package config

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

func TestLoadDotEnv(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, ".env")
	content := `# full-line comment
PLAIN=hello
INLINE=value # trailing comment
QUOTED="quoted # not a comment"
SINGLE='single quoted'
export EXPORTED=yes
EMPTY=
SPACED =  padded value
`
	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
		t.Fatal(err)
	}

	t.Setenv("PLAIN", "preexisting") // real env must win
	for _, k := range []string{"INLINE", "QUOTED", "SINGLE", "EXPORTED", "EMPTY", "SPACED"} {
		os.Unsetenv(k)
		t.Cleanup(func() { os.Unsetenv(k) })
	}

	if err := LoadDotEnv(path); err != nil {
		t.Fatalf("LoadDotEnv: %v", err)
	}

	want := map[string]string{
		"PLAIN":    "preexisting",
		"INLINE":   "value",
		"QUOTED":   "quoted # not a comment",
		"SINGLE":   "single quoted",
		"EXPORTED": "yes",
		"EMPTY":    "",
		"SPACED":   "padded value",
	}
	for k, v := range want {
		if got := os.Getenv(k); got != v {
			t.Errorf("%s = %q, want %q", k, got, v)
		}
	}
}

func TestLoadDotEnvMissingFileIsOK(t *testing.T) {
	if err := LoadDotEnv(filepath.Join(t.TempDir(), "absent")); err != nil {
		t.Fatalf("missing file should not error, got %v", err)
	}
}

func TestLoadDotEnvMalformed(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, ".env")
	if err := os.WriteFile(path, []byte("NOT A KV LINE\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	if err := LoadDotEnv(path); err == nil {
		t.Fatal("want error for malformed line")
	}
}