using COA.Common;
using COA.PartnerApis.QuickBase;
using System;
using System.Collections.Generic;
using System.Linq.Expressions;
using System.Reflection;

namespace COA.EnterpriseServices.DataAccess.QuickBase
{
    /// <summary>
    /// Represents a map between a CLR type, its QuickBase table, and fields
    /// </summary>
    internal abstract class RecordMap
    {
        internal Type ItemType { get; set; }
        internal string Table { get; set; }
        internal ICollection<FieldMap> FieldMaps { get; } = new List<FieldMap>();
    }

    internal class RecordMap<TEntity, TEnumFieldMap> : RecordMap where TEntity : IRecord where TEnumFieldMap : Enum
    {
        internal RecordMap()
        {
            ItemType = typeof(TEntity);

            var tableNameAttribute = typeof(TEnumFieldMap).GetCustomAttribute<QuickBaseNameAttribute>();

            if (tableNameAttribute != null)
            {
                Table = tableNameAttribute.Name;
            }
        }

        /// <summary>
        /// Adds a propery mapping for an entity property
        /// </summary>
        /// <param name="property"></param>
        /// <param name="field"></param>
        /// <returns></returns>
        internal RecordMap<TEntity, TEnumFieldMap> WithProperty(Expression<Func<TEntity, object>> property, TEnumFieldMap field)
        {
            if (property.Body is MemberExpression memberExpression)
            {
                FieldMaps.Add(new FieldMap
                {
                    PropertyName = memberExpression.Member.Name,
                    FieldId = field.To<int>()
                });
            }
            else if (property.Body is UnaryExpression unaryExpression && unaryExpression.Operand is MemberExpression unaryMemberExpression)
            {
                FieldMaps.Add(new FieldMap
                {
                    PropertyName = unaryMemberExpression.Member.Name,
                    FieldId = field.To<int>()
                });
            }

            return this;
        }

        /// <summary>
        /// Adds default property mappings for common entity fields
        /// </summary>
        /// <typeparam name="TEntity"></typeparam>
        /// <typeparam name="TEnumFieldMap"></typeparam>
        /// <param name="table"></param>
        /// <returns></returns>
        internal RecordMap<TEntity, TEnumFieldMap> WithDefaults()
        {
            FieldMaps.Add(new FieldMap
            {
                PropertyName = nameof(IRecord.Id),
                FieldId = PartnerApis.QuickBase.Constants.RecordIdFieldId
            });

            FieldMaps.Add(new FieldMap
            {
                PropertyName = nameof(IRecord.Created),
                FieldId = PartnerApis.QuickBase.Constants.DateCreatedFieldId
            });

            FieldMaps.Add(new FieldMap
            {
                PropertyName = nameof(IRecord.Modified),
                FieldId = PartnerApis.QuickBase.Constants.DateModifiedFieldId
            });

            return this;
        }
    }
}