// 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 imports

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"log"
	"strings"

	"gemma.intevation.de/gemma/pkg/common"
	"gemma.intevation.de/gemma/pkg/models"
	"gemma.intevation.de/gemma/pkg/soap"
	"gemma.intevation.de/gemma/pkg/soap/erdms"
)

type WaterwayGauge struct {
	// URL is the URL of the SOAP service.
	URL string `json:"url"`
	// Username is the username used to authenticate.
	Username string `json:"username"`
	// Passwort is the password to authenticate.
	Password string `json:"password"`
	// Insecure indicates if HTTPS traffic
	// should validate certificates or not.
	Insecure bool `json:"insecure"`
}

const WGJobKind JobKind = "wg"

type wgJobCreator struct{}

func init() {
	RegisterJobCreator(WGJobKind, wgJobCreator{})
}

func (wgJobCreator) Description() string { return "waterway gauges" }

func (wgJobCreator) AutoAccept() bool { return true }

func (wgJobCreator) Create(_ JobKind, data string) (Job, error) {
	wg := new(WaterwayGauge)
	if err := common.FromJSONString(data, wg); err != nil {
		return nil, err
	}
	return wg, nil
}

func (wgJobCreator) Depends() []string {
	return []string{
		"gauges",
		"gauges_reference_water_levels",
	}
}

// StageDone does nothing as there is no staging for gauges.
func (wgJobCreator) StageDone(context.Context, *sql.Tx, int64) error { return nil }

// CleanUp does nothing as there is nothing to cleanup with gauges.
func (*WaterwayGauge) CleanUp() error { return nil }

const (
	selectCurrentUserCountrySQL = `SELECT users.current_user_country()`

	hasGaugeSQL = `
SELECT true
FROM waterway.gauges
WHERE location = ($1::char(2), $2::char(3), $3::char(5), $4::char(5), $5::int)`

	deleteReferenceWaterLevelsSQL = `
DELETE FROM waterway.gauges_reference_water_levels
WHERE gauge_id = ($1::char(2), $2::char(3), $3::char(5), $4::char(5), $5::int)`

	deleteGaugeSQL = `
DELETE FROM waterway.gauges
WHERE location = ($1::char(2), $2::char(3), $3::char(5), $4::char(5), $5::int)`
)

func (wg *WaterwayGauge) Do(
	ctx context.Context,
	importID int64,
	conn *sql.Conn,
	feedback Feedback,
) (interface{}, error) {

	tx, err := conn.BeginTx(ctx, nil)
	if err != nil {
		return nil, err
	}
	defer tx.Rollback()

	var country string
	err = tx.QueryRowContext(ctx, selectCurrentUserCountrySQL).Scan(&country)
	switch {
	case err == sql.ErrNoRows:
		return nil, errors.New("Cannot figure out user country")
	case err != nil:
		return nil, err
	}

	country = strings.ToUpper(country)
	feedback.Info("Using country '%s'.", country)

	var auth *soap.BasicAuth
	if wg.Username != "" {
		auth = &soap.BasicAuth{
			Login:    wg.Username,
			Password: wg.Password,
		}
	}

	client := erdms.NewRefService(wg.URL, wg.Insecure, auth)

	request := &erdms.GetRisDataXML{
		GetRisDataXMLType: &erdms.GetRisDataXMLType{
			Subcode: erdms.NoNS{Text: country + "%"},
			Funcode: erdms.NoNS{Text: "wtwgag"},
		},
	}

	data, err := client.GetRisDataXML(request)

	if err != nil {
		log.Printf("error: %v\n", err)
		return nil, fmt.Errorf("Error requesting ERDMS service: %v", err)
	}

	hasGaugeStmt, err := tx.PrepareContext(ctx, hasGaugeSQL)
	if err != nil {
		return nil, err
	}
	defer hasGaugeStmt.Close()

	var ignored int

	type idxCode struct {
		idx  int
		code *models.Isrs
	}

	var news, olds []idxCode

	for i, dr := range data.RisdataReturn {
		if dr.RisidxCode == nil {
			ignored++
			continue
		}
		code, err := models.IsrsFromString(string(*dr.RisidxCode))
		if err != nil {
			feedback.Warn("invalid ISRS code %v", err)
			ignored++
			continue
		}

		if dr.Objname.Loc == nil {
			feedback.Warn("missing objname: %s", code)
			ignored++
			continue
		}

		if dr.Lat == nil || dr.Lon == nil {
			feedback.Warn("missing lat/lon: %s", code)
			ignored++
			continue
		}

		if dr.Zeropoint == nil {
			feedback.Warn("missing zeropoint: %s", code)
			ignored++
			continue
		}

		var dummy bool
		err = hasGaugeStmt.QueryRowContext(ctx,
			code.CountryCode,
			code.LoCode,
			code.FairwaySection,
			code.Orc,
			code.Hectometre,
		).Scan(&dummy)
		switch {
		case err == sql.ErrNoRows:
			olds = append(olds, idxCode{idx: i, code: code})
		case err != nil:
			return nil, err
		case !dummy:
			return nil, errors.New("Unexpected result")
		default:
			news = append(news, idxCode{idx: i, code: code})
		}
	}
	feedback.Info("ignored gauges: %d", ignored)
	feedback.Info("new gauges: %d", len(news))
	feedback.Info("update gauges: %d", len(olds))

	if len(news) == 0 && len(olds) == 0 {
		return nil, errors.New("nothing to do")
	}

	// delete the old
	if len(olds) > 0 {
		deleteReferenceWaterLevelsStmt, err := tx.PrepareContext(ctx, deleteReferenceWaterLevelsSQL)
		if err != nil {
			return nil, err
		}
		defer deleteReferenceWaterLevelsStmt.Close()
		deleteGaugeStmt, err := tx.PrepareContext(ctx, deleteGaugeSQL)
		if err != nil {
			return nil, err
		}
		for i := range olds {
			ic := &olds[i]

			if _, err := deleteReferenceWaterLevelsStmt.ExecContext(ctx,
				ic.code.CountryCode,
				ic.code.LoCode,
				ic.code.FairwaySection,
				ic.code.Orc,
				ic.code.Hectometre,
			); err != nil {
				return nil, err
			}
			if _, err := deleteGaugeStmt.ExecContext(ctx,
				ic.code.CountryCode,
				ic.code.LoCode,
				ic.code.FairwaySection,
				ic.code.Orc,
				ic.code.Hectometre,
			); err != nil {
				return nil, err
			}
		}
		// treat them as new
		news = append(news, olds...)
	}

	// TODO: Implement me!
	return nil, errors.New("Not implemented, yet!")
}