package config

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

func writeTemp(t *testing.T, content string) string {
	t.Helper()
	dir := t.TempDir()
	path := filepath.Join(dir, "config.toml")
	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
		t.Fatal(err)
	}
	return path
}

func TestLoadDefault(t *testing.T) {
	cfg, err := LoadDefault()
	if err != nil {
		t.Fatalf("LoadDefault: %v", err)
	}
	if cfg.Database.Driver != "sqlite" {
		t.Errorf("default driver = %q, want sqlite", cfg.Database.Driver)
	}
	if cfg.Policy.DefaultTTL != 90*24*time.Hour {
		t.Errorf("default ttl = %v", cfg.Policy.DefaultTTL)
	}
	if cfg.System.UserPrefix != "ext_" {
		t.Errorf("default user_prefix = %q", cfg.System.UserPrefix)
	}
}

func TestLoadFileOverrides(t *testing.T) {
	path := writeTemp(t, `
[server]
listen = "0.0.0.0:9999"
session_ttl = "2h"

[policy]
default_ttl = "720h"
`)
	cfg, err := Load(path)
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if cfg.Server.Listen != "0.0.0.0:9999" {
		t.Errorf("listen = %q", cfg.Server.Listen)
	}
	if cfg.Server.SessionTTL != 2*time.Hour {
		t.Errorf("session_ttl = %v", cfg.Server.SessionTTL)
	}
	if cfg.Policy.DefaultTTL != 30*24*time.Hour {
		t.Errorf("default_ttl = %v", cfg.Policy.DefaultTTL)
	}
}

func TestEnvOverrides(t *testing.T) {
	t.Setenv("USERNODE_DATABASE_DRIVER", "mysql")
	t.Setenv("USERNODE_DATABASE_DSN", "u:p@tcp(h:3306)/db")
	t.Setenv("USERNODE_POLICY_OTPTTL", "5m")
	t.Setenv("USERNODE_SYSTEM_SUDO", "true")
	t.Setenv("USERNODE_SERVER_TRUSTED_PROXIES", "10.0.0.1, 10.0.0.2")

	cfg, err := LoadDefault()
	if err != nil {
		t.Fatalf("LoadDefault: %v", err)
	}
	if cfg.Database.Driver != "mysql" || cfg.Database.DSN != "u:p@tcp(h:3306)/db" {
		t.Errorf("database = %+v", cfg.Database)
	}
	if cfg.Policy.OTPTTL != 5*time.Minute {
		t.Errorf("otp_ttl = %v", cfg.Policy.OTPTTL)
	}
	if !cfg.System.Sudo {
		t.Error("system.sudo should be true")
	}
	if len(cfg.Server.TrustedProxies) != 2 || cfg.Server.TrustedProxies[0] != "10.0.0.1" {
		t.Errorf("trusted_proxies = %v", cfg.Server.TrustedProxies)
	}
}

func TestInvalidDriver(t *testing.T) {
	path := writeTemp(t, "[database]\ndriver = \"oracle\"\ndsn = \"x\"\n")
	if _, err := Load(path); err == nil {
		t.Fatal("expected error for unsupported driver")
	}
}

func TestCamelToSnake(t *testing.T) {
	cases := map[string]string{
		"SessionTTL":         "session_ttl",
		"Listen":             "listen",
		"OTPTTL":             "otpttl", // 全大写缩写按一个词处理（与 strcase 行为一致）
		"OTPCooldown":        "otp_cooldown",
		"TrustedProxies":     "trusted_proxies",
		"AuthorizedKeysDir":  "authorized_keys_dir",
		"HomeBase":           "home_base",
	}
	for in, want := range cases {
		if got := camelToSnake(in); got != want {
			t.Errorf("camelToSnake(%q) = %q, want %q", in, got, want)
		}
	}
}