package config

import (
	"encoding/hex"
	"errors"
	"github.com/google/uuid"
	"net/netip"
	"net/url"
	"os"
	"regexp"
	"strings"
)

var smsNumericID = regexp.MustCompile(`^[0-9]+$`)

type OnboardingConfig struct {
	SaaSCaptchaDisabled                                                      bool
	TencentCaptcha                                                           TencentCaptchaConfig
	TencentSMSTemplateParams                                                 map[string][]string
	Enabled, PauseClaims, ActivationEnabled, SMSLoginEnabled, AllowLocalHTTP bool
	MasterKey, EntryURL, SMSGatewayURL, SMSGatewayToken, SMSProvider         string
	TencentSMSSecretID, TencentSMSSecretKey, TencentSMSAppID                 string
	TencentSMSSignName, TencentSMSTemplateID                                 string
	TencentSMSTemplates                                                      map[string]string
	WeChatAppID, WeChatAppSecret                                             string
	TrustedProxyCIDRs, SelfSignupTenantIDs                                   []string
}

func loadOnboardingConfig(secrets map[string]string) (OnboardingConfig, error) {
	c := OnboardingConfig{MasterKey: secrets["ONBOARDING_MASTER_KEY"], SMSGatewayToken: secrets["ONBOARDING_SMS_GATEWAY_TOKEN"], EntryURL: strings.TrimSpace(os.Getenv("ONBOARDING_ENTRY_URL")), SMSGatewayURL: strings.TrimSpace(os.Getenv("ONBOARDING_SMS_GATEWAY_URL")), SMSProvider: strings.TrimSpace(os.Getenv("ONBOARDING_SMS_PROVIDER")), TencentSMSSecretID: secrets["TENCENT_SMS_SECRET_ID"], TencentSMSSecretKey: secrets["TENCENT_SMS_SECRET_KEY"], TencentSMSAppID: strings.TrimSpace(os.Getenv("TENCENT_SMS_SDK_APP_ID")), TencentSMSSignName: strings.TrimSpace(os.Getenv("TENCENT_SMS_SIGN_NAME")), TencentSMSTemplateID: strings.TrimSpace(os.Getenv("TENCENT_SMS_TEMPLATE_ID"))}
	c.WeChatAppID = strings.TrimSpace(os.Getenv("WECHAT_MINI_APP_ID"))
	c.WeChatAppSecret = secrets["WECHAT_MINI_APP_SECRET"]
	for name, target := range map[string]*bool{"ONBOARDING_SAAS_CAPTCHA_DISABLED": &c.SaaSCaptchaDisabled, "ONBOARDING_ENABLED": &c.Enabled, "ONBOARDING_PAUSE_CLAIMS": &c.PauseClaims, "ONBOARDING_ACTIVATION_ENABLED": &c.ActivationEnabled, "ONBOARDING_SMS_LOGIN_ENABLED": &c.SMSLoginEnabled, "ONBOARDING_ALLOW_LOCAL_HTTP": &c.AllowLocalHTTP} {
		v, err := boolEnv(name, false)
		if err != nil {
			return c, err
		}
		*target = v
	}
	split := func(name string) []string {
		items := []string{}
		for _, v := range strings.Split(os.Getenv(name), ",") {
			if strings.TrimSpace(v) != "" {
				items = append(items, strings.TrimSpace(v))
			}
		}
		return items
	}
	c.TrustedProxyCIDRs = split("ONBOARDING_TRUSTED_PROXY_CIDRS")
	c.SelfSignupTenantIDs = split("ONBOARDING_SELF_SIGNUP_TENANT_IDS")
	return c, nil
}
func (c OnboardingConfig) validate(environment string) error {
	if c.WeChatAppSecret != "" {
		if len(c.WeChatAppID) != 18 || !strings.HasPrefix(c.WeChatAppID, "wx") || len(c.WeChatAppSecret) < 16 {
			return errors.New("WeChat login requires WECHAT_MINI_APP_ID and WECHAT_MINI_APP_SECRET")
		}
		if _, err := hex.DecodeString(c.WeChatAppID[2:]); err != nil {
			return errors.New("invalid WECHAT_MINI_APP_ID")
		}
	}
	if c.AllowLocalHTTP && environment != EnvironmentLocal && environment != EnvironmentTest {
		return errors.New("ONBOARDING_ALLOW_LOCAL_HTTP is limited to local/test")
	}
	if c.MasterKey == "" {
		if c.Enabled || c.ActivationEnabled || c.SMSLoginEnabled {
			return errors.New("onboarding requires ONBOARDING_MASTER_KEY")
		}
		return nil
	}
	key, err := hex.DecodeString(c.MasterKey)
	if err != nil || len(key) != 32 {
		return errors.New("ONBOARDING_MASTER_KEY must encode 32 bytes as hex")
	}
	u, err := url.Parse(c.EntryURL)
	if err != nil || u.Host == "" || u.User != nil || u.RawQuery != "" || u.Fragment != "" || (u.Scheme != "https" && !(c.AllowLocalHTTP && u.Scheme == "http" && (u.Hostname() == "localhost" || u.Hostname() == "127.0.0.1"))) {
		return errors.New("ONBOARDING_ENTRY_URL must be a fixed HTTPS URL")
	}
	for _, cidr := range c.TrustedProxyCIDRs {
		p, err := netip.ParsePrefix(cidr)
		if err != nil || p.Bits() == 0 {
			return errors.New("onboarding trusted proxies must be explicit non-global CIDRs")
		}
	}
	for _, id := range c.SelfSignupTenantIDs {
		if _, err := uuid.Parse(id); err != nil {
			return errors.New("onboarding signup tenants must be UUIDs")
		}
	}
	if c.SMSLoginEnabled {
		switch c.SMSProvider {
		case "", "gateway":
			u, err := url.Parse(c.SMSGatewayURL)
			if err != nil || u.Scheme != "https" || u.Host == "" || u.User != nil || u.RawQuery != "" || u.Fragment != "" || c.SMSGatewayToken == "" {
				return errors.New("onboarding SMS requires HTTPS gateway and token")
			}
		case "tencent":
			if c.TencentSMSSecretID == "" || c.TencentSMSSecretKey == "" || !smsNumericID.MatchString(c.TencentSMSAppID) || c.TencentSMSSignName == "" {
				return errors.New("Tencent SMS requires SecretId, SecretKey, SDK AppID and sign name")
			}
			if c.TencentSMSTemplates != nil {
				for _, name := range []string{"login", "register", "change_password", "change_phone"} {
					if !smsNumericID.MatchString(c.TencentSMSTemplates[name]) {
						return errors.New("Tencent SMS requires numeric login, register, change_password and change_phone template IDs")
					}
				}
			} else if !smsNumericID.MatchString(c.TencentSMSTemplateID) {
				return errors.New("Tencent SMS requires a numeric template ID")
			}
			for name, params := range c.TencentSMSTemplateParams {
				if name != "login" && name != "register" && name != "change_password" && name != "change_phone" {
					return errors.New("Tencent SMS template_params contains an unknown purpose")
				}
				seen := map[string]bool{}
				for _, value := range params {
					if (value != "code" && value != "expires_minutes") || seen[value] {
						return errors.New("Tencent SMS template_params must contain code and optionally expires_minutes without duplicates")
					}
					seen[value] = true
				}
				if !seen["code"] {
					return errors.New("Tencent SMS template_params must include code")
				}
			}
		default:
			return errors.New("ONBOARDING_SMS_PROVIDER must be gateway or tencent")
		}
	}
	return nil
}