// 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, 2019 by via donau
//   – Österreichische Wasserstraßen-Gesellschaft mbH
// Software engineering by Intevation GmbH
//
// Author(s):
//  * Sascha L. Teichmann <sascha.teichmann@intevation.de>
//  * Tom Gottfried <tom.gottfried@intevation.de>

package imports

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

	"github.com/jackc/pgx/pgtype"

	"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() Job { return new(WaterwayGauge) }

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)`

	insertGaugeSQL = `
INSERT INTO waterway.gauges (
  location,
  objname,
  geom,
  applicability_from_km,
  applicability_to_km,
  validity,
  zero_point,
  geodref,
  date_info,
  source_organization
) VALUES (
  ($1::char(2), $2::char(3), $3::char(5), $4::char(5), $5::int),
  $6,
  ST_SetSRID(ST_MakePoint($7, $8), 4326)::geography,
  $9,
  $10,
  $11,
  $12,
  $13,
  $14,
  $15
) ON CONFLICT (location) DO UPDATE SET
  objname = $6,
  geom = ST_SetSRID(ST_MakePoint($7, $8), 4326)::geography,
  applicability_from_km = $9,
  applicability_to_km = $10,
  validity = $11,
  zero_point = $12,
  geodref = $13,
  date_info = $14,
  source_organization = $15
`
	isNtSDepthRefSQL = `
SELECT EXISTS(SELECT 1 FROM depth_references WHERE depth_reference = $1)`

	insertReferenceWaterLevelsSQL = `
INSERT INTO waterway.gauges_reference_water_levels (
  gauge_id,
  depth_reference,
  value
) VALUES (
  ($1::char(2), $2::char(3), $3::char(5), $4::char(5), $5::int),
  $6,
  $7
)
`
)

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

	start := time.Now()

	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 {
		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:
			news = append(news, idxCode{idx: i, code: code})
		case err != nil:
			return nil, err
		case !dummy:
			return nil, errors.New("Unexpected result")
		default:
			olds = append(olds, 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, UnchangedError("nothing to do")
	}

	// delete reference water leves of the old.
	if len(olds) > 0 {
		deleteReferenceWaterLevelsStmt, err := tx.PrepareContext(
			ctx, deleteReferenceWaterLevelsSQL)
		if err != nil {
			return nil, err
		}
		defer deleteReferenceWaterLevelsStmt.Close()
		for i := range olds {
			code := olds[i].code
			if _, err := deleteReferenceWaterLevelsStmt.ExecContext(ctx,
				code.CountryCode,
				code.LoCode,
				code.FairwaySection,
				code.Orc,
				code.Hectometre,
			); err != nil {
				return nil, err
			}
		}
		// treat them as new
		news = append(news, olds...)
	}

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

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

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

	// insert/update the gauges
	for i := range news {
		ic := &news[i]
		dr := data.RisdataReturn[ic.idx]

		feedback.Info("insert/update %s", ic.code)

		var from, to sql.NullInt64

		if dr.Applicabilityfromkm != nil {
			from = sql.NullInt64{
				Int64: int64(*dr.Applicabilityfromkm),
				Valid: true,
			}
		}
		if dr.Applicabilitytokm != nil {
			to = sql.NullInt64{
				Int64: int64(*dr.Applicabilitytokm),
				Valid: true,
			}
		}

		var tfrom, tto, dateInfo pgtype.Timestamptz

		if dr.Startdate != nil {
			tfrom = pgtype.Timestamptz{
				Time:   time.Time(*dr.Startdate),
				Status: pgtype.Present,
			}
		} else {
			tfrom = pgtype.Timestamptz{
				Status: pgtype.Null,
			}
		}

		if dr.Enddate != nil {
			tto = pgtype.Timestamptz{
				Time:   time.Time(*dr.Enddate),
				Status: pgtype.Present,
			}
		} else {
			tto = pgtype.Timestamptz{
				Status: pgtype.Null,
			}
		}

		validity := pgtype.Tstzrange{
			Lower:     tfrom,
			Upper:     tto,
			LowerType: pgtype.Inclusive,
			UpperType: pgtype.Inclusive,
			Status:    pgtype.Present,
		}

		if dr.Infodate != nil {
			dateInfo = pgtype.Timestamptz{
				Time:   time.Time(*dr.Infodate),
				Status: pgtype.Present,
			}
		} else {
			dateInfo = pgtype.Timestamptz{
				Status: pgtype.Null,
			}
		}

		var geodref sql.NullString
		if dr.Geodref != nil {
			geodref = sql.NullString{
				String: string(*dr.Geodref),
				Valid:  true,
			}
		}

		var source sql.NullString
		if dr.Source != nil {
			source = sql.NullString{
				String: string(*dr.Source),
				Valid:  true,
			}
		}

		if _, err := insertStmt.ExecContext(ctx,
			ic.code.CountryCode,
			ic.code.LoCode,
			ic.code.FairwaySection,
			ic.code.Orc,
			ic.code.Hectometre,
			string(*dr.Objname.Loc),
			float64(*dr.Lon), float64(*dr.Lat),
			from,
			to,
			&validity,
			float64(*dr.Zeropoint),
			geodref,
			&dateInfo,
			source,
		); err != nil {
			return nil, err
		}

		for _, wl := range []struct {
			level **erdms.RisreflevelcodeType
			value **erdms.RisreflevelvalueType
		}{
			{&dr.Reflevel1code, &dr.Reflevel1value},
			{&dr.Reflevel2code, &dr.Reflevel2value},
			{&dr.Reflevel3code, &dr.Reflevel3value},
		} {
			if *wl.level == nil || *wl.value == nil {
				continue
			}

			var isNtSDepthRef bool
			if err := isNtSDepthRefStmt.QueryRowContext(
				ctx,
				string(**wl.level),
			).Scan(
				&isNtSDepthRef,
			); err != nil {
				return nil, err
			}
			if !isNtSDepthRef {
				feedback.Warn(
					"Reference level code '%s' is not in line with the NtS reference_code table",
					string(**wl.level))
			}

			if _, err := insertWaterLevelStmt.ExecContext(
				ctx,
				ic.code.CountryCode,
				ic.code.LoCode,
				ic.code.FairwaySection,
				ic.code.Orc,
				ic.code.Hectometre,
				string(**wl.level),
				int64(**wl.value),
			); err != nil {
				return nil, err
			}
		}
	}

	if err = tx.Commit(); err == nil {
		feedback.Info("Refreshing gauges successfully took %s.",
			time.Since(start))
	} else {
		feedback.Error("Refreshing gauges failed after %s.",
			time.Since(start))
	}

	return nil, err
}