Enterprise-Knowledge-Base/internal/handler/system.go

package handler

import (
	"context"
	"fmt"
	"net"
	"net/http"
	"os"
	"regexp"
	"strconv"
	"strings"

	"github.com/Tencent/WeKnora/internal/application/service"
	"github.com/Tencent/WeKnora/internal/application/service/file"
	"github.com/Tencent/WeKnora/internal/config"
	"github.com/Tencent/WeKnora/internal/database"
	"github.com/Tencent/WeKnora/internal/infrastructure/docparser"
	"github.com/Tencent/WeKnora/internal/logger"
	"github.com/Tencent/WeKnora/internal/types"
	"github.com/Tencent/WeKnora/internal/types/interfaces"
	secutils "github.com/Tencent/WeKnora/internal/utils"
	"github.com/gin-gonic/gin"
	"github.com/minio/minio-go/v7"
	"github.com/minio/minio-go/v7/pkg/credentials"
	"github.com/neo4j/neo4j-go-driver/v6/neo4j"
)

// SystemHandler handles system-related requests
type SystemHandler struct {
	cfg              *config.Config
	neo4jDriver      neo4j.Driver
	documentReader   interfaces.DocumentReader
	tenantSvc        interfaces.TenantService
	userSvc          interfaces.UserService
	systemSettingSvc interfaces.SystemSettingService
}

// NewSystemHandler creates a new system handler
func NewSystemHandler(cfg *config.Config,
	neo4jDriver neo4j.Driver,
	documentReader interfaces.DocumentReader,
	tenantSvc interfaces.TenantService,
	userSvc interfaces.UserService,
	systemSettingSvc interfaces.SystemSettingService,
) *SystemHandler {
	return &SystemHandler{
		cfg:              cfg,
		neo4jDriver:      neo4jDriver,
		documentReader:   documentReader,
		tenantSvc:        tenantSvc,
		userSvc:          userSvc,
		systemSettingSvc: systemSettingSvc,
	}
}

// GetSystemInfoResponse defines the response structure for system info
type GetSystemInfoResponse struct {
	Version             string `json:"version"`
	Edition             string `json:"edition"`
	CommitID            string `json:"commit_id,omitempty"`
	BuildTime           string `json:"build_time,omitempty"`
	GoVersion           string `json:"go_version,omitempty"`
	KeywordIndexEngine  string `json:"keyword_index_engine,omitempty"`
	VectorStoreEngine   string `json:"vector_store_engine,omitempty"`
	GraphDatabaseEngine string `json:"graph_database_engine,omitempty"`
	MinioEnabled        bool   `json:"minio_enabled,omitempty"`
	DBVersion           string `json:"db_version,omitempty"`
	// DBMigrationError carries the human-readable error message recorded when
	// the most recent startup migration attempt failed. Empty when migrations
	// succeeded; non-empty values let the frontend surface a troubleshooting
	// banner instead of silently hiding the DB version row (see issue #1319).
	DBMigrationError string `json:"db_migration_error,omitempty"`
}

// 编译时注入的版本信息
var (
	Version   = "unknown"
	Edition   = "standard"
	CommitID  = "unknown"
	BuildTime = "unknown"
	GoVersion = "unknown"
)

// GetSystemInfo godoc
// @Summary      获取系统信息
// @Description  获取系统版本、构建信息和引擎配置
// @Tags         系统
// @Accept       json
// @Produce      json
// @Success      200  {object}  GetSystemInfoResponse  "系统信息"
// @Router       /system/info [get]
func (h *SystemHandler) GetSystemInfo(c *gin.Context) {
	ctx := logger.CloneContext(c.Request.Context())

	// Get keyword index engine from RETRIEVE_DRIVER
	keywordIndexEngine := h.getKeywordIndexEngine()

	// Get vector store engine from config or RETRIEVE_DRIVER
	vectorStoreEngine := h.getVectorStoreEngine()

	// Get graph database engine from NEO4J_ENABLE
	graphDatabaseEngine := h.getGraphDatabaseEngine()

	// Get MinIO enabled status
	minioEnabled := h.isMinioConfigured(c)

	dbMigrationErr := database.CachedMigrationError()
	var dbVersion string
	if ver, dirty, ok := database.CachedMigrationVersion(); ok {
		dbVersion = fmt.Sprintf("%d", ver)
		if dirty {
			dbVersion += " (dirty)"
		}
		if dbMigrationErr != "" {
			dbVersion += " (failed)"
		}
	} else if dbMigrationErr != "" {
		// Failure happened before m.Version() could be read (e.g. could not
		// open the database). Still emit a placeholder so the frontend renders
		// the row and shows the troubleshooting banner.
		dbVersion = "unknown"
	}

	response := GetSystemInfoResponse{
		Version:             Version,
		Edition:             Edition,
		CommitID:            CommitID,
		BuildTime:           BuildTime,
		GoVersion:           GoVersion,
		KeywordIndexEngine:  keywordIndexEngine,
		VectorStoreEngine:   vectorStoreEngine,
		GraphDatabaseEngine: graphDatabaseEngine,
		MinioEnabled:        minioEnabled,
		DBVersion:           dbVersion,
		DBMigrationError:    dbMigrationErr,
	}

	logger.Info(ctx, "System info retrieved successfully")
	c.JSON(200, gin.H{
		"code": 0,
		"msg":  "success",
		"data": response,
	})
}

func (h *SystemHandler) getDocReaderConnInfo() (addr, transport string) {
	addr = strings.TrimSpace(os.Getenv("DOCREADER_ADDR"))
	transport = strings.TrimSpace(os.Getenv("DOCREADER_TRANSPORT"))
	if transport == "" {
		transport = "grpc"
	}
	transport = strings.ToLower(transport)
	return addr, transport
}

// ListParserEngines returns available document parser engines.
// Merges Go-native static engines with engines discovered from the remote
// docreader service, so newly added Python engines are auto-discovered.
// @Summary      列出可用的文档解析引擎
// @Tags         系统
// @Produce      json
// @Success      200  {object}  map[string]interface{}  "解析引擎列表"
// @Router       /system/parser-engines [get]
func (h *SystemHandler) ListParserEngines(c *gin.Context) {
	var overrides map[string]string
	if v, exists := c.Get(types.TenantInfoContextKey.String()); exists {
		if tenant, ok := v.(*types.Tenant); ok && tenant != nil {
			if tenant.ParserEngineConfig != nil {
				overrides = tenant.ParserEngineConfig.ToOverridesMap()
			}
			if creds := tenant.Credentials.GetWeKnoraCloud(); creds != nil {
				if overrides == nil {
					overrides = make(map[string]string)
				}
				overrides["weknoracloud_app_id"] = creds.AppID
			}
		}
	}

	reader, docreaderAddr, docreaderTransport := h.resolveDocReader(c.Request.Context(), overrides)
	connected := reader != nil && reader.IsConnected()
	remoteEngines := h.fetchRemoteEngines(c.Request.Context(), reader, overrides)
	engines := docparser.ListAllEngines(connected, overrides, remoteEngines)
	c.JSON(200, gin.H{"code": 0, "msg": "success", "data": engines, "docreader_addr": docreaderAddr, "docreader_transport": docreaderTransport, "connected": connected})
}

// ReconnectDocReader reconnects the document converter to a new (or same) DocReader address.
// @Summary      重连文档解析服务
// @Tags         系统
// @Accept       json
// @Produce      json
// @Param        request  body  object{addr string} true "DocReader 地址"
// @Success      200
// @Router       /system/docreader/reconnect [post]
func (h *SystemHandler) ReconnectDocReader(c *gin.Context) {
	var req struct {
		Addr string `json:"addr" binding:"required"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(400, gin.H{"code": 1, "msg": "请提供 addr 参数"})
		return
	}
	addr := strings.TrimSpace(req.Addr)
	if addr == "" {
		c.JSON(400, gin.H{"code": 1, "msg": "addr 不能为空"})
		return
	}

	// SSRF validation for docreader address
	if err := secutils.ValidateURLForSSRF(addr); err != nil {
		logger.Warnf(c.Request.Context(), "SSRF validation failed for docreader addr: %v", err)
		c.JSON(400, gin.H{"code": 1, "msg": secutils.FormatSSRFError("DocReader 地址", addr, err)})
		return
	}

	if h.documentReader == nil {
		c.JSON(500, gin.H{"code": 1, "msg": "document converter not initialized"})
		return
	}

	if err := h.documentReader.Reconnect(addr); err != nil {
		logger.Errorf(c.Request.Context(), "Failed to reconnect docreader to %s: %v", addr, err)
		c.JSON(200, gin.H{"code": 1, "msg": fmt.Sprintf("连接失败: %v", err)})
		return
	}

	var overrides map[string]string
	if v, exists := c.Get(types.TenantInfoContextKey.String()); exists {
		if tenant, ok := v.(*types.Tenant); ok && tenant != nil {
			if tenant.ParserEngineConfig != nil {
				overrides = tenant.ParserEngineConfig.ToOverridesMap()
			}
			if creds := tenant.Credentials.GetWeKnoraCloud(); creds != nil {
				if overrides == nil {
					overrides = make(map[string]string)
				}
				overrides["weknoracloud_app_id"] = creds.AppID
			}
		}
	}
	remoteEngines := h.fetchRemoteEngines(c.Request.Context(), h.documentReader, overrides)
	engines := docparser.ListAllEngines(true, overrides, remoteEngines)

	_, docreaderTransport := h.getDocReaderConnInfo()
	c.JSON(200, gin.H{"code": 0, "msg": "连接成功", "data": engines, "docreader_addr": addr, "docreader_transport": docreaderTransport, "connected": true})
}

// CheckParserEngines runs availability check with the given config overrides (e.g. current form values).
// Used to test engine availability without saving; body shape matches ParserEngineConfig.
// @Summary      使用当前参数检测解析引擎可用性
// @Tags         系统
// @Accept       json
// @Produce      json
// @Param        body  body  object  true  "解析引擎配置（与保存接口同结构）"
// @Success      200
// @Router       /system/parser-engines/check [post]
func (h *SystemHandler) CheckParserEngines(c *gin.Context) {
	var body types.ParserEngineConfig
	if err := c.ShouldBindJSON(&body); err != nil {
		c.JSON(400, gin.H{"code": 1, "msg": "请求体格式错误"})
		return
	}
	overrides := body.ToOverridesMap()
	if v, exists := c.Get(types.TenantInfoContextKey.String()); exists {
		if tenant, ok := v.(*types.Tenant); ok && tenant != nil {
			if creds := tenant.Credentials.GetWeKnoraCloud(); creds != nil {
				if overrides == nil {
					overrides = make(map[string]string)
				}
				overrides["weknoracloud_app_id"] = creds.AppID
			}
		}
	}
	reader, docreaderAddr, docreaderTransport := h.resolveDocReader(c.Request.Context(), overrides)
	connected := reader != nil && reader.IsConnected()
	remoteEngines := h.fetchRemoteEngines(c.Request.Context(), reader, overrides)
	engines := docparser.ListAllEngines(connected, overrides, remoteEngines)
	c.JSON(200, gin.H{"code": 0, "msg": "success", "data": engines, "docreader_addr": docreaderAddr, "docreader_transport": docreaderTransport, "connected": connected})
}

func (h *SystemHandler) resolveDocReader(ctx context.Context, overrides map[string]string) (interfaces.DocumentReader, string, string) {
	if len(overrides) > 0 {
		if addr := strings.TrimSpace(overrides["docreader_addr"]); addr != "" && service.IsWeKnoraCloudDocReaderAddr(addr) {
			reader := h.ResolveDocumentReader(ctx, addr)
			return reader, addr, transportFromDocReaderAddr(addr)
		}
	}

	addr, transport := h.getDocReaderConnInfo()
	return h.documentReader, addr, transport
}

func transportFromDocReaderAddr(addr string) string {
	if strings.HasPrefix(strings.ToLower(strings.TrimSpace(addr)), "https://") {
		return "https"
	}
	return "http"
}

// fetchRemoteEngines queries the remote docreader for its engine list.
// Returns nil on any error (e.g. not connected), letting the caller
// fall back to Go's static registry only.
func (h *SystemHandler) fetchRemoteEngines(ctx context.Context, reader interfaces.DocumentReader, overrides map[string]string) []types.ParserEngineInfo {
	if reader == nil || !reader.IsConnected() {
		return nil
	}
	engines, err := reader.ListEngines(ctx, overrides)
	if err != nil {
		logger.Warnf(ctx, "Failed to fetch remote engines from docreader: %v", err)
		return nil
	}
	return engines
}

// getKeywordIndexEngine returns the keyword index engine name
func (h *SystemHandler) getKeywordIndexEngine() string {
	retrieveDriver := os.Getenv("RETRIEVE_DRIVER")
	if retrieveDriver == "" {
		return "未配置"
	}

	drivers := strings.Split(retrieveDriver, ",")
	// Filter out engines that support keyword retrieval
	keywordEngines := []string{}
	for _, driver := range drivers {
		driver = strings.TrimSpace(driver)
		if h.supportsRetrieverType(driver, types.KeywordsRetrieverType) {
			keywordEngines = append(keywordEngines, driver)
		}
	}

	if len(keywordEngines) == 0 {
		return "未配置"
	}
	return strings.Join(keywordEngines, ", ")
}

// getVectorStoreEngine returns the vector store engine name
func (h *SystemHandler) getVectorStoreEngine() string {
	// First check config.yaml
	if h.cfg != nil && h.cfg.VectorDatabase != nil && h.cfg.VectorDatabase.Driver != "" {
		return h.cfg.VectorDatabase.Driver
	}

	// Fallback to RETRIEVE_DRIVER for vector support
	retrieveDriver := os.Getenv("RETRIEVE_DRIVER")
	if retrieveDriver == "" {
		return "未配置"
	}

	drivers := strings.Split(retrieveDriver, ",")
	// Filter out engines that support vector retrieval
	vectorEngines := []string{}
	for _, driver := range drivers {
		driver = strings.TrimSpace(driver)
		if h.supportsRetrieverType(driver, types.VectorRetrieverType) {
			vectorEngines = append(vectorEngines, driver)
		}
	}

	if len(vectorEngines) == 0 {
		return "未配置"
	}
	return strings.Join(vectorEngines, ", ")
}

// getGraphDatabaseEngine returns the graph database engine name
func (h *SystemHandler) getGraphDatabaseEngine() string {
	if h.neo4jDriver == nil {
		return "Not Enabled"
	}
	return "Neo4j"
}

// supportsRetrieverType checks if a driver supports a specific retriever type
// by looking up the retrieverEngineMapping from types package
func (h *SystemHandler) supportsRetrieverType(driver string, retrieverType types.RetrieverType) bool {
	// Get the mapping of all supported drivers and their capabilities
	mapping := types.GetRetrieverEngineMapping()

	// Check if the driver exists in the mapping
	engines, exists := mapping[driver]
	if !exists {
		return false
	}

	// Check if any of the engine configurations support the requested retriever type
	for _, engine := range engines {
		if engine.RetrieverType == retrieverType {
			return true
		}
	}
	return false
}

// getMinioConfig resolves MinIO connection parameters from tenant config (if mode=remote) or env vars (mode=docker/default).
func (h *SystemHandler) getMinioConfig(c *gin.Context) (endpoint, accessKeyID, secretAccessKey string) {
	if v, exists := c.Get(types.TenantInfoContextKey.String()); exists {
		if tenant, ok := v.(*types.Tenant); ok && tenant != nil && tenant.StorageEngineConfig != nil && tenant.StorageEngineConfig.MinIO != nil {
			m := tenant.StorageEngineConfig.MinIO
			if m.Mode == "remote" {
				return m.Endpoint, m.AccessKeyID, m.SecretAccessKey
			}
		}
	}
	endpoint = os.Getenv("MINIO_ENDPOINT")
	accessKeyID = os.Getenv("MINIO_ACCESS_KEY_ID")
	secretAccessKey = os.Getenv("MINIO_SECRET_ACCESS_KEY")
	return
}

// isMinioConfigured checks whether MinIO connection info is available (from tenant config or env).
func (h *SystemHandler) isMinioConfigured(c *gin.Context) bool {
	endpoint, accessKeyID, secretAccessKey := h.getMinioConfig(c)
	return endpoint != "" && accessKeyID != "" && secretAccessKey != ""
}

// isMinioEnvAvailable checks whether MinIO env vars (MINIO_ENDPOINT etc.) are set.
func (h *SystemHandler) isMinioEnvAvailable() bool {
	return os.Getenv("MINIO_ENDPOINT") != "" &&
		os.Getenv("MINIO_ACCESS_KEY_ID") != "" &&
		os.Getenv("MINIO_SECRET_ACCESS_KEY") != ""
}

// isCOSConfigured checks whether COS connection info is available from tenant config.
func (h *SystemHandler) isCOSConfigured(c *gin.Context) bool {
	if v, exists := c.Get(types.TenantInfoContextKey.String()); exists {
		if tenant, ok := v.(*types.Tenant); ok && tenant != nil && tenant.StorageEngineConfig != nil && tenant.StorageEngineConfig.COS != nil {
			cosConf := tenant.StorageEngineConfig.COS
			return cosConf.SecretID != "" && cosConf.SecretKey != "" && cosConf.Region != "" && cosConf.BucketName != ""
		}
	}
	return false
}

// isTOSConfigured checks whether TOS connection info is available from tenant config or env.
func (h *SystemHandler) isTOSConfigured(c *gin.Context) bool {
	if v, exists := c.Get(types.TenantInfoContextKey.String()); exists {
		if tenant, ok := v.(*types.Tenant); ok && tenant != nil && tenant.StorageEngineConfig != nil && tenant.StorageEngineConfig.TOS != nil {
			tosConf := tenant.StorageEngineConfig.TOS
			return tosConf.Endpoint != "" && tosConf.Region != "" && tosConf.AccessKey != "" && tosConf.SecretKey != "" && tosConf.BucketName != ""
		}
	}
	return h.isTOSEnvAvailable()
}

// isOSSConfigured checks whether OSS connection info is available from tenant config.
func (h *SystemHandler) isOSSConfigured(c *gin.Context) bool {
	if v, exists := c.Get(types.TenantInfoContextKey.String()); exists {
		if tenant, ok := v.(*types.Tenant); ok && tenant != nil && tenant.StorageEngineConfig != nil && tenant.StorageEngineConfig.OSS != nil {
			ossConf := tenant.StorageEngineConfig.OSS
			return ossConf.Endpoint != "" && ossConf.Region != "" && ossConf.AccessKey != "" && ossConf.SecretKey != "" && ossConf.BucketName != ""
		}
	}
	return false
}

// isKS3Configured checks whether KS3 connection info is available from tenant config.
func (h *SystemHandler) isKS3Configured(c *gin.Context) bool {
	if v, exists := c.Get(types.TenantInfoContextKey.String()); exists {
		if tenant, ok := v.(*types.Tenant); ok && tenant != nil && tenant.StorageEngineConfig != nil && tenant.StorageEngineConfig.KS3 != nil {
			ks3Conf := tenant.StorageEngineConfig.KS3
			return ks3Conf.Endpoint != "" && ks3Conf.Region != "" && ks3Conf.AccessKey != "" && ks3Conf.SecretKey != "" && ks3Conf.BucketName != ""
		}
	}
	return false
}

// isTOSEnvAvailable checks whether TOS env vars are set.
func (h *SystemHandler) isTOSEnvAvailable() bool {
	return os.Getenv("TOS_ENDPOINT") != "" &&
		os.Getenv("TOS_REGION") != "" &&
		os.Getenv("TOS_ACCESS_KEY") != "" &&
		os.Getenv("TOS_SECRET_KEY") != "" &&
		os.Getenv("TOS_BUCKET_NAME") != ""
}

// StorageEngineStatusItem describes one storage engine's availability and description.
type StorageEngineStatusItem struct {
	Name        string `json:"name"` // "local", "minio", "cos", "tos", "s3", "oss", "ks3"
	Allowed     bool   `json:"allowed"`
	Available   bool   `json:"available"`   // whether the engine can be used
	Description string `json:"description"` // short description for UI
}

// GetStorageEngineStatusResponse is the response for GET /system/storage-engine-status.
type GetStorageEngineStatusResponse struct {
	Engines           []StorageEngineStatusItem `json:"engines"`
	AllowedProviders  []string                  `json:"allowed_providers"`
	MinioEnvAvailable bool                      `json:"minio_env_available"`
}

// GetStorageEngineStatus godoc
// @Summary      获取存储引擎状态
// @Description  返回 Local、MinIO、COS 各存储引擎的可用状态及说明，供全局设置与知识库选择使用
// @Tags         系统
// @Produce      json
// @Success      200  {object}  GetStorageEngineStatusResponse
// @Router       /system/storage-engine-status [get]
func (h *SystemHandler) GetStorageEngineStatus(c *gin.Context) {
	minioConfigured := h.isMinioConfigured(c)
	minioEnvAvailable := h.isMinioEnvAvailable()
	cosConfigured := h.isCOSConfigured(c)
	tosConfigured := h.isTOSConfigured(c)
	s3Configured := h.isS3Configured(c)
	ossConfigured := h.isOSSConfigured(c)
	ks3Configured := h.isKS3Configured(c)
	allowed := getAllowedStorageProviders()
	allowedProviders := make([]string, 0, len(supportedStorageProviders))
	for _, provider := range getSupportedStorageProviders() {
		if allowed[provider] {
			allowedProviders = append(allowedProviders, provider)
		}
	}
	engines := []StorageEngineStatusItem{
		{Name: "local", Allowed: allowed["local"], Available: true, Description: "本地文件系统存储，仅适合单机部署"},
		{Name: "minio", Allowed: allowed["minio"], Available: minioConfigured || minioEnvAvailable, Description: "S3 兼容的自托管对象存储，适合内网和私有云部署"},
		{Name: "cos", Allowed: allowed["cos"], Available: cosConfigured, Description: "腾讯云对象存储服务，适合公有云部署，支持 CDN 加速"},
		{Name: "tos", Allowed: allowed["tos"], Available: tosConfigured, Description: "火山引擎对象存储服务，适合公有云部署"},
		{Name: "s3", Allowed: allowed["s3"], Available: s3Configured, Description: "AWS S3 与兼容对象存储服务，适合公有云与混合云部署"},
		{Name: "oss", Allowed: allowed["oss"], Available: ossConfigured, Description: "阿里云对象存储服务，适合公有云部署，支持 S3 兼容协议"},
		{Name: "ks3", Allowed: allowed["ks3"], Available: ks3Configured, Description: "金山云对象存储服务，适合公有云部署"},
	}
	c.JSON(200, gin.H{
		"code": 0,
		"msg":  "success",
		"data": GetStorageEngineStatusResponse{Engines: engines, AllowedProviders: allowedProviders, MinioEnvAvailable: minioEnvAvailable},
	})
}

// --- Storage engine helpers ---
// cosFieldPattern validates COS region and bucket name format to prevent URL injection.
var cosFieldPattern = regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9._-]{0,62}$`)

// ossFieldPattern validates OSS region and bucket name format to prevent URL injection.
var ossFieldPattern = regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9._-]{0,62}$`)

// sanitizeStorageCheckError converts a raw storage connectivity error into a safe
// user-facing message that does not leak internal network details (hostnames, IPs, ports).
func sanitizeStorageCheckError(err error) string {
	msg := err.Error()
	switch {
	case strings.Contains(msg, "Endpoint url cannot have fully qualified paths"):
		return "Endpoint 地址格式错误：请去除 http:// 或 https:// 前缀，只填写域名或 IP 地址和端口（例如：minio.example.com:9000）"
	case strings.Contains(msg, "no such host"):
		return "DNS 解析失败，请检查地址是否正确"
	case strings.Contains(msg, "connection refused"):
		return "连接被拒绝，请确认服务已启动且端口正确"
	case strings.Contains(msg, "no route to host"):
		return "无法路由到目标地址，请检查网络配置"
	case strings.Contains(msg, "i/o timeout") || strings.Contains(msg, "deadline exceeded") || strings.Contains(msg, "context deadline"):
		return "连接超时，请检查网络或服务状态"
	case strings.Contains(msg, "403") || strings.Contains(msg, "AccessDenied") || strings.Contains(msg, "access denied"):
		return "认证失败，请检查访问凭证是否正确"
	case strings.Contains(msg, "certificate") || strings.Contains(msg, "tls") || strings.Contains(msg, "x509"):
		return "TLS/SSL 证书错误，请检查 SSL 配置"
	case strings.Contains(msg, "404") || strings.Contains(msg, "NoSuchBucket"):
		return "Bucket 不存在，请检查名称和 Region"
	default:
		return "连接失败，请检查配置参数是否正确"
	}
}

// isBlockedStorageEndpoint checks whether a storage endpoint resolves to a dangerous
// address (cloud metadata, loopback, link-local). Unlike the stricter isSSRFSafeURL,
// this allows private IPs since MinIO is commonly deployed on internal networks.
// It also respects the SSRF_WHITELIST environment variable for whitelisted hosts.
func isBlockedStorageEndpoint(endpoint string) (bool, string) {
	host, _, err := net.SplitHostPort(endpoint)
	if err != nil {
		host = endpoint
	}

	// Check SSRF whitelist first – whitelisted hosts bypass the block check.
	if secutils.IsSSRFWhitelisted(host) {
		return false, ""
	}

	hostLower := strings.ToLower(host)

	blockedHosts := []string{
		"metadata.google.internal",
		"metadata.tencentyun.com",
		"metadata.aws.internal",
	}
	for _, bh := range blockedHosts {
		if hostLower == bh {
			return true, "该地址不允许访问"
		}
	}

	checkIP := func(ip net.IP) (bool, string) {
		if ip.IsLoopback() {
			return true, "不允许访问本地回环地址"
		}
		if ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
			return true, "不允许访问链路本地地址"
		}
		if ip.IsUnspecified() {
			return true, "无效的地址"
		}
		return false, ""
	}

	if ip := net.ParseIP(host); ip != nil {
		return checkIP(ip)
	}

	ips, err := net.LookupIP(host)
	if err != nil {
		return false, ""
	}
	for _, ip := range ips {
		if blocked, reason := checkIP(ip); blocked {
			return blocked, reason
		}
	}
	return false, ""
}

// --- Storage engine connectivity check ---

// StorageCheckRequest is the body for POST /system/storage-engine-check.
type StorageCheckRequest struct {
	Provider string                   `json:"provider"` // "minio", "cos", "tos", "s3", "oss", "ks3", "obs"
	MinIO    *types.MinIOEngineConfig `json:"minio,omitempty"`
	COS      *types.COSEngineConfig   `json:"cos,omitempty"`
	TOS      *types.TOSEngineConfig   `json:"tos,omitempty"`
	S3       *types.S3EngineConfig    `json:"s3,omitempty"`
	OSS      *types.OSSEngineConfig   `json:"oss,omitempty"`
	KS3      *types.KS3EngineConfig   `json:"ks3,omitempty"`
	OBS      *types.OBSEngineConfig   `json:"obs,omitempty"`
}

// StorageCheckResponse is the response for a single-engine connectivity check.
type StorageCheckResponse struct {
	OK            bool   `json:"ok"`
	Message       string `json:"message"`
	BucketCreated bool   `json:"bucket_created,omitempty"`
}

// CheckStorageEngine tests connectivity for a single storage engine using the provided config.
// @Summary      测试存储引擎连通性
// @Description  使用当前填写的参数测试 MinIO/COS 连通性，不保存配置
// @Tags         系统
// @Accept       json
// @Produce      json
// @Param        body  body  StorageCheckRequest  true  "存储引擎配置"
// @Success      200   {object}  StorageCheckResponse
// @Router       /system/storage-engine-check [post]
func (h *SystemHandler) CheckStorageEngine(c *gin.Context) {
	ctx := logger.CloneContext(c.Request.Context())

	var req StorageCheckRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(400, gin.H{"code": 1, "msg": "请求体格式错误"})
		return
	}
	if !isStorageProviderAllowed(req.Provider) {
		c.JSON(403, gin.H{"code": 1, "msg": "该存储引擎已被禁用"})
		return
	}

	switch req.Provider {
	case "minio":
		h.checkMinio(c, ctx, req.MinIO)
	case "cos":
		h.checkCOS(c, ctx, req.COS)
	case "tos":
		h.checkTOS(c, ctx, req.TOS)
	case "s3":
		h.checkS3(c, ctx, req.S3)
	case "oss":
		h.checkOSS(c, ctx, req.OSS)
	case "ks3":
		h.checkKS3(c, ctx, req.KS3)
	case "obs":
		h.checkOBS(c, ctx, req.OBS)
	default:
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: true, Message: "本地存储无需检测"}})
	}
}

func (h *SystemHandler) isS3Configured(c *gin.Context) bool {
	if v, exists := c.Get(types.TenantInfoContextKey.String()); exists {
		if tenant, ok := v.(*types.Tenant); ok && tenant != nil && tenant.StorageEngineConfig != nil && tenant.StorageEngineConfig.S3 != nil {
			s3Conf := tenant.StorageEngineConfig.S3
			return s3Conf.Endpoint != "" && s3Conf.Region != "" && s3Conf.AccessKey != "" && s3Conf.SecretKey != "" && s3Conf.BucketName != ""
		}
	}
	return false
}

func (h *SystemHandler) checkMinio(c *gin.Context, ctx context.Context, cfg *types.MinIOEngineConfig) {
	if cfg == nil {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "未提供 MinIO 配置"}})
		return
	}

	if cfg.BucketName != "" && !cosFieldPattern.MatchString(cfg.BucketName) {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Bucket 名称格式不正确，仅允许字母、数字、点、连字符"}})
		return
	}

	endpoint, accessKeyID, secretAccessKey := cfg.Endpoint, cfg.AccessKeyID, cfg.SecretAccessKey
	if cfg.Mode != "remote" {
		endpoint = os.Getenv("MINIO_ENDPOINT")
		accessKeyID = os.Getenv("MINIO_ACCESS_KEY_ID")
		secretAccessKey = os.Getenv("MINIO_SECRET_ACCESS_KEY")
	}
	if endpoint == "" || accessKeyID == "" || secretAccessKey == "" {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Endpoint、Access Key、Secret Key 不能为空"}})
		return
	}

	if cfg.Mode == "remote" {
		if blocked, reason := isBlockedStorageEndpoint(endpoint); blocked {
			logger.Warnf(ctx, "Storage check: MinIO endpoint blocked by SSRF protection, endpoint: %s", endpoint)
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: reason}})
			return
		}
	}

	err := file.CheckMinioConnectivity(ctx, endpoint, accessKeyID, secretAccessKey, cfg.BucketName, cfg.UseSSL)
	if err != nil {
		errMsg := err.Error()
		// If bucket does not exist, auto-create it
		if strings.Contains(errMsg, "does not exist") && cfg.BucketName != "" {
			logger.Info(ctx, "Storage check: bucket does not exist, attempting auto-creation", "bucket", cfg.BucketName)
			minioClient, clientErr := minio.New(endpoint, &minio.Options{
				Creds:  credentials.NewStaticV4(accessKeyID, secretAccessKey, ""),
				Secure: cfg.UseSSL,
			})
			if clientErr != nil {
				c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: fmt.Sprintf("Failed to create MinIO client: %s", sanitizeStorageCheckError(clientErr))}})
				return
			}
			if mkErr := minioClient.MakeBucket(ctx, cfg.BucketName, minio.MakeBucketOptions{}); mkErr != nil {
				logger.Error(ctx, "Storage check: failed to create bucket", "bucket", cfg.BucketName, "error", mkErr)
				c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: fmt.Sprintf("Failed to auto-create Bucket '%s': %s", cfg.BucketName, sanitizeStorageCheckError(mkErr))}})
				return
			}
			logger.Info(ctx, "Storage check: bucket created", "bucket", cfg.BucketName)
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: true, BucketCreated: true, Message: fmt.Sprintf("Bucket '%s' does not exist, and has been automatically created", cfg.BucketName)}})
			return
		}
		logger.Error(ctx, "Storage check: MinIO connectivity failed", "error", err)
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: sanitizeStorageCheckError(err)}})
		return
	}

	msg := "连接成功"
	if cfg.BucketName != "" {
		msg = fmt.Sprintf("连接成功，Bucket「%s」已确认存在", cfg.BucketName)
	}
	c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: true, Message: msg}})
}

func (h *SystemHandler) checkCOS(c *gin.Context, ctx context.Context, cfg *types.COSEngineConfig) {
	if cfg == nil {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "未提供 COS 配置"}})
		return
	}
	if cfg.SecretID == "" || cfg.SecretKey == "" || cfg.Region == "" || cfg.BucketName == "" {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Secret ID、Secret Key、Region、Bucket 名称不能为空"}})
		return
	}
	if !cosFieldPattern.MatchString(cfg.Region) {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Region 格式不正确，仅允许字母、数字、点、连字符"}})
		return
	}
	if !cosFieldPattern.MatchString(cfg.BucketName) {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Bucket 名称格式不正确，仅允许字母、数字、点、连字符"}})
		return
	}

	err := file.CheckCosConnectivity(ctx, cfg.BucketName, cfg.Region, cfg.SecretID, cfg.SecretKey)
	if err != nil {
		logger.Errorf(ctx, "Storage check: COS connectivity failed, bucket: %s, error: %v", cfg.BucketName, err)
		errMsg := err.Error()
		if strings.Contains(errMsg, "403") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "认证失败，请检查 Secret ID / Secret Key 是否正确"}})
			return
		}
		if strings.Contains(errMsg, "404") || strings.Contains(errMsg, "NoSuchBucket") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: fmt.Sprintf("Bucket「%s」不存在，请检查名称和 Region", cfg.BucketName)}})
			return
		}
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: sanitizeStorageCheckError(err)}})
		return
	}
	c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: true, Message: fmt.Sprintf("连接成功，Bucket「%s」已确认存在", cfg.BucketName)}})
}

func (h *SystemHandler) checkTOS(c *gin.Context, ctx context.Context, cfg *types.TOSEngineConfig) {
	if cfg == nil {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "未提供 TOS 配置"}})
		return
	}
	if cfg.Endpoint == "" || cfg.Region == "" || cfg.AccessKey == "" || cfg.SecretKey == "" || cfg.BucketName == "" {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Endpoint、Region、Access Key、Secret Key、Bucket 名称不能为空"}})
		return
	}

	if blocked, reason := isBlockedStorageEndpoint(cfg.Endpoint); blocked {
		logger.Warnf(ctx, "Storage check: TOS endpoint blocked by SSRF protection, endpoint: %s", cfg.Endpoint)
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: reason}})
		return
	}

	err := file.CheckTosConnectivity(ctx, cfg.Endpoint, cfg.Region, cfg.AccessKey, cfg.SecretKey, cfg.BucketName)
	if err != nil {
		logger.Errorf(ctx, "Storage check: TOS connectivity failed, bucket: %s, error: %v", cfg.BucketName, err)
		errMsg := err.Error()
		if strings.Contains(errMsg, "403") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "认证失败，请检查 Access Key / Secret Key 是否正确"}})
			return
		}
		if strings.Contains(errMsg, "404") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: fmt.Sprintf("Bucket「%s」不存在，请检查名称和 Region", cfg.BucketName)}})
			return
		}
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: sanitizeStorageCheckError(err)}})
		return
	}
	c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: true, Message: fmt.Sprintf("连接成功，Bucket「%s」已确认存在", cfg.BucketName)}})
}

func (h *SystemHandler) checkS3(c *gin.Context, ctx context.Context, cfg *types.S3EngineConfig) {
	if cfg == nil {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "未提供 S3 配置"}})
		return
	}
	if cfg.Endpoint == "" || cfg.Region == "" || cfg.AccessKey == "" || cfg.SecretKey == "" || cfg.BucketName == "" {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Endpoint、Region、Access Key、Secret Key、Bucket 名称不能为空"}})
		return
	}

	if blocked, reason := isBlockedStorageEndpoint(cfg.Endpoint); blocked {
		logger.Warnf(ctx, "Storage check: S3 endpoint blocked by SSRF protection, endpoint: %s", cfg.Endpoint)
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: reason}})
		return
	}

	err := file.CheckS3Connectivity(ctx, cfg.Endpoint, cfg.AccessKey, cfg.SecretKey, cfg.BucketName, cfg.Region)
	if err != nil {
		logger.Errorf(ctx, "Storage check: S3 connectivity failed, bucket: %s, error: %v", cfg.BucketName, err)
		errMsg := err.Error()
		if strings.Contains(errMsg, "403") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "认证失败，请检查 Access Key / Secret Key 是否正确"}})
			return
		}
		if strings.Contains(errMsg, "404") || strings.Contains(errMsg, "NotFound") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: fmt.Sprintf("Bucket「%s」不存在，请检查名称和 Region", cfg.BucketName)}})
			return
		}
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: sanitizeStorageCheckError(err)}})
		return
	}
	c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: true, Message: fmt.Sprintf("连接成功，Bucket「%s」已确认存在", cfg.BucketName)}})
}

func (h *SystemHandler) checkOSS(c *gin.Context, ctx context.Context, cfg *types.OSSEngineConfig) {
	if cfg == nil {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "未提供 OSS 配置"}})
		return
	}

	endpoint, accessKey, secretKey := cfg.Endpoint, cfg.AccessKey, cfg.SecretKey
	if endpoint == "" || accessKey == "" || secretKey == "" || cfg.BucketName == "" {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Endpoint、Access Key、Secret Key、Bucket Name 不能为空"}})
		return
	}

	// Strip URL scheme before SSRF check — OSS endpoint may include http:// or https://
	ssrfEndpoint := strings.TrimPrefix(strings.TrimPrefix(endpoint, "https://"), "http://")
	if blocked, reason := isBlockedStorageEndpoint(ssrfEndpoint); blocked {
		logger.Warnf(ctx, "Storage check: OSS endpoint blocked by SSRF protection, endpoint: %s", endpoint)
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: reason}})
		return
	}
	if !ossFieldPattern.MatchString(cfg.Region) {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Region 格式不正确，仅允许字母、数字、点、连字符"}})
		return
	}
	if !ossFieldPattern.MatchString(cfg.BucketName) {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Bucket 名称格式不正确，仅允许字母、数字、点、连字符"}})
		return
	}

	err := file.CheckOssConnectivity(ctx, endpoint, cfg.Region, accessKey, secretKey, cfg.BucketName)
	if err != nil {
		errMsg := err.Error()
		if strings.Contains(errMsg, "403") || strings.Contains(errMsg, "AccessDenied") {
			logger.Errorf(ctx, "Storage check: OSS auth failed, endpoint: %s, bucket: %s", endpoint, cfg.BucketName)
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "认证失败，请检查 Access Key / Secret Key 是否正确"}})
			return
		}
		if strings.Contains(errMsg, "404") || strings.Contains(errMsg, "NoSuchBucket") {
			logger.Errorf(ctx, "Storage check: OSS bucket not found, bucket: %s", cfg.BucketName)
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: fmt.Sprintf("Bucket「%s」不存在", cfg.BucketName)}})
			return
		}
		logger.Errorf(ctx, "Storage check: OSS connectivity failed, endpoint: %s, bucket: %s, error: %v", endpoint, cfg.BucketName, err)
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: fmt.Sprintf("OSS 连通性检测失败: %s", sanitizeStorageCheckError(err))}})
		return
	}

	c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: true, Message: fmt.Sprintf("连接成功，Bucket「%s」已确认存在", cfg.BucketName)}})
}

func (h *SystemHandler) checkKS3(c *gin.Context, ctx context.Context, cfg *types.KS3EngineConfig) {
	if cfg == nil {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "未提供 KS3 配置"}})
		return
	}

	endpoint, region, accessKey, secretKey := cfg.Endpoint, cfg.Region, cfg.AccessKey, cfg.SecretKey
	if endpoint == "" || region == "" || accessKey == "" || secretKey == "" || cfg.BucketName == "" {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Endpoint、Region、Access Key、Secret Key、Bucket 名称不能为空"}})
		return
	}

	if blocked, reason := isBlockedStorageEndpoint(endpoint); blocked {
		logger.Warnf(ctx, "Storage check: KS3 endpoint blocked by SSRF protection, endpoint: %s", endpoint)
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: reason}})
		return
	}

	err := file.CheckKS3Connectivity(ctx, endpoint, region, accessKey, secretKey, cfg.BucketName)
	if err != nil {
		logger.Errorf(ctx, "Storage check: KS3 connectivity failed, bucket: %s, error: %v", cfg.BucketName, err)
		errMsg := err.Error()
		if strings.Contains(errMsg, "403") || strings.Contains(errMsg, "AccessDenied") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "认证失败，请检查 Access Key / Secret Key 是否正确"}})
			return
		}
		if strings.Contains(errMsg, "404") || strings.Contains(errMsg, "NoSuchBucket") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: fmt.Sprintf("Bucket「%s」不存在，请检查名称和 Region", cfg.BucketName)}})
			return
		}
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: sanitizeStorageCheckError(err)}})
		return
	}
	c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: true, Message: fmt.Sprintf("连接成功，Bucket「%s」已确认存在", cfg.BucketName)}})
}

func (h *SystemHandler) checkOBS(c *gin.Context, ctx context.Context, cfg *types.OBSEngineConfig) {
	if cfg == nil {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "未提供 OBS 配置"}})
		return
	}

	endpoint, region, accessKey, secretKey := cfg.Endpoint, cfg.Region, cfg.AccessKey, cfg.SecretKey
	if endpoint == "" || region == "" || accessKey == "" || secretKey == "" || cfg.BucketName == "" {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Endpoint、Region、Access Key、Secret Key、Bucket 名称不能为空"}})
		return
	}

	ssrfEndpoint := strings.TrimPrefix(strings.TrimPrefix(endpoint, "https://"), "http://")
	if blocked, reason := isBlockedStorageEndpoint(ssrfEndpoint); blocked {
		logger.Warnf(ctx, "Storage check: OBS endpoint blocked by SSRF protection, endpoint: %s", endpoint)
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: reason}})
		return
	}

	if !ossFieldPattern.MatchString(cfg.Region) {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Region 格式不正确，仅允许字母、数字、点、连字符"}})
		return
	}
	if !ossFieldPattern.MatchString(cfg.BucketName) {
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "Bucket 名称格式不正确，仅允许字母、数字、点、连字符"}})
		return
	}

	err := file.CheckObsConnectivity(ctx, endpoint, region, accessKey, secretKey, cfg.BucketName)
	if err != nil {
		logger.Errorf(ctx, "Storage check: OBS connectivity failed, bucket: %s, error: %v", cfg.BucketName, err)
		errMsg := err.Error()
		if strings.Contains(errMsg, "403") || strings.Contains(errMsg, "AccessDenied") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: "认证失败，请检查 Access Key / Secret Key 是否正确"}})
			return
		}
		if strings.Contains(errMsg, "404") || strings.Contains(errMsg, "NoSuchBucket") {
			c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: fmt.Sprintf("Bucket「%s」不存在，请检查名称和 Region", cfg.BucketName)}})
			return
		}
		c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: false, Message: sanitizeStorageCheckError(err)}})
		return
	}
	c.JSON(200, gin.H{"code": 0, "data": StorageCheckResponse{OK: true, Message: fmt.Sprintf("连接成功，Bucket「%s」已确认存在", cfg.BucketName)}})
}

func (h *SystemHandler) ResolveDocumentReader(ctx context.Context, addr string) interfaces.DocumentReader {
	if addr == "" {
		return h.documentReader
	}

	if service.IsWeKnoraCloudDocReaderAddr(addr) {
		creds := h.tenantSvc.GetWeKnoraCloudCredentials(ctx)
		if creds == nil {
			return nil
		}
		reader, err := docparser.NewWeKnoraCloudSignedDocumentReader(creds.AppID, creds.AppSecret)
		if err != nil {
			return nil
		}
		return reader
	}

	reader, err := docparser.NewHTTPDocumentReader(addr)
	if err != nil || reader == nil {
		return reader
	}
	return reader
}

// PromoteUserToSystemAdminRequest defines the request for promoting a user to system admin
type PromoteUserToSystemAdminRequest struct {
	UserID string `json:"user_id" binding:"required"`
}

// PromoteUserToSystemAdmin godoc
// @Summary      Promote a user to system administrator
// @Description  Grant system administrator privileges to a user (SystemAdmin only).
// @Description  Idempotent: re-promoting an existing system admin returns 200 with no DB write.
// @Tags         System Admin
// @Accept       json
// @Produce      json
// @Param        request body PromoteUserToSystemAdminRequest true "User promotion request"
// @Success      200  {object}  types.UserInfo  "User promoted successfully"
// @Failure      400  {object}  map[string]interface{}  "Bad request"
// @Failure      403  {object}  map[string]interface{}  "Forbidden: not a system admin"
// @Failure      404  {object}  map[string]interface{}  "User not found"
// @Router       /system/admin/promote [post]
func (h *SystemHandler) PromoteUserToSystemAdmin(c *gin.Context) {
	ctx := logger.CloneContext(c.Request.Context())

	var req PromoteUserToSystemAdminRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid request: " + err.Error()})
		return
	}

	user, err := h.userSvc.GetUserByID(ctx, req.UserID)
	if err != nil {
		logger.Errorf(ctx, "Error fetching user %s: %v", req.UserID, err)
		c.JSON(http.StatusNotFound, gin.H{"error": "User not found"})
		return
	}
	if user == nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "User not found"})
		return
	}

	if user.IsSystemAdmin {
		// Idempotent: re-promoting an existing system admin is a no-op success.
		c.JSON(http.StatusOK, user.ToUserInfo())
		return
	}
	user.IsSystemAdmin = true
	if err := h.userSvc.UpdateUser(ctx, user); err != nil {
		logger.Errorf(ctx, "Error promoting user %s to system admin: %v", req.UserID, err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to promote user"})
		return
	}

	logger.Infof(ctx, "User %s (ID: %s) promoted to system admin", user.Username, user.ID)
	c.JSON(http.StatusOK, user.ToUserInfo())
}

// RevokeSystemAdminRequest defines the request for revoking system admin privileges
type RevokeSystemAdminRequest struct {
	UserID string `json:"user_id" binding:"required"`
}

// RevokeSystemAdmin godoc
// @Summary      Revoke system administrator privileges from a user
// @Description  Remove system administrator privileges from a user (SystemAdmin only).
// @Description  Two safety guards: the caller cannot revoke their own privileges,
// @Description  and revoking the last remaining system admin is rejected — both
// @Description  prevent a SystemAdmin from accidentally locking the platform out
// @Description  of system-level administration. Idempotent on already-non-admin users.
// @Tags         System Admin
// @Accept       json
// @Produce      json
// @Param        request body RevokeSystemAdminRequest true "User revocation request"
// @Success      200  {object}  types.UserInfo  "Privileges revoked successfully"
// @Failure      400  {object}  map[string]interface{}  "Bad request / would remove last admin / self-revoke"
// @Failure      403  {object}  map[string]interface{}  "Forbidden: not a system admin"
// @Failure      404  {object}  map[string]interface{}  "User not found"
// @Router       /system/admin/revoke [post]
func (h *SystemHandler) RevokeSystemAdmin(c *gin.Context) {
	ctx := logger.CloneContext(c.Request.Context())

	var req RevokeSystemAdminRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid request: " + err.Error()})
		return
	}

	// Self-revoke guard. Without it, a single careless click could leave a
	// deployment with zero system admins and no UI path to recover —
	// operators would have to set the env-var bootstrap or hand-edit the DB.
	if callerID, _ := types.UserIDFromContext(ctx); callerID == req.UserID {
		c.JSON(http.StatusBadRequest, gin.H{
			"error": "Cannot revoke your own system admin privileges",
		})
		return
	}

	user, err := h.userSvc.GetUserByID(ctx, req.UserID)
	if err != nil {
		logger.Errorf(ctx, "Error fetching user %s: %v", req.UserID, err)
		c.JSON(http.StatusNotFound, gin.H{"error": "User not found"})
		return
	}
	if user == nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "User not found"})
		return
	}

	if !user.IsSystemAdmin {
		// Idempotent: revoking from a non-admin is a no-op success.
		c.JSON(http.StatusOK, user.ToUserInfo())
		return
	}

	// Last-admin guard. ListSystemAdmins is bounded to a single row here
	// because we only need the total count; this stays O(1) on the
	// is_system_admin index. Combined with the self-revoke guard above,
	// these two checks make it impossible for a SystemAdmin to lock
	// themselves out of system-level administration via this endpoint.
	_, total, err := h.userSvc.ListSystemAdmins(ctx, 0, 1)
	if err != nil {
		logger.Errorf(ctx, "Error counting system admins for last-admin check: %v", err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to verify admin count"})
		return
	}
	if total <= 1 {
		c.JSON(http.StatusBadRequest, gin.H{
			"error": "Cannot revoke the last remaining system administrator",
		})
		return
	}

	user.IsSystemAdmin = false
	if err := h.userSvc.UpdateUser(ctx, user); err != nil {
		logger.Errorf(ctx, "Error revoking system admin from user %s: %v", req.UserID, err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to revoke system admin privileges"})
		return
	}

	logger.Infof(ctx, "System admin privileges revoked from user %s (ID: %s)", user.Username, user.ID)
	c.JSON(http.StatusOK, user.ToUserInfo())
}

// ListSystemAdminsResponse defines the response structure for listing system admins.
// Total reflects the underlying COUNT(*), not just the page size, so the front
// end can render pagination metadata without a follow-up call.
type ListSystemAdminsResponse struct {
	Total  int64             `json:"total"`
	Admins []*types.UserInfo `json:"admins"`
}

// ListSystemAdmins godoc
// @Summary      List all system administrators
// @Description  Retrieve a paginated list of users with system administrator
// @Description  privileges (SystemAdmin only). Supports `offset` (default 0)
// @Description  and `limit` (default 50, max 200) query parameters. Walks the
// @Description  partial-friendly idx_users_is_system_admin index.
// @Tags         System Admin
// @Produce      json
// @Param        offset query int false "Page offset" default(0)
// @Param        limit  query int false "Page size (max 200)" default(50)
// @Success      200  {object}  ListSystemAdminsResponse  "System admins retrieved successfully"
// @Failure      403  {object}  map[string]interface{}  "Forbidden: not a system admin"
// @Router       /system/admin/list [get]
func (h *SystemHandler) ListSystemAdmins(c *gin.Context) {
	ctx := logger.CloneContext(c.Request.Context())

	// Best-effort pagination parsing — a malformed `limit=foo` falls back
	// to defaults rather than 400-ing, since the call is still safe and a
	// failed-page is more user-hostile than a soft default.
	offset := 0
	limit := 50
	if v := c.Query("offset"); v != "" {
		if n, err := strconv.Atoi(v); err == nil && n >= 0 {
			offset = n
		}
	}
	if v := c.Query("limit"); v != "" {
		if n, err := strconv.Atoi(v); err == nil && n > 0 {
			limit = n
		}
	}
	// Cap so a client can't ask for the entire table.
	if limit > 200 {
		limit = 200
	}

	users, total, err := h.userSvc.ListSystemAdmins(ctx, offset, limit)
	if err != nil {
		logger.Errorf(ctx, "Error listing system admins: %v", err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to list system admins"})
		return
	}

	// Always emit a non-nil slice so the JSON serialises to `[]` rather
	// than `null` for an empty page — front-end iteration is safer.
	infos := make([]*types.UserInfo, 0, len(users))
	for _, u := range users {
		infos = append(infos, u.ToUserInfo())
	}

	c.JSON(http.StatusOK, ListSystemAdminsResponse{
		Total:  total,
		Admins: infos,
	})
}

// ============================================================================
// System Settings (P1)
// ----------------------------------------------------------------------------
// Endpoints below are mounted under /api/v1/system/admin/settings*, all
// gated to SystemAdmin via the route group's middleware. Every response
// is the raw model — no `gin.H{"data": ...}` wrapping — to match the
// project's axios interceptor contract (response.data is unwrapped at the
// HTTP layer; see frontend/src/utils/request.ts:97). The P0 ListSystemAdmins
// already follows this; do not break the convention.
// ============================================================================

// ListSystemSettings godoc
// @Summary      List all system settings
// @Description  Return every row in the system_settings table (system-scope,
// @Description  not tenant-scope). SystemAdmin only.
// @Tags         System Admin
// @Produce      json
// @Success      200 {array} types.SystemSetting "list of settings"
// @Failure      403 {object} map[string]interface{} "Forbidden: not a system admin"
// @Router       /system/admin/settings [get]
func (h *SystemHandler) ListSystemSettings(c *gin.Context) {
	ctx := logger.CloneContext(c.Request.Context())
	rows, err := h.systemSettingSvc.List(ctx)
	if err != nil {
		logger.Errorf(ctx, "list system settings failed: %v", err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to list system settings"})
		return
	}
	if rows == nil {
		// Always emit a non-nil array so the JSON serialises to `[]`
		// rather than `null` on an empty table — front-end iteration
		// is safer.
		rows = []*types.SystemSetting{}
	}
	c.JSON(http.StatusOK, rows)
}

// GetSystemSetting godoc
// @Summary      Get a single system setting by key
// @Description  Returns the row matching :key. 404 when the key is unknown
// @Description  to the registry; 200 with the row when known.
// @Tags         System Admin
// @Produce      json
// @Param        key path string true "Setting key (e.g. file.max_size_mb)"
// @Success      200 {object} types.SystemSetting "the setting row"
// @Failure      400 {object} map[string]interface{} "Unknown key"
// @Failure      404 {object} map[string]interface{} "Key registered but DB row absent"
// @Router       /system/admin/settings/{key} [get]
func (h *SystemHandler) GetSystemSetting(c *gin.Context) {
	ctx := logger.CloneContext(c.Request.Context())
	key := c.Param("key")
	row, err := h.systemSettingSvc.Get(ctx, key)
	if err != nil {
		// Service-layer "unknown key" surfaces as a generic error here;
		// distinguish via the error string rather than typed errors so
		// we don't grow a sentinel package for a single error class.
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if row == nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "setting not yet persisted"})
		return
	}
	c.JSON(http.StatusOK, row)
}

// UpdateSystemSettingRequest is the body for PUT /system/admin/settings/:key.
// `value` carries the new value as raw JSON — int / string / bool depending
// on the registry-declared value_type. The service validates the type
// strictly and rejects mismatches with 400.
type UpdateSystemSettingRequest struct {
	// Value is intentionally `any` (decoded as float64 / string / bool /
	// etc. by the JSON unmarshaller). Service.encodeForType normalises
	// these against the registry's declared type and rejects mismatches.
	Value any `json:"value"`
}

// UpdateSystemSetting godoc
// @Summary      Update a system setting value
// @Description  Persist a new value for :key. Service validates the
// @Description  rawValue against the registry's declared value_type and
// @Description  rejects mismatches with 400. SystemAdmin only. Emits an
// @Description  audit row (action=system.setting_changed) on success.
// @Tags         System Admin
// @Accept       json
// @Produce      json
// @Param        key     path string                       true "Setting key"
// @Param        request body UpdateSystemSettingRequest   true "New value"
// @Success      200 {object} types.SystemSetting "the updated row"
// @Failure      400 {object} map[string]interface{} "Bad request / unknown key / type mismatch"
// @Failure      403 {object} map[string]interface{} "Forbidden: not a system admin"
// @Router       /system/admin/settings/{key} [put]
func (h *SystemHandler) UpdateSystemSetting(c *gin.Context) {
	ctx := logger.CloneContext(c.Request.Context())
	key := c.Param("key")

	var req UpdateSystemSettingRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid request: " + err.Error()})
		return
	}
	if req.Value == nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "value is required"})
		return
	}

	row, err := h.systemSettingSvc.Update(ctx, key, req.Value)
	if err != nil {
		// Whether this is "unknown key" / "type mismatch" / "DB error"
		// is encoded in the error message at the service layer; surface
		// it verbatim. UI captures it as the toast text.
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, row)
}