package config

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

func unsetEnv(t *testing.T, key string) {
	t.Helper()
	os.Unsetenv(key)
	t.Cleanup(func() { os.Unsetenv(key) })
}

func TestLoadDotEnvLoadsValues(t *testing.T) {
	const key = "WIKIJS_TEST_DOTENV_LOAD"
	unsetEnv(t, key)

	path := filepath.Join(t.TempDir(), ".env")
	body := "# comment\n\nWIKIJS_TEST_DOTENV_LOAD=\"hello world\"\n"
	if err := os.WriteFile(path, []byte(body), 0o600); err != nil {
		t.Fatalf("write env file: %v", err)
	}
	t.Setenv("ENV_FILE", path)

	if err := LoadDotEnv(); err != nil {
		t.Fatalf("LoadDotEnv() error = %v", err)
	}
	if got, want := os.Getenv(key), "hello world"; got != want {
		t.Errorf("%s = %q, want %q", key, got, want)
	}
}

func TestLoadEnvFileExplicit(t *testing.T) {
	const key = "WIKIJS_TEST_ENVFILE_EXPLICIT"
	unsetEnv(t, key)

	path := filepath.Join(t.TempDir(), "custom.env")
	if err := os.WriteFile(path, []byte(key+"=value\n"), 0o600); err != nil {
		t.Fatalf("write env file: %v", err)
	}

	if err := LoadEnvFile(path); err != nil {
		t.Fatalf("LoadEnvFile() error = %v", err)
	}
	if got, want := os.Getenv(key), "value"; got != want {
		t.Errorf("%s = %q, want %q", key, got, want)
	}
}

func TestLoadEnvFileEmptyPath(t *testing.T) {
	if err := LoadEnvFile("  "); err == nil {
		t.Fatal("LoadEnvFile() error = nil, want error")
	}
}

func TestLoadDotEnvDoesNotOverrideProcessEnv(t *testing.T) {
	const key = "WIKIJS_TEST_DOTENV_OVERRIDE"

	path := filepath.Join(t.TempDir(), ".env")
	if err := os.WriteFile(path, []byte(key+"=from-file\n"), 0o600); err != nil {
		t.Fatalf("write env file: %v", err)
	}
	t.Setenv("ENV_FILE", path)
	t.Setenv(key, "from-process")

	if err := LoadDotEnv(); err != nil {
		t.Fatalf("LoadDotEnv() error = %v", err)
	}
	if got, want := os.Getenv(key), "from-process"; got != want {
		t.Errorf("%s = %q, want %q", key, got, want)
	}
}

func TestLoadDotEnvMissingDefaultIsIgnored(t *testing.T) {
	t.Chdir(t.TempDir())
	t.Setenv("ENV_FILE", "")

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

func TestLoadDotEnvMissingExplicitFileFails(t *testing.T) {
	t.Setenv("ENV_FILE", filepath.Join(t.TempDir(), "does-not-exist.env"))

	if err := LoadDotEnv(); err == nil {
		t.Fatal("LoadDotEnv() error = nil, want error")
	}
}