"""Tests for YAML configuration module."""

from __future__ import annotations

import os
from unittest.mock import patch

import pytest

from gitea_dashboard.config import load_config, merge_config, resolve_env_vars


class TestResolveEnvVars:
    """Test resolve_env_vars function."""

    def test_resolve_env_vars_simple(self):
        """${VAR} is replaced by the environment variable value."""
        with patch.dict(os.environ, {"GITEA_TOKEN": "abc123"}):
            result = resolve_env_vars("${GITEA_TOKEN}")

        assert result == "abc123"

    def test_resolve_env_vars_undefined(self):
        """${UNDEFINED} is left as-is when the variable is not set."""
        with patch.dict(os.environ, {}, clear=True):
            result = resolve_env_vars("${UNDEFINED_VAR}")

        assert result == "${UNDEFINED_VAR}"

    def test_resolve_env_vars_in_list(self):
        """resolve_env_vars works on individual string elements."""
        with patch.dict(os.environ, {"MY_VAR": "resolved"}):
            result = resolve_env_vars("prefix-${MY_VAR}-suffix")

        assert result == "prefix-resolved-suffix"


class TestLoadConfig:
    """Test load_config function."""

    def test_load_config_valid_yaml(self, tmp_path):
        """Valid YAML file is loaded as a dict with all keys."""
        config_file = tmp_path / "config.yml"
        config_file.write_text(
            "url: http://localhost:3000\ntoken: ${GITEA_TOKEN}\nsort: activity\n"
        )

        with patch.dict(os.environ, {"GITEA_TOKEN": "secret123"}):
            result = load_config(str(config_file))

        assert result["url"] == "http://localhost:3000"
        assert result["token"] == "secret123"
        assert result["sort"] == "activity"

    def test_load_config_partial_yaml(self, tmp_path):
        """YAML with only some keys returns a partial dict."""
        config_file = tmp_path / "config.yml"
        config_file.write_text("url: http://localhost:3000\nsort: name\n")

        result = load_config(str(config_file))

        assert result["url"] == "http://localhost:3000"
        assert result["sort"] == "name"
        assert "token" not in result

    def test_load_config_empty_file(self, tmp_path):
        """Empty YAML file returns an empty dict."""
        config_file = tmp_path / "config.yml"
        config_file.write_text("")

        result = load_config(str(config_file))

        assert result == {}

    def test_load_config_invalid_yaml(self, tmp_path):
        """Syntactically invalid YAML raises a clear error."""
        config_file = tmp_path / "config.yml"
        config_file.write_text("invalid: yaml: content: [unclosed")

        with pytest.raises(ValueError, match="[Ii]nvalid"):
            load_config(str(config_file))

    def test_load_config_custom_path(self, tmp_path):
        """--config /path/to/custom.yml loads the specified file."""
        config_file = tmp_path / "custom.yml"
        config_file.write_text("sort: issues\n")

        result = load_config(str(config_file))

        assert result["sort"] == "issues"

    def test_load_config_missing_custom_path(self):
        """--config with a nonexistent path raises FileNotFoundError."""
        with pytest.raises(FileNotFoundError):
            load_config("/nonexistent/path/config.yml")

    def test_load_config_default_paths(self, tmp_path, monkeypatch):
        """Config file in current directory is auto-discovered."""
        config_file = tmp_path / ".gitea-dashboard.yml"
        config_file.write_text("sort: activity\n")
        monkeypatch.chdir(tmp_path)

        result = load_config()

        assert result["sort"] == "activity"


class TestMergeConfig:
    """Test merge_config function."""

    def test_merge_config_priority(self):
        """CLI > env > config > defaults — CLI wins."""
        cli = {"sort": "name", "url": None}
        env = {"sort": "issues", "url": "http://env:3000"}
        config = {"sort": "activity", "url": "http://config:3000", "exclude": ["old"]}
        defaults = {"sort": "name", "url": "http://default:3000", "exclude": None}

        result = merge_config(cli, env, config, defaults)

        assert result["sort"] == "name"  # CLI wins
        assert result["url"] == "http://env:3000"  # CLI is None, env wins
        assert result["exclude"] == ["old"]  # env has no exclude, config wins

    def test_merge_config_none_does_not_override(self):
        """None in a higher-priority source does not mask a lower-priority value."""
        cli = {"token": None}
        env = {"token": None}
        config = {"token": "from-config"}
        defaults = {"token": "default-token"}

        result = merge_config(cli, env, config, defaults)

        assert result["token"] == "from-config"