using Microsoft.AspNetCore.Mvc; // [Route], [ApiController], ControllerBase
using Packt.Shared; // Customer
using Northwind.WebApi.Repositories; // ICustomerRepository

namespace Northwind.WebApi.Controllers;

// base address: api/customers
[Route("api/[controller]")]
[ApiController]
public class CustomersController : ControllerBase
{
  private readonly ICustomerRepository repo;

  // constructor injects repository registered in Startup
  public CustomersController(ICustomerRepository repo)
  {
    this.repo = repo;
  }

  // GET: api/customers
  // GET: api/customers/?country=[country]
  // this will always return a list of customers (but it might be empty)
  [HttpGet]
  [ProducesResponseType(200, Type = typeof(IEnumerable<Customer>))]
  public async Task<IEnumerable<Customer>> GetCustomers(string? country)
  {
    if (string.IsNullOrWhiteSpace(country))
    {
      return await repo.RetrieveAllAsync();
    }
    else
    {
      return (await repo.RetrieveAllAsync())
        .Where(customer => customer.Country == country);
    }
  }

  // GET: api/customers/[id]
  [HttpGet("{id}", Name = nameof(GetCustomer))] // named route
  [ProducesResponseType(200, Type = typeof(Customer))]
  [ProducesResponseType(404)]
  public async Task<IActionResult> GetCustomer(string id)
  {
    Customer? c = await repo.RetrieveAsync(id);
    if (c == null)
    {
      return NotFound(); // 404 Resource not found
    }
    return Ok(c); // 200 OK with customer in body
  }

  // POST: api/customers
  // BODY: Customer (JSON, XML)
  [HttpPost]
  [ProducesResponseType(201, Type = typeof(Customer))]
  [ProducesResponseType(400)]
  public async Task<IActionResult> Create([FromBody] Customer c)
  {
    if (c == null)
    {
      return BadRequest(); // 400 Bad request
    }
    Customer? addedCustomer = await repo.CreateAsync(c);
    if (addedCustomer == null)
    {
      return BadRequest("Repository failed to create customer.");
    }
    else
    {
      return CreatedAtRoute( // 201 Created
        routeName: nameof(GetCustomer),
        routeValues: new { id = addedCustomer.CustomerId.ToLower() },
        value: addedCustomer);
    }
  }

  // PUT: api/customers/[id]
  // BODY: Customer (JSON, XML)
  [HttpPut("{id}")]
  [ProducesResponseType(204)]
  [ProducesResponseType(400)]
  [ProducesResponseType(404)]
  public async Task<IActionResult> Update(
    string id, [FromBody] Customer c)
  {
    id = id.ToUpper();
    c.CustomerId = c.CustomerId.ToUpper();
    if (c == null || c.CustomerId != id)
    {
      return BadRequest(); // 400 Bad request
    }
    Customer? existing = await repo.RetrieveAsync(id);
    if (existing == null)
    {
      return NotFound(); // 404 Resource not found
    }
    await repo.UpdateAsync(id, c);
    return new NoContentResult(); // 204 No content
  }

  // DELETE: api/customers/[id]
  [HttpDelete("{id}")]
  [ProducesResponseType(204)]
  [ProducesResponseType(400)]
  [ProducesResponseType(404)]
  public async Task<IActionResult> Delete(string id)
  {
    // take control of problem details
    if (id == "bad")
    {
      ProblemDetails problemDetails = new()
      {
        Status = StatusCodes.Status400BadRequest,
        Type = "https://localhost:5001/customers/failed-to-delete",
        Title = $"Customer ID {id} found but failed to delete.",
        Detail = "More details like Company Name, Country and so on.",
        Instance = HttpContext.Request.Path
      };
      return BadRequest(problemDetails); // 400 Bad Request
    }

    Customer? existing = await repo.RetrieveAsync(id);
    if (existing == null)
    {
      return NotFound(); // 404 Resource not found
    }
    bool? deleted = await repo.DeleteAsync(id);
    if (deleted.HasValue && deleted.Value) // short circuit AND
    {
      return new NoContentResult(); // 204 No content
    }
    else
    {
      return BadRequest( // 400 Bad request
        $"Customer {id} was found but failed to delete.");
    }
  }
}