feat(api-ai): add provider registry and routing fallback

2026-04-06 11:44:05 +08:00
parent 019436507e
commit 180f7a9baa
11 changed files with 1425 additions and 1 deletions
@@ -0,0 +1,197 @@
+import { Injectable } from "@nestjs/common";
+import {
+  AiChannelExecutor,
+  AiChatInput,
+  AiChatResult,
+  AiResolvedRouteCandidate,
+  AiRouteFailureError
+} from "../ai.types";
+
+@Injectable()
+export class AstrbotProvider implements AiChannelExecutor {
+  async execute(candidate: AiResolvedRouteCandidate, input: AiChatInput): Promise<AiChatResult> {
+    if (!candidate.endpoint) {
+      throw new AiRouteFailureError(
+        candidate.channel,
+        candidate.providerName,
+        "MISSING_ENDPOINT",
+        "缺少 AstrBot 服务地址配置"
+      );
+    }
+
+    if (!candidate.apiKey) {
+      throw new AiRouteFailureError(
+        candidate.channel,
+        candidate.providerName,
+        "MISSING_API_KEY",
+        "缺少 AstrBot API Key 配置"
+      );
+    }
+
+    const requestUrl = this.buildRequestUrl(candidate.endpoint);
+
+    let response: Response;
+    try {
+      response = await fetch(requestUrl, {
+        method: "POST",
+        headers: {
+          "Content-Type": "application/json",
+          Authorization: `Bearer ${candidate.apiKey}`
+        },
+        body: JSON.stringify({
+          username: input.userId,
+          session_id: input.sessionId ?? undefined,
+          message: input.message,
+          enable_streaming: false,
+          selected_provider: candidate.providerName || undefined,
+          selected_model: candidate.model ?? undefined
+        }),
+        signal: AbortSignal.timeout(30000)
+      });
+    } catch (error) {
+      throw new AiRouteFailureError(
+        candidate.channel,
+        candidate.providerName,
+        "UPSTREAM_UNREACHABLE",
+        this.toErrorMessage(error, "AstrBot 服务请求失败")
+      );
+    }
+
+    const rawText = await response.text();
+    if (!response.ok) {
+      throw new AiRouteFailureError(
+        candidate.channel,
+        candidate.providerName,
+        `UPSTREAM_HTTP_${response.status}`,
+        this.extractHttpErrorMessage(rawText, response.status)
+      );
+    }
+
+    const events = this.parseSseEvents(rawText);
+    let content = "";
+    let sessionId = input.sessionId;
+
+    for (const event of events) {
+      const type = this.readString(event["type"]);
+      if (type === "session_id") {
+        sessionId = this.readString(event["session_id"]) ?? sessionId;
+        continue;
+      }
+
+      if (type === "error") {
+        throw new AiRouteFailureError(
+          candidate.channel,
+          candidate.providerName,
+          this.readString(event["code"]) ?? "ASTRBOT_ERROR",
+          this.readString(event["data"]) ?? "AstrBot 返回错误"
+        );
+      }
+
+      if (type !== "plain") {
+        continue;
+      }
+
+      const chainType = this.readString(event["chain_type"]);
+      if (
+        chainType === "reasoning" ||
+        chainType === "tool_call" ||
+        chainType === "tool_call_result"
+      ) {
+        continue;
+      }
+
+      const data = this.readString(event["data"]);
+      if (!data) {
+        continue;
+      }
+
+      if (event["streaming"] === true) {
+        content += data;
+        continue;
+      }
+
+      content = data;
+    }
+
+    if (!content.trim()) {
+      throw new AiRouteFailureError(
+        candidate.channel,
+        candidate.providerName,
+        "EMPTY_RESPONSE",
+        "AstrBot 没有返回有效内容"
+      );
+    }
+
+    return {
+      channel: candidate.channel,
+      providerName: candidate.providerName,
+      model: candidate.model,
+      content,
+      sessionId,
+      raw: events
+    };
+  }
+
+  private buildRequestUrl(endpoint: string): string {
+    const normalizedEndpoint = endpoint.replace(/\/+$/, "");
+    if (normalizedEndpoint.endsWith("/api/v1/chat")) {
+      return normalizedEndpoint;
+    }
+    if (normalizedEndpoint.endsWith("/api/v1")) {
+      return `${normalizedEndpoint}/chat`;
+    }
+    if (normalizedEndpoint.endsWith("/api")) {
+      return `${normalizedEndpoint}/v1/chat`;
+    }
+    return `${normalizedEndpoint}/api/v1/chat`;
+  }
+
+  private parseSseEvents(rawText: string): Array<Record<string, unknown>> {
+    return rawText
+      .split(/\r?\n\r?\n/)
+      .map((block) =>
+        block
+          .split(/\r?\n/)
+          .filter((line) => line.startsWith("data:"))
+          .map((line) => line.slice(5).trim())
+          .join("\n")
+      )
+      .filter((payload) => payload.length > 0)
+      .map((payload) => {
+        try {
+          return JSON.parse(payload) as Record<string, unknown>;
+        } catch {
+          return null;
+        }
+      })
+      .filter((item): item is Record<string, unknown> => item !== null);
+  }
+
+  private extractHttpErrorMessage(rawText: string, statusCode: number): string {
+    try {
+      const payload = JSON.parse(rawText) as Record<string, unknown>;
+      if (typeof payload["message"] === "string") {
+        return payload["message"];
+      }
+      if (typeof payload["data"] === "string") {
+        return payload["data"];
+      }
+    } catch {
+      return `AstrBot 服务调用失败，状态码 ${statusCode}`;
+    }
+
+    return `AstrBot 服务调用失败，状态码 ${statusCode}`;
+  }
+
+  private readString(value: unknown): string | null {
+    return typeof value === "string" ? value : null;
+  }
+
+  private toErrorMessage(error: unknown, fallback: string): string {
+    if (error instanceof Error && error.message) {
+      return error.message;
+    }
+
+    return fallback;
+  }
+}