package config

import (
	"log/slog"
	"net/url"
	"os"
	"strings"
)

type Config struct {
	AppEnv                  string
	HTTPAddr                string
	DatabaseURL             string
	JWTSecret               string
	ServerMainBaseURL        string
	ServerMainInternalToken  string
	CORSAllowedOrigin       string
	LogLevel                slog.Level
}

func Load() Config {
	return Config{
		AppEnv:       env("APP_ENV", "development"),
		HTTPAddr:     env("HTTP_ADDR", ":8088"),
		DatabaseURL:  gatewayDatabaseURL(),
		JWTSecret:    env("CONFIG_JWT_SECRET", "this is a very secret secret"),
		ServerMainBaseURL: strings.TrimRight(
			env("SERVER_MAIN_BASE_URL", "http://localhost:3000"),
			"/",
		),
		ServerMainInternalToken: env("SERVER_MAIN_INTERNAL_TOKEN", ""),
		CORSAllowedOrigin:      env("CORS_ALLOWED_ORIGIN", "http://localhost:5178"),
		LogLevel:               logLevel(env("LOG_LEVEL", "info")),
	}
}

func gatewayDatabaseURL() string {
	if value := envValue("AI_GATEWAY_DATABASE_URL"); value != "" {
		return normalizePostgresURL(value)
	}
	if value := envValue("DATABASE_URL"); value != "" {
		return normalizePostgresURL(value)
	}
	if memoryURL := envValue("MEMORY_DATABASE_URL"); memoryURL != "" {
		return normalizePostgresURL(withDatabase(memoryURL, env("AI_GATEWAY_DATABASE_NAME", "easyai_ai_gateway")))
	}
	return normalizePostgresURL("postgresql://easyai:easyai2025@localhost:5432/easyai_ai_gateway?sslmode=disable")
}

func normalizePostgresURL(raw string) string {
	parsed, err := url.Parse(raw)
	if err != nil {
		return raw
	}
	values := parsed.Query()
	schema := values.Get("schema")
	if schema == "" {
		return raw
	}
	values.Del("schema")
	if values.Get("search_path") == "" {
		values.Set("search_path", schema)
	}
	parsed.RawQuery = values.Encode()
	return parsed.String()
}

func withDatabase(raw string, databaseName string) string {
	parsed, err := url.Parse(raw)
	if err != nil || databaseName == "" {
		return raw
	}
	parsed.Path = "/" + databaseName
	return parsed.String()
}

func envValue(key string) string {
	return strings.TrimSpace(os.Getenv(key))
}

func env(key string, fallback string) string {
	if value := envValue(key); value != "" {
		return value
	}
	return fallback
}

func logLevel(value string) slog.Level {
	switch strings.ToLower(value) {
	case "debug":
		return slog.LevelDebug
	case "warn", "warning":
		return slog.LevelWarn
	case "error":
		return slog.LevelError
	default:
		return slog.LevelInfo
	}
}