package config

import (
	"log/slog"
	"os"
	"sync"
	"time"
)

type Config struct {
	BaseURL  string
	Semester string
	TWFID    string
	Recognizer RecognizerConfig
}

type RecognizerConfig struct {
	APIURL  string
	APIKey  string
	Model   string
	Timeout time.Duration
}

var (
	cfg     *Config
	cfgOnce sync.Once
)

func Load() *Config {
	cfgOnce.Do(func() {
		cfg = &Config{
			BaseURL:  getEnv("JWTS_BASE_URL", "http://jwts.hitwh.edu.cn"),
			Semester: getEnv("JWTS_SEMESTER", ""),
			TWFID:    getEnv("JWTS_TWFID", ""),
			Recognizer: RecognizerConfig{
				APIURL:  getEnv("RECOGNIZER_API_URL", "https://api.littlelan.cn/v1/chat/completions"),
				APIKey:  getEnv("RECOGNIZER_API_KEY", ""),
				Model:   getEnv("RECOGNIZER_MODEL", "qwen3.5-plus"),
				Timeout: getEnvDuration("RECOGNIZER_TIMEOUT", 120*time.Second),
			},
		}

		if cfg.Recognizer.APIKey == "" {
			slog.Warn("RECOGNIZER_API_KEY not set, image recognition will not work")
		}
	})
	return cfg
}

func Get() *Config {
	if cfg == nil {
		return Load()
	}
	return cfg
}

func getEnv(key, defaultValue string) string {
	val := os.Getenv(key)
	if val == "" {
		return defaultValue
	}
	return val
}

func getEnvDuration(key string, defaultValue time.Duration) time.Duration {
	val := os.Getenv(key)
	if val == "" {
		return defaultValue
	}
	if d, err := time.ParseDuration(val); err == nil {
		return d
	}
	return defaultValue
}

var (
	BaseURL          = Get().BaseURL
	Semester         = Get().Semester
	TWFID            = Get().TWFID
	RecognizerAPIURL = Get().Recognizer.APIURL
	RecognizerAPIKey = Get().Recognizer.APIKey
	RecognizerModel  = Get().Recognizer.Model
)