import pytest
import os
import sys
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from functions.io_utils import *
import warnings
import io
from unittest import mock

def test_write_file(tmp_path):
    # Write content to file and verify write success
    file = tmp_path / "test_write.txt"
    write_file(str(file), "data")
    assert file.read_text() == "data"

def test_read_file(tmp_path):
    # Write and read file, normal operation
    file = tmp_path / "test.txt"
    file.write_text("hello")
    content = read_file(str(file))
    assert content == "hello"

def test_cause_io_error():
    # Raises manual IOError to simulate IO failure
    cause_io_error()

def test_file_not_found():
    # Reading non-existing file raises FileNotFoundError
    read_file("nonexistent.file")

def test_permission_error(monkeypatch):
    # Patch open to raise PermissionError simulating access denial
    def raise_perm_error(*args, **kwargs):
        raise PermissionError("Permission denied")
    monkeypatch.setattr("builtins.open", raise_perm_error)
    read_file("anyfile.txt")

def test_mock_open_error(monkeypatch):
    # Mock open() to raise IOError simulating read error
    mocked_open = mock.mock_open()
    mocked_open.side_effect = IOError("Mocked IOError")
    monkeypatch.setattr("builtins.open", mocked_open)
    with open("file.txt", "r") as f:
        f.read()

def test_file_handle_closed_error():
    # Accessing closed file raises ValueError
    f = io.StringIO("content")
    f.close()
    f.read()

def test_os_error(monkeypatch):
    # Patch os.remove to raise OSError simulating filesystem error
    def raise_os_error(path):
        raise OSError("Simulated OSError")
    monkeypatch.setattr("os.remove", raise_os_error)
    os.remove("file.txt")

def test_write_file_in_readonly_mode(tmp_path):
    # Writing to read-only file raises PermissionError
    file = tmp_path / "readonly.txt"
    file.write_text("data")
    # Change the file's permissions to read-only : no write permission
    os.chmod(file, 0o444)
    with open(file, "w") as f:
        f.write("new content")

def test_file_not_found_error():
    # Raises FileNotFoundError when opening a non-existent file
    open("no_such_file.txt", "r")