Adding player sensing

microservices/CharacterApi/Controllers/CharactersController.cs

@@ -13,6 +13,7 @@ namespace CharacterApi.Controllers;
 [Route("api/[controller]")]
 public class CharactersController : ControllerBase
 {
+    private static readonly TimeSpan PresenceTimeout = TimeSpan.FromSeconds(45);
     private readonly CharacterStore _characters;
     private readonly IHttpClientFactory _httpClientFactory;
     private readonly IConfiguration _configuration;
@@ -43,6 +44,7 @@ public class CharactersController : ControllerBase
             Name = req.Name.Trim(),
             Coord = new Coord { X = 0, Y = 0 },
             VisionRadius = 3,
+            LastSeenUtc = DateTime.UtcNow,
             CreatedUtc = DateTime.UtcNow
         };
 
@@ -89,6 +91,8 @@ public class CharactersController : ControllerBase
             return Forbid();
         }
 
+        await _characters.TouchAsync(id);
+
         _logger.LogInformation(
             "Visible locations requested for character {CharacterId} at ({X},{Y}) radius {VisionRadius} by user {UserId}",
             character.Id,
@@ -164,6 +168,53 @@ public class CharactersController : ControllerBase
         }
     }
 
+    [HttpGet("{id}/visible-characters")]
+    [Authorize(Roles = "USER,SUPER")]
+    public async Task<IActionResult> VisibleCharacters(string id)
+    {
+        var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
+        if (string.IsNullOrWhiteSpace(userId))
+            return Unauthorized();
+
+        var allowAnyOwner = User.IsInRole("SUPER");
+        var character = await _characters.GetByIdAsync(id);
+        if (character is null)
+            return NotFound();
+        if (!allowAnyOwner && character.OwnerUserId != userId)
+            return Forbid();
+
+        await _characters.TouchAsync(id);
+
+        var onlineSinceUtc = DateTime.UtcNow.Subtract(PresenceTimeout);
+        var visibleCharacters = await _characters.GetVisibleOthersAsync(
+            id,
+            character.Coord.X,
+            character.Coord.Y,
+            character.VisionRadius > 0 ? character.VisionRadius : 3,
+            onlineSinceUtc);
+
+        return Ok(visibleCharacters);
+    }
+
+    [HttpPost("{id}/heartbeat")]
+    [Authorize(Roles = "USER,SUPER")]
+    public async Task<IActionResult> Heartbeat(string id)
+    {
+        var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
+        if (string.IsNullOrWhiteSpace(userId))
+            return Unauthorized();
+
+        var allowAnyOwner = User.IsInRole("SUPER");
+        var character = await _characters.GetByIdAsync(id);
+        if (character is null)
+            return NotFound();
+        if (!allowAnyOwner && character.OwnerUserId != userId)
+            return Forbid();
+
+        await _characters.TouchAsync(id);
+        return Ok(new { lastSeenUtc = DateTime.UtcNow });
+    }
+
     [HttpPut("{id}/coord")]
     [Authorize(Roles = "USER,SUPER")]
     public async Task<IActionResult> UpdateCoord(string id, [FromBody] UpdateCharacterCoordRequest req)