from pathlib import Path

import pytest

from tht.config import ConfigError, load_config, workspace_id_from_path
from tht.paths import resolve_workspace_paths


def _write_config(path: Path, *, sessions: str = "sessions", absolute: Path | None = None) -> Path:
    root = absolute or Path("artifacts")
    path.write_text(
        "dwh:\n"
        "  type: postgres_direct\n"
        "  connection:\n"
        "    database: db\n"
        "    schema: public\n"
        "    user: user\n"
        "    password: secret\n"
        "roots:\n"
        f"  artifacts: {root}\n"
        f"  indexes: {root if absolute else 'indexes'}\n"
        f"  sessions: {absolute if absolute else sessions}\n"
    )
    return path


def test_relative_paths_resolve_under_workspace_root(tmp_path):
    cfg_path = _write_config(tmp_path / "demo.yaml")
    cfg = load_config(cfg_path)

    resolved = resolve_workspace_paths(cfg_path, cfg, tmp_path / "data")

    assert resolved.workspace == tmp_path / "data/workspaces/demo"
    assert resolved.sessions == tmp_path / "data/workspaces/demo/sessions"
    assert resolved.artifacts == tmp_path / "data/workspaces/demo/artifacts"
    assert resolved.indexes == tmp_path / "data/workspaces/demo/indexes"
    assert resolved.corpus == tmp_path / "data/workspaces/demo/corpus"


def test_absolute_legacy_paths_are_preserved(tmp_path):
    legacy = tmp_path / "existing-workspace"
    cfg_path = _write_config(tmp_path / "demo.yaml", absolute=legacy)
    cfg = load_config(cfg_path)

    resolved = resolve_workspace_paths(cfg_path, cfg, tmp_path / "data")

    assert resolved.sessions == legacy
    assert resolved.artifacts == legacy
    assert resolved.indexes == legacy


def test_path_escape_is_rejected(tmp_path):
    cfg_path = _write_config(tmp_path / "demo.yaml", sessions="../../private")
    cfg = load_config(cfg_path)

    with pytest.raises(ConfigError, match="outside workspace root"):
        resolve_workspace_paths(cfg_path, cfg, tmp_path / "data")


def test_workspace_symlink_escape_is_rejected(tmp_path):
    cfg_path = _write_config(tmp_path / "demo.yaml")
    cfg = load_config(cfg_path)
    data_root = tmp_path / "data"
    (data_root / "workspaces").mkdir(parents=True)
    (data_root / "workspaces" / "demo").symlink_to(tmp_path / "private", target_is_directory=True)

    with pytest.raises(ConfigError, match="outside workspaces root"):
        resolve_workspace_paths(cfg_path, cfg, data_root)


def test_nested_root_symlink_escape_is_rejected(tmp_path):
    cfg_path = _write_config(tmp_path / "demo.yaml")
    cfg = load_config(cfg_path)
    workspace = tmp_path / "data/workspaces/demo"
    workspace.mkdir(parents=True)
    (workspace / "sessions").symlink_to(tmp_path / "private", target_is_directory=True)

    with pytest.raises(ConfigError, match="outside workspace root"):
        resolve_workspace_paths(cfg_path, cfg, tmp_path / "data")


def test_corpus_symlink_escape_is_rejected(tmp_path):
    cfg_path = _write_config(tmp_path / "demo.yaml")
    cfg = load_config(cfg_path)
    workspace = tmp_path / "data/workspaces/demo"
    workspace.mkdir(parents=True)
    (workspace / "corpus").symlink_to(tmp_path / "private", target_is_directory=True)

    with pytest.raises(ConfigError, match="outside workspace root"):
        resolve_workspace_paths(cfg_path, cfg, tmp_path / "data")


def test_data_root_environment_activates_portable_paths(monkeypatch, tmp_path):
    cfg_path = _write_config(tmp_path / "demo.yaml")
    monkeypatch.setenv("THT_DATA_ROOT", str(tmp_path / "data"))

    cfg = load_config(cfg_path)

    assert cfg.paths.sessions == tmp_path / "data/workspaces/demo/sessions"
    assert cfg.paths.artifacts == tmp_path / "data/workspaces/demo/artifacts"


def test_no_data_root_preserves_legacy_relative_paths(monkeypatch, tmp_path):
    cfg_path = _write_config(tmp_path / "demo.yaml")
    monkeypatch.delenv("THT_DATA_ROOT", raising=False)

    cfg = load_config(cfg_path)

    assert cfg.paths.sessions == Path("sessions")
    assert cfg.paths.artifacts == Path("artifacts")


def test_workspace_identity_resolves_config_symlink(tmp_path):
    (tmp_path / "workspaces").mkdir()
    workspace = _write_config(tmp_path / "workspaces/local.yaml")
    alias = tmp_path / "config/tht.yaml"
    alias.parent.mkdir()
    alias.symlink_to(workspace)

    assert workspace_id_from_path(alias) == "local"
    assert load_config(alias)._workspace_id == "local"
    assert load_config(alias)._config_source == workspace.resolve().as_posix()