package bellconfig

import (
	"errors"
	"fmt"
	"os"
	"strconv"
	"strings"

	"github.com/go-admin-team/go-admin-core/sdk/config"
)

const (
	DatabaseURLEnv = "BELL_DATABASE_URL"
	JWTSecretEnv   = "BELL_JWT_SECRET"
)

// Environment contains Bell's process-owned settings. It deliberately has no
// credentials or secret defaults so Sense and Bell cannot silently share them.
type Environment struct {
	DatabaseURL string
	JWTSecret   string
	Host        string
	Port        int64
}

func Load(getenv func(string) string) (Environment, error) {
	env := Environment{
		DatabaseURL: strings.TrimSpace(getenv(DatabaseURLEnv)),
		JWTSecret:   strings.TrimSpace(getenv(JWTSecretEnv)),
		Host:        strings.TrimSpace(getenv("BELL_HOST")),
	}
	if env.DatabaseURL == "" {
		return Environment{}, fmt.Errorf("%s is required", DatabaseURLEnv)
	}
	if env.JWTSecret == "" {
		return Environment{}, fmt.Errorf("%s is required", JWTSecretEnv)
	}
	if len(env.JWTSecret) < 32 || env.JWTSecret == "go-admin" || strings.HasPrefix(env.JWTSecret, "__BELL_") {
		return Environment{}, errors.New("BELL_JWT_SECRET must be a non-default value of at least 32 characters")
	}
	if env.Host == "" {
		env.Host = "127.0.0.1"
	}
	if rawPort := strings.TrimSpace(getenv("BELL_PORT")); rawPort != "" {
		port, err := strconv.ParseInt(rawPort, 10, 64)
		if err != nil || port < 1 || port > 65535 {
			return Environment{}, errors.New("BELL_PORT must be between 1 and 65535")
		}
		env.Port = port
	}
	return env, nil
}

func ApplyRequiredEnvironment() error {
	env, err := Load(os.Getenv)
	if err != nil {
		return err
	}
	config.ApplicationConfig.Name = "bell"
	config.ApplicationConfig.Host = env.Host
	if env.Port != 0 {
		config.ApplicationConfig.Port = env.Port
	}
	config.JwtConfig.Secret = env.JWTSecret
	config.DatabaseConfig.Driver = "postgres"
	config.DatabaseConfig.Source = env.DatabaseURL
	for _, database := range config.DatabasesConfig {
		database.Driver = "postgres"
		database.Source = env.DatabaseURL
	}
	return nil
}