using Microsoft.EntityFrameworkCore;

namespace Api;

public static class OrderQueries
{
    public const int PageSize = 20;

    // One page of a customer's orders with every navigation the order page needs.
    public static Task<List<Order>> PageAsync(AppDbContext db, int customerId, int page, CancellationToken ct) =>
        db.Orders
            .Where(o => o.CustomerId == customerId)
            .OrderByDescending(o => o.OrderedAt)
            .ThenBy(o => o.Id)
            .Skip(page * PageSize)
            .Take(PageSize)
            .Include(o => o.Customer)
            .Include(o => o.Lines)
                .ThenInclude(l => l.Product)
            .Include(o => o.Payments)
            .AsSplitQuery()
            .AsNoTracking()
            .ToListAsync(ct);

    // Every order in a date range, the shape a report or an export loads.
    public static Task<List<Order>> RangeAsync(AppDbContext db, DateTime from, DateTime to, CancellationToken ct) =>
        db.Orders
            .Where(o => o.OrderedAt >= from && o.OrderedAt < to)
            .Include(o => o.Customer)
            .Include(o => o.Lines)
                .ThenInclude(l => l.Product)
            .Include(o => o.Payments)
            .AsSplitQuery()
            .AsNoTracking()
            .ToListAsync(ct);

    // The same page with four references on the order instead of one:
    // two required (Customer, ShippingAddress) and two optional (BillingAddress, Carrier).
    public static Task<List<Order>> PageWithReferencesAsync(AppDbContext db, int customerId, int page, CancellationToken ct) =>
        db.Orders
            .Where(o => o.CustomerId == customerId)
            .OrderByDescending(o => o.OrderedAt)
            .ThenBy(o => o.Id)
            .Skip(page * PageSize)
            .Take(PageSize)
            .Include(o => o.Customer)
            .Include(o => o.ShippingAddress)
            .Include(o => o.BillingAddress)
            .Include(o => o.Carrier)
            .Include(o => o.Lines)
                .ThenInclude(l => l.Product)
            .Include(o => o.Payments)
            .AsSplitQuery()
            .AsNoTracking()
            .ToListAsync(ct);

    // The same report with the four references.
    public static Task<List<Order>> RangeWithReferencesAsync(AppDbContext db, DateTime from, DateTime to, CancellationToken ct) =>
        db.Orders
            .Where(o => o.OrderedAt >= from && o.OrderedAt < to)
            .Include(o => o.Customer)
            .Include(o => o.ShippingAddress)
            .Include(o => o.BillingAddress)
            .Include(o => o.Carrier)
            .Include(o => o.Lines)
                .ThenInclude(l => l.Product)
            .Include(o => o.Payments)
            .AsSplitQuery()
            .AsNoTracking()
            .ToListAsync(ct);
}