import type { AssistantMessage } from "@mariozechner/pi-ai";
import { describe, expect, it, vi } from "vitest";
import { subscribeEmbeddedPiSession } from "./pi-embedded-subscribe.js";

type StubSession = {
  subscribe: (fn: (evt: unknown) => void) => () => void;
};

type SessionEventHandler = (evt: unknown) => void;

describe("subscribeEmbeddedPiSession", () => {
  const _THINKING_TAG_CASES = [
    { tag: "think", open: "<think>", close: "</think>" },
    { tag: "thinking", open: "<thinking>", close: "</thinking>" },
    { tag: "thought", open: "<thought>", close: "</thought>" },
    { tag: "antthinking", open: "<antthinking>", close: "</antthinking>" },
  ] as const;

  it("does not emit duplicate block replies when text_end repeats", () => {
    let handler: SessionEventHandler | undefined;
    const session: StubSession = {
      subscribe: (fn) => {
        handler = fn;
        return () => {};
      },
    };

    const onBlockReply = vi.fn();

    const subscription = subscribeEmbeddedPiSession({
      session: session as unknown as Parameters<typeof subscribeEmbeddedPiSession>[0]["session"],
      runId: "run",
      onBlockReply,
      blockReplyBreak: "text_end",
    });

    handler?.({
      type: "message_update",
      message: { role: "assistant" },
      assistantMessageEvent: {
        type: "text_delta",
        delta: "Hello block",
      },
    });

    handler?.({
      type: "message_update",
      message: { role: "assistant" },
      assistantMessageEvent: {
        type: "text_end",
      },
    });

    handler?.({
      type: "message_update",
      message: { role: "assistant" },
      assistantMessageEvent: {
        type: "text_end",
      },
    });

    expect(onBlockReply).toHaveBeenCalledTimes(1);
    expect(subscription.assistantTexts).toEqual(["Hello block"]);
  });
  it("does not duplicate assistantTexts when message_end repeats", () => {
    let handler: SessionEventHandler | undefined;
    const session: StubSession = {
      subscribe: (fn) => {
        handler = fn;
        return () => {};
      },
    };

    const subscription = subscribeEmbeddedPiSession({
      session: session as unknown as Parameters<typeof subscribeEmbeddedPiSession>[0]["session"],
      runId: "run",
    });

    const assistantMessage = {
      role: "assistant",
      content: [{ type: "text", text: "Hello world" }],
    } as AssistantMessage;

    handler?.({ type: "message_end", message: assistantMessage });
    handler?.({ type: "message_end", message: assistantMessage });

    expect(subscription.assistantTexts).toEqual(["Hello world"]);
  });
  it("does not duplicate assistantTexts when message_end repeats with reasoning blocks", () => {
    let handler: SessionEventHandler | undefined;
    const session: StubSession = {
      subscribe: (fn) => {
        handler = fn;
        return () => {};
      },
    };

    const subscription = subscribeEmbeddedPiSession({
      session: session as unknown as Parameters<typeof subscribeEmbeddedPiSession>[0]["session"],
      runId: "run",
      reasoningMode: "on",
    });

    const assistantMessage = {
      role: "assistant",
      content: [
        { type: "thinking", thinking: "Because" },
        { type: "text", text: "Hello world" },
      ],
    } as AssistantMessage;

    handler?.({ type: "message_end", message: assistantMessage });
    handler?.({ type: "message_end", message: assistantMessage });

    expect(subscription.assistantTexts).toEqual(["Hello world"]);
  });
  it("populates assistantTexts for non-streaming models with chunking enabled", () => {
    // Non-streaming models (e.g. zai/glm-4.7): no text_delta events; message_end
    // must still populate assistantTexts so providers can deliver a final reply.
    let handler: SessionEventHandler | undefined;
    const session: StubSession = {
      subscribe: (fn) => {
        handler = fn;
        return () => {};
      },
    };

    const subscription = subscribeEmbeddedPiSession({
      session: session as unknown as Parameters<typeof subscribeEmbeddedPiSession>[0]["session"],
      runId: "run",
      blockReplyChunking: { minChars: 50, maxChars: 200 }, // Chunking enabled
    });

    // Simulate non-streaming model: only message_start and message_end, no text_delta
    handler?.({ type: "message_start", message: { role: "assistant" } });

    const assistantMessage = {
      role: "assistant",
      content: [{ type: "text", text: "Response from non-streaming model" }],
    } as AssistantMessage;

    handler?.({ type: "message_end", message: assistantMessage });

    expect(subscription.assistantTexts).toEqual(["Response from non-streaming model"]);
  });
});