// 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 (
	"errors"
	"fmt"
	"log"

	"gemma.intevation.de/gemma/pkg/common"
	"gemma.intevation.de/gemma/pkg/scheduler"
)

// JobKindSetups maps JobKinds to special setup functions.
var JobKindSetups = map[JobKind]func(*IDConfig) (interface{}, error){

	GMJobKind: func(cfg *IDConfig) (interface{}, error) {
		log.Println("info: schedule 'gm' import")
		insecure := cfg.Attributes.Bool("insecure")
		return &GaugeMeasurement{
			URL:      *cfg.URL,
			Insecure: insecure,
		}, nil
	},

	FAJobKind: func(cfg *IDConfig) (interface{}, error) {
		log.Println("info: schedule 'fa' import")
		insecure := cfg.Attributes.Bool("insecure")
		return &FairwayAvailability{
			URL:      *cfg.URL,
			Insecure: insecure,
		}, nil
	},

	BNJobKind: func(cfg *IDConfig) (interface{}, error) {
		log.Println("info: schedule 'bn' import")
		insecure := cfg.Attributes.Bool("insecure")
		return &Bottleneck{
			URL:      *cfg.URL,
			Insecure: insecure,
		}, nil
	},

	WXJobKind: func(cfg *IDConfig) (interface{}, error) {
		log.Println("info: schedule 'wx' import")
		ft, found := cfg.Attributes.Get("feature-type")
		if !found {
			return nil, errors.New("cannot find 'feature-type' attribute")
		}
		sb, found := cfg.Attributes.Get("sort-by")
		if !found {
			return nil, errors.New("cannot find 'sort-by' attribute")
		}
		return &WaterwayAxis{
			URL:         *cfg.URL,
			FeatureType: ft,
			SortBy:      sb,
		}, nil
	},
}

func init() {
	run := func(cfgID int64) {
		jobID, err := RunConfiguredImport(cfgID)
		if err != nil {
			log.Printf("error: running scheduled import failed: %v\n", err)
			return
		}
		log.Printf("info: added import #%d to queue\n", jobID)
	}

	for kind := range JobKindSetups {
		scheduler.RegisterAction(string(kind), run)
	}
}

// RunConfiguredImport runs an import configured from the database.
func RunConfiguredImport(id int64) (int64, error) {
	cfg, err := loadIDConfig(id)
	if err != nil {
		return 0, err
	}
	if cfg == nil {
		return 0, fmt.Errorf("no config found for id %d.\n", id)
	}
	if cfg.URL == nil {
		return 0, errors.New("error: No URL specified")
	}

	kind := JobKind(cfg.Kind)

	var setup func(*IDConfig) (interface{}, error)
	if setup = JobKindSetups[kind]; setup == nil {
		return 0, fmt.Errorf("unknown job kind: %s", cfg.Kind)
	}

	what, err := setup(cfg)
	if err != nil {
		return 0, err
	}

	var serialized string
	if serialized, err = common.ToJSONString(what); err != nil {
		return 0, err
	}

	due, _ := cfg.Attributes.Time("due")

	retries, found := cfg.Attributes.Int("retries")
	if !found {
		retries = -1
	}

	var jobID int64
	if jobID, err = AddJob(
		kind,
		due, retries,
		cfg.User,
		cfg.SendEMail, cfg.AutoAccept,
		serialized,
	); err != nil {
		return 0, err
	}

	return jobID, nil
}