using Microsoft.AspNetCore.Mvc; // [ApiController], [Route]
using Microsoft.EntityFrameworkCore; // ToListAsync, FirstOrDefaultAsync
using Packt.Shared; // NorthwindContext, Customer

namespace Northwind.BlazorWasm.Server.Controllers;

[ApiController]
[Route("api/[controller]")]
public class CustomersController : ControllerBase
{
  private readonly NorthwindContext db;

  public CustomersController(NorthwindContext db)
  {
    this.db = db;
  }

  [HttpGet]
  public async Task<List<Customer>> GetCustomersAsync()
  {
    return await db.Customers.ToListAsync();
  }

  [HttpGet("in/{country}")] // different path to disambiguate
  public async Task<List<Customer>> GetCustomersAsync(string country)
  {
    return await db.Customers
      .Where(c => c.Country == country).ToListAsync();
  }

  [HttpGet("{id}")]
  public async Task<Customer?> GetCustomerAsync(string id)
  {
    return await db.Customers
      .FirstOrDefaultAsync(c => c.CustomerId == id);
  }

  [HttpPost]
  public async Task<Customer?> CreateCustomerAsync
    (Customer customerToAdd)
  {
    Customer? existing = await db.Customers.FirstOrDefaultAsync
      (c => c.CustomerId == customerToAdd.CustomerId);

    if (existing == null)
    {
      db.Customers.Add(customerToAdd);

      int affected = await db.SaveChangesAsync();

      if (affected == 1)
      {
        return customerToAdd;
      }
    }
    return existing;
  }

  [HttpPut]
  public async Task<Customer?> UpdateCustomerAsync(Customer c)
  {
    db.Entry(c).State = EntityState.Modified;

    int affected = await db.SaveChangesAsync();

    if (affected == 1)
    {
      return c;
    }
    return null;
  }

  [HttpDelete("{id}")]
  public async Task<int> DeleteCustomerAsync(string id)
  {
    Customer? c = await db.Customers.FirstOrDefaultAsync
      (c => c.CustomerId == id);

    if (c != null)
    {
      db.Customers.Remove(c);
      int affected = await db.SaveChangesAsync();
      return affected;
    }
    return 0;
  }
}