feat(orchestrator): MS23-P1-002 InternalAgentProvider (#719)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/orchestrator/src/api/agents/internal-agent.provider.ts

@@ -0,0 +1,218 @@
+import { Injectable } from "@nestjs/common";
+import type {
+  AgentMessage,
+  AgentMessageRole,
+  AgentSession,
+  AgentSessionList,
+  AgentSessionStatus,
+  IAgentProvider,
+  InjectResult,
+} from "@mosaic/shared";
+import type { AgentConversationMessage, AgentSessionTree } from "@prisma/client";
+import { AgentControlService } from "./agent-control.service";
+import { AgentMessagesService } from "./agent-messages.service";
+import { AgentTreeService } from "./agent-tree.service";
+
+const DEFAULT_SESSION_LIMIT = 50;
+const DEFAULT_MESSAGE_LIMIT = 50;
+const MAX_MESSAGE_LIMIT = 200;
+const STREAM_POLL_INTERVAL_MS = 1000;
+const INTERNAL_OPERATOR_ID = "internal-provider";
+
+@Injectable()
+export class InternalAgentProvider implements IAgentProvider {
+  readonly providerId = "internal";
+  readonly providerType = "internal";
+  readonly displayName = "Internal Orchestrator";
+
+  constructor(
+    private readonly messagesService: AgentMessagesService,
+    private readonly controlService: AgentControlService,
+    private readonly treeService: AgentTreeService
+  ) {}
+
+  async listSessions(cursor?: string, limit = DEFAULT_SESSION_LIMIT): Promise<AgentSessionList> {
+    const {
+      sessions,
+      total,
+      cursor: nextCursor,
+    } = await this.treeService.listSessions(cursor, limit);
+
+    return {
+      sessions: sessions.map((session) => this.toAgentSession(session)),
+      total,
+      ...(nextCursor !== undefined ? { cursor: nextCursor } : {}),
+    };
+  }
+
+  async getSession(sessionId: string): Promise<AgentSession | null> {
+    const session = await this.treeService.getSession(sessionId);
+    return session ? this.toAgentSession(session) : null;
+  }
+
+  async getMessages(
+    sessionId: string,
+    limit = DEFAULT_MESSAGE_LIMIT,
+    before?: string
+  ): Promise<AgentMessage[]> {
+    const safeLimit = this.normalizeMessageLimit(limit);
+    const skip = this.parseSkip(before);
+
+    const result = await this.messagesService.getMessages(sessionId, safeLimit, skip);
+    return result.messages.map((message) => this.toAgentMessage(message));
+  }
+
+  async injectMessage(sessionId: string, content: string): Promise<InjectResult> {
+    await this.controlService.injectMessage(sessionId, INTERNAL_OPERATOR_ID, content);
+
+    return {
+      accepted: true,
+    };
+  }
+
+  async pauseSession(sessionId: string): Promise<void> {
+    await this.controlService.pauseAgent(sessionId, INTERNAL_OPERATOR_ID);
+  }
+
+  async resumeSession(sessionId: string): Promise<void> {
+    await this.controlService.resumeAgent(sessionId, INTERNAL_OPERATOR_ID);
+  }
+
+  async killSession(sessionId: string, force = true): Promise<void> {
+    await this.controlService.killAgent(sessionId, INTERNAL_OPERATOR_ID, force);
+  }
+
+  async *streamMessages(sessionId: string): AsyncIterable<AgentMessage> {
+    const replayMessages = await this.messagesService.getReplayMessages(
+      sessionId,
+      DEFAULT_MESSAGE_LIMIT
+    );
+
+    let lastSeenTimestamp = new Date();
+    let lastSeenMessageId: string | null = null;
+
+    for (const message of replayMessages) {
+      yield this.toAgentMessage(message);
+      lastSeenTimestamp = message.timestamp;
+      lastSeenMessageId = message.id;
+    }
+
+    for (;;) {
+      const newMessages = await this.messagesService.getMessagesAfter(
+        sessionId,
+        lastSeenTimestamp,
+        lastSeenMessageId
+      );
+
+      for (const message of newMessages) {
+        yield this.toAgentMessage(message);
+        lastSeenTimestamp = message.timestamp;
+        lastSeenMessageId = message.id;
+      }
+
+      await this.delay(STREAM_POLL_INTERVAL_MS);
+    }
+  }
+
+  isAvailable(): Promise<boolean> {
+    return Promise.resolve(true);
+  }
+
+  private toAgentSession(session: AgentSessionTree): AgentSession {
+    const metadata = this.toMetadata(session.metadata);
+
+    return {
+      id: session.sessionId,
+      providerId: this.providerId,
+      providerType: this.providerType,
+      ...(session.taskId !== null ? { label: session.taskId } : {}),
+      status: this.toSessionStatus(session.status),
+      ...(session.parentSessionId !== null ? { parentSessionId: session.parentSessionId } : {}),
+      createdAt: session.spawnedAt,
+      updatedAt: session.completedAt ?? session.spawnedAt,
+      ...(metadata !== undefined ? { metadata } : {}),
+    };
+  }
+
+  private toAgentMessage(message: AgentConversationMessage): AgentMessage {
+    const metadata = this.toMetadata(message.metadata);
+
+    return {
+      id: message.id,
+      sessionId: message.sessionId,
+      role: this.toMessageRole(message.role),
+      content: message.content,
+      timestamp: message.timestamp,
+      ...(metadata !== undefined ? { metadata } : {}),
+    };
+  }
+
+  private toSessionStatus(status: string): AgentSessionStatus {
+    switch (status) {
+      case "running":
+        return "active";
+      case "paused":
+        return "paused";
+      case "completed":
+        return "completed";
+      case "failed":
+      case "killed":
+        return "failed";
+      case "spawning":
+      default:
+        return "idle";
+    }
+  }
+
+  private toMessageRole(role: string): AgentMessageRole {
+    switch (role) {
+      case "agent":
+      case "assistant":
+        return "assistant";
+      case "system":
+        return "system";
+      case "tool":
+        return "tool";
+      case "operator":
+      case "user":
+      default:
+        return "user";
+    }
+  }
+
+  private normalizeMessageLimit(limit: number): number {
+    const normalized = Number.isFinite(limit) ? Math.trunc(limit) : DEFAULT_MESSAGE_LIMIT;
+    if (normalized < 1) {
+      return 1;
+    }
+
+    return Math.min(normalized, MAX_MESSAGE_LIMIT);
+  }
+
+  private parseSkip(before?: string): number {
+    if (!before) {
+      return 0;
+    }
+
+    const parsed = Number.parseInt(before, 10);
+    if (Number.isNaN(parsed) || parsed < 0) {
+      return 0;
+    }
+
+    return parsed;
+  }
+
+  private toMetadata(value: unknown): Record<string, unknown> | undefined {
+    if (value !== null && typeof value === "object" && !Array.isArray(value)) {
+      return value as Record<string, unknown>;
+    }
+
+    return undefined;
+  }
+
+  private async delay(ms: number): Promise<void> {
+    await new Promise((resolve) => {
+      setTimeout(resolve, ms);
+    });
+  }
+}