package config

import (
	"os"
	"path/filepath"
	"strings"
	"time"

	"git.misaka.ren/M1saka/zhanlu_proxy/internal/auth"
)

type Config struct {
	ListenAddr        string
	ServerBaseURL     string
	UpstreamPath      string
	CredentialsPath   string
	SSOExchangeURL    string
	SSOBaseURL        string
	TokenDecryptKey   string
	PublicKeyPEM      string
	PhonePublicKeyPEM string
	Models            []string
	DefaultModel      string
	OpenAIAPIKey      string
	LoginPassword     string
	UpstreamTimeout   time.Duration
	StreamIdleTimout  time.Duration
	Debug             bool
	Credentials       auth.Credentials
}

func Load() (Config, error) {
	cfg := Config{
		ListenAddr:        getenv("ZHANLU_LISTEN_ADDR", ":8080"),
		ServerBaseURL:     getenv("ZHANLU_SERVER_BASE_URL", "https://api-wuxi-1.cmecloud.cn:8443"),
		UpstreamPath:      getenv("ZHANLU_UPSTREAM_PATH", "/api/acepilot/zhanlu/aiDeveloper/chat"),
		CredentialsPath:   getenv("ZHANLU_CREDENTIALS_FILE", defaultCredentialsPath()),
		SSOBaseURL:        getenv("ZHANLU_SSO_BASE_URL", "http://rdcloud.4c.hq.cmcc"),
		SSOExchangeURL:    getenv("ZHANLU_SSO_EXCHANGE_URL", "https://api-wuxi-1.cmecloud.cn:8443/cmdevops-aiplus-agent-gateway/api/acepilot/zhanlu/checkoutCode"),
		TokenDecryptKey:   os.Getenv("ZHANLU_TOKEN_DECRYPT_KEY"),
		PublicKeyPEM:      getenv("ZHANLU_PUBLIC_KEY_PEM", defaultPublicKeyPEM),
		PhonePublicKeyPEM: getenv("ZHANLU_PHONE_PUBLIC_KEY_PEM", defaultPhonePublicKeyPEM),
		DefaultModel:      getenv("ZHANLU_DEFAULT_MODEL", "minimax-m25"),
		OpenAIAPIKey:      os.Getenv("OPENAI_COMPAT_API_KEY"),
		LoginPassword:     os.Getenv("ZHANLU_LOGIN_PASSWORD"),
		UpstreamTimeout:   durationEnv("ZHANLU_UPSTREAM_TIMEOUT", 300*time.Second),
		StreamIdleTimout:  durationEnv("ZHANLU_STREAM_IDLE_TIMEOUT", 300*time.Second),
		Debug:             strings.EqualFold(os.Getenv("ZHANLU_DEBUG"), "true"),
	}
	cfg.Models = splitCSV(getenv("ZHANLU_MODELS", "glm47,minimax-m25"))
	cfg.Credentials = auth.Credentials{
		AccessKey: os.Getenv("ZHANLU_ACCESS_KEY"),
		SecretKey: os.Getenv("ZHANLU_SECRET_KEY"),
		Token:     os.Getenv("ZHANLU_TOKEN"),
	}
	if cfg.Credentials.Validate() == nil {
		return cfg, nil
	}
	if creds, err := auth.LoadCredentials(cfg.CredentialsPath); err == nil {
		cfg.Credentials = creds
	}
	return cfg, nil
}

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

func splitCSV(s string) []string {
	parts := strings.Split(s, ",")
	out := make([]string, 0, len(parts))
	for _, p := range parts {
		p = strings.TrimSpace(p)
		if p != "" {
			out = append(out, p)
		}
	}
	return out
}

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

func defaultCredentialsPath() string {
	return filepath.Join(".", "credentials.json")
}

const defaultPublicKeyPEM = `-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAhxudxTewPgljUHEZHkusP7m3I+zA4/RGvuUMt6TtII/m4zwUOm/Y31zHBTmkCCt8k5vj9y+AmO0TsGmHooNQuMebakdmEWdcA5h7YAHHFbF2w5LcxIXjib08vgVpA+m3R5xPbLK+vfHe2aAX36b5nHReDNncY5vAl3U4CgIEBGPqyG67vJytRWqP+sfEdw5+m192Rf4SCGyiBzRmjiVlH3zeEBjdbOrkAnzKOVz6AHBl2q7LPLJKIzxjoAyhEp5qnDjHUFo5VZUgFwUOt83A/jbGMyzmjRoxBuvKcs9tBuorZyUwIsZN6E+rtQk2YqMPj4RkDsZ7LRmj6on8sN2rHQIDAQAB
-----END PUBLIC KEY-----`

const defaultPhonePublicKeyPEM = `-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnqiA2qP9BNvKw5DnVnrBVBhd+5gJDVn3mDemCfq/AN1cdaHV57hQo6R1ufp45mOkSwLaJcTE82zFKmgKoEAKwD1SR10rp0xJC7x3yvx2FbpEsiW9TeZlvJdri1BYKUMS8OP8ykjHSJoy0oMaV6e95R2rsu4DEH7JuA9+Bt0sOoLewvHx/fs1e28tH+928uUEKdLug+cv/XTKjLudpLjiSMPZU6EHFqrUhA9zmEasOMmg9Dj0j4sChBooCeCGnh/pYHJaosH5amhlSQ8FnEG0BQBrQbZ+qhRH4LYyqGYN8grDNeSnPj7vPDcwiEm++85i5AngZfEMnGWZg5jYDhO9+QIDAQAB
-----END PUBLIC KEY-----`