package service

import (
	"context"
	"encoding/json"
	"fmt"
	"log/slog"
	"strconv"
	"strings"
	"time"

	"github.com/Wei-Shaw/sub2api/internal/config"
	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
	"github.com/imroc/req/v3"
)

// CoerceDingTalkCorpPolicyForWrite 是 coerceDeprecatedDingTalkCorpPolicy 的导出版本，
// 用于 admin handler 在写入路径上对客户端直传的入参做防御性 coerce（前端 UI 虽已无 whitelist 选项，
// 但 API 可被直接调用）。
func CoerceDingTalkCorpPolicyForWrite(policy string) string {
	return coerceDeprecatedDingTalkCorpPolicy(policy)
}

// coerceDeprecatedDingTalkCorpPolicy 把已废弃的 corp_restriction_policy 值替换成安全的等价值。
// 升级前残留在 DB 中的 "whitelist" 会导致 callback 链路在 default case 静默 fail-closed
// （所有钉钉登录被拒）。这里统一退化为 "none" 让服务保持可用，并 warn 日志提醒 admin 重新保存设置。
func coerceDeprecatedDingTalkCorpPolicy(policy string) string {
	if policy == "whitelist" {
		slog.Warn("dingtalk: corp_restriction_policy=whitelist is deprecated and unsupported, coercing to none",
			"hint", "re-save DingTalk settings in admin UI to clear this warning")
		return "none"
	}
	return policy
}

func normalizeWeChatConnectModeSetting(raw string) string {
	switch strings.ToLower(strings.TrimSpace(raw)) {
	case "mp":
		return "mp"
	case "mobile":
		return "mobile"
	default:
		return "open"
	}
}

func defaultWeChatConnectScopeForMode(mode string) string {
	switch normalizeWeChatConnectModeSetting(mode) {
	case "mp":
		return "snsapi_userinfo"
	case "mobile":
		return ""
	}
	return defaultWeChatConnectScopes
}

func normalizeWeChatConnectScopeSetting(raw, mode string) string {
	switch normalizeWeChatConnectModeSetting(mode) {
	case "mp":
		switch strings.TrimSpace(raw) {
		case "snsapi_base":
			return "snsapi_base"
		case "snsapi_userinfo":
			return "snsapi_userinfo"
		default:
			return defaultWeChatConnectScopeForMode(mode)
		}
	case "mobile":
		return ""
	default:
		return defaultWeChatConnectScopes
	}
}

func parseWeChatConnectCapabilitySettings(settings map[string]string, enabled bool, mode string) (bool, bool, bool) {
	mode = normalizeWeChatConnectModeSetting(mode)
	rawOpen, hasOpen := settings[SettingKeyWeChatConnectOpenEnabled]
	rawMP, hasMP := settings[SettingKeyWeChatConnectMPEnabled]
	rawMobile, hasMobile := settings[SettingKeyWeChatConnectMobileEnabled]
	openConfigured := hasOpen && strings.TrimSpace(rawOpen) != ""
	mpConfigured := hasMP && strings.TrimSpace(rawMP) != ""
	mobileConfigured := hasMobile && strings.TrimSpace(rawMobile) != ""

	if openConfigured || mpConfigured || mobileConfigured {
		openEnabled := strings.TrimSpace(rawOpen) == "true"
		mpEnabled := strings.TrimSpace(rawMP) == "true"
		mobileEnabled := strings.TrimSpace(rawMobile) == "true"
		return openEnabled, mpEnabled, mobileEnabled
	}

	if !enabled {
		return false, false, false
	}
	if mode == "mp" {
		return false, true, false
	}
	if mode == "mobile" {
		return false, false, true
	}
	return true, false, false
}

func normalizeWeChatConnectStoredMode(openEnabled, mpEnabled, mobileEnabled bool, mode string) string {
	mode = normalizeWeChatConnectModeSetting(mode)
	switch mode {
	case "open":
		if openEnabled {
			return "open"
		}
	case "mp":
		if mpEnabled {
			return "mp"
		}
	case "mobile":
		if mobileEnabled {
			return "mobile"
		}
	}
	switch {
	case openEnabled:
		return "open"
	case mpEnabled:
		return "mp"
	case mobileEnabled:
		return "mobile"
	default:
		return mode
	}
}

func mergeWeChatConnectCapabilitySettings(settings map[string]string, base config.WeChatConnectConfig, enabled bool, mode string) (bool, bool, bool) {
	mode = normalizeWeChatConnectModeSetting(firstNonEmpty(mode, base.Mode))
	rawOpen, hasOpen := settings[SettingKeyWeChatConnectOpenEnabled]
	rawMP, hasMP := settings[SettingKeyWeChatConnectMPEnabled]
	rawMobile, hasMobile := settings[SettingKeyWeChatConnectMobileEnabled]
	openConfigured := hasOpen && strings.TrimSpace(rawOpen) != ""
	mpConfigured := hasMP && strings.TrimSpace(rawMP) != ""
	mobileConfigured := hasMobile && strings.TrimSpace(rawMobile) != ""

	if openConfigured || mpConfigured || mobileConfigured {
		openEnabled := strings.TrimSpace(rawOpen) == "true"
		mpEnabled := strings.TrimSpace(rawMP) == "true"
		mobileEnabled := strings.TrimSpace(rawMobile) == "true"
		_, enabledConfigured := settings[SettingKeyWeChatConnectEnabled]
		if !enabledConfigured &&
			enabled &&
			!openEnabled &&
			!mpEnabled &&
			!mobileEnabled &&
			(base.OpenEnabled || base.MPEnabled || base.MobileEnabled) {
			return base.OpenEnabled, base.MPEnabled, base.MobileEnabled
		}
		return openEnabled, mpEnabled, mobileEnabled
	}
	if !enabled {
		return false, false, false
	}
	if base.OpenEnabled || base.MPEnabled || base.MobileEnabled {
		return base.OpenEnabled, base.MPEnabled, base.MobileEnabled
	}
	return parseWeChatConnectCapabilitySettings(settings, enabled, mode)
}

func (s *SettingService) effectiveWeChatConnectOAuthConfig(settings map[string]string) WeChatConnectOAuthConfig {
	base := config.WeChatConnectConfig{}
	if s != nil && s.cfg != nil {
		base = s.cfg.WeChat
	}

	enabled := base.Enabled
	if raw, ok := settings[SettingKeyWeChatConnectEnabled]; ok {
		enabled = strings.TrimSpace(raw) == "true"
	}

	legacyAppID := strings.TrimSpace(firstNonEmpty(
		settings[SettingKeyWeChatConnectAppID],
		base.AppID,
		base.OpenAppID,
		base.MPAppID,
		base.MobileAppID,
	))
	legacyAppSecret := strings.TrimSpace(firstNonEmpty(
		settings[SettingKeyWeChatConnectAppSecret],
		base.AppSecret,
		base.OpenAppSecret,
		base.MPAppSecret,
		base.MobileAppSecret,
	))
	openAppID := strings.TrimSpace(firstNonEmpty(settings[SettingKeyWeChatConnectOpenAppID], base.OpenAppID, legacyAppID))
	openAppSecret := strings.TrimSpace(firstNonEmpty(settings[SettingKeyWeChatConnectOpenAppSecret], base.OpenAppSecret, legacyAppSecret))
	mpAppID := strings.TrimSpace(firstNonEmpty(settings[SettingKeyWeChatConnectMPAppID], base.MPAppID, legacyAppID))
	mpAppSecret := strings.TrimSpace(firstNonEmpty(settings[SettingKeyWeChatConnectMPAppSecret], base.MPAppSecret, legacyAppSecret))
	mobileAppID := strings.TrimSpace(firstNonEmpty(settings[SettingKeyWeChatConnectMobileAppID], base.MobileAppID, legacyAppID))
	mobileAppSecret := strings.TrimSpace(firstNonEmpty(settings[SettingKeyWeChatConnectMobileAppSecret], base.MobileAppSecret, legacyAppSecret))

	modeRaw := firstNonEmpty(settings[SettingKeyWeChatConnectMode], base.Mode)
	openEnabled, mpEnabled, mobileEnabled := mergeWeChatConnectCapabilitySettings(settings, base, enabled, modeRaw)
	mode := normalizeWeChatConnectStoredMode(openEnabled, mpEnabled, mobileEnabled, modeRaw)

	return WeChatConnectOAuthConfig{
		Enabled:             enabled,
		LegacyAppID:         legacyAppID,
		LegacyAppSecret:     legacyAppSecret,
		OpenAppID:           openAppID,
		OpenAppSecret:       openAppSecret,
		MPAppID:             mpAppID,
		MPAppSecret:         mpAppSecret,
		MobileAppID:         mobileAppID,
		MobileAppSecret:     mobileAppSecret,
		OpenEnabled:         openEnabled,
		MPEnabled:           mpEnabled,
		MobileEnabled:       mobileEnabled,
		Mode:                mode,
		Scopes:              normalizeWeChatConnectScopeSetting(firstNonEmpty(settings[SettingKeyWeChatConnectScopes], base.Scopes), mode),
		RedirectURL:         strings.TrimSpace(firstNonEmpty(settings[SettingKeyWeChatConnectRedirectURL], base.RedirectURL)),
		FrontendRedirectURL: strings.TrimSpace(firstNonEmpty(settings[SettingKeyWeChatConnectFrontendRedirectURL], base.FrontendRedirectURL, defaultWeChatConnectFrontend)),
	}
}

func DefaultWeChatConnectScopesForMode(mode string) string {
	return defaultWeChatConnectScopeForMode(mode)
}

func (s *SettingService) parseWeChatConnectOAuthConfig(settings map[string]string) (WeChatConnectOAuthConfig, error) {
	cfg := s.effectiveWeChatConnectOAuthConfig(settings)

	if !cfg.Enabled || (!cfg.OpenEnabled && !cfg.MPEnabled) {
		return WeChatConnectOAuthConfig{}, infraerrors.NotFound("OAUTH_DISABLED", "wechat oauth is disabled")
	}
	if cfg.OpenEnabled {
		if cfg.AppIDForMode("open") == "" {
			return WeChatConnectOAuthConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "wechat oauth pc app id not configured")
		}
		if cfg.AppSecretForMode("open") == "" {
			return WeChatConnectOAuthConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "wechat oauth pc app secret not configured")
		}
	}
	if cfg.MPEnabled {
		if cfg.AppIDForMode("mp") == "" {
			return WeChatConnectOAuthConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "wechat oauth official account app id not configured")
		}
		if cfg.AppSecretForMode("mp") == "" {
			return WeChatConnectOAuthConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "wechat oauth official account app secret not configured")
		}
	}
	if cfg.MobileEnabled {
		if cfg.AppIDForMode("mobile") == "" {
			return WeChatConnectOAuthConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "wechat oauth mobile app id not configured")
		}
		if cfg.AppSecretForMode("mobile") == "" {
			return WeChatConnectOAuthConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "wechat oauth mobile app secret not configured")
		}
	}
	if v := strings.TrimSpace(cfg.RedirectURL); v != "" {
		if err := config.ValidateAbsoluteHTTPURL(v); err != nil {
			return WeChatConnectOAuthConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "wechat oauth redirect url invalid")
		}
	}
	if err := config.ValidateFrontendRedirectURL(cfg.FrontendRedirectURL); err != nil {
		return WeChatConnectOAuthConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "wechat oauth frontend redirect url invalid")
	}
	return cfg, nil
}

func (s *SettingService) weChatOAuthCapabilitiesFromSettings(settings map[string]string) (bool, bool, bool, bool) {
	cfg := s.effectiveWeChatConnectOAuthConfig(settings)
	if !cfg.Enabled {
		return false, false, false, false
	}

	openReady := cfg.OpenEnabled && cfg.AppIDForMode("open") != "" && cfg.AppSecretForMode("open") != ""
	mpReady := cfg.MPEnabled && cfg.AppIDForMode("mp") != "" && cfg.AppSecretForMode("mp") != ""
	mobileReady := cfg.MobileEnabled && cfg.AppIDForMode("mobile") != "" && cfg.AppSecretForMode("mobile") != ""

	return openReady || mpReady, openReady, mpReady, mobileReady
}

func (s *SettingService) emailOAuthBaseConfig(provider string) config.EmailOAuthProviderConfig {
	switch strings.ToLower(strings.TrimSpace(provider)) {
	case "github":
		cfg := config.EmailOAuthProviderConfig{
			AuthorizeURL:        defaultGitHubOAuthAuthorize,
			TokenURL:            defaultGitHubOAuthToken,
			UserInfoURL:         defaultGitHubOAuthUserInfo,
			EmailsURL:           defaultGitHubOAuthEmails,
			Scopes:              defaultGitHubOAuthScopes,
			FrontendRedirectURL: defaultGitHubOAuthFrontend,
		}
		if s != nil && s.cfg != nil {
			cfg = mergeEmailOAuthBaseConfig(cfg, s.cfg.GitHubOAuth)
		}
		return cfg
	case "google":
		cfg := config.EmailOAuthProviderConfig{
			AuthorizeURL:        defaultGoogleOAuthAuthorize,
			TokenURL:            defaultGoogleOAuthToken,
			UserInfoURL:         defaultGoogleOAuthUserInfo,
			Scopes:              defaultGoogleOAuthScopes,
			FrontendRedirectURL: defaultGoogleOAuthFrontend,
		}
		if s != nil && s.cfg != nil {
			cfg = mergeEmailOAuthBaseConfig(cfg, s.cfg.GoogleOAuth)
		}
		return cfg
	default:
		return config.EmailOAuthProviderConfig{}
	}
}

func mergeEmailOAuthBaseConfig(base, override config.EmailOAuthProviderConfig) config.EmailOAuthProviderConfig {
	base.Enabled = override.Enabled
	if strings.TrimSpace(override.ClientID) != "" {
		base.ClientID = strings.TrimSpace(override.ClientID)
	}
	if strings.TrimSpace(override.ClientSecret) != "" {
		base.ClientSecret = strings.TrimSpace(override.ClientSecret)
	}
	if strings.TrimSpace(override.AuthorizeURL) != "" {
		base.AuthorizeURL = strings.TrimSpace(override.AuthorizeURL)
	}
	if strings.TrimSpace(override.TokenURL) != "" {
		base.TokenURL = strings.TrimSpace(override.TokenURL)
	}
	if strings.TrimSpace(override.UserInfoURL) != "" {
		base.UserInfoURL = strings.TrimSpace(override.UserInfoURL)
	}
	if strings.TrimSpace(override.EmailsURL) != "" {
		base.EmailsURL = strings.TrimSpace(override.EmailsURL)
	}
	if strings.TrimSpace(override.Scopes) != "" {
		base.Scopes = strings.TrimSpace(override.Scopes)
	}
	if strings.TrimSpace(override.RedirectURL) != "" {
		base.RedirectURL = strings.TrimSpace(override.RedirectURL)
	}
	if strings.TrimSpace(override.FrontendRedirectURL) != "" {
		base.FrontendRedirectURL = strings.TrimSpace(override.FrontendRedirectURL)
	}
	return base
}

func (s *SettingService) emailOAuthPublicEnabled(settings map[string]string, provider string) bool {
	cfg := s.effectiveEmailOAuthConfig(settings, provider)
	return cfg.Enabled && strings.TrimSpace(cfg.ClientID) != "" && strings.TrimSpace(cfg.ClientSecret) != ""
}

func (s *SettingService) effectiveEmailOAuthConfig(settings map[string]string, provider string) config.EmailOAuthProviderConfig {
	cfg := s.emailOAuthBaseConfig(provider)
	switch strings.ToLower(strings.TrimSpace(provider)) {
	case "github":
		if raw, ok := settings[SettingKeyGitHubOAuthEnabled]; ok {
			cfg.Enabled = raw == "true"
		}
		cfg.ClientID = firstNonEmpty(settings[SettingKeyGitHubOAuthClientID], cfg.ClientID)
		cfg.ClientSecret = firstNonEmpty(settings[SettingKeyGitHubOAuthClientSecret], cfg.ClientSecret)
		cfg.RedirectURL = firstNonEmpty(settings[SettingKeyGitHubOAuthRedirectURL], cfg.RedirectURL)
		cfg.FrontendRedirectURL = firstNonEmpty(settings[SettingKeyGitHubOAuthFrontendRedirectURL], cfg.FrontendRedirectURL, defaultGitHubOAuthFrontend)
	case "google":
		if raw, ok := settings[SettingKeyGoogleOAuthEnabled]; ok {
			cfg.Enabled = raw == "true"
		}
		cfg.ClientID = firstNonEmpty(settings[SettingKeyGoogleOAuthClientID], cfg.ClientID)
		cfg.ClientSecret = firstNonEmpty(settings[SettingKeyGoogleOAuthClientSecret], cfg.ClientSecret)
		cfg.RedirectURL = firstNonEmpty(settings[SettingKeyGoogleOAuthRedirectURL], cfg.RedirectURL)
		cfg.FrontendRedirectURL = firstNonEmpty(settings[SettingKeyGoogleOAuthFrontendRedirectURL], cfg.FrontendRedirectURL, defaultGoogleOAuthFrontend)
	}
	return cfg
}

func oidcUsePKCECompatibilityDefault(base config.OIDCConnectConfig) bool {
	if base.UsePKCEExplicit {
		return base.UsePKCE
	}
	return true
}

func oidcValidateIDTokenCompatibilityDefault(base config.OIDCConnectConfig) bool {
	if base.ValidateIDTokenExplicit {
		return base.ValidateIDToken
	}
	return true
}

func oidcCompatibilityWriteDefault(base config.OIDCConnectConfig, configured bool, raw string, explicit bool, explicitValue bool) bool {
	if configured {
		return strings.TrimSpace(raw) == "true"
	}
	if explicit {
		return explicitValue
	}
	return false
}

func (s *SettingService) OIDCSecurityWriteDefaults(ctx context.Context) (bool, bool, error) {
	rawSettings, err := s.settingRepo.GetMultiple(ctx, []string{
		SettingKeyOIDCConnectUsePKCE,
		SettingKeyOIDCConnectValidateIDToken,
	})
	if err != nil {
		return false, false, fmt.Errorf("get oidc security write defaults: %w", err)
	}

	base := config.OIDCConnectConfig{}
	if s != nil && s.cfg != nil {
		base = s.cfg.OIDC
	}

	rawUsePKCE, hasUsePKCE := rawSettings[SettingKeyOIDCConnectUsePKCE]
	rawValidateIDToken, hasValidateIDToken := rawSettings[SettingKeyOIDCConnectValidateIDToken]

	return oidcCompatibilityWriteDefault(base, hasUsePKCE, rawUsePKCE, base.UsePKCEExplicit, base.UsePKCE),
		oidcCompatibilityWriteDefault(base, hasValidateIDToken, rawValidateIDToken, base.ValidateIDTokenExplicit, base.ValidateIDToken),
		nil
}

func (s *SettingService) GetEmailOAuthProviderConfig(ctx context.Context, provider string) (config.EmailOAuthProviderConfig, error) {
	provider = strings.ToLower(strings.TrimSpace(provider))
	if provider != "github" && provider != "google" {
		return config.EmailOAuthProviderConfig{}, infraerrors.NotFound("OAUTH_PROVIDER_NOT_FOUND", "oauth provider not found")
	}
	keys := []string{
		SettingKeyGitHubOAuthEnabled,
		SettingKeyGitHubOAuthClientID,
		SettingKeyGitHubOAuthClientSecret,
		SettingKeyGitHubOAuthRedirectURL,
		SettingKeyGitHubOAuthFrontendRedirectURL,
		SettingKeyGoogleOAuthEnabled,
		SettingKeyGoogleOAuthClientID,
		SettingKeyGoogleOAuthClientSecret,
		SettingKeyGoogleOAuthRedirectURL,
		SettingKeyGoogleOAuthFrontendRedirectURL,
	}
	settings, err := s.settingRepo.GetMultiple(ctx, keys)
	if err != nil {
		return config.EmailOAuthProviderConfig{}, fmt.Errorf("get email oauth settings: %w", err)
	}
	cfg := s.effectiveEmailOAuthConfig(settings, provider)
	if !cfg.Enabled {
		return config.EmailOAuthProviderConfig{}, infraerrors.NotFound("OAUTH_DISABLED", "oauth login is disabled")
	}
	if strings.TrimSpace(cfg.ClientID) == "" {
		return config.EmailOAuthProviderConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth client id not configured")
	}
	if strings.TrimSpace(cfg.ClientSecret) == "" {
		return config.EmailOAuthProviderConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth client secret not configured")
	}
	for label, rawURL := range map[string]string{
		"authorize": cfg.AuthorizeURL,
		"token":     cfg.TokenURL,
		"userinfo":  cfg.UserInfoURL,
		"redirect":  cfg.RedirectURL,
	} {
		if strings.TrimSpace(rawURL) == "" {
			return config.EmailOAuthProviderConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth "+label+" url not configured")
		}
		if err := config.ValidateAbsoluteHTTPURL(rawURL); err != nil {
			return config.EmailOAuthProviderConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth "+label+" url invalid")
		}
	}
	if strings.TrimSpace(cfg.EmailsURL) != "" {
		if err := config.ValidateAbsoluteHTTPURL(cfg.EmailsURL); err != nil {
			return config.EmailOAuthProviderConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth emails url invalid")
		}
	}
	if err := config.ValidateFrontendRedirectURL(cfg.FrontendRedirectURL); err != nil {
		return config.EmailOAuthProviderConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth frontend redirect url invalid")
	}
	return cfg, nil
}

// GetLinuxDoConnectOAuthConfig 返回用于登录的"最终生效" LinuxDo Connect 配置。
//
// 优先级：
// - 若对应系统设置键存在，则覆盖 config.yaml/env 的值
// - 否则回退到 config.yaml/env 的值
func (s *SettingService) GetLinuxDoConnectOAuthConfig(ctx context.Context) (config.LinuxDoConnectConfig, error) {
	if s == nil || s.cfg == nil {
		return config.LinuxDoConnectConfig{}, infraerrors.ServiceUnavailable("CONFIG_NOT_READY", "config not loaded")
	}

	effective := s.cfg.LinuxDo

	keys := []string{
		SettingKeyLinuxDoConnectEnabled,
		SettingKeyLinuxDoConnectClientID,
		SettingKeyLinuxDoConnectClientSecret,
		SettingKeyLinuxDoConnectRedirectURL,
	}
	settings, err := s.settingRepo.GetMultiple(ctx, keys)
	if err != nil {
		return config.LinuxDoConnectConfig{}, fmt.Errorf("get linuxdo connect settings: %w", err)
	}

	if raw, ok := settings[SettingKeyLinuxDoConnectEnabled]; ok {
		effective.Enabled = raw == "true"
	}
	if v, ok := settings[SettingKeyLinuxDoConnectClientID]; ok && strings.TrimSpace(v) != "" {
		effective.ClientID = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyLinuxDoConnectClientSecret]; ok && strings.TrimSpace(v) != "" {
		effective.ClientSecret = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyLinuxDoConnectRedirectURL]; ok && strings.TrimSpace(v) != "" {
		effective.RedirectURL = strings.TrimSpace(v)
	}
	if !effective.Enabled {
		return config.LinuxDoConnectConfig{}, infraerrors.NotFound("OAUTH_DISABLED", "oauth login is disabled")
	}

	// 基础健壮性校验（避免把用户重定向到一个必然失败或不安全的 OAuth 流程里）。
	if strings.TrimSpace(effective.ClientID) == "" {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth client id not configured")
	}
	if strings.TrimSpace(effective.AuthorizeURL) == "" {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth authorize url not configured")
	}
	if strings.TrimSpace(effective.TokenURL) == "" {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth token url not configured")
	}
	if strings.TrimSpace(effective.UserInfoURL) == "" {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth userinfo url not configured")
	}
	if strings.TrimSpace(effective.RedirectURL) == "" {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth redirect url not configured")
	}
	if strings.TrimSpace(effective.FrontendRedirectURL) == "" {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth frontend redirect url not configured")
	}

	if err := config.ValidateAbsoluteHTTPURL(effective.AuthorizeURL); err != nil {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth authorize url invalid")
	}
	if err := config.ValidateAbsoluteHTTPURL(effective.TokenURL); err != nil {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth token url invalid")
	}
	if err := config.ValidateAbsoluteHTTPURL(effective.UserInfoURL); err != nil {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth userinfo url invalid")
	}
	if err := config.ValidateAbsoluteHTTPURL(effective.RedirectURL); err != nil {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth redirect url invalid")
	}
	if err := config.ValidateFrontendRedirectURL(effective.FrontendRedirectURL); err != nil {
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth frontend redirect url invalid")
	}

	method := strings.ToLower(strings.TrimSpace(effective.TokenAuthMethod))
	switch method {
	case "", "client_secret_post", "client_secret_basic":
		if strings.TrimSpace(effective.ClientSecret) == "" {
			return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth client secret not configured")
		}
	case "none":
	default:
		return config.LinuxDoConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth token_auth_method invalid")
	}

	return effective, nil
}

// GetDingTalkConnectOAuthConfig 返回用于登录的"最终生效" DingTalk Connect 配置。
//
// 优先级：
// - 若对应系统设置键存在，则覆盖 config.yaml/env 的值
// - 否则回退到 config.yaml/env 的值
func (s *SettingService) GetDingTalkConnectOAuthConfig(ctx context.Context) (config.DingTalkConnectConfig, error) {
	if s == nil || s.cfg == nil {
		return config.DingTalkConnectConfig{}, infraerrors.ServiceUnavailable("CONFIG_NOT_READY", "config not loaded")
	}

	effective := s.cfg.DingTalk

	keys := []string{
		SettingKeyDingTalkConnectEnabled,
		SettingKeyDingTalkConnectClientID,
		SettingKeyDingTalkConnectClientSecret,
		SettingKeyDingTalkConnectRedirectURL,
		SettingKeyDingTalkConnectCorpRestrictionPolicy,
		SettingKeyDingTalkConnectInternalCorpID,
		SettingKeyDingTalkConnectBypassRegistration,
		SettingKeyDingTalkConnectSyncCorpEmail,
		SettingKeyDingTalkConnectSyncDisplayName,
		SettingKeyDingTalkConnectSyncDept,
		SettingKeyDingTalkConnectSyncCorpEmailAttrKey,
		SettingKeyDingTalkConnectSyncDisplayNameAttrKey,
		SettingKeyDingTalkConnectSyncDeptAttrKey,
	}
	settings, err := s.settingRepo.GetMultiple(ctx, keys)
	if err != nil {
		return config.DingTalkConnectConfig{}, fmt.Errorf("get dingtalk connect settings: %w", err)
	}

	if raw, ok := settings[SettingKeyDingTalkConnectEnabled]; ok {
		effective.Enabled = raw == "true"
	}
	if v, ok := settings[SettingKeyDingTalkConnectClientID]; ok && strings.TrimSpace(v) != "" {
		effective.ClientID = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyDingTalkConnectClientSecret]; ok && strings.TrimSpace(v) != "" {
		effective.ClientSecret = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyDingTalkConnectRedirectURL]; ok && strings.TrimSpace(v) != "" {
		effective.RedirectURL = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyDingTalkConnectCorpRestrictionPolicy]; ok && strings.TrimSpace(v) != "" {
		effective.CorpRestrictionPolicy = strings.TrimSpace(v)
	}
	effective.CorpRestrictionPolicy = coerceDeprecatedDingTalkCorpPolicy(effective.CorpRestrictionPolicy)
	if v, ok := settings[SettingKeyDingTalkConnectInternalCorpID]; ok && strings.TrimSpace(v) != "" {
		effective.InternalCorpID = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyDingTalkConnectBypassRegistration]; ok && strings.TrimSpace(v) != "" {
		effective.BypassRegistration = strings.EqualFold(strings.TrimSpace(v), "true")
	}
	// bypass_registration 仅在 internal_only 模式下有意义；其它策略下强制 false，
	// 以保证 OAuth callback 看到的 effective config 永远是一致状态。
	if effective.CorpRestrictionPolicy != "internal_only" {
		effective.BypassRegistration = false
	}

	if v, ok := settings[SettingKeyDingTalkConnectSyncCorpEmail]; ok && strings.TrimSpace(v) != "" {
		effective.SyncCorpEmail = strings.EqualFold(strings.TrimSpace(v), "true")
	}
	if v, ok := settings[SettingKeyDingTalkConnectSyncDisplayName]; ok && strings.TrimSpace(v) != "" {
		effective.SyncDisplayName = strings.EqualFold(strings.TrimSpace(v), "true")
	}
	if v, ok := settings[SettingKeyDingTalkConnectSyncDept]; ok && strings.TrimSpace(v) != "" {
		effective.SyncDept = strings.EqualFold(strings.TrimSpace(v), "true")
	}
	// 身份同步三开关仅在 internal_only 模式下有意义；其它策略强制 false。
	if effective.CorpRestrictionPolicy != "internal_only" {
		effective.SyncCorpEmail = false
		effective.SyncDisplayName = false
		effective.SyncDept = false
	}

	// 身份同步目标 attr key（DB 空 → fallback 默认值）
	if v := strings.TrimSpace(settings[SettingKeyDingTalkConnectSyncCorpEmailAttrKey]); v != "" {
		effective.SyncCorpEmailAttrKey = v
	}
	if effective.SyncCorpEmailAttrKey == "" {
		effective.SyncCorpEmailAttrKey = "dingtalk_email"
	}
	if v := strings.TrimSpace(settings[SettingKeyDingTalkConnectSyncDisplayNameAttrKey]); v != "" {
		effective.SyncDisplayNameAttrKey = v
	}
	if effective.SyncDisplayNameAttrKey == "" {
		effective.SyncDisplayNameAttrKey = "dingtalk_name"
	}
	if v := strings.TrimSpace(settings[SettingKeyDingTalkConnectSyncDeptAttrKey]); v != "" {
		effective.SyncDeptAttrKey = v
	}
	if effective.SyncDeptAttrKey == "" {
		effective.SyncDeptAttrKey = "dingtalk_department"
	}

	if !effective.Enabled {
		return config.DingTalkConnectConfig{}, infraerrors.NotFound("OAUTH_DISABLED", "dingtalk oauth login is disabled")
	}

	// 基础健壮性校验（避免把用户重定向到一个必然失败或不安全的 OAuth 流程里）。
	if strings.TrimSpace(effective.ClientID) == "" {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth client id not configured")
	}
	if strings.TrimSpace(effective.AuthorizeURL) == "" {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth authorize url not configured")
	}
	if strings.TrimSpace(effective.TokenURL) == "" {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth token url not configured")
	}
	if strings.TrimSpace(effective.UserInfoURL) == "" {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth userinfo url not configured")
	}
	if strings.TrimSpace(effective.RedirectURL) == "" {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth redirect url not configured")
	}
	if strings.TrimSpace(effective.FrontendRedirectURL) == "" {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth frontend redirect url not configured")
	}

	if err := config.ValidateAbsoluteHTTPURL(effective.AuthorizeURL); err != nil {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth authorize url invalid")
	}
	if err := config.ValidateAbsoluteHTTPURL(effective.TokenURL); err != nil {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth token url invalid")
	}
	if err := config.ValidateAbsoluteHTTPURL(effective.UserInfoURL); err != nil {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth userinfo url invalid")
	}
	if err := config.ValidateAbsoluteHTTPURL(effective.RedirectURL); err != nil {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth redirect url invalid")
	}
	if err := config.ValidateFrontendRedirectURL(effective.FrontendRedirectURL); err != nil {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth frontend redirect url invalid")
	}
	if strings.TrimSpace(effective.ClientSecret) == "" {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "dingtalk oauth client secret not configured")
	}

	// 镜像 admin handler 行为：internal_only policy 隐式要求 AppType=internal
	if effective.CorpRestrictionPolicy == "internal_only" {
		effective.AppType = "internal"
	}

	if err := config.ValidateDingTalkConfig(effective); err != nil {
		return config.DingTalkConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", err.Error())
	}

	return effective, nil
}

// GetWeChatConnectOAuthConfig 返回用于登录的最终生效 WeChat Connect 配置。
//
// WeChat Connect 已回归 DB 系统设置模型，不再回退到 config/env。
func (s *SettingService) GetWeChatConnectOAuthConfig(ctx context.Context) (WeChatConnectOAuthConfig, error) {
	keys := []string{
		SettingKeyWeChatConnectEnabled,
		SettingKeyWeChatConnectAppID,
		SettingKeyWeChatConnectAppSecret,
		SettingKeyWeChatConnectOpenAppID,
		SettingKeyWeChatConnectOpenAppSecret,
		SettingKeyWeChatConnectMPAppID,
		SettingKeyWeChatConnectMPAppSecret,
		SettingKeyWeChatConnectMobileAppID,
		SettingKeyWeChatConnectMobileAppSecret,
		SettingKeyWeChatConnectOpenEnabled,
		SettingKeyWeChatConnectMPEnabled,
		SettingKeyWeChatConnectMobileEnabled,
		SettingKeyWeChatConnectMode,
		SettingKeyWeChatConnectScopes,
		SettingKeyWeChatConnectRedirectURL,
		SettingKeyWeChatConnectFrontendRedirectURL,
	}
	settings, err := s.settingRepo.GetMultiple(ctx, keys)
	if err != nil {
		return WeChatConnectOAuthConfig{}, fmt.Errorf("get wechat connect settings: %w", err)
	}
	return s.parseWeChatConnectOAuthConfig(settings)
}

// GetOIDCConnectOAuthConfig 返回用于登录的“最终生效” OIDC 配置。
//
// 优先级：
// - 若对应系统设置键存在，则覆盖 config.yaml/env 的值
// - 否则回退到 config.yaml/env 的值
func (s *SettingService) GetOIDCConnectOAuthConfig(ctx context.Context) (config.OIDCConnectConfig, error) {
	if s == nil || s.cfg == nil {
		return config.OIDCConnectConfig{}, infraerrors.ServiceUnavailable("CONFIG_NOT_READY", "config not loaded")
	}

	effective := s.cfg.OIDC

	keys := []string{
		SettingKeyOIDCConnectEnabled,
		SettingKeyOIDCConnectProviderName,
		SettingKeyOIDCConnectClientID,
		SettingKeyOIDCConnectClientSecret,
		SettingKeyOIDCConnectIssuerURL,
		SettingKeyOIDCConnectDiscoveryURL,
		SettingKeyOIDCConnectAuthorizeURL,
		SettingKeyOIDCConnectTokenURL,
		SettingKeyOIDCConnectUserInfoURL,
		SettingKeyOIDCConnectJWKSURL,
		SettingKeyOIDCConnectScopes,
		SettingKeyOIDCConnectRedirectURL,
		SettingKeyOIDCConnectFrontendRedirectURL,
		SettingKeyOIDCConnectTokenAuthMethod,
		SettingKeyOIDCConnectUsePKCE,
		SettingKeyOIDCConnectValidateIDToken,
		SettingKeyOIDCConnectAllowedSigningAlgs,
		SettingKeyOIDCConnectClockSkewSeconds,
		SettingKeyOIDCConnectRequireEmailVerified,
		SettingKeyOIDCConnectUserInfoEmailPath,
		SettingKeyOIDCConnectUserInfoIDPath,
		SettingKeyOIDCConnectUserInfoUsernamePath,
	}
	settings, err := s.settingRepo.GetMultiple(ctx, keys)
	if err != nil {
		return config.OIDCConnectConfig{}, fmt.Errorf("get oidc connect settings: %w", err)
	}

	if raw, ok := settings[SettingKeyOIDCConnectEnabled]; ok {
		effective.Enabled = raw == "true"
	}
	if v, ok := settings[SettingKeyOIDCConnectProviderName]; ok && strings.TrimSpace(v) != "" {
		effective.ProviderName = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectClientID]; ok && strings.TrimSpace(v) != "" {
		effective.ClientID = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectClientSecret]; ok && strings.TrimSpace(v) != "" {
		effective.ClientSecret = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectIssuerURL]; ok && strings.TrimSpace(v) != "" {
		effective.IssuerURL = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectDiscoveryURL]; ok && strings.TrimSpace(v) != "" {
		effective.DiscoveryURL = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectAuthorizeURL]; ok && strings.TrimSpace(v) != "" {
		effective.AuthorizeURL = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectTokenURL]; ok && strings.TrimSpace(v) != "" {
		effective.TokenURL = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectUserInfoURL]; ok && strings.TrimSpace(v) != "" {
		effective.UserInfoURL = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectJWKSURL]; ok && strings.TrimSpace(v) != "" {
		effective.JWKSURL = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectScopes]; ok && strings.TrimSpace(v) != "" {
		effective.Scopes = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectRedirectURL]; ok && strings.TrimSpace(v) != "" {
		effective.RedirectURL = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectFrontendRedirectURL]; ok && strings.TrimSpace(v) != "" {
		effective.FrontendRedirectURL = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectTokenAuthMethod]; ok && strings.TrimSpace(v) != "" {
		effective.TokenAuthMethod = strings.ToLower(strings.TrimSpace(v))
	}
	if raw, ok := settings[SettingKeyOIDCConnectUsePKCE]; ok {
		effective.UsePKCE = raw == "true"
	} else {
		effective.UsePKCE = oidcUsePKCECompatibilityDefault(effective)
	}
	if raw, ok := settings[SettingKeyOIDCConnectValidateIDToken]; ok {
		effective.ValidateIDToken = raw == "true"
	} else {
		effective.ValidateIDToken = oidcValidateIDTokenCompatibilityDefault(effective)
	}
	if v, ok := settings[SettingKeyOIDCConnectAllowedSigningAlgs]; ok && strings.TrimSpace(v) != "" {
		effective.AllowedSigningAlgs = strings.TrimSpace(v)
	}
	if raw, ok := settings[SettingKeyOIDCConnectClockSkewSeconds]; ok && strings.TrimSpace(raw) != "" {
		if parsed, parseErr := strconv.Atoi(strings.TrimSpace(raw)); parseErr == nil {
			effective.ClockSkewSeconds = parsed
		}
	}
	if raw, ok := settings[SettingKeyOIDCConnectRequireEmailVerified]; ok {
		effective.RequireEmailVerified = raw == "true"
	}
	if v, ok := settings[SettingKeyOIDCConnectUserInfoEmailPath]; ok {
		effective.UserInfoEmailPath = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectUserInfoIDPath]; ok {
		effective.UserInfoIDPath = strings.TrimSpace(v)
	}
	if v, ok := settings[SettingKeyOIDCConnectUserInfoUsernamePath]; ok {
		effective.UserInfoUsernamePath = strings.TrimSpace(v)
	}

	if !effective.Enabled {
		return config.OIDCConnectConfig{}, infraerrors.NotFound("OAUTH_DISABLED", "oauth login is disabled")
	}
	if strings.TrimSpace(effective.ProviderName) == "" {
		effective.ProviderName = "OIDC"
	}
	if strings.TrimSpace(effective.ClientID) == "" {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth client id not configured")
	}
	if strings.TrimSpace(effective.IssuerURL) == "" {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth issuer url not configured")
	}
	if strings.TrimSpace(effective.RedirectURL) == "" {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth redirect url not configured")
	}
	if strings.TrimSpace(effective.FrontendRedirectURL) == "" {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth frontend redirect url not configured")
	}
	if !scopesContainOpenID(effective.Scopes) {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth scopes must contain openid")
	}
	if effective.ClockSkewSeconds < 0 || effective.ClockSkewSeconds > 600 {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth clock skew must be between 0 and 600")
	}

	if err := config.ValidateAbsoluteHTTPURL(effective.IssuerURL); err != nil {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth issuer url invalid")
	}

	discoveryURL := strings.TrimSpace(effective.DiscoveryURL)
	if discoveryURL == "" {
		discoveryURL = oidcDefaultDiscoveryURL(effective.IssuerURL)
		effective.DiscoveryURL = discoveryURL
	}
	if discoveryURL != "" {
		if err := config.ValidateAbsoluteHTTPURL(discoveryURL); err != nil {
			return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth discovery url invalid")
		}
	}

	needsDiscovery := strings.TrimSpace(effective.AuthorizeURL) == "" ||
		strings.TrimSpace(effective.TokenURL) == "" ||
		(effective.ValidateIDToken && strings.TrimSpace(effective.JWKSURL) == "")
	if needsDiscovery && discoveryURL != "" {
		metadata, resolveErr := oidcResolveProviderMetadata(ctx, discoveryURL)
		if resolveErr != nil {
			return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth discovery resolve failed").WithCause(resolveErr)
		}
		if strings.TrimSpace(effective.AuthorizeURL) == "" {
			effective.AuthorizeURL = strings.TrimSpace(metadata.AuthorizationEndpoint)
		}
		if strings.TrimSpace(effective.TokenURL) == "" {
			effective.TokenURL = strings.TrimSpace(metadata.TokenEndpoint)
		}
		if strings.TrimSpace(effective.UserInfoURL) == "" {
			effective.UserInfoURL = strings.TrimSpace(metadata.UserInfoEndpoint)
		}
		if strings.TrimSpace(effective.JWKSURL) == "" {
			effective.JWKSURL = strings.TrimSpace(metadata.JWKSURI)
		}
	}

	if strings.TrimSpace(effective.AuthorizeURL) == "" {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth authorize url not configured")
	}
	if strings.TrimSpace(effective.TokenURL) == "" {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth token url not configured")
	}
	if err := config.ValidateAbsoluteHTTPURL(effective.AuthorizeURL); err != nil {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth authorize url invalid")
	}
	if err := config.ValidateAbsoluteHTTPURL(effective.TokenURL); err != nil {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth token url invalid")
	}
	if v := strings.TrimSpace(effective.UserInfoURL); v != "" {
		if err := config.ValidateAbsoluteHTTPURL(v); err != nil {
			return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth userinfo url invalid")
		}
	}
	if effective.ValidateIDToken {
		if strings.TrimSpace(effective.JWKSURL) == "" {
			return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth jwks url not configured")
		}
		if strings.TrimSpace(effective.AllowedSigningAlgs) == "" {
			return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth signing algs not configured")
		}
	}
	if v := strings.TrimSpace(effective.JWKSURL); v != "" {
		if err := config.ValidateAbsoluteHTTPURL(v); err != nil {
			return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth jwks url invalid")
		}
	}
	if err := config.ValidateAbsoluteHTTPURL(effective.RedirectURL); err != nil {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth redirect url invalid")
	}
	if err := config.ValidateFrontendRedirectURL(effective.FrontendRedirectURL); err != nil {
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth frontend redirect url invalid")
	}

	method := strings.ToLower(strings.TrimSpace(effective.TokenAuthMethod))
	switch method {
	case "", "client_secret_post", "client_secret_basic":
		if strings.TrimSpace(effective.ClientSecret) == "" {
			return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth client secret not configured")
		}
	case "none":
	default:
		return config.OIDCConnectConfig{}, infraerrors.InternalServer("OAUTH_CONFIG_INVALID", "oauth token_auth_method invalid")
	}

	return effective, nil
}

func scopesContainOpenID(scopes string) bool {
	for _, scope := range strings.Fields(strings.ToLower(strings.TrimSpace(scopes))) {
		if scope == "openid" {
			return true
		}
	}
	return false
}

type oidcProviderMetadata struct {
	AuthorizationEndpoint string `json:"authorization_endpoint"`
	TokenEndpoint         string `json:"token_endpoint"`
	UserInfoEndpoint      string `json:"userinfo_endpoint"`
	JWKSURI               string `json:"jwks_uri"`
}

func oidcDefaultDiscoveryURL(issuerURL string) string {
	issuerURL = strings.TrimSpace(issuerURL)
	if issuerURL == "" {
		return ""
	}
	return strings.TrimRight(issuerURL, "/") + "/.well-known/openid-configuration"
}

func oidcResolveProviderMetadata(ctx context.Context, discoveryURL string) (*oidcProviderMetadata, error) {
	discoveryURL = strings.TrimSpace(discoveryURL)
	if discoveryURL == "" {
		return nil, fmt.Errorf("discovery url is empty")
	}

	resp, err := req.C().
		SetTimeout(15*time.Second).
		R().
		SetContext(ctx).
		SetHeader("Accept", "application/json").
		Get(discoveryURL)
	if err != nil {
		return nil, fmt.Errorf("request discovery document: %w", err)
	}
	if !resp.IsSuccessState() {
		return nil, fmt.Errorf("discovery request failed: status=%d", resp.StatusCode)
	}

	metadata := &oidcProviderMetadata{}
	if err := json.Unmarshal(resp.Bytes(), metadata); err != nil {
		return nil, fmt.Errorf("parse discovery document: %w", err)
	}
	return metadata, nil
}