// SPDX-License-Identifier: Apache-2.0
//
// Copyright The Prometheus Authors
// Licensed 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.

//go:build windows

package msmq

import (
	"fmt"
	"log/slog"

	"github.com/alecthomas/kingpin/v2"
	"github.com/prometheus-community/windows_exporter/internal/mi"
	"github.com/prometheus-community/windows_exporter/internal/pdh"
	"github.com/prometheus-community/windows_exporter/internal/types"
	"github.com/prometheus/client_golang/prometheus"
)

const Name = "msmq"

type Config struct{}

//nolint:gochecknoglobals
var ConfigDefaults = Config{}

// A Collector is a Prometheus Collector for WMI Win32_PerfRawData_MSMQ_MSMQQueue metrics.
type Collector struct {
	config            Config
	perfDataCollector *pdh.Collector
	perfDataObject    []perfDataCounterValues

	bytesInJournalQueue    *prometheus.Desc
	bytesInQueue           *prometheus.Desc
	messagesInJournalQueue *prometheus.Desc
	messagesInQueue        *prometheus.Desc
}

func New(config *Config) *Collector {
	if config == nil {
		config = &ConfigDefaults
	}

	c := &Collector{
		config: *config,
	}

	return c
}

func NewWithFlags(_ *kingpin.Application) *Collector {
	c := &Collector{
		config: ConfigDefaults,
	}

	return c
}

func (c *Collector) GetName() string {
	return Name
}

func (c *Collector) Close() error {
	return nil
}

func (c *Collector) Build(_ *slog.Logger, _ *mi.Session) error {
	c.bytesInJournalQueue = prometheus.NewDesc(
		prometheus.BuildFQName(types.Namespace, Name, "bytes_in_journal_queue"),
		"Size of queue journal in bytes",
		[]string{"name"},
		nil,
	)
	c.bytesInQueue = prometheus.NewDesc(
		prometheus.BuildFQName(types.Namespace, Name, "bytes_in_queue"),
		"Size of queue in bytes",
		[]string{"name"},
		nil,
	)
	c.messagesInJournalQueue = prometheus.NewDesc(
		prometheus.BuildFQName(types.Namespace, Name, "messages_in_journal_queue"),
		"Count messages in queue journal",
		[]string{"name"},
		nil,
	)
	c.messagesInQueue = prometheus.NewDesc(
		prometheus.BuildFQName(types.Namespace, Name, "messages_in_queue"),
		"Count messages in queue",
		[]string{"name"},
		nil,
	)

	var err error

	c.perfDataCollector, err = pdh.NewCollector[perfDataCounterValues](pdh.CounterTypeRaw, "MSMQ Queue", pdh.InstancesAll)
	if err != nil {
		return fmt.Errorf("failed to create MSMQ Queue collector: %w", err)
	}

	return nil
}

// Collect sends the metric values for each metric
// to the provided prometheus Metric channel.
func (c *Collector) Collect(ch chan<- prometheus.Metric) error {
	err := c.perfDataCollector.Collect(&c.perfDataObject)
	if err != nil {
		return fmt.Errorf("failed to collect MSMQ Queue metrics: %w", err)
	}

	for _, data := range c.perfDataObject {
		ch <- prometheus.MustNewConstMetric(
			c.bytesInJournalQueue,
			prometheus.GaugeValue,
			data.BytesInJournalQueue,
			data.Name,
		)

		ch <- prometheus.MustNewConstMetric(
			c.bytesInQueue,
			prometheus.GaugeValue,
			data.BytesInQueue,
			data.Name,
		)

		ch <- prometheus.MustNewConstMetric(
			c.messagesInJournalQueue,
			prometheus.GaugeValue,
			data.MessagesInJournalQueue,
			data.Name,
		)

		ch <- prometheus.MustNewConstMetric(
			c.messagesInQueue,
			prometheus.GaugeValue,
			data.MessagesInQueue,
			data.Name,
		)
	}

	return nil
}