// Copyright 2022 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.

package main

import (
	"fmt"
	"strings"

	"github.com/go-kit/log"
	"github.com/go-kit/log/level"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/tidwall/gjson"
)

// SMARTDevice - short info about device
type SMARTDevice struct {
	device string
	serial string
	family string
	model  string
}

// SMARTctl object
type SMARTctl struct {
	ch     chan<- prometheus.Metric
	json   gjson.Result
	logger log.Logger
	device SMARTDevice
}

// NewSMARTctl is smartctl constructor
func NewSMARTctl(logger log.Logger, json gjson.Result, ch chan<- prometheus.Metric) SMARTctl {
	return SMARTctl{
		ch:     ch,
		json:   json,
		logger: logger,
		device: SMARTDevice{
			device: strings.TrimPrefix(strings.TrimSpace(json.Get("device.name").String()), "/dev/"),
			serial: strings.TrimSpace(json.Get("serial_number").String()),
			family: strings.TrimSpace(json.Get("model_family").String()),
			model:  strings.TrimSpace(json.Get("model_name").String()),
		},
	}
}

// Collect metrics
func (smart *SMARTctl) Collect() {
	level.Debug(smart.logger).Log("msg", "Collecting metrics from", "device", smart.device.device, "family", smart.device.family, "model", smart.device.model)
	smart.mineExitStatus()
	smart.mineDevice()
	smart.mineCapacity()
	smart.mineInterfaceSpeed()
	smart.mineDeviceAttribute()
	smart.minePowerOnSeconds()
	smart.mineRotationRate()
	smart.mineTemperatures()
	smart.minePowerCycleCount()
	smart.mineDeviceSCTStatus()
	smart.mineDeviceStatistics()
	smart.mineDeviceErrorLog()
	smart.mineDeviceSelfTestLog()
	smart.mineDeviceERC()
	smart.minePercentageUsed()
	smart.mineAvailableSpare()
	smart.mineAvailableSpareThreshold()
	smart.mineCriticalWarning()
	smart.mineMediaErrors()
	smart.mineNumErrLogEntries()
	smart.mineBytesRead()
	smart.mineBytesWritten()
	smart.mineSmartStatus()

}

func (smart *SMARTctl) mineExitStatus() {
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceExitStatus,
		prometheus.GaugeValue,
		smart.json.Get("smartctl.exit_status").Float(),
		smart.device.device,
	)
}

func (smart *SMARTctl) mineDevice() {
	device := smart.json.Get("device")
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceModel,
		prometheus.GaugeValue,
		1,
		smart.device.device,
		device.Get("type").String(),
		device.Get("protocol").String(),
		smart.device.family,
		smart.device.model,
		smart.device.serial,
		GetStringIfExists(smart.json, "ata_additional_product_id", "unknown"),
		smart.json.Get("firmware_version").String(),
		smart.json.Get("ata_version.string").String(),
		smart.json.Get("sata_version.string").String(),
		smart.json.Get("form_factor.name").String(),
	)
}

func (smart *SMARTctl) mineCapacity() {
	capacity := smart.json.Get("user_capacity")
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceCapacityBlocks,
		prometheus.GaugeValue,
		capacity.Get("blocks").Float(),
		smart.device.device,
	)
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceCapacityBytes,
		prometheus.GaugeValue,
		capacity.Get("bytes").Float(),
		smart.device.device,
	)
	for _, blockType := range []string{"logical", "physical"} {
		smart.ch <- prometheus.MustNewConstMetric(
			metricDeviceBlockSize,
			prometheus.GaugeValue,
			smart.json.Get(fmt.Sprintf("%s_block_size", blockType)).Float(),
			smart.device.device,
			blockType,
		)
	}
}

func (smart *SMARTctl) mineInterfaceSpeed() {
	iSpeed := smart.json.Get("interface_speed")
	for _, speedType := range []string{"max", "current"} {
		tSpeed := iSpeed.Get(speedType)
		smart.ch <- prometheus.MustNewConstMetric(
			metricDeviceInterfaceSpeed,
			prometheus.GaugeValue,
			tSpeed.Get("units_per_second").Float()*tSpeed.Get("bits_per_unit").Float(),
			smart.device.device,
			speedType,
		)
	}
}

func (smart *SMARTctl) mineDeviceAttribute() {
	for _, attribute := range smart.json.Get("ata_smart_attributes.table").Array() {
		name := strings.TrimSpace(attribute.Get("name").String())
		flagsShort := strings.TrimSpace(attribute.Get("flags.string").String())
		flagsLong := smart.mineLongFlags(attribute.Get("flags"), []string{
			"prefailure",
			"updated_online",
			"performance",
			"error_rate",
			"event_count",
			"auto_keep",
		})
		id := attribute.Get("id").String()
		for key, path := range map[string]string{
			"value":  "value",
			"worst":  "worst",
			"thresh": "thresh",
			"raw":    "raw.value",
		} {
			smart.ch <- prometheus.MustNewConstMetric(
				metricDeviceAttribute,
				prometheus.GaugeValue,
				attribute.Get(path).Float(),
				smart.device.device,
				name,
				flagsShort,
				flagsLong,
				key,
				id,
			)
		}
	}
}

func (smart *SMARTctl) minePowerOnSeconds() {
	pot := smart.json.Get("power_on_time")
	smart.ch <- prometheus.MustNewConstMetric(
		metricDevicePowerOnSeconds,
		prometheus.CounterValue,
		GetFloatIfExists(pot, "hours", 0)*60*60+GetFloatIfExists(pot, "minutes", 0)*60,
		smart.device.device,
	)
}

func (smart *SMARTctl) mineRotationRate() {
	rRate := GetFloatIfExists(smart.json, "rotation_rate", 0)
	if rRate > 0 {
		smart.ch <- prometheus.MustNewConstMetric(
			metricDeviceRotationRate,
			prometheus.GaugeValue,
			rRate,
			smart.device.device,
		)
	}
}

func (smart *SMARTctl) mineTemperatures() {
	temperatures := smart.json.Get("temperature")
	if temperatures.Exists() {
		temperatures.ForEach(func(key, value gjson.Result) bool {
			smart.ch <- prometheus.MustNewConstMetric(
				metricDeviceTemperature,
				prometheus.GaugeValue,
				value.Float(),
				smart.device.device,
				key.String(),
			)
			return true
		})
	}
}

func (smart *SMARTctl) minePowerCycleCount() {
	smart.ch <- prometheus.MustNewConstMetric(
		metricDevicePowerCycleCount,
		prometheus.CounterValue,
		smart.json.Get("power_cycle_count").Float(),
		smart.device.device,
	)
}

func (smart *SMARTctl) mineDeviceSCTStatus() {
	status := smart.json.Get("ata_sct_status")
	if status.Exists() {
		smart.ch <- prometheus.MustNewConstMetric(
			metricDeviceState,
			prometheus.GaugeValue,
			status.Get("device_state").Float(),
			smart.device.device,
		)
	}
}

func (smart *SMARTctl) minePercentageUsed() {
	smart.ch <- prometheus.MustNewConstMetric(
		metricDevicePercentageUsed,
		prometheus.CounterValue,
		smart.json.Get("nvme_smart_health_information_log.percentage_used").Float(),
		smart.device.device,
	)
}

func (smart *SMARTctl) mineAvailableSpare() {
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceAvailableSpare,
		prometheus.CounterValue,
		smart.json.Get("nvme_smart_health_information_log.available_spare").Float(),
		smart.device.device,
	)
}

func (smart *SMARTctl) mineAvailableSpareThreshold() {
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceAvailableSpareThreshold,
		prometheus.CounterValue,
		smart.json.Get("nvme_smart_health_information_log.available_spare_threshold").Float(),
		smart.device.device,
	)
}

func (smart *SMARTctl) mineCriticalWarning() {
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceCriticalWarning,
		prometheus.CounterValue,
		smart.json.Get("nvme_smart_health_information_log.critical_warning").Float(),
		smart.device.device,
	)
}

func (smart *SMARTctl) mineMediaErrors() {
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceMediaErrors,
		prometheus.CounterValue,
		smart.json.Get("nvme_smart_health_information_log.media_errors").Float(),
		smart.device.device,
	)
}

func (smart *SMARTctl) mineNumErrLogEntries() {
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceNumErrLogEntries,
		prometheus.CounterValue,
		smart.json.Get("nvme_smart_health_information_log.num_err_log_entries").Float(),
		smart.device.device,
	)
}

func (smart *SMARTctl) mineBytesRead() {
	blockSize := smart.json.Get("logical_block_size").Float() * 1024
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceBytesRead,
		prometheus.CounterValue,
		smart.json.Get("nvme_smart_health_information_log.data_units_read").Float()*blockSize,
		smart.device.device,
	)
}

func (smart *SMARTctl) mineBytesWritten() {
	blockSize := smart.json.Get("logical_block_size").Float() * 1024
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceBytesWritten,
		prometheus.CounterValue,
		smart.json.Get("nvme_smart_health_information_log.data_units_written").Float()*blockSize,
		smart.device.device,
	)
}

func (smart *SMARTctl) mineSmartStatus() {
	smart.ch <- prometheus.MustNewConstMetric(
		metricDeviceSmartStatus,
		prometheus.GaugeValue,
		smart.json.Get("smart_status.passed").Float(),
		smart.device.device,
	)
}

func (smart *SMARTctl) mineDeviceStatistics() {
	for _, page := range smart.json.Get("ata_device_statistics.pages").Array() {
		table := strings.TrimSpace(page.Get("name").String())
		// skip vendor-specific statistics (they lead to duplicate metric labels on Seagate Exos drives,
		// see https://github.com/Sheridan/smartctl_exporter/issues/3 for details)
		if table == "Vendor Specific Statistics" {
			continue
		}
		for _, statistic := range page.Get("table").Array() {
			smart.ch <- prometheus.MustNewConstMetric(
				metricDeviceStatistics,
				prometheus.GaugeValue,
				statistic.Get("value").Float(),
				smart.device.device,
				smart.device.family,
				smart.device.model,
				smart.device.serial,
				table,
				strings.TrimSpace(statistic.Get("name").String()),
				strings.TrimSpace(statistic.Get("flags.string").String()),
				smart.mineLongFlags(statistic.Get("flags"), []string{
					"valid",
					"normalized",
					"supports_dsn",
					"monitored_condition_met",
				}),
			)
		}
	}

	for _, statistic := range smart.json.Get("sata_phy_event_counters.table").Array() {
		smart.ch <- prometheus.MustNewConstMetric(
			metricDeviceStatistics,
			prometheus.GaugeValue,
			statistic.Get("value").Float(),
			smart.device.device,
			"SATA PHY Event Counters",
			strings.TrimSpace(statistic.Get("name").String()),
			"V---",
			"valid",
		)
	}
}

func (smart *SMARTctl) mineLongFlags(json gjson.Result, flags []string) string {
	var result []string
	for _, flag := range flags {
		jFlag := json.Get(flag)
		if jFlag.Exists() && jFlag.Bool() {
			result = append(result, flag)
		}
	}
	return strings.Join(result, ",")
}

func (smart *SMARTctl) mineDeviceErrorLog() {
	for logType, status := range smart.json.Get("ata_smart_error_log").Map() {
		smart.ch <- prometheus.MustNewConstMetric(
			metricDeviceErrorLogCount,
			prometheus.GaugeValue,
			status.Get("count").Float(),
			smart.device.device,
			logType,
		)
	}
}

func (smart *SMARTctl) mineDeviceSelfTestLog() {
	for logType, status := range smart.json.Get("ata_smart_self_test_log").Map() {
		smart.ch <- prometheus.MustNewConstMetric(
			metricDeviceSelfTestLogCount,
			prometheus.GaugeValue,
			status.Get("count").Float(),
			smart.device.device,
			logType,
		)
		smart.ch <- prometheus.MustNewConstMetric(
			metricDeviceSelfTestLogErrorCount,
			prometheus.GaugeValue,
			status.Get("error_count_total").Float(),
			smart.device.device,
			logType,
		)
	}
}

func (smart *SMARTctl) mineDeviceERC() {
	for ercType, status := range smart.json.Get("ata_sct_erc").Map() {
		smart.ch <- prometheus.MustNewConstMetric(
			metricDeviceERCSeconds,
			prometheus.GaugeValue,
			status.Get("deciseconds").Float()/10.0,
			smart.device.device,
			ercType,
		)
	}
}