package server

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

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

// handleListDailyDigests 获取会话的历史每日摘要列表 (时间轴侧栏数据源)
// GET /api/v1/chat/digests?session_id=&from=&to=
func (s *Server) handleListDailyDigests(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
		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
	}

	from := strings.TrimSpace(r.URL.Query().Get("from"))
	to := strings.TrimSpace(r.URL.Query().Get("to"))

	digests, err := s.svc.ContextManager().ListDailyDigests(r.Context(), sessionID, from, to)
	if err != nil {
		http.Error(w, "ListDailyDigests error: "+err.Error(), http.StatusInternalServerError)
		return
	}

	if digests == nil {
		digests = []ctxmgr.DailyDigest{}
	}

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

// GenerateDigestRequest 手动触发单日摘要生成请求体
type GenerateDigestRequest struct {
	SessionID string `json:"session_id"`
	DayKey    string `json:"day_key"`
}

// handleGenerateDailyDigest 手动触发或重试生成单日摘要
// POST /api/v1/chat/digests/generate
func (s *Server) handleGenerateDailyDigest(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
		return
	}

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

	var req GenerateDigestRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid request json body: "+err.Error(), http.StatusBadRequest)
		return
	}

	req.SessionID = strings.TrimSpace(req.SessionID)
	req.DayKey = strings.TrimSpace(req.DayKey)

	if req.SessionID == "" || req.DayKey == "" {
		http.Error(w, "missing required fields 'session_id' or 'day_key'", http.StatusBadRequest)
		return
	}

	digest, err := s.svc.ContextManager().GenerateDailyDigest(r.Context(), req.SessionID, req.DayKey)
	if err != nil {
		http.Error(w, "GenerateDailyDigest error: "+err.Error(), http.StatusInternalServerError)
		return
	}

	resp := map[string]any{
		"queued": true,
		"digest": digest,
	}

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