/**
 * Tests for error handling utilities
 */

import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
import { logAndFormatError, withErrorHandling, ErrorCategory } from "./errorHandler";
import { ValidationError } from "./validation";
import type { MCPToolResult } from "./types";

describe("logAndFormatError", () => {
  let consoleErrorSpy: ReturnType<typeof vi.spyOn>;

  beforeEach(() => {
    consoleErrorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
  });

  afterEach(() => {
    consoleErrorSpy.mockRestore();
  });

  it("should pass through ValidationError message directly", () => {
    const error = new ValidationError("Invalid user ID format");
    const result = logAndFormatError("testFunction", error);

    expect(result).toEqual({
      content: [{ type: "text", text: "Invalid user ID format" }],
      isError: true,
    });
    expect(consoleErrorSpy).toHaveBeenCalled();
  });

  it("should generate error code for generic Error", () => {
    const error = new Error("Something went wrong");
    const result = logAndFormatError("testFunction", error);

    expect(result.isError).toBe(true);
    expect(result.content[0].text).toMatch(/An error occurred \(code: GEN-ERR-\d{3}\)/);
    expect(consoleErrorSpy).toHaveBeenCalled();
  });

  it("should use VALIDATION-001 code for ErrorCategory.VALIDATION", () => {
    const error = new Error("Validation failed");
    const result = logAndFormatError("testFunction", error, ErrorCategory.VALIDATION);

    expect(result.isError).toBe(true);
    expect(result.content[0].text).toBe("An error occurred (code: VALIDATION-001). Check logs for details.");
    expect(consoleErrorSpy).toHaveBeenCalledWith(
      expect.stringContaining("Code: VALIDATION-001"),
      error
    );
  });

  it("should use category-specific error code", () => {
    const error = new Error("Chat not found");
    const result = logAndFormatError("getChatInfo", error, ErrorCategory.CHAT);

    expect(result.isError).toBe(true);
    expect(result.content[0].text).toMatch(/An error occurred \(code: CHAT-ERR-\d{3}\)/);
    expect(consoleErrorSpy).toHaveBeenCalledWith(
      expect.stringContaining("CHAT-ERR-"),
      error
    );
  });

  it("should include context in console log", () => {
    const error = new Error("Test error");
    const context = { userId: 123, chatId: "456" };

    logAndFormatError("sendMessage", error, ErrorCategory.MSG, context);

    expect(consoleErrorSpy).toHaveBeenCalledWith(
      expect.stringContaining("userId=123, chatId=456"),
      error
    );
  });

  it("should work without category parameter", () => {
    const error = new Error("Generic error");
    const result = logAndFormatError("genericFunction", error);

    expect(result.isError).toBe(true);
    expect(result.content[0].text).toMatch(/An error occurred \(code: GEN-ERR-\d{3}\)/);
  });

  it("should work without context parameter", () => {
    const error = new Error("Test error");
    const result = logAndFormatError("testFunction", error, ErrorCategory.CONTACT);

    expect(result.isError).toBe(true);
    expect(consoleErrorSpy).toHaveBeenCalledWith(
      expect.stringContaining("[MCP] Error in testFunction ()"),
      error
    );
  });

  it("should handle different error categories", () => {
    const categories = [
      ErrorCategory.CHAT,
      ErrorCategory.MSG,
      ErrorCategory.CONTACT,
      ErrorCategory.GROUP,
      ErrorCategory.MEDIA,
      ErrorCategory.PROFILE,
      ErrorCategory.AUTH,
      ErrorCategory.ADMIN,
      ErrorCategory.SEARCH,
      ErrorCategory.DRAFT,
    ];

    categories.forEach((category) => {
      const error = new Error("Test");
      const result = logAndFormatError("test", error, category);

      expect(result.isError).toBe(true);
      expect(result.content[0].text).toMatch(
        new RegExp(`An error occurred \\(code: ${category}-ERR-\\d{3}\\)`)
      );
    });
  });
});

describe("withErrorHandling", () => {
  let consoleErrorSpy: ReturnType<typeof vi.spyOn>;

  beforeEach(() => {
    consoleErrorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
  });

  afterEach(() => {
    consoleErrorSpy.mockRestore();
  });

  it("should return result when async function succeeds", async () => {
    const successResult: MCPToolResult = {
      content: [{ type: "text", text: "Success" }],
    };

    const fn = async () => successResult;
    const wrapped = withErrorHandling(fn);
    const result = await wrapped();

    expect(result).toEqual(successResult);
    expect(consoleErrorSpy).not.toHaveBeenCalled();
  });

  it("should catch and format errors from async function", async () => {
    const fn = async () => {
      throw new Error("Function failed");
    };

    const wrapped = withErrorHandling(fn as any, ErrorCategory.CHAT);
    const result: any = await wrapped();

    expect(result.isError).toBe(true);
    expect(result.content[0].text).toMatch(/An error occurred \(code: CHAT-ERR-\d{3}\)/);
    expect(consoleErrorSpy).toHaveBeenCalled();
  });

  it("should catch ValidationError and pass through message", async () => {
    const fn = async () => {
      throw new ValidationError("Invalid input parameter");
    };

    const wrapped = withErrorHandling(fn as any);
    const result: any = await wrapped();

    expect(result.isError).toBe(true);
    expect(result.content[0].text).toBe("Invalid input parameter");
  });

  it("should handle non-Error throws by converting to Error", async () => {
    const fn = async () => {
      throw "String error";
    };

    const wrapped = withErrorHandling(fn as any);
    const result: any = await wrapped();

    expect(result.isError).toBe(true);
    expect(result.content[0].text).toMatch(/An error occurred \(code: GEN-ERR-\d{3}\)/);
  });

  it("should preserve function arguments in error context", async () => {
    const fn = async (_chatId: number, _message: string) => {
      throw new Error("Test error");
    };

    const wrapped = withErrorHandling(fn as any, ErrorCategory.MSG);
    await wrapped(123, "Hello");

    expect(consoleErrorSpy).toHaveBeenCalledWith(
      expect.stringContaining('args='),
      expect.any(Error)
    );
  });

  it("should use function name in error code generation", async () => {
    async function namedFunction() {
      throw new Error("Test");
    }

    const wrapped = withErrorHandling(namedFunction as any);
    await wrapped();

    expect(consoleErrorSpy).toHaveBeenCalledWith(
      expect.stringContaining("[MCP] Error in namedFunction"),
      expect.any(Error)
    );
  });

  it("should handle anonymous functions with 'unknown' name", async () => {
    const wrapped = withErrorHandling((() => {
      const f = async () => { throw new Error("Test"); };
      Object.defineProperty(f, "name", { value: "" });
      return f;
    })() as any);

    await wrapped();

    expect(consoleErrorSpy).toHaveBeenCalledWith(
      expect.stringContaining("[MCP] Error in unknown"),
      expect.any(Error)
    );
  });
});