package server

import (
	"encoding/json"
	"net/http"
	"strconv"

	"chat-agent-system/internal/ctxmgr"
)

// -----------------------------------------------------------------------------
// 多级上下文与偏好记忆 RESTful 控制器
// -----------------------------------------------------------------------------

// handleGetUserContext 获取单用户私有上下文与个性化偏好
// user_id 仅允许等于当前认证用户本人（或系统管理员），不再默认回落 user id=1。
func (s *Server) handleGetUserContext(w http.ResponseWriter, r *http.Request) {
	user, ok := s.requirePrincipal(w, r)
	if !ok {
		return
	}
	userIDStr := r.URL.Query().Get("user_id")
	projectIDStr := r.URL.Query().Get("project_id")
	sessionID := r.URL.Query().Get("session_id")

	userID, _ := strconv.ParseInt(userIDStr, 10, 64)
	if userID <= 0 {
		userID = user.ID
	}
	if userID != user.ID && !s.isSystemAdminUser(r.Context(), user) {
		writeJSONResponse(w, http.StatusForbidden, map[string]string{
			"error_code": "ERR_FORBIDDEN",
			"message":    "无权查询其他用户的上下文",
		})
		return
	}
	projectID, _ := strconv.ParseInt(projectIDStr, 10, 64)

	if s.ctxMgr() == nil {
		writeSafeError(w, r, http.StatusServiceUnavailable, "context manager not initialized")
		return
	}

	// FIND-SEC-01 回归：session_id 必须归属于目标用户本人，否则拒绝。
	// 会话不存在与归属他人同样返回 403，避免泄露会话存在性。
	if sessionID != "" {
		ownerID, err := s.ctxMgr().GetSessionOwnerID(r.Context(), sessionID)
		if err != nil || ownerID <= 0 || ownerID != userID {
			writeJSONResponse(w, http.StatusForbidden, map[string]string{
				"error_code": "ERR_FORBIDDEN",
				"message":    "无权访问该会话上下文",
			})
			return
		}
	}

	uCtx, err := s.ctxMgr().GetUserContext(r.Context(), projectID, userID, sessionID)
	if err != nil {
		writeDomainError(w, r, http.StatusInternalServerError, err)
		return
	}

	writeJSONResponse(w, http.StatusOK, uCtx)
}

// handleUpdateUserPreference 定期整理或前端保存用户习惯偏好
func (s *Server) handleUpdateUserPreference(w http.ResponseWriter, r *http.Request) {
	user, ok := s.requireAuthenticatedUser(w, r)
	if !ok {
		return
	}
	var req UpdateUserPreferenceRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeDomainError(w, r, http.StatusBadRequest, err)
		return
	}
	if req.UserID <= 0 {
		req.UserID = user.ID
	}
	if req.UserID != user.ID && !s.isSystemAdminUser(r.Context(), user) {
		writeJSONResponse(w, http.StatusForbidden, map[string]string{
			"error_code": "ERR_FORBIDDEN",
			"message":    "无权修改其他用户的偏好",
		})
		return
	}

	if s.ctxMgr() == nil {
		writeSafeError(w, r, http.StatusServiceUnavailable, "context manager not initialized")
		return
	}

	pref := &ctxmgr.UserPreference{
		UserID:             req.UserID,
		CommunicationStyle: req.CommunicationStyle,
		FocusAreas:         req.FocusAreas,
		OutputFormatPref:   req.OutputFormatPref,
		CustomInstructions: req.CustomInstructions,
	}

	if err := s.ctxMgr().UpdateUserPreference(r.Context(), pref); err != nil {
		writeDomainError(w, r, http.StatusInternalServerError, err)
		return
	}

	writeJSONResponse(w, http.StatusOK, map[string]any{"status": "ok", "user_id": req.UserID})
}

// handleGetProjectContext 获取项目级多方协同事实黑板与里程碑决策流
func (s *Server) handleGetProjectContext(w http.ResponseWriter, r *http.Request) {
	user, ok := s.requireAuthenticatedUser(w, r)
	if !ok {
		return
	}

	projectIDStr := r.URL.Query().Get("project_id")
	projectID, _ := strconv.ParseInt(projectIDStr, 10, 64)
	if projectID <= 0 {
		writeSafeError(w, r, http.StatusBadRequest, "missing or invalid project_id query param")
		return
	}

	// Membership first: allowAnyStageAccess assumes the caller already passed
	// project membership (see ResolveStageAccess). Without this guard any
	// authenticated user can read an activated project's collaborative context.
	if !s.enforceChatProjectAccess(w, r, user, projectID) {
		return
	}
	if !s.allowAnyStageAccess(r.Context(), projectID, user.ID) {
		s.writeWorkflowAccessDenied(w)
		return
	}

	if s.ctxMgr() == nil {
		writeSafeError(w, r, http.StatusServiceUnavailable, "context manager not initialized")
		return
	}

	pCtx, err := s.ctxMgr().GetProjectContext(r.Context(), projectID)
	if err != nil {
		writeDomainError(w, r, http.StatusInternalServerError, err)
		return
	}

	writeJSONResponse(w, http.StatusOK, pCtx)
}