Initial commit: GM-Relay Telegram Bot

src/GmRelay.Bot/Infrastructure/Scheduling/SessionSchedulerService.cs

@@ -0,0 +1,117 @@
+using Dapper;
+using GmRelay.Bot.Domain;
+using GmRelay.Bot.Features.Confirmation.SendConfirmation;
+using GmRelay.Bot.Features.Reminders.SendJoinLink;
+using Npgsql;
+
+namespace GmRelay.Bot.Infrastructure.Scheduling;
+
+/// <summary>
+/// Stateless scheduler: wakes every 60 seconds, queries PostgreSQL for actionable sessions.
+/// Two triggers:
+///   T-24h: send confirmation request with inline keyboard
+///   T-5min: send join link to all confirmed players
+///
+/// If the Raspberry Pi reboots, nothing is lost — all state is in the DB.
+/// </summary>
+public sealed class SessionSchedulerService(
+    NpgsqlDataSource dataSource,
+    SendConfirmationHandler confirmationHandler,
+    SendJoinLinkHandler joinLinkHandler,
+    ILogger<SessionSchedulerService> logger) : BackgroundService
+{
+    private static readonly TimeSpan TickInterval = TimeSpan.FromMinutes(1);
+    private static readonly TimeSpan ConfirmationLeadTime = TimeSpan.FromHours(24);
+    private static readonly TimeSpan JoinLinkLeadTime = TimeSpan.FromMinutes(5);
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        logger.LogInformation("Session scheduler started (interval: {Interval})", TickInterval);
+
+        using var timer = new PeriodicTimer(TickInterval);
+
+        // Run immediately on startup, then on each tick
+        do
+        {
+            try
+            {
+                await ProcessConfirmationTriggers(stoppingToken);
+                await ProcessJoinLinkTriggers(stoppingToken);
+            }
+            catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+            {
+                break;
+            }
+            catch (Exception ex)
+            {
+                logger.LogError(ex, "Scheduler tick failed, will retry next tick");
+            }
+        }
+        while (await timer.WaitForNextTickAsync(stoppingToken));
+
+        logger.LogInformation("Session scheduler stopped");
+    }
+
+    /// <summary>
+    /// T-24h trigger: find sessions that need confirmation requests sent.
+    /// Condition: status='Planned' AND scheduled_at minus 24h is in the past.
+    /// </summary>
+    private async Task ProcessConfirmationTriggers(CancellationToken ct)
+    {
+        await using var connection = await dataSource.OpenConnectionAsync(ct);
+
+        var sessionIds = await connection.QueryAsync<Guid>(
+            """
+            SELECT id
+            FROM sessions
+            WHERE status = @Planned
+              AND scheduled_at - @LeadTime <= now()
+            """,
+            new { Planned = SessionStatus.Planned, LeadTime = ConfirmationLeadTime });
+
+        foreach (var sessionId in sessionIds)
+        {
+            try
+            {
+                await confirmationHandler.HandleAsync(sessionId, ct);
+                logger.LogInformation("Confirmation sent for session {SessionId}", sessionId);
+            }
+            catch (Exception ex)
+            {
+                logger.LogError(ex, "Failed to send confirmation for session {SessionId}", sessionId);
+            }
+        }
+    }
+
+    /// <summary>
+    /// T-5min trigger: find confirmed sessions that need join links sent.
+    /// Condition: status='Confirmed' AND scheduled_at minus 5min is in the past AND link not yet sent.
+    /// </summary>
+    private async Task ProcessJoinLinkTriggers(CancellationToken ct)
+    {
+        await using var connection = await dataSource.OpenConnectionAsync(ct);
+
+        var sessionIds = await connection.QueryAsync<Guid>(
+            """
+            SELECT id
+            FROM sessions
+            WHERE status = @Confirmed
+              AND scheduled_at - @LeadTime <= now()
+              AND link_message_id IS NULL
+            """,
+            new { Confirmed = SessionStatus.Confirmed, LeadTime = JoinLinkLeadTime });
+
+        foreach (var sessionId in sessionIds)
+        {
+            try
+            {
+                await joinLinkHandler.HandleAsync(sessionId, ct);
+                logger.LogInformation("Join link sent for session {SessionId}", sessionId);
+            }
+            catch (Exception ex)
+            {
+                logger.LogError(ex, "Failed to send join link for session {SessionId}", sessionId);
+            }
+        }
+    }
+}