package app

import (
	"archive/zip"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"strconv"

	"github.com/andyleap/hnh-map/internal/app/store"
	"go.etcd.io/bbolt"
)

type mapData struct {
	Grids   map[string]string
	Markers map[string][]Marker
}

func (a *App) export(rw http.ResponseWriter, req *http.Request) {
	s := a.getSession(req)
	if s == nil || !s.Auths.Has(AUTH_ADMIN) {
		http.Error(rw, "Unauthorized", http.StatusUnauthorized)
		return
	}
	rw.Header().Set("Content-Type", "application/zip")
	rw.Header().Set("Content-Disposition", "attachment; filename=\"griddata.zip\"")

	zw := zip.NewWriter(rw)
	defer zw.Close()

	err := a.db.Update(func(tx *bbolt.Tx) error {
		maps := map[int]mapData{}
		gridMap := map[string]int{}

		grids := tx.Bucket(store.BucketGrids)
		if grids == nil {
			return nil
		}
		tiles := tx.Bucket(store.BucketTiles)
		if tiles == nil {
			return nil
		}

		err := grids.ForEach(func(k, v []byte) error {
			gd := GridData{}
			err := json.Unmarshal(v, &gd)
			if err != nil {
				return err
			}
			md, ok := maps[gd.Map]
			if !ok {
				md = mapData{
					Grids:   map[string]string{},
					Markers: map[string][]Marker{},
				}
				maps[gd.Map] = md
			}
			md.Grids[gd.Coord.Name()] = gd.ID
			gridMap[gd.ID] = gd.Map
			mapb := tiles.Bucket([]byte(strconv.Itoa(gd.Map)))
			if mapb == nil {
				return nil
			}
			zoom := mapb.Bucket([]byte("0"))
			if zoom == nil {
				return nil
			}
			tdraw := zoom.Get([]byte(gd.Coord.Name()))
			if tdraw == nil {
				return nil
			}
			td := TileData{}
			err = json.Unmarshal(tdraw, &td)
			if err != nil {
				return err
			}
			w, err := zw.Create(fmt.Sprintf("%d/%s.png", gd.Map, gd.ID))
			if err != nil {
				return err
			}
			f, err := os.Open(filepath.Join(a.gridStorage, td.File))
			if err != nil {
				return err
			}
			_, err = io.Copy(w, f)
			f.Close()
			return err
		})
		if err != nil {
			return err
		}

		err = func() error {
			markersb := tx.Bucket(store.BucketMarkers)
			if markersb == nil {
				return nil
			}
			markersgrid := markersb.Bucket(store.BucketMarkersGrid)
			if markersgrid == nil {
				return nil
			}
			return markersgrid.ForEach(func(k, v []byte) error {
				marker := Marker{}
				err := json.Unmarshal(v, &marker)
				if err != nil {
					return nil
				}
				if _, ok := maps[gridMap[marker.GridID]]; ok {
					maps[gridMap[marker.GridID]].Markers[marker.GridID] = append(maps[gridMap[marker.GridID]].Markers[marker.GridID], marker)
				}
				return nil
			})
		}()
		if err != nil {
			return err
		}

		for mapid, mapdata := range maps {
			w, err := zw.Create(fmt.Sprintf("%d/grids.json", mapid))
			if err != nil {
				return err
			}
			json.NewEncoder(w).Encode(mapdata)
		}
		return nil
	})
	if err != nil {
		log.Println(err)
	}
}