// Copyright Jan Dittberner
// SPDX-License-Identifier: GPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package icinga2

import (
	"errors"
	"fmt"
	"net/url"
	"strings"
)

type URLValue struct {
	URL *url.URL
}

func (u *URLValue) Set(value string) error {
	var err error

	u.URL, err = url.Parse(value)
	if err != nil {
		return fmt.Errorf("could not parse URL: %w", err)
	}

	return nil
}

func (u *URLValue) String() string {
	if u.URL != nil {
		return u.URL.String()
	}

	return ""
}

type HostStateValue string

func (v *HostStateValue) Set(value string) error {
	if strings.EqualFold(value, "Up") || strings.EqualFold(value, "Down") {
		*v = HostStateValue(strings.ToUpper(value))

		return nil
	}

	return fmt.Errorf("invalid host state value: %s", value)
}

func (v *HostStateValue) String() string {
	return string(*v)
}

type ServiceStateValue string

func (v *ServiceStateValue) Set(value string) error {
	allowedValues := []string{"OK", "Warning", "Critical", "Unknown"}

	for _, allowed := range allowedValues {
		if strings.EqualFold(value, allowed) {
			*v = ServiceStateValue(strings.ToUpper(value))

			return nil
		}
	}

	return fmt.Errorf("invalid service state value: %s", value)
}

func (v *ServiceStateValue) String() string {
	return string(*v)
}

type NotificationTypeValue string

func (v *NotificationTypeValue) Set(value string) error {
	allowedValues := []string{
		"DowntimeStart", "DowntimeEnd", "DownTimeRemoved", "Custom", "Acknowledgement", "Problem", "Recovery",
		"FlappingStart", "FlappingEnd",
	}

	for _, allowed := range allowedValues {
		if strings.EqualFold(value, allowed) {
			*v = NotificationTypeValue(strings.ToUpper(value))

			return nil
		}
	}

	return fmt.Errorf("invalid notification type value: %s", value)
}

func (v *NotificationTypeValue) String() string {
	return string(*v)
}

type MatrixParameters struct {
	MatrixRoom   string
	MatrixServer URLValue
	MatrixToken  string
}

func (m *MatrixParameters) HasRequired() bool {
	return !(m.MatrixRoom == "" || m.MatrixServer.URL == nil || m.MatrixToken == "")
}

type BaseParameters struct {
	NotificationAuthorName string
	NotificationComment    string
	NotificationType       NotificationTypeValue
	IcingaWeb2URL          URLValue
	LongDateTime           string
	Hostname               string
	HostDisplayName        string
	HostAddress            string
	HostAddress6           string
}

func (p BaseParameters) HasRequired() bool {
	return !(p.LongDateTime == "" || p.Hostname == "" || p.HostDisplayName == "" || p.NotificationType == "")
}

type HostParameters struct {
	HostOutput string
	HostState  HostStateValue
	BaseParameters
	MatrixParameters
}

func (p *HostParameters) ValidateRequired() error {
	if !p.BaseParameters.HasRequired() || !p.MatrixParameters.HasRequired() ||
		p.HostOutput == "" || p.HostState == "" {
		return errors.New("missing required fields")
	}

	return nil
}

type ServiceParameters struct {
	ServiceName        string
	ServiceDisplayName string
	ServiceOutput      string
	ServiceState       ServiceStateValue
	BaseParameters
	MatrixParameters
}

func (p *ServiceParameters) ValidateRequired() error {
	if !p.BaseParameters.HasRequired() || !p.MatrixParameters.HasRequired() ||
		p.ServiceName == "" || p.ServiceDisplayName == "" || p.ServiceState == "" || p.ServiceOutput == "" {
		return errors.New("missing required fields")
	}

	return nil
}