/*
Copyright 2011 The Perkeep Authors

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package server

import (
	"io"
	"log"
	"net/http"

	"go4.org/types"
	"perkeep.org/internal/httputil"
	"perkeep.org/pkg/blob"
	"perkeep.org/pkg/schema"
)

// uploadHelperResponse is the response from serveUploadHelper.
type uploadHelperResponse struct {
	Got []*uploadHelperGotItem `json:"got"`
}

type uploadHelperGotItem struct {
	FileName string         `json:"filename"`
	ModTime  types.Time3339 `json:"modtime"`
	FormName string         `json:"formname"`
	FileRef  blob.Ref       `json:"fileref"`
}

func (ui *UIHandler) serveUploadHelper(rw http.ResponseWriter, req *http.Request) {
	ctx := req.Context()
	if ui.root.Storage == nil {
		httputil.ServeJSONError(rw, httputil.ServerError("No BlobRoot configured"))
		return
	}

	mr, err := req.MultipartReader()
	if err != nil {
		httputil.ServeJSONError(rw, httputil.ServerError("reading body: "+err.Error()))
		return
	}

	var got []*uploadHelperGotItem
	var modTime types.Time3339
	for {
		part, err := mr.NextPart()
		if err == io.EOF {
			break
		}
		if err != nil {
			httputil.ServeJSONError(rw, httputil.ServerError("reading body: "+err.Error()))
			break
		}
		if part.FormName() == "modtime" {
			payload, err := io.ReadAll(part)
			if err != nil {
				log.Printf("ui uploadhelper: unable to read part for modtime: %v", err)
				continue
			}
			modTime = types.ParseTime3339OrZero(string(payload))
			continue
		}
		fileName := part.FileName()
		if fileName == "" {
			continue
		}
		br, err := schema.WriteFileFromReaderWithModTime(ctx, ui.root.Storage, fileName, modTime.Time(), part)
		if err != nil {
			httputil.ServeJSONError(rw, httputil.ServerError("writing to blobserver: "+err.Error()))
			return
		}
		got = append(got, &uploadHelperGotItem{
			FileName: part.FileName(),
			ModTime:  modTime,
			FormName: part.FormName(),
			FileRef:  br,
		})
	}

	httputil.ReturnJSON(rw, &uploadHelperResponse{Got: got})
}