// Licensed to Elasticsearch B.V. under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Elasticsearch B.V. licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

package osd_tree

import (
	"github.com/pkg/errors"

	"github.com/elastic/beats/v7/metricbeat/helper"
	"github.com/elastic/beats/v7/metricbeat/mb"
	"github.com/elastic/beats/v7/metricbeat/mb/parse"
)

const (
	defaultScheme = "http"
	defaultPath   = "/api/v0.1/osd/tree"
)

var (
	hostParser = parse.URLHostParserBuilder{
		DefaultScheme: defaultScheme,
		DefaultPath:   defaultPath,
	}.Build()
)

func init() {
	mb.Registry.MustAddMetricSet("ceph", "osd_tree", New,
		mb.WithHostParser(hostParser),
		mb.DefaultMetricSet(),
	)
}

// MetricSet type defines all fields of the MetricSet
type MetricSet struct {
	mb.BaseMetricSet
	*helper.HTTP
}

// New creates a new instance of the osd_tree MetricSet.
func New(base mb.BaseMetricSet) (mb.MetricSet, error) {
	http, err := helper.NewHTTP(base)
	if err != nil {
		return nil, err
	}
	http.SetHeader("Accept", "application/json")

	return &MetricSet{
		base,
		http,
	}, nil
}

// Fetch methods implements the data gathering and data conversion to the right
// format. It publishes the event which is then forwarded to the output. In case
// of an error set the Error field of mb.Event or simply call report.Error().
func (m *MetricSet) Fetch(reporter mb.ReporterV2) error {
	content, err := m.HTTP.FetchContent()
	if err != nil {
		return errors.Wrap(err, "error in fetch")
	}

	events, err := eventsMapping(content)
	if err != nil {
		return errors.Wrap(err, "error in mapping")
	}

	for _, event := range events {
		reported := reporter.Event(mb.Event{MetricSetFields: event})
		if !reported {
			return nil
		}
	}

	return nil
}
