Working on '{form.Code} - {form.Description}'");
                var variables = DbFactory.NewProvider(Logger.Main).Query(
                    new Filter<DigitalFormVariable>(x => x.Form.ID).IsEqualTo(form.ID),
                    null).ToObjects<DigitalFormVariable>().ToArray();
                if(skip(form, variables))
                {
                    continue;
                }

                var formType = DFUtils.GetFormInstanceType(form.AppliesTo);
                if(formType is null)
                {
                    Logger.Send(LogType.Error, "", $"{form.AppliesTo} does not refer to a digital form instance class.");
                    continue;
                }

                var IDs = DbFactory.NewProvider(Logger.Main).Query(formType,
                    Filter.Create<IDigitalFormInstance>(formType, x => x.Form.ID).IsEqualTo(form.ID),
                    Columns.Create<IDigitalFormInstance>(formType, ColumnTypeFlags.None)
                        .Add<IDigitalFormInstance>(x => x.ID)).Rows.Select(x => x.Get<Guid>("ID")).ToArray();

                for(int i = 0; i < IDs.Length; i += step)
                {
                    int j = Math.Min(i + step, IDs.Length);
                    var ids = IDs[i..j];

                    Logger.Send(LogType.Information, "", $"Converting {j - i} items; {IDs.Length - j} left.");
                    var formInstances = DbFactory.NewProvider(Logger.Main).Query(formType,
                        Filter.Create<IDigitalFormInstance>(formType, x => x.ID).InList(ids),
                        Columns.Create<IDigitalFormInstance>(formType, ColumnTypeFlags.None)
                            .Add<IDigitalFormInstance>(x => x.ID)
                            .Add<IDigitalFormInstance>(x => x.FormData)
                            .Add<IDigitalFormInstance>(x => x.BlobData));

                    var save = new List<Entity>();
                    foreach (var row in formInstances.Rows)
                    {
                        var formInstance = (row.ToObject(formType) as IDigitalFormInstance)!;
                        if (convert(formType, formInstance, form, variables))
                        {
                            save.Add((formInstance as Entity)!);
                        }
                    }
                    if(save.Count > 0)
                    {
                        DbFactory.NewProvider(Logger.Main).Save(formType, save);
                    }
                }
            }
        }
    }
}