import pytest
from pathlib import Path
from backend.agent.servers import mcp_server_file_search as server


# =========================================================
# FIXTURES
# =========================================================

@pytest.fixture()
def workspace(tmp_path, monkeypatch):
    """
    Erstellt einen isolierten Workspace für jeden Test.
    """
    ws = tmp_path / "workspace"
    ws.mkdir()

    monkeypatch.setattr(server, "ALLOWED_DIR", ws)

    return ws


# =========================================================
# BASIC TESTS (1–10)
# =========================================================


# ---------------------------------------------------------
# 1. _safe_path erlaubt gültige Pfade
# ---------------------------------------------------------

def test_safe_path_valid(workspace):
    result = server._safe_path("test.txt")

    assert result == workspace / "test.txt"


# ---------------------------------------------------------
# 2. _safe_path blockiert Path Traversal
# ---------------------------------------------------------

def test_safe_path_blocks_traversal(workspace):
    with pytest.raises(ValueError):
        server._safe_path("../secret.txt")


# ---------------------------------------------------------
# 3. list_files liefert leeren Hinweis
# ---------------------------------------------------------

def test_list_files_empty(workspace):
    result = server.list_files()

    assert result == "No files found in the project directory."


# ---------------------------------------------------------
# 4. list_files findet Dateien rekursiv
# ---------------------------------------------------------

def test_list_files_recursive(workspace):
    src = workspace / "src"
    src.mkdir()

    (src / "main.py").write_text("print('hello')")

    result = server.list_files()

    assert "src/main.py" in result


# ---------------------------------------------------------
# 5. read_file liest Datei korrekt
# ---------------------------------------------------------

def test_read_file_success(workspace):
    file = workspace / "hello.txt"
    file.write_text("Hello World")

    result = server.read_file("hello.txt")

    assert result == "Hello World"


# ---------------------------------------------------------
# 6. read_file erkennt fehlende Datei
# ---------------------------------------------------------

def test_read_file_missing(workspace):
    result = server.read_file("missing.txt")

    assert "does not exist" in result


# ---------------------------------------------------------
# 7. write_new_file erstellt Datei
# ---------------------------------------------------------

def test_write_new_file_success(workspace):
    result = server.write_new_file("new.txt", "content")

    assert "OK:" in result
    assert (workspace / "new.txt").exists()


# ---------------------------------------------------------
# 8. write_new_file verhindert Überschreiben
# ---------------------------------------------------------

def test_write_new_file_existing(workspace):
    file = workspace / "exists.txt"
    file.write_text("old")

    result = server.write_new_file("exists.txt", "new")

    assert "already exists" in result


# ---------------------------------------------------------
# 9. create_new_directory erstellt Verzeichnis
# ---------------------------------------------------------

def test_create_new_directory_success(workspace):
    result = server.create_new_directory("mydir")

    assert "OK:" in result
    assert (workspace / "mydir").is_dir()


# ---------------------------------------------------------
# 10. search_files findet Inhalte
# ---------------------------------------------------------

def test_search_files_content_match(workspace):
    file = workspace / "notes.txt"
    file.write_text("Python MCP Server")

    result = server.search_files("mcp")

    assert "[content]" in result


# =========================================================
# EDGE CASE TESTS (11–20)
# =========================================================


# ---------------------------------------------------------
# 11. Mehrfaches Traversal blockieren
# ---------------------------------------------------------

def test_safe_path_double_traversal(workspace):
    with pytest.raises(ValueError):
        server._safe_path("../../../../etc/passwd")


# ---------------------------------------------------------
# 12. Symlink Escape verhindern
# ---------------------------------------------------------

def test_safe_path_symlink_escape(workspace):
    outside = workspace.parent / "outside"
    outside.mkdir()

    target = outside / "evil.txt"
    target.write_text("bad")

    link = workspace / "link"
    link.symlink_to(outside)

    with pytest.raises(ValueError):
        server._safe_path("link/evil.txt")


# ---------------------------------------------------------
# 13. Dateien ohne Extension blockieren
# ---------------------------------------------------------

def test_write_file_without_extension(workspace):
    result = server.write_new_file("README", "test")

    assert "can only write" in result


# ---------------------------------------------------------
# 14. Hidden Files blockieren
# ---------------------------------------------------------

def test_write_hidden_file(workspace):
    result = server.write_new_file(".env", "SECRET=123")

    assert "can only write" in result


# ---------------------------------------------------------
# 15. Binary Files korrekt behandeln
# ---------------------------------------------------------

def test_read_binary_file(workspace):
    binary = workspace / "data.bin"
    binary.write_bytes(b"\xFF\xFE\xFD")

    result = server.read_file("data.bin")

    assert "not a text file" in result


# ---------------------------------------------------------
# 16. Sehr große Zeilen durchsuchen
# ---------------------------------------------------------

def test_search_huge_line(workspace):
    huge_text = "A" * 1_000_000 + "needle"

    file = workspace / "huge.txt"
    file.write_text(huge_text)

    result = server.search_files("needle")

    assert "[content]" in result


# ---------------------------------------------------------
# 17. Leere Dateien lesen
# ---------------------------------------------------------

def test_read_empty_file(workspace):
    file = workspace / "empty.txt"
    file.write_text("")

    result = server.read_file("empty.txt")

    assert result == ""


# ---------------------------------------------------------
# 18. Sonderzeichen im Query
# ---------------------------------------------------------

def test_search_special_characters(workspace):
    file = workspace / "test.txt"
    file.write_text("hello [world] (test)")

    result = server.search_files("[world]")

    assert "[content]" in result


# ---------------------------------------------------------
# 19. Unicode-Dateinamen unterstützen
# ---------------------------------------------------------

def test_write_unicode_filename(workspace):
    filename = "🔥_überraschung.txt"

    result = server.write_new_file(filename, "unicode")

    assert "OK:" in result
    assert (workspace / filename).exists()


# ---------------------------------------------------------
# 20. Tiefe Verzeichnisstrukturen
# ---------------------------------------------------------

def test_list_files_deep_nesting(workspace):
    current = workspace

    for i in range(50):
        current = current / f"dir_{i}"
        current.mkdir()

    file = current / "deep.txt"
    file.write_text("deep")

    result = server.list_files()

    assert "deep.txt" in result