// 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"
	"encoding/json"
	"fmt"

	"gemma.intevation.de/gemma/pkg/auth"
	"github.com/robfig/cron"
)

type (
	CronSpec   string
	ImportKind string

	Config struct {
		Kind       ImportKind `json:"kind"`
		SendEMail  bool       `json:"send-email"`
		AutoAccept bool       `json:"auto-accept"`
		Cron       *CronSpec  `json:"cron"`
		URL        *string    `json:"url"`
	}

	IDConfig struct {
		ID         int64      `json:"id"`
		User       string     `json:"user"`
		Kind       ImportKind `json:"kind"`
		SendEMail  bool       `json:"send-email"`
		AutoAccept bool       `json:"auto-accept"`
		Cron       *CronSpec  `json:"cron,omitempty"`
		URL        *string    `json:"url,omitempty"`
	}
)

func (ik *ImportKind) UnmarshalJSON(data []byte) error {
	var s string
	if err := json.Unmarshal(data, &s); err != nil {
		return err
	}

	if !HasImportKindName(s) {
		return fmt.Errorf("Unknown kind '%s'", s)
	}

	*ik = ImportKind(s)

	return nil
}

func (cs *CronSpec) UnmarshalJSON(data []byte) error {
	var spec string
	if err := json.Unmarshal(data, &spec); err != nil {
		return err
	}
	if _, err := cron.Parse(spec); err != nil {
		return err
	}
	*cs = CronSpec(spec)

	return nil
}

const (
	configUser = "sys_admin"

	loadConfigSQL = `
SELECT
  username,
  kind,
  send_email,
  auto_accept,
  cron,
  url
FROM waterway.import_configuration
WHERE id = $1`
)

func loadIDConfig(id int64) (*IDConfig, error) {

	ctx := context.Background()
	cfg := &IDConfig{ID: id}

	err := auth.RunAs(ctx, configUser, func(conn *sql.Conn) error {
		var kind ImportKind
		var cron, url sql.NullString
		if err := conn.QueryRowContext(ctx, loadConfigSQL, id).Scan(
			&cfg.User,
			&kind,
			&cfg.SendEMail,
			&cfg.AutoAccept,
			&cron,
			&url,
		); err != nil {
			return err
		}
		cfg.Kind = ImportKind(kind)
		if cron.Valid {
			c := CronSpec(cron.String)
			cfg.Cron = &c
		}
		if url.Valid {
			cfg.URL = &url.String
		}
		return nil
	})

	switch {
	case err == sql.ErrNoRows:
		return nil, nil
	case err != nil:
		return nil, err
	}

	return cfg, nil
}