ts: add streaming

src/index.ts

@@ -59,13 +59,86 @@ export interface Choice {
   finish_reason: string | null;
 }
 
-export interface SendResponse {
+export class SendResponse {
   choices: Choice[];
   usage?: {
     prompt_tokens: number;
     completion_tokens: number;
     total_tokens: number;
   };
+
+  constructor(
+    choices: Choice[],
+    usage?: {
+      prompt_tokens: number;
+      completion_tokens: number;
+      total_tokens: number;
+    }
+  ) {
+    this.choices = choices;
+    this.usage = usage;
+  }
+
+  get text(): string | null {
+    if (this.choices[0]?.message?.content) {
+      return this.choices[0].message.content;
+    }
+    return null;
+  }
+
+  get message() {
+    return this.choices[0]?.message ?? null;
+  }
+
+  get finishReason(): string | null {
+    return this.choices[0]?.finish_reason ?? null;
+  }
+
+  get toolCalls(): ToolCall[] | null {
+    return this.choices[0]?.message?.tool_calls ?? null;
+  }
+}
+
+// Streaming types
+export interface StreamDelta {
+  role?: string;
+  content?: string;
+  tool_calls?: ToolCall[];
+}
+
+export interface StreamChoice {
+  index: number;
+  delta: StreamDelta;
+  finish_reason?: string | null;
+}
+
+export class StreamChunk {
+  choices: StreamChoice[];
+
+  constructor(choices: StreamChoice[]) {
+    this.choices = choices;
+  }
+
+  get text(): string | null {
+    if (this.choices[0]?.delta?.content) {
+      return this.choices[0].delta.content;
+    }
+    return null;
+  }
+
+  get role(): string | null {
+    if (this.choices[0]?.delta?.role) {
+      return this.choices[0].delta.role;
+    }
+    return null;
+  }
+
+  get finishReason(): string | null {
+    if (this.choices[0]?.finish_reason) {
+      return this.choices[0].finish_reason;
+    }
+    return null;
+  }
 }
 
 export interface EdgeeConfig {
@@ -123,11 +196,100 @@ export default class Edgee {
       body: JSON.stringify(body),
     });
 
-    const data = (await res.json()) as SendResponse;
+    if (!res.ok) {
+      const errorBody = await res.text();
+      throw new Error(`API error ${res.status}: ${errorBody}`);
+    }
+
+    const data = await res.json() as {
+      choices: Choice[];
+      usage?: {
+        prompt_tokens: number;
+        completion_tokens: number;
+        total_tokens: number;
+      }
+    };
+
+    return new SendResponse(data.choices, data.usage);
+  }
+
+  private async *_handleStreamingResponse(
+    url: string,
+    body: Record<string, unknown>
+  ): AsyncGenerator<StreamChunk> {
+    const res = await fetch(url, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+        Authorization: `Bearer ${this.apiKey}`,
+      },
+      body: JSON.stringify(body),
+    });
+
+    if (!res.ok) {
+      const errorBody = await res.text();
+      throw new Error(`API error ${res.status}: ${errorBody}`);
+    }
+
+    if (!res.body) {
+      throw new Error("Response body is null");
+    }
+
+    const reader = res.body.getReader();
+    const decoder = new TextDecoder();
+    let buffer = "";
+
+    while (true) {
+      const { done, value } = await reader.read();
+      if (done) break;
 
-    return {
-      choices: data.choices,
-      usage: data.usage,
+      buffer += decoder.decode(value, { stream: true });
+      const lines = buffer.split("\n");
+      buffer = lines.pop() || "";
+
+      for (const line of lines) {
+        const trimmed = line.trim();
+        if (trimmed === "" || !trimmed.startsWith("data: ")) {
+          continue;
+        }
+
+        const data = trimmed.slice(6);
+        if (data === "[DONE]") {
+          return;
+        }
+
+        try {
+          const parsed = JSON.parse(data);
+          yield new StreamChunk(parsed.choices);
+        } catch {
+          // Skip malformed JSON
+          continue;
+        }
+      }
+    }
+  }
+
+  async *stream(
+    model: string,
+    input: string | InputObject
+  ): AsyncGenerator<StreamChunk> {
+    const body: Record<string, unknown> = {
+      model,
+      messages:
+        typeof input === "string"
+          ? [{ role: "user", content: input }]
+          : input.messages,
+      stream: true,
     };
+
+    if (typeof input !== "string") {
+      if (input.tools) body.tools = input.tools;
+      if (input.tool_choice) body.tool_choice = input.tool_choice;
+    }
+
+    yield* this._handleStreamingResponse(
+      `${this.baseUrl}/v1/chat/completions`,
+      body
+    );
   }
 }