package config

import (
	"os"
	"strconv"
)

// Config holds all runtime configuration loaded from environment variables.
type Config struct {
	Port                  string
	OpenAIBackend         string
	OpenAIApiKey          string
	PostgresDSN           string
	DBPath                string // SQLite database file path (when DB_MODE=sqlite)
	DBMode                string // "sqlite" or "pgs" — selects database driver
	LogLevel              string // "debug", "info", or "warn" — console log verbosity
	RequestTimeoutSeconds int
	OpenAIModel           string // default model when client omits it
}

// Load reads environment variables and returns a populated Config.
// All values MUST come from env — no hardcoded IPs or ports.
func Load() *Config {
	timeoutSec := 30
	if v := os.Getenv("REQUEST_TIMEOUT_SECONDS"); v != "" {
		if parsed, err := strconv.Atoi(v); err == nil {
			timeoutSec = parsed
		}
	}

	dbMode := os.Getenv("DB_MODE")
	dbPath := os.Getenv("DB_PATH")
	logLevel := os.Getenv("LOG_LEVEL")

	// Support both POSTGRES_DSN and DATABASE_DSN env keys
	postgresDSN := os.Getenv("POSTGRES_DSN")
	if postgresDSN == "" {
		postgresDSN = os.Getenv("DATABASE_DSN")
	}

	port := os.Getenv("PORT")
	if port == "" {
		port = "8000"
	}

	openAIBackend := os.Getenv("OPENAI_BACKEND")
	if openAIBackend == "" {
		openAIBackend = "https://api.deepseek.com"
	}

	openAIApiKey := os.Getenv("OPENAI_KEY")
	openAIModel := os.Getenv("OPENAI_MODEL")

	return &Config{
		Port:                  port,
		OpenAIBackend:         openAIBackend,
		OpenAIApiKey:          openAIApiKey,
		PostgresDSN:           postgresDSN,
		DBPath:                dbPath,
		DBMode:                dbMode,
		LogLevel:              logLevel,
		RequestTimeoutSeconds: timeoutSec,
		OpenAIModel:           openAIModel,
	}
}