// 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 (
	"fmt"
	"log"
	"net/http"
	"os"
	"strconv"
	"time"

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

const maxUploadSize = 25 * 1024 * 1024

type BadUploadParameterError string

func importWaterwayProfiles() http.HandlerFunc {
	return uploadedImport(
		imports.WPJobKind,
		"wp.csv",
		func(req *http.Request, dir string) (imports.Job, error) {
			url := req.FormValue("url")
			if url == "" {
				return nil, BadUploadParameterError("missing 'url' parameter")
			}

			featureType := req.FormValue("feature-type")
			if featureType == "" {
				return nil, BadUploadParameterError("missing 'feature-type' parameter")
			}

			sortBy := req.FormValue("sort-by")

			var precision *float64
			if p := req.FormValue("precision"); p != "" {
				v, err := strconv.ParseFloat(p, 64)
				if err != nil {
					return nil, BadUploadParameterError(
						fmt.Sprintf("Invalid 'precision' parameter: %v", err))
				}
				precision = &v
			}

			return &imports.WaterwayProfiles{
				Dir:         dir,
				URL:         url,
				FeatureType: featureType,
				SortBy:      sortBy,
				Precision:   precision,
			}, nil
		},
	)
}

func importApprovedGaugeMeasurements() http.HandlerFunc {
	return uploadedImport(
		imports.AGMJobKind,
		"agm.csv",
		func(req *http.Request, dir string) (imports.Job, error) {
			originator := req.FormValue("originator")
			if originator == "" {
				return nil, BadUploadParameterError("missing 'originator' parameter")
			}

			return &imports.ApprovedGaugeMeasurements{
				Dir:        dir,
				Originator: originator,
			}, nil
		},
	)
}

func importUploadedBottleneck() http.HandlerFunc {
	return uploadedImport(
		imports.UBNJobKind,
		"data.xml",
		func(_ *http.Request, dir string) (imports.Job, error) {
			// TODO expose tolerance to endpoint
			return &imports.UploadedBottleneck{Dir: dir, Tolerance: 5}, nil
		},
	)
}

func importUploadedFairwayAvailability() http.HandlerFunc {
	return uploadedImport(
		imports.UFAJobKind,
		"data.xml",
		func(_ *http.Request, dir string) (imports.Job, error) {
			return &imports.UploadedFairwayAvailability{Dir: dir}, nil
		},
	)
}

func importUploadedGaugeMeasurement() http.HandlerFunc {
	return uploadedImport(
		imports.UGMJobKind,
		"data.xml",
		func(_ *http.Request, dir string) (imports.Job, error) {
			return &imports.UploadedGaugeMeasurement{Dir: dir}, nil
		},
	)
}

func (bup BadUploadParameterError) Error() string {
	return string(bup)
}

func uploadedImport(
	kind imports.JobKind,
	fname string,
	create func(*http.Request, string) (imports.Job, error),
) http.HandlerFunc {

	return func(rw http.ResponseWriter, req *http.Request) {
		dir, err := misc.StoreUploadedFile(
			req,
			string(kind),
			fname,
			maxUploadSize)
		if err != nil {
			log.Printf("error: %v\n", err)
			http.Error(rw, "error: "+err.Error(), http.StatusInternalServerError)
			return
		}

		job, err := create(req, dir)
		if err != nil {
			if err2 := os.RemoveAll(dir); err2 != nil {
				log.Printf("warn: %v\n", err2)
			}
			if err2, ok := err.(BadUploadParameterError); ok {
				http.Error(rw, string(err2), http.StatusBadRequest)
				return
			}
			log.Printf("error: %v\n", err)
			http.Error(rw, "error: "+err.Error(), http.StatusInternalServerError)
			return
		}

		serialized, err := common.ToJSONString(job)
		if err != nil {
			log.Printf("error: %v\n", err)
			http.Error(rw, "error: "+err.Error(), http.StatusInternalServerError)
			return
		}

		session, _ := auth.GetSession(req)

		sendEmail := req.FormValue("email") != ""

		jobID, err := imports.AddJob(
			kind,
			time.Time{}, // due
			nil,         // trys
			nil,         // retry wait
			session.User,
			sendEmail,
			serialized)

		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)
	}
}