"""Tests for flow.core.variables."""

from flow.core.variables import substitute, substitute_template


def test_substitute_dollar():
    result = substitute("hello $NAME", {"NAME": "world"})
    assert result == "hello world"


def test_substitute_braces():
    result = substitute("hello ${NAME}", {"NAME": "world"})
    assert result == "hello world"


def test_substitute_multiple():
    result = substitute("$A and ${B}", {"A": "1", "B": "2"})
    assert result == "1 and 2"


def test_substitute_home():
    result = substitute("dir=$HOME", {})
    assert "$HOME" not in result


def test_substitute_user():
    import os
    result = substitute("u=$USER", {})
    assert result == f"u={os.getenv('USER', '')}"


def test_substitute_non_string():
    assert substitute(123, {}) == 123


def test_substitute_template_basic():
    result = substitute_template("nvim-{{os}}-{{arch}}.tar.gz", {"os": "linux", "arch": "x86_64"})
    assert result == "nvim-linux-x86_64.tar.gz"


def test_substitute_template_missing_key():
    result = substitute_template("{{missing}}", {})
    assert result == "{{missing}}"


def test_substitute_template_non_string():
    assert substitute_template(42, {}) == 42


def test_substitute_template_no_placeholders():
    result = substitute_template("plain text", {"os": "linux"})
    assert result == "plain text"


def test_substitute_template_env_namespace():
    result = substitute_template("{{ env.USER_EMAIL }}", {"env": {"USER_EMAIL": "you@example.com"}})
    assert result == "you@example.com"