import { describe, it, expect } from "vitest";
import { combineUIMessages } from "./UIMessages.js";

describe("combineUIMessages", () => {
  it("combines messages spanning two pages correctly", () => {
    const message1 = {
      id: "msg1",
      key: "msg1-key",
      _creationTime: Date.now(),
      order: 1,
      stepOrder: 1,
      status: "success" as const,
      role: "assistant" as const,
      text: "",
      parts: [
        {
          type: "dynamic-tool" as const,
          state: "input-available" as const,
          toolCallId: "call_123",
          toolName: "calculator",
          input: { operation: "add", a: 2, b: 3 },
        },
      ],
    };

    const message2 = {
      id: "msg2",
      key: "msg2-key",
      _creationTime: Date.now() + 1,
      order: 1,
      stepOrder: 2,
      status: "success" as const,
      role: "assistant" as const,
      text: "The result is 5.",
      parts: [
        {
          type: "tool-calculator" as const,
          state: "output-available" as const,
          toolCallId: "call_123",
          input: { operation: "add", a: 2, b: 3 },
          output: { result: 5 },
        },
        {
          type: "text" as const,
          text: "The result is 5.",
          state: "done" as const,
        },
      ],
    };

    const combined = combineUIMessages([message1, message2]);

    expect(combined).toHaveLength(1);
    expect(combined[0].role).toBe("assistant");
    expect(combined[0].text).toBe("The result is 5.");
    expect(combined[0].parts).toHaveLength(2);

    const toolPart = combined[0].parts.find(
      (p) => p.type === "tool-calculator",
    );
    expect(toolPart).toMatchObject({
      type: "tool-calculator",
      state: "output-available",
      toolCallId: "call_123",
      input: { operation: "add", a: 2, b: 3 },
      output: { result: 5 },
    });

    const textPart = combined[0].parts.find((p) => p.type === "text");
    expect(textPart).toMatchObject({
      type: "text",
      text: "The result is 5.",
      state: "done",
    });
  });

  it("preserves separate messages with different roles", () => {
    const userMessage = {
      id: "user1",
      key: "user1-key",
      _creationTime: Date.now(),
      order: 1,
      stepOrder: 0,
      status: "success" as const,
      role: "user" as const,
      text: "Calculate 2 + 3",
      parts: [{ type: "text" as const, text: "Calculate 2 + 3" }],
    };

    const assistantMessage = {
      id: "assistant1",
      key: "assistant1-key",
      _creationTime: Date.now() + 1,
      order: 2,
      stepOrder: 0,
      status: "success" as const,
      role: "assistant" as const,
      text: "The result is 5.",
      parts: [
        {
          type: "text" as const,
          text: "The result is 5.",
          state: "done" as const,
        },
      ],
    };

    const combined = combineUIMessages([userMessage, assistantMessage]);

    expect(combined).toHaveLength(2);
    expect(combined[0]).toEqual(userMessage);
    expect(combined[1]).toEqual(assistantMessage);
  });

  it("combines multiple tool calls across pages", () => {
    const message1 = {
      id: "msg1",
      key: "msg1-key",
      _creationTime: Date.now(),
      order: 1,
      stepOrder: 1,
      status: "success" as const,
      role: "assistant" as const,
      text: "",
      parts: [
        {
          type: "dynamic-tool" as const,
          state: "input-available" as const,
          toolCallId: "call_1",
          toolName: "calculator",
          input: { operation: "add", a: 2, b: 3 },
        },
        {
          type: "dynamic-tool" as const,
          state: "input-available" as const,
          toolCallId: "call_2",
          toolName: "formatter",
          input: { text: "result" },
        },
      ],
    };

    const message2 = {
      id: "msg2",
      key: "msg2-key",
      _creationTime: Date.now() + 1,
      order: 1,
      stepOrder: 2,
      status: "success" as const,
      role: "assistant" as const,
      text: "The formatted result is: 5",
      parts: [
        {
          type: "tool-calculator" as const,
          state: "output-available" as const,
          toolCallId: "call_1",
          input: { operation: "add", a: 2, b: 3 },
          output: { result: 5 },
        },
        {
          type: "tool-formatter" as const,
          state: "output-available" as const,
          toolCallId: "call_2",
          input: { text: "result" },
          output: { formatted: "The formatted result is: 5" },
        },
        {
          type: "text" as const,
          text: "The formatted result is: 5",
          state: "done" as const,
        },
      ],
    };

    const combined = combineUIMessages([message1, message2]);

    expect(combined).toHaveLength(1);
    expect(combined[0].role).toBe("assistant");
    expect(combined[0].text).toBe("The formatted result is: 5");
    expect(combined[0].parts).toHaveLength(3);

    const calculatorPart = combined[0].parts.find(
      (p) =>
        p.type === "tool-calculator" &&
        "toolCallId" in p &&
        p.toolCallId === "call_1",
    );
    expect(calculatorPart).toMatchObject({
      type: "tool-calculator",
      state: "output-available",
      toolCallId: "call_1",
      input: { operation: "add", a: 2, b: 3 },
      output: { result: 5 },
    });

    const formatterPart = combined[0].parts.find(
      (p) =>
        p.type === "tool-formatter" &&
        "toolCallId" in p &&
        p.toolCallId === "call_2",
    );
    expect(formatterPart).toMatchObject({
      type: "tool-formatter",
      state: "output-available",
      toolCallId: "call_2",
      input: { text: "result" },
      output: { formatted: "The formatted result is: 5" },
    });
  });

  it("handles tool call without corresponding output", () => {
    const message1 = {
      id: "msg1",
      key: "msg1-key",
      _creationTime: Date.now(),
      order: 1,
      stepOrder: 1,
      status: "success" as const,
      role: "assistant" as const,
      text: "",
      parts: [
        {
          type: "dynamic-tool" as const,
          state: "input-available" as const,
          toolCallId: "call_orphan",
          toolName: "calculator",
          input: { operation: "add", a: 2, b: 3 },
        },
      ],
    };

    const message2 = {
      id: "msg2",
      key: "msg2-key",
      _creationTime: Date.now() + 1,
      order: 1,
      stepOrder: 2,
      status: "success" as const,
      role: "assistant" as const,
      text: "Still processing...",
      parts: [
        {
          type: "text" as const,
          text: "Still processing...",
          state: "done" as const,
        },
      ],
    };

    const combined = combineUIMessages([message1, message2]);

    expect(combined).toHaveLength(1);
    expect(combined[0].role).toBe("assistant");
    expect(combined[0].text).toBe("Still processing...");
    expect(combined[0].parts).toHaveLength(2);

    const toolPart = combined[0].parts.find((p) => p.type === "dynamic-tool");
    expect(toolPart).toMatchObject({
      type: "dynamic-tool",
      state: "input-available",
      toolCallId: "call_orphan",
      toolName: "calculator",
      input: { operation: "add", a: 2, b: 3 },
    });

    const textPart = combined[0].parts.find((p) => p.type === "text");
    expect(textPart).toMatchObject({
      type: "text",
      text: "Still processing...",
      state: "done",
    });
  });
});