package config

import (
	"os"
	"time"
)

// Config holds all runtime configuration, loaded from environment variables.
// See .env.example for the full list and defaults.
type Config struct {
	Port         string
	BaseURL      string
	DatabasePath string

	// LLM
	LLMBackend   string // "vllm" | "ollama"
	LLMEndpoint  string
	LLMModel     string // checkpoint model (small, fast)
	LLMChatModel string // Ask Petal model; falls back to LLMModel if empty
	LLMTimeout   time.Duration

	// Auth (deferred — not wired in the local-dev build, kept for later)
	AuthentikURL          string
	AuthentikClientID     string
	AuthentikClientSecret string
	SessionSecret         string
}

// Load reads configuration from the environment, applying sane local-dev defaults.
func Load() *Config {
	return &Config{
		Port:         env("PORT", "8080"),
		BaseURL:      env("BASE_URL", "http://localhost:8080"),
		DatabasePath: env("DATABASE_PATH", "./data/petal.db"),

		LLMBackend:   env("LLM_BACKEND", "vllm"),
		LLMEndpoint:  env("LLM_ENDPOINT", "http://localhost:8000"),
		LLMModel:     env("LLM_MODEL", ""),
		LLMChatModel: env("LLM_CHAT_MODEL", ""),
		LLMTimeout:   envDuration("LLM_TIMEOUT", 30*time.Second),

		AuthentikURL:          env("AUTHENTIK_URL", ""),
		AuthentikClientID:     env("AUTHENTIK_CLIENT_ID", ""),
		AuthentikClientSecret: env("AUTHENTIK_CLIENT_SECRET", ""),
		SessionSecret:         env("SESSION_SECRET", "dev-insecure-secret-change-me"),
	}
}

func env(key, fallback string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return fallback
}

func envDuration(key string, fallback time.Duration) time.Duration {
	if v := os.Getenv(key); v != "" {
		if d, err := time.ParseDuration(v); err == nil {
			return d
		}
	}
	return fallback
}