using System.Collections.Generic;
using NzbDrone.Api.ClientSchema;
using NzbDrone.Common.Reflection;
using NzbDrone.Core.Indexers;
using NzbDrone.Core.ThingiProvider;
using Omu.ValueInjecter;
using FluentValidation;
using NzbDrone.Api.Mapping;

namespace NzbDrone.Api.Indexers
{
    public class IndexerModule : NzbDroneRestModule<IndexerResource>
    {
        private readonly IIndexerService _indexerService;

        public IndexerModule(IIndexerService indexerService)
        {
            _indexerService = indexerService;
            GetResourceAll = GetAll;
            GetResourceById = GetIndexer;
            CreateResource = CreateIndexer;
            UpdateResource = UpdateIndexer;
            DeleteResource = DeleteIndexer;


            SharedValidator.RuleFor(c => c.Name).NotEmpty();
            SharedValidator.RuleFor(c => c.Implementation).NotEmpty();

            PostValidator.RuleFor(c => c.Fields).NotEmpty();
        }

        private IndexerResource GetIndexer(int id)
        {
            return _indexerService.Get(id).InjectTo<IndexerResource>();
        }

        private List<IndexerResource> GetAll()
        {
            var indexerDefinitions = _indexerService.All();

            var result = new List<IndexerResource>(indexerDefinitions.Count);

            foreach (var definition in indexerDefinitions)
            {
                var indexerResource = new IndexerResource();
                indexerResource.InjectFrom(definition);
                indexerResource.Fields = SchemaBuilder.ToSchema(definition.Settings);

                result.Add(indexerResource);
            }

            return result;
        }

        private int CreateIndexer(IndexerResource indexerResource)
        {
            var indexer = GetDefinition(indexerResource);
            indexer = _indexerService.Create(indexer);
            return indexer.Id;
        }

        private void UpdateIndexer(IndexerResource indexerResource)
        {
            var indexer = GetDefinition(indexerResource);

            ValidateIndexer(indexer);

            _indexerService.Update(indexer);
        }


        private static void ValidateIndexer(ProviderDefinition definition)
        {
            if (!definition.Enable) return;

            var validationResult = definition.Settings.Validate();

            if (!validationResult.IsValid)
            {
                throw new ValidationException(validationResult.Errors);
            }
        }

        private IndexerDefinition GetDefinition(IndexerResource indexerResource)
        {

            var definition = new IndexerDefinition();

            definition.InjectFrom(indexerResource);

            var configContract = ReflectionExtensions.CoreAssembly.FindTypeByName(definition.ConfigContract);
            definition.Settings = (IProviderConfig)SchemaBuilder.ReadFormSchema(indexerResource.Fields, configContract);

            ValidateIndexer(definition);

            return definition;
        }

        private void DeleteIndexer(int id)
        {
            _indexerService.Delete(id);
        }
    }
}