package main

import (
	"encoding/json"
	"fmt"
)

type DiskInfo struct {
	ModelFamily  string `json:"model_family"`
	ModelName    string `json:"model_name"`
	SerialNumber string `json:"serial_number"`
	RotationRate uint   `json:"rotation_rate"`
}

func getDiskInfo(diskpath string) *DiskInfo {
	rawsmart := execSystem("smartctl", "-i", "-json", diskpath)
	if rawsmart == nil {
		fmt.Println("error while getting smart info")
	}

	var info DiskInfo

	// decoding country1 struct
	// from json format
	err := json.Unmarshal(rawsmart, &info)

	if err != nil {
		fmt.Println(err)
	}
	return &info
}

type Item struct {
	Name string `json:"name"`
	Raw  struct {
		Value int64 `json:"value"`
	} `json:"raw"`
}

type RawAttr struct {
	AtaSmartAttr struct {
		Table []Item `json:"table"`
	} `json:"ata_smart_attributes"`
}

func getSmartValues(diskpath string) *RawAttr {
	rawsmart := execSystem("smartctl", "-A", "-json", diskpath)
	if rawsmart == nil {
		fmt.Println("error while getting smart info")
	}

	var rawattr RawAttr

	err := json.Unmarshal(rawsmart, &rawattr)

	if err != nil {
		fmt.Println(err)
	}
	return &rawattr
}

func getTemp(diskpath string) (uint32, uint32, uint32) {
	rawattr := getSmartValues(diskpath)
	temp := getItemValue(rawattr.AtaSmartAttr.Table, "Temperature_Celsius")

	// temp value is storead as following:
	// 		4bytes			  4bytes		   4bytes
	// [----------------|----------------|---------------]
	// 		max temp		 min temp		  curr temp

	max := temp >> 32
	min := (temp & 0xff00ff) >> 16
	currtemp := temp & 0x0000ff

	return uint32(max), uint32(min), uint32(currtemp)
}

func checkSmartAttributes(diskpath string, isSeagate bool, isHdd bool) {
	rawattr := getSmartValues(diskpath)

	rrerrrate := getItemValue(rawattr.AtaSmartAttr.Table, "Raw_Read_Error_Rate")
	// seagate hdds have a special way to represent their error rates
	if isSeagate {
		// [--16bits---|---32bits---]
		//  error count| operation count
		rrerrrate = rrerrrate >> 32
	}
	fmt.Println("Raw_Read_Error_Rate: " + evalStrZero(rrerrrate))
	fmt.Println("Reallocated_Sector_Ct: " + evalStrZero(getItemValue(rawattr.AtaSmartAttr.Table, "Reallocated_Sector_Ct")))

	// todo further investigate if this smart attributes can occur within hdds/ssds
	// https://www.backblaze.com/blog/what-smart-stats-indicate-hard-drive-failures/
	fmt.Println("Reported_Uncorrect: " + evalStrZero(getItemValue(rawattr.AtaSmartAttr.Table, "Reported_Uncorrect")))
	fmt.Println("Command_Timeout: " + evalStrZero(getItemValue(rawattr.AtaSmartAttr.Table, "Command_Timeout")))
	fmt.Println("Current_Pending_Sector: " + evalStrZero(getItemValue(rawattr.AtaSmartAttr.Table, "Current_Pending_Sector")))
	fmt.Println("Offline_Uncorrectable: " + evalStrZero(getItemValue(rawattr.AtaSmartAttr.Table, "Offline_Uncorrectable")))

	// there are some additinoal hdd smart values
	if isHdd {
		rrerrrate = getItemValue(rawattr.AtaSmartAttr.Table, "Seek_Error_Rate")
		if isSeagate {
			// [--16bits---|---32bits---]
			//  error count| operation count
			rrerrrate = rrerrrate >> 32
		}
		fmt.Println("Seek_Error_Rate:\t" + evalStrZero(rrerrrate))
		fmt.Println("Spin_Retry_Count:\t" + evalStrZero(getItemValue(rawattr.AtaSmartAttr.Table, "Spin_Retry_Count")))
		fmt.Println("Spin_Up_Time:\t\t" + evalStrZero(getItemValue(rawattr.AtaSmartAttr.Table, "Spin_Up_Time")))
	}
}

func evalStrZero(nr int64) string {
	if nr < 0 {
		return "N/A"
	} else if nr == 0 {
		return "\tPASS"
	} else {
		return fmt.Sprintf("\tFAIL :: raw value=%d", nr)
	}
}

func getItemValue(arr []Item, name string) int64 {
	for i := range arr {
		if arr[i].Name == name {
			return arr[i].Raw.Value
		}
	}
	return -1
}