// This is Free Software under GNU Affero General Public License v >= 3.0
// without warranty, see README.md and license for details.
//
// SPDX-License-Identifier: AGPL-3.0-or-later
// License-Filename: LICENSES/AGPL-3.0.txt
//
// Copyright (C) 2018 by via donau
//   – Österreichische Wasserstraßen-Gesellschaft mbH
// Software engineering by Intevation GmbH
//
// Author(s):
//  * Sascha L. Teichmann <sascha.teichmann@intevation.de>

package controllers

import (
	"bufio"
	"encoding/hex"
	"io"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"time"

	"gemma.intevation.de/gemma/pkg/auth"
	"gemma.intevation.de/gemma/pkg/config"
	"gemma.intevation.de/gemma/pkg/imports"
	"gemma.intevation.de/gemma/pkg/misc"
)

const (
	maxSoundingResultSize = 25 * 1024 * 1024
	soundingResultName    = "soundingresult"
)

func downloadSoundingResult(req *http.Request) (string, error) {

	// Check first if we have a token.
	if token := req.FormValue("token"); token != "" {
		if _, err := hex.DecodeString(token); err != nil {
			return "", err
		}
		dir := config.TmpDir()
		if dir == "" {
			dir = os.TempDir()
		}
		// XXX: This should hopefully be race-free enough.
		now := time.Now().Format("2006-15-04-05")
		dst := filepath.Join(dir, soundingResultName+"-"+token+"-"+now)
		if err := misc.UnmakeTempFile(token, dst); err != nil {
			return "", err
		}
	}

	// Check for direct upload.
	f, _, err := req.FormFile(soundingResultName)
	if err != nil {
		return "", err
	}
	defer f.Close()

	dir, err := ioutil.TempDir(config.TmpDir(), soundingResultName)
	if err != nil {
		return "", err
	}

	o, err := os.Create(filepath.Join(dir, "sr.zip"))
	if err != nil {
		os.RemoveAll(dir)
		return "", err
	}

	out := bufio.NewWriter(o)

	if _, err = io.Copy(out, io.LimitReader(f, maxSoundingResultSize)); err != nil {
		o.Close()
		os.RemoveAll(dir)
		return "", err
	}

	if err = out.Flush(); err != nil {
		o.Close()
		os.RemoveAll(dir)
		return "", err
	}

	return dir, nil
}

func importSoundingResult(rw http.ResponseWriter, req *http.Request) {

	dir, err := downloadSoundingResult(req)
	if err != nil {
		log.Printf("error: %v\n", err)
		http.Error(rw, "error: "+err.Error(), http.StatusInternalServerError)
		return
	}

	session, _ := auth.GetSession(req)

	jobID, err := imports.AddJob(imports.SRJobKind, session.User, dir)
	if err != nil {
		log.Printf("error: %v\n", err)
		http.Error(rw, "error: "+err.Error(), http.StatusInternalServerError)
		return
	}

	log.Printf("info: added import #%d to queue\n", jobID)

	result := struct {
		ID int64 `json:"id"`
	}{
		ID: jobID,
	}
	SendJSON(rw, http.StatusCreated, &result)
}