Libation/DtoImporterService/UNTESTED/ContributorImporter.cs

94 lines
2.5 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using AudibleApiDTOs;
using DataLayer;
using InternalUtilities;
namespace DtoImporterService
{
public class ContributorImporter : ItemsImporterBase
{
public ContributorImporter(LibationContext context) : base(context) { }
public override IEnumerable<Exception> Validate(IEnumerable<Item> items) => new ContributorValidator().Validate(items);
protected override int DoImport(IEnumerable<Item> items)
{
// get distinct
var authors = items.GetAuthorsDistinct().ToList();
var narrators = items.GetNarratorsDistinct().ToList();
var publishers = items.GetPublishersDistinct().ToList();
// load db existing => .Local
var allNames = publishers
.Union(authors.Select(n => n.Name))
.Union(narrators.Select(n => n.Name))
.Where(name => !string.IsNullOrWhiteSpace(name))
.ToList();
loadLocal_contributors(allNames);
// upsert
var qtyNew = 0;
qtyNew += upsertPeople(authors);
qtyNew += upsertPeople(narrators);
qtyNew += upsertPublishers(publishers);
return qtyNew;
}
private void loadLocal_contributors(List<string> contributorNames)
{
//// BAD: very inefficient
// var x = context.Contributors.Local.Where(c => !contribNames.Contains(c.Name));
// GOOD: Except() is efficient. Due to hashing, it's close to O(n)
var localNames = DbContext.Contributors.Local.Select(c => c.Name);
var remainingContribNames = contributorNames
.Distinct()
.Except(localNames)
.ToList();
// load existing => local
// remember to include default/empty/missing
var emptyName = Contributor.GetEmpty().Name;
if (remainingContribNames.Any())
DbContext.Contributors.Where(c => remainingContribNames.Contains(c.Name) || c.Name == emptyName).ToList();
}
// only use after loading contributors => local
private int upsertPeople(List<Person> people)
{
var qtyNew = 0;
foreach (var p in people)
{
var person = DbContext.Contributors.Local.SingleOrDefault(c => c.Name == p.Name);
if (person == null)
{
person = DbContext.Contributors.Add(new Contributor(p.Name, p.Asin)).Entity;
qtyNew++;
}
}
return qtyNew;
}
// only use after loading contributors => local
private int upsertPublishers(List<string> publishers)
{
var qtyNew = 0;
foreach (var publisherName in publishers)
{
if (DbContext.Contributors.Local.SingleOrDefault(c => c.Name == publisherName) == null)
{
DbContext.Contributors.Add(new Contributor(publisherName));
qtyNew++;
}
}
return qtyNew;
}
}
}