import os
import time
from pathlib import Path

import pytest

import tkinter as tk

from main import (
    BackgroundFileCopyApp,
    find_latest_file_in_folder,
    should_copy_file,
    compute_file_checksum,
    verify_copy,
)



def _touch(path: Path, mtime: float) -> None:
    path.write_text('data', encoding='utf-8')
    os.utime(path, (mtime, mtime))



def test_find_latest_file_returns_none_for_missing_folder(tmp_path):
    missing = tmp_path / 'missing'
    assert find_latest_file_in_folder(str(missing)) is None



def test_find_latest_file_picks_newest(tmp_path):
    folder = tmp_path / 'src'
    folder.mkdir()

    now = time.time()
    older = folder / 'older.bak'
    newer = folder / 'newer.bak'
    other = folder / 'other.sql'

    _touch(older, now - 10)
    _touch(newer, now - 5)
    _touch(other, now - 1)

    latest = find_latest_file_in_folder(str(folder))
    assert latest is not None
    assert latest.name == 'other.sql'



def test_should_copy_file_when_target_missing(tmp_path):
    src = tmp_path / 'src.bak'
    src.write_text('x', encoding='utf-8')
    dst = tmp_path / 'dst.bak'

    assert should_copy_file(src, dst) is True



def test_should_copy_file_when_source_newer(tmp_path):
    now = time.time()
    src = tmp_path / 'src.bak'
    dst = tmp_path / 'dst.bak'

    _touch(dst, now - 10)
    _touch(src, now)

    assert should_copy_file(src, dst) is True



def test_should_copy_file_when_target_newer_or_equal(tmp_path):
    now = time.time()
    src = tmp_path / 'src.bak'
    dst = tmp_path / 'dst.bak'

    _touch(src, now)
    _touch(dst, now)

    assert should_copy_file(src, dst) is False


def test_compute_file_checksum_stable(tmp_path):
    src = tmp_path / 'a.bak'
    src.write_text('hello', encoding='utf-8')
    c1 = compute_file_checksum(src)
    c2 = compute_file_checksum(src)
    assert c1 == c2


def test_verify_copy_true_for_equal_files(tmp_path):
    src = tmp_path / 'src.bak'
    dst = tmp_path / 'dst.bak'
    src.write_text('data', encoding='utf-8')
    dst.write_text('data', encoding='utf-8')
    assert verify_copy(src, dst) is True


def test_verify_copy_false_for_different_files(tmp_path):
    src = tmp_path / 'src.bak'
    dst = tmp_path / 'dst.bak'
    src.write_text('data1', encoding='utf-8')
    dst.write_text('data2', encoding='utf-8')
    assert verify_copy(src, dst) is False


def _create_app():
    root = tk.Tk()
    root.withdraw()
    app = BackgroundFileCopyApp(root)
    return app, root


def test_copy_full_folder(tmp_path):
    app, root = _create_app()
    try:
        src = tmp_path / "src"
        dst = tmp_path / "dst"
        (src / "sub").mkdir(parents=True)
        (src / "a.bak").write_text("a", encoding="utf-8")
        (src / "sub" / "b.sql").write_text("b", encoding="utf-8")

        app.min_free_gb_var.set(0)
        app.include_masks_var.set("*.bak;*.sql")
        app.exclude_masks_var.set("")

        copied, skipped, errors = app.copy_full_folder(src, dst)
        assert errors == 0
        assert copied == 2
        assert (dst / "a.bak").exists()
        assert (dst / "sub" / "b.sql").exists()
    finally:
        root.destroy()


def test_save_and_load_settings(tmp_path, monkeypatch):
    app, root = _create_app()
    try:
        settings_path = tmp_path / "settings.json"
        monkeypatch.setattr(app, "get_settings_path", lambda: str(settings_path))

        app.add_path_pair("C:/src", "D:/dst", False)
        app.include_masks_var.set("*.bak")
        app.exclude_masks_var.set("*.tmp")
        app.min_free_gb_var.set(2)
        app.max_workers_var.set(4)
        app.schedules = [{"time": "01:00", "days": ["Mon", "Wed"]}]
        app.refresh_schedules_tree()
        app.save_settings()

        app2, root2 = _create_app()
        try:
            monkeypatch.setattr(app2, "get_settings_path", lambda: str(settings_path))
            app2.load_settings()
            profile = app2.profiles.get(app2.active_profile.get())
            assert profile is not None
            assert profile.get("include_masks") == "*.bak"
            assert profile.get("exclude_masks") == "*.tmp"
            assert int(profile.get("max_workers")) == 4
            assert profile.get("min_free_gb") == 2
            assert profile.get("schedules") == [{"time": "01:00", "days": ["Mon", "Wed"]}]
            assert len(profile.get("pairs")) == 1
        finally:
            root2.destroy()
    finally:
        root.destroy()