import * as fs from "node:fs";
import * as path from "node:path";
import * as os from "node:os";
import { ToolRegistry, TOOL_DEFINITIONS } from "../backends/tool-registry.js";

describe("ToolRegistry", () => {
  let tempDir: string;
  let registry: ToolRegistry;

  beforeEach(() => {
    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), "ci-tool-registry-test-"));
    registry = new ToolRegistry(tempDir);
  });

  afterEach(() => {
    fs.rmSync(tempDir, { recursive: true, force: true });
  });

  describe("definitions", () => {
    it("provides 6 tool definitions", () => {
      expect(TOOL_DEFINITIONS).toHaveLength(6);
      const names = TOOL_DEFINITIONS.map((d) => d.name);
      expect(names).toContain("readFile");
      expect(names).toContain("writeFile");
      expect(names).toContain("editFile");
      expect(names).toContain("runBash");
      expect(names).toContain("glob");
      expect(names).toContain("grep");
    });

    it("getOpenAIToolSchema returns function-type schema", () => {
      const schema = registry.getOpenAIToolSchema();
      expect(schema.length).toBe(6);
      expect(schema[0].type).toBe("function");
      expect((schema[0].function as Record<string, unknown>).name).toBeDefined();
      expect((schema[0].function as Record<string, unknown>).parameters).toBeDefined();
    });
  });

  describe("readFile", () => {
    it("reads an existing file", () => {
      const filePath = path.join(tempDir, "test.txt");
      fs.writeFileSync(filePath, "hello world");
      const result = registry.execute({ name: "readFile", arguments: { path: filePath } });
      expect(result.name).toBe("readFile");
      expect(result.content).toBe("hello world");
      expect(result.isError).toBeFalsy();
    });

    it("returns error for missing file", () => {
      const result = registry.execute({ name: "readFile", arguments: { path: "/nonexistent/file.txt" } });
      expect(result.isError).toBe(true);
      expect(result.content).toContain("not found");
    });

    it("returns error for files exceeding max size", () => {
      const bigRegistry = new ToolRegistry(tempDir, 10);
      const filePath = path.join(tempDir, "big.txt");
      fs.writeFileSync(filePath, "x".repeat(100));
      const result = bigRegistry.execute({ name: "readFile", arguments: { path: filePath } });
      expect(result.isError).toBe(true);
      expect(result.content).toContain("too large");
    });
  });

  describe("writeFile", () => {
    it("writes a file creating parent directories", () => {
      const filePath = path.join(tempDir, "sub", "dir", "test.txt");
      const result = registry.execute({ name: "writeFile", arguments: { path: filePath, content: "written" } });
      expect(result.isError).toBeFalsy();
      expect(fs.readFileSync(filePath, "utf-8")).toBe("written");
    });
  });

  describe("editFile", () => {
    it("replaces an exact string in a file", () => {
      const filePath = path.join(tempDir, "edit.txt");
      fs.writeFileSync(filePath, "hello world");
      const result = registry.execute({ name: "editFile", arguments: { path: filePath, old: "hello", new: "goodbye" } });
      expect(result.isError).toBeFalsy();
      expect(fs.readFileSync(filePath, "utf-8")).toBe("goodbye world");
    });

    it("returns error when old string not found", () => {
      const filePath = path.join(tempDir, "edit.txt");
      fs.writeFileSync(filePath, "hello world");
      const result = registry.execute({ name: "editFile", arguments: { path: filePath, old: "missing", new: "replacement" } });
      expect(result.isError).toBe(true);
    });

    it("returns error for missing file", () => {
      const result = registry.execute({ name: "editFile", arguments: { path: "/nonexistent", old: "a", new: "b" } });
      expect(result.isError).toBe(true);
    });
  });

  describe("runBash", () => {
    it("executes a command and returns stdout", () => {
      const result = registry.execute({ name: "runBash", arguments: { command: "echo hello" } });
      expect(result.content).toContain("hello");
      expect(result.isError).toBeFalsy();
    });

    it("returns error with stderr for failing commands", () => {
      const result = registry.execute({ name: "runBash", arguments: { command: "false" } });
      expect(result.isError).toBe(true);
      expect(result.content).toContain("Exit code");
    });
  });

  describe("glob", () => {
    it("finds files matching a pattern", () => {
      fs.writeFileSync(path.join(tempDir, "app.ts"), "");
      fs.writeFileSync(path.join(tempDir, "app.test.ts"), "");
      fs.writeFileSync(path.join(tempDir, "README.md"), "");
      const result = registry.execute({ name: "glob", arguments: { pattern: "*.ts" } });
      const matches = JSON.parse(result.content);
      expect(matches.length).toBeGreaterThanOrEqual(2);
    });
  });

  describe("grep", () => {
    it("finds matching lines", () => {
      fs.writeFileSync(path.join(tempDir, "app.ts"), "export function main() {}\nconst x = 1;\n");
      const result = registry.execute({ name: "grep", arguments: { pattern: "export", include: "*.ts" } });
      const matches = JSON.parse(result.content);
      expect(matches.length).toBe(1);
      expect(matches[0].content).toContain("export");
    });
  });

  describe("unknown tool", () => {
    it("returns error for unknown tool name", () => {
      const result = registry.execute({ name: "unknownTool", arguments: {} });
      expect(result.isError).toBe(true);
      expect(result.content).toContain("Unknown tool");
    });
  });
});