package memory

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

	"aigateway.local/core/internal/identity"
	"aigateway.local/core/internal/platform/apiresponse"
)

// HTTPHandler 提供门户个人记忆 CRUD 与召回。
type HTTPHandler struct {
	service  *Service
	identity *identity.Service
	mux      *http.ServeMux
}

func NewHTTPHandler(service *Service, identityService *identity.Service) *HTTPHandler {
	h := &HTTPHandler{service: service, identity: identityService, mux: http.NewServeMux()}
	h.mux.HandleFunc("GET /api/v1/portal/memories", h.list)
	h.mux.HandleFunc("POST /api/v1/portal/memories", h.save)
	h.mux.HandleFunc("PUT /api/v1/portal/memories/{id}", h.save)
	h.mux.HandleFunc("DELETE /api/v1/portal/memories/{id}", h.delete)
	h.mux.HandleFunc("POST /api/v1/portal/memories/recall", h.recall)
	return h
}

func (h *HTTPHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { h.mux.ServeHTTP(w, r) }

func (h *HTTPHandler) account(w http.ResponseWriter, r *http.Request) (identity.Account, bool) {
	account, err := h.identity.Authenticate(r.Context(), identity.KindPortal, r.Header.Get("Authorization"))
	if err != nil {
		apiresponse.Error(w, http.StatusUnauthorized, "登录状态无效或已过期")
		return identity.Account{}, false
	}
	return account, true
}

type memoryInput struct {
	Category   string   `json:"category"`
	Content    string   `json:"content"`
	Importance int      `json:"importance"`
	SharedWith []string `json:"shared_with"`
	Source     string   `json:"source"`
}

func (h *HTTPHandler) decode(w http.ResponseWriter, r *http.Request) (memoryInput, bool) {
	var input memoryInput
	decoder := json.NewDecoder(http.MaxBytesReader(w, r.Body, 1<<20))
	decoder.DisallowUnknownFields()
	if decoder.Decode(&input) != nil {
		apiresponse.Error(w, http.StatusBadRequest, "请求格式无效")
		return input, false
	}
	return input, true
}

func (h *HTTPHandler) list(w http.ResponseWriter, r *http.Request) {
	a, ok := h.account(w, r)
	if !ok {
		return
	}
	items, err := h.service.List(r.Context(), OwnerUser, a.ID, 200)
	if err != nil {
		apiresponse.Error(w, http.StatusServiceUnavailable, "记忆查询失败")
		return
	}
	apiresponse.OK(w, items)
}

func (h *HTTPHandler) save(w http.ResponseWriter, r *http.Request) {
	a, ok := h.account(w, r)
	if !ok {
		return
	}
	input, ok := h.decode(w, r)
	if !ok {
		return
	}
	entry, err := h.service.Save(r.Context(), OwnerUser, a.ID, r.PathValue("id"), input.Category, input.Content, input.Source, input.Importance, input.SharedWith, a.ID)
	if err != nil {
		apiresponse.Error(w, http.StatusBadRequest, err.Error())
		return
	}
	apiresponse.OK(w, entry)
}

func (h *HTTPHandler) delete(w http.ResponseWriter, r *http.Request) {
	a, ok := h.account(w, r)
	if !ok {
		return
	}
	entry, err := h.service.Get(r.Context(), r.PathValue("id"))
	if err != nil {
		apiresponse.Error(w, http.StatusNotFound, "记忆不存在")
		return
	}
	// 仅本人或共享给本人的可删。
	if entry.OwnerKind == OwnerUser && entry.OwnerID != a.ID {
		apiresponse.Error(w, http.StatusForbidden, "无权删除该记忆")
		return
	}
	if err := h.service.Delete(r.Context(), r.PathValue("id")); err != nil {
		apiresponse.Error(w, http.StatusBadRequest, err.Error())
		return
	}
	apiresponse.OK(w, map[string]bool{"deleted": true})
}

func (h *HTTPHandler) recall(w http.ResponseWriter, r *http.Request) {
	a, ok := h.account(w, r)
	if !ok {
		return
	}
	var input struct {
		Query string `json:"query"`
		Limit int    `json:"limit"`
	}
	decoder := json.NewDecoder(http.MaxBytesReader(w, r.Body, 1<<20))
	decoder.DisallowUnknownFields()
	if decoder.Decode(&input) != nil || input.Query == "" {
		apiresponse.Error(w, http.StatusBadRequest, "查询内容不能为空")
		return
	}
	if input.Limit <= 0 {
		input.Limit = 5
	}
	items, err := h.service.Recall(r.Context(), a.ID, a.DepartmentID, input.Query, input.Limit)
	if err != nil {
		apiresponse.Error(w, http.StatusServiceUnavailable, "记忆召回失败")
		return
	}
	apiresponse.OK(w, items)
}

var _ = strconv.Itoa