using System;
using MongoDB.Driver;
using PolyTraderSharp.Extensions;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using PolyTraderSharp.Models;

namespace PolyTraderSharp.Extensions
{
    public static class MongoDbLiteDBShim
    {
        // 1. LiteDB: FindOne(predicate) -> MongoDB: Find(predicate).FirstOrDefault()
        public static T LiteFindOne<T>(this IMongoCollection<T> col, Expression<Func<T, bool>> predicate)
        {
            return col.Find(predicate).FirstOrDefault();
        }

        // 2. LiteDB: Find(predicate) -> MongoDB: Find(predicate).ToList() 
        // Note: LiteDB returns IEnumerable<T>. ToList() is perfectly fine for iteration.
        public static List<T> LiteFind<T>(this IMongoCollection<T> col, Expression<Func<T, bool>> predicate)
        {
            return col.Find(predicate).ToList();
        }

        // 3. LiteDB: FindAll() -> MongoDB: Find(_ => true).ToList()
        public static List<T> LiteFindAll<T>(this IMongoCollection<T> col)
        {
            return col.Find(_ => true).ToList();
        }

        // 4. Upsert extensions mapped to Primary Keys 
        public static void Upsert(this IMongoCollection<AccountState> col, AccountState doc)
        {
            col.ReplaceOne(x => x.AccountId == doc.AccountId, doc, new ReplaceOptions { IsUpsert = true });
        }

        public static void Upsert(this IMongoCollection<TrackedTrader> col, TrackedTrader doc)
        {
            col.ReplaceOne(x => x.Id == doc.Id, doc, new ReplaceOptions { IsUpsert = true });
        }

        public static void Upsert(this IMongoCollection<Position> col, Position doc)
        {
            col.ReplaceOne(x => x.TokenId == doc.TokenId, doc, new ReplaceOptions { IsUpsert = true });
        }

        public static void Upsert(this IMongoCollection<MarketData> col, MarketData doc)
        {
            col.ReplaceOne(x => x.Id == doc.Id, doc, new ReplaceOptions { IsUpsert = true });
        }

        // 5. Update (Updates without upserting if it doesn't exist)
        public static void Update(this IMongoCollection<TrackedTrader> col, TrackedTrader doc)
        {
            col.ReplaceOne(x => x.Id == doc.Id, doc);
        }

        public static void Update(this IMongoCollection<AccountState> col, AccountState doc)
        {
            col.ReplaceOne(x => x.AccountId == doc.AccountId, doc);
        }

        public static void Update(this IMongoCollection<MarketData> col, MarketData doc)
        {
            col.ReplaceOne(x => x.Id == doc.Id, doc);
        }

        // 6. Insert maps perfectly to InsertOne
        public static void Insert<T>(this IMongoCollection<T> col, T doc)
        {
            col.InsertOne(doc);
        }

        // 7. Delete (by TokenId / String ID)
        public static void Delete(this IMongoCollection<Position> col, string tokenId)
        {
            col.DeleteOne(x => x.TokenId == tokenId);
        }

        // 8. EnsureIndex shim (MongoDB Index Creation)
        public static void EnsureIndex<T>(this IMongoCollection<T> col, Expression<Func<T, object>> property)
        {
            try 
            {
                var indexKeys = Builders<T>.IndexKeys.Ascending(property);
                var indexModel = new CreateIndexModel<T>(indexKeys);
                col.Indexes.CreateOne(indexModel);
            } 
            catch { }
        }
    }
}