package server

import (
	"encoding/json"
	"fmt"
	"net/http"
	"regexp"
	"sort"
	"strconv"

	"github.com/usememos/memos/api"

	"github.com/labstack/echo/v4"
)

func (s *Server) registerTagRoutes(g *echo.Group) {
	g.GET("/tag", func(c echo.Context) error {
		userID, ok := c.Get(getUserIDContextKey()).(int)
		if !ok {
			if c.QueryParam("userID") != "" {
				var err error
				userID, err = strconv.Atoi(c.QueryParam("userID"))
				if err != nil {
					return echo.NewHTTPError(http.StatusBadRequest, fmt.Sprintf("ID is not a number: %s", c.QueryParam("userID")))
				}
			} else {
				ownerUserType := api.Owner
				ownerUser, err := s.Store.FindUser(&api.UserFind{
					Role: &ownerUserType,
				})
				if err != nil {
					return echo.NewHTTPError(http.StatusInternalServerError, "Failed to find owner user").SetInternal(err)
				}
				if ownerUser == nil {
					return echo.NewHTTPError(http.StatusNotFound, "Owner user do not exist")
				}
				userID = ownerUser.ID
			}
		}

		contentSearch := "#"
		normalRowStatus := api.Normal
		memoFind := api.MemoFind{
			CreatorID:     &userID,
			ContentSearch: &contentSearch,
			RowStatus:     &normalRowStatus,
		}

		memoList, err := s.Store.FindMemoList(&memoFind)
		if err != nil {
			return echo.NewHTTPError(http.StatusInternalServerError, "Failed to find memo list").SetInternal(err)
		}

		tagMapSet := make(map[string]bool)

		r, err := regexp.Compile("#(.+?) ")
		if err != nil {
			return echo.NewHTTPError(http.StatusInternalServerError, "Failed to compile regexp").SetInternal(err)
		}
		for _, memo := range memoList {
			for _, rawTag := range r.FindAllString(memo.Content, -1) {
				tag := r.ReplaceAllString(rawTag, "$1")
				tagMapSet[tag] = true
			}
		}

		tagList := []string{}
		for tag := range tagMapSet {
			tagList = append(tagList, tag)
		}

		sort.Strings(tagList)

		c.Response().Header().Set(echo.HeaderContentType, echo.MIMEApplicationJSONCharsetUTF8)
		if err := json.NewEncoder(c.Response().Writer).Encode(composeResponse(tagList)); err != nil {
			return echo.NewHTTPError(http.StatusInternalServerError, "Failed to encode tags response").SetInternal(err)
		}
		return nil
	})
}