import { beforeEach, describe, expect, it, jest } from "@jest/globals";

const mockReadFileSync = jest.fn();
const mockWarning = jest.fn();

jest.unstable_mockModule("node:fs", () => ({
  default: {
    readFileSync: mockReadFileSync,
  },
}));

jest.unstable_mockModule("@actions/core", () => ({
  warning: mockWarning,
}));

async function getVersionFromToolVersions(filePath: string) {
  const { getUvVersionFromToolVersions } = await import(
    "../../src/version/tool-versions-file"
  );

  return getUvVersionFromToolVersions(filePath);
}

async function getPythonVersionFromToolVersions(filePath: string) {
  const module = await import("../../src/version/tool-versions-file");
  return module.getPythonVersionFromToolVersions(filePath);
}

describe("getUvVersionFromToolVersions", () => {
  beforeEach(() => {
    jest.resetModules();
    jest.clearAllMocks();
  });

  it("should return undefined for non-.tool-versions files", async () => {
    const result = await getVersionFromToolVersions("package.json");
    expect(result).toBeUndefined();
    expect(mockReadFileSync).not.toHaveBeenCalled();
  });

  it("should return version for valid uv entry", async () => {
    const fileContent = "python 3.11.0\nuv 0.1.0\nnodejs 18.0.0";
    mockReadFileSync.mockReturnValue(fileContent);

    const result = await getVersionFromToolVersions(".tool-versions");

    expect(result).toBe("0.1.0");
    expect(mockReadFileSync).toHaveBeenCalledWith(".tool-versions", "utf8");
  });

  it("should return version for uv entry with v prefix", async () => {
    const fileContent = "uv v0.2.0";
    mockReadFileSync.mockReturnValue(fileContent);

    const result = await getVersionFromToolVersions(".tool-versions");

    expect(result).toBe("0.2.0");
  });

  it("should handle whitespace around uv entry", async () => {
    const fileContent = "  uv   0.3.0  ";
    mockReadFileSync.mockReturnValue(fileContent);

    const result = await getVersionFromToolVersions(".tool-versions");

    expect(result).toBe("0.3.0");
  });

  it("should skip comments", async () => {
    const fileContent = "# uv 0.1.0\npython 3.11.0\nuv 0.2.0 # inline comment";
    mockReadFileSync.mockReturnValue(fileContent);

    const result = await getVersionFromToolVersions(".tool-versions");

    expect(result).toBe("0.2.0");
  });

  it("should return first matching uv version", async () => {
    const fileContent = "uv 0.1.0\npython 3.11.0\nuv 0.2.0";
    mockReadFileSync.mockReturnValue(fileContent);

    const result = await getVersionFromToolVersions(".tool-versions");

    expect(result).toBe("0.1.0");
  });

  it("should return undefined when no uv entry found", async () => {
    const fileContent = "python 3.11.0\nnodejs 18.0.0";
    mockReadFileSync.mockReturnValue(fileContent);

    const result = await getVersionFromToolVersions(".tool-versions");

    expect(result).toBeUndefined();
  });

  it("should return undefined for empty file", async () => {
    mockReadFileSync.mockReturnValue("");

    const result = await getVersionFromToolVersions(".tool-versions");

    expect(result).toBeUndefined();
  });

  it("should warn and return undefined for ref syntax", async () => {
    const fileContent = "uv ref:main";
    mockReadFileSync.mockReturnValue(fileContent);

    const result = await getVersionFromToolVersions(".tool-versions");

    expect(result).toBeUndefined();
    expect(mockWarning).toHaveBeenCalledWith(
      "The ref syntax of .tool-versions is not supported. Please use a released version instead.",
    );
  });

  it("should handle file path with .tool-versions extension", async () => {
    const fileContent = "uv 0.1.0";
    mockReadFileSync.mockReturnValue(fileContent);

    const result = await getVersionFromToolVersions("path/to/.tool-versions");

    expect(result).toBe("0.1.0");
    expect(mockReadFileSync).toHaveBeenCalledWith(
      "path/to/.tool-versions",
      "utf8",
    );
  });
});

describe("getPythonVersionFromToolVersions", () => {
  beforeEach(() => {
    jest.resetModules();
    jest.clearAllMocks();
  });

  it("should return version for a valid Python entry", async () => {
    mockReadFileSync.mockReturnValue(
      "nodejs 24.0.0\r\npython v3.13.1t # use free-threaded Python\r\nuv 0.12.3",
    );

    const result = await getPythonVersionFromToolVersions(".tool-versions");

    expect(result).toBe("3.13.1t");
  });

  it("should return the first matching Python version", async () => {
    mockReadFileSync.mockReturnValue("python 3.12\npython 3.13");

    const result = await getPythonVersionFromToolVersions(".tool-versions");

    expect(result).toBe("3.12");
  });

  it("should return undefined when no Python entry is found", async () => {
    mockReadFileSync.mockReturnValue("uv 0.12.3\nnodejs 24.0.0");

    const result = await getPythonVersionFromToolVersions(".tool-versions");

    expect(result).toBeUndefined();
  });

  it("should warn and return undefined for multiple Python versions", async () => {
    mockReadFileSync.mockReturnValue("python 3.13 3.12 system");

    const result = await getPythonVersionFromToolVersions(".tool-versions");

    expect(result).toBeUndefined();
    expect(mockWarning).toHaveBeenCalledWith(
      "Multiple Python versions in .tool-versions are not supported. The Python entry will be ignored.",
    );
  });

  it.each(["ref:main", "path:~/src/python", "system"])(
    "should warn and return undefined for %s",
    async (version) => {
      mockReadFileSync.mockReturnValue(`python ${version}`);

      const result = await getPythonVersionFromToolVersions(".tool-versions");

      expect(result).toBeUndefined();
      expect(mockWarning).toHaveBeenCalledWith(
        `The Python version ${version} in .tool-versions is not supported. The Python entry will be ignored.`,
      );
    },
  );

  it("should return undefined for non-.tool-versions files", async () => {
    const result = await getPythonVersionFromToolVersions(".python-version");

    expect(result).toBeUndefined();
    expect(mockReadFileSync).not.toHaveBeenCalled();
  });
});