package dotenv

import (
	"os"
	"path/filepath"
	"testing"
)

func TestLoadParsesAndNeverOverridesTheRealEnvironment(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, ".env")
	os.WriteFile(path, []byte(`# a comment
PLAIN=value one
export EXPORTED=yes
QUOTED="has # hash and \"quotes\"\nnewline"
SINGLE='no $expansion \n here'
TRAILING=kept # dropped
EMPTY=
 SPACED = trimmed
BAD LINE
=novalue
ALREADY=from-file
`), 0o600)
	t.Setenv("ALREADY", "from-environment")
	for _, k := range []string{"PLAIN", "EXPORTED", "QUOTED", "SINGLE", "TRAILING", "EMPTY", "SPACED"} {
		os.Unsetenv(k)
		defer os.Unsetenv(k)
	}
	used, err := Load(filepath.Join(dir, "missing.env"), path)
	if err != nil || used != path {
		t.Fatalf("Load = %q, %v", used, err)
	}
	want := map[string]string{
		"PLAIN": "value one", "EXPORTED": "yes", "QUOTED": "has # hash and \"quotes\"\nnewline",
		"SINGLE": `no $expansion \n here`, "TRAILING": "kept", "EMPTY": "", "SPACED": "trimmed", "ALREADY": "from-environment",
	}
	for k, v := range want {
		if got, ok := os.LookupEnv(k); !ok || got != v {
			t.Errorf("%s = %q (set=%v), want %q", k, got, ok, v)
		}
	}
	if used, _ := Load(filepath.Join(dir, "nope")); used != "" {
		t.Errorf("a missing file should load nothing, got %q", used)
	}
}

func TestArgPath(t *testing.T) {
	for _, tc := range []struct {
		args []string
		want string
	}{
		{[]string{"-listen", ":1"}, ".env"},
		{[]string{"-env", "/etc/x.env"}, "/etc/x.env"},
		{[]string{"--env=/a/b"}, "/a/b"},
		{[]string{"-env"}, ".env"},
	} {
		if got := ArgPath(tc.args, ".env"); got != tc.want {
			t.Errorf("ArgPath(%v) = %q, want %q", tc.args, got, tc.want)
		}
	}
}