DorkNet/DorkNet.Server/Controllers/API/PlayerSubscriptions/PlayerSubscriptionsController.cs

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using DorkNet.Models.Notification;
using DorkNet.Server.Auth;
using DorkNet.Server.Data;
using DorkNet.Server.Data.Entities;
using DorkNet.Server.Services;

namespace DorkNet.Server.Controllers.API.PlayerSubscriptions;

/// <summary>
/// api.rec.net/api/playersubscriptions/v1/* — asymmetric follow
/// graph. The <c>my</c> endpoint returns who the caller follows;
/// subscribe/unsubscribe mutate the row directly. Reputation
/// aggregates pull SubscriberCount / SubscribedCount counts from
/// here.
/// </summary>
[ApiController]
[Route("api/[controller]/v1")]
[Authorize]
public class PlayerSubscriptionsController(
    DorkNetDbContext db,
    NotificationService notifications) : ControllerBase
{
    private long Me => this.RequireCurrentPlayerId();

    [HttpGet("my")]
    public async Task<ActionResult> My()
    {
        var subs = await db.Subscriptions
            .Where(s => s.SubscriberPlayerId == Me)
            .Select(s => new { s.TargetPlayerId, s.CreatedAt })
            .ToListAsync();
        return Ok(subs);
    }

    [HttpGet("{playerId:long}/subscribers")]
    public async Task<ActionResult> Subscribers(long playerId)
    {
        var subs = await db.Subscriptions
            .Where(s => s.TargetPlayerId == playerId)
            .Select(s => new { s.SubscriberPlayerId, s.CreatedAt })
            .ToListAsync();
        return Ok(subs);
    }

    [HttpPost("subscribe/{targetId:long}")]
    public async Task<ActionResult> Subscribe(long targetId)
    {
        if (targetId == Me) return BadRequest("cannot_subscribe_to_self");

        var existing = await db.Subscriptions.FirstOrDefaultAsync(s =>
            s.SubscriberPlayerId == Me && s.TargetPlayerId == targetId);
        if (existing is not null) return Ok(new { already_subscribed = true });

        db.Subscriptions.Add(new SubscriptionEntity
        {
            SubscriberPlayerId = Me,
            TargetPlayerId = targetId,
        });
        await db.SaveChangesAsync();

        // Tell the target their subscriber count changed so the watch
        // refreshes their profile page if open.
        await notifications.NotifyAsync(targetId,
            PushNotificationId.SubscriptionUpdateProfile,
            new { Reason = "NewSubscriber", From = Me });
        return Ok();
    }

    [HttpDelete("subscribe/{targetId:long}")]
    [HttpPost("unsubscribe/{targetId:long}")]
    public async Task<ActionResult> Unsubscribe(long targetId)
    {
        var row = await db.Subscriptions.FirstOrDefaultAsync(s =>
            s.SubscriberPlayerId == Me && s.TargetPlayerId == targetId);
        if (row is null) return NotFound();
        db.Subscriptions.Remove(row);
        await db.SaveChangesAsync();
        return Ok();
    }
}