using Microsoft.EntityFrameworkCore;
using WebApp.Data;
using WebApp.DTOs;
using WebApp.Entities;
using WebApp.Mapping;

namespace WebApp.Endpoints
{
    public static class EventsEndpoints
    {
        const string GetEventEndpointName = "GetEvent"; 

        public static RouteGroupBuilder MapEventsEndpoints(this WebApplication app)
        {
            var group = app.MapGroup("api/events")
                                    .WithParameterValidation();

            // GET /events
            group.MapGet("/", async (ApplicationDbContext dbContext) => 
                await dbContext.Events
                               .Include(Eve => Eve.Organisation)
                               .Select(Eve => Eve.ToEventSummaryDto()) //EventSummaryDto
                               .AsNoTracking()
                               .ToListAsync());

            // GET /events/1
            group.MapGet("/{id}", async (int id, ApplicationDbContext dbContext) =>
            {
                Event? Eve = await dbContext.Events.FindAsync(id);


                return Eve is null ? 
                    Results.NotFound() : Results.Ok(Eve.ToEventDetailsDto()); //EventDetailsDto
            })
            .WithName(GetEventEndpointName);

            // POST /events
            group.MapPost("/", async (EventCreateDto newEvent, ApplicationDbContext dbContext) =>
            {
                Event Eve = newEvent.ToEntity();

                dbContext.Events.Add(Eve);
                await dbContext.SaveChangesAsync();

                return Results.CreatedAtRoute(
                    GetEventEndpointName, 
                    new { id = Eve.EventId }, 
                    Eve.ToEventDetailsDto()); //EventDetailsDto
            });

            // PUT /events/1
            group.MapPut("/{id}", async (int id, EventUpdateDto updatedEvent, ApplicationDbContext dbContext) =>
            {
                var existingEvent = await dbContext.Events.FindAsync(id);

                if (existingEvent is null)
                {
                    return Results.NotFound();
                }


                dbContext.Entry(existingEvent)
                         .CurrentValues
                         .SetValues(updatedEvent.ToEntity(id));

                dbContext.Entry(existingEvent)
                         .Collection(Eve => Eve.EventRegistrations)
                         .IsModified = false;

                await dbContext.SaveChangesAsync();

                return Results.NoContent();
            });

            // DELETE /events/1
            group.MapDelete("/{id}", async (int id, ApplicationDbContext dbContext) =>
            {
                await dbContext.Events
                         .Where(Eve => Eve.EventId == id)
                         .ExecuteDeleteAsync();

                return Results.NoContent();
            });

            return group;
        }
    }
}