package server

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

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

// handleChatSearch 处理消息三模检索 (keyword/fuzzy/semantic/hybrid)
// GET /api/v1/chat/search?session_id=&q=&mode=&category=&date_from=&date_to=&limit=&user_id=
func (s *Server) handleChatSearch(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
		return
	}

	user, ok := s.requireAuthenticatedUser(w, r)
	if !ok {
		return
	}

	if s.svc == nil || s.svc.ContextManager() == nil {
		http.Error(w, "context manager not initialized", http.StatusServiceUnavailable)
		return
	}

	sessionID := strings.TrimSpace(r.URL.Query().Get("session_id"))
	if sessionID == "" {
		http.Error(w, "missing required query param 'session_id'", http.StatusBadRequest)
		return
	}

	authCtx, ok := s.authorizeSessionRead(w, r, sessionID, user)
	if !ok {
		return
	}

	query := strings.TrimSpace(r.URL.Query().Get("q"))
	if query == "" {
		http.Error(w, "missing or empty query param 'q'", http.StatusBadRequest)
		return
	}

	mode := ctxmgr.ChatSearchMode(strings.TrimSpace(r.URL.Query().Get("mode")))
	category := strings.TrimSpace(r.URL.Query().Get("category"))
	dateFrom := strings.TrimSpace(r.URL.Query().Get("date_from"))
	dateTo := strings.TrimSpace(r.URL.Query().Get("date_to"))

	limit := 50
	if limStr := r.URL.Query().Get("limit"); limStr != "" {
		if val, err := strconv.Atoi(limStr); err == nil && val > 0 {
			limit = val
		}
	}

	searchQuery := ctxmgr.ChatSearchQuery{
		SessionID: sessionID,
		UserID:    user.ID,
		Query:     query,
		Mode:      mode,
		Category:  category,
		DateFrom:  dateFrom,
		DateTo:    dateTo,
		Limit:     limit,
	}

	hits, err := s.svc.ContextManager().SearchChatMessages(r.Context(), searchQuery)
	if err != nil {
		http.Error(w, "SearchChatMessages error: "+err.Error(), http.StatusInternalServerError)
		return
	}

	hits = s.filterChatSearchHitsByAuth(authCtx, hits)

	if hits == nil {
		hits = []ctxmgr.ChatSearchHit{}
	}

	w.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(w).Encode(hits)
}