import hashlib
import json
from pathlib import Path

import pytest
from utils import checksum


def test_json_checksum():
    data = {"b": 1, "a": 2}
    expected = hashlib.sha256(
        json.dumps(data, sort_keys=True, separators=(",", ":")).encode()
    ).hexdigest()
    assert checksum.json_checksum(data) == expected


def test_calculate_checksum(tmp_path):
    file = tmp_path / "data.txt"
    content = "hello world"
    file.write_text(content)
    expected = hashlib.sha256(content.encode()).hexdigest()
    result = checksum.calculate_checksum(str(file))
    assert result == expected


def test_calculate_checksum_missing(tmp_path):
    missing = tmp_path / "missing.txt"
    assert checksum.calculate_checksum(str(missing)) is None


def test_verify_and_update(tmp_path):
    chk_file = tmp_path / "chk.txt"
    chk_file.write_text("abc")
    assert checksum.verify_checksum("abc", str(chk_file))
    assert not checksum.verify_checksum("def", str(chk_file))

    assert checksum.update_checksum("payload", str(chk_file))
    expected = hashlib.sha256("payload".encode()).hexdigest()
    assert chk_file.read_text() == expected


def test_initialize_checksum(tmp_path):
    data = tmp_path / "file.bin"
    data.write_text("payload")
    chk_file = tmp_path / "chk2.txt"
    assert checksum.initialize_checksum(str(data), str(chk_file))
    expected = hashlib.sha256("payload".encode()).hexdigest()
    assert chk_file.read_text() == expected


def test_verify_checksum_missing(tmp_path, caplog):
    missing_file = tmp_path / "missing_chk.txt"
    with pytest.raises(FileNotFoundError):
        checksum.verify_checksum("abc", str(missing_file))

    assert f"Checksum file '{missing_file}' not found." in caplog.text