package client

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"path"
	"strconv"
	"strings"
	"time"

	"github.com/gosimple/slug"
)

// HardwareType type
// https://github.com/openhardwaremonitor/openhardwaremonitor/blob/e199e0ccc69b4da92495266ebc0faf7daad97608/Hardware/IHardware.cs
type HardwareType int

const (
	// UnknownHardware type
	UnknownHardware HardwareType = iota
	// Mainboard type
	Mainboard
	// SuperIO type
	SuperIO
	// CPU type
	CPU
	// RAM type
	RAM
	// GpuNvidia type
	GpuNvidia
	// GpuAti type
	GpuAti
	// TBalancer type
	TBalancer
	// Heatmaster type
	Heatmaster
	// HDD type
	HDD
	// Controller type for TBalancer or Heatmaster
	Controller
	// Computer type for host
	Computer
)

// Hardware value
type Hardware struct {
	Type      HardwareType
	Value     string
	TypeIndex int
	TypeCount int
}

// Sensor for unit
// https://github.com/openhardwaremonitor/openhardwaremonitor/blob/e199e0ccc69b4da92495266ebc0faf7daad97608/Hardware/ISensor.cs
type Sensor int

const (
	// UnknownSensor in V
	UnknownSensor Sensor = iota
	// Voltage in V
	Voltage
	// Clock in MHz
	Clock
	// Temperature in °C
	Temperature
	// Load in %
	Load
	// Fan in RPM
	Fan
	// Flow in L/h
	Flow
	// Control in %
	Control
	// Level in %
	Level
	// Factor in 1
	Factor
	// Power in W
	Power
	// Data in GB = 2^30 Bytes
	Data
	// SmallData in MB = 2^20 Bytes
	SmallData
)

var hardwareToMetric = map[HardwareType]string{
	UnknownHardware: "unknown",
	Mainboard:       "mainboard",
	SuperIO:         "superio",
	CPU:             "cpu",
	RAM:             "ram",
	GpuNvidia:       "gpu",
	GpuAti:          "gpu",
	TBalancer:       "tbalancer",
	Heatmaster:      "heatmaster",
	HDD:             "hdd",
	Controller:      "controller",
	Computer:        "host",
}

var sensorToMetric = map[Sensor]string{
	UnknownSensor: "unknown",
	Voltage:       "voltage",
	Clock:         "mhz",
	Temperature:   "temp",
	Load:          "load",
	Fan:           "rpm",
	Flow:          "flow",
	Control:       "control",
	Level:         "level",
	Factor:        "factor",
	Power:         "power",
	Data:          "gb",
	SmallData:     "mb",
}

var imageToHardware = map[string]HardwareType{
	"ati.png": GpuAti,
	// "bigng.png":     Heatmaster,
	// "bigng.png":     TBalancer,
	"bigng.png":     Controller,
	"chip.png":      SuperIO,
	"cpu.png":       CPU,
	"hdd.png":       HDD,
	"mainboard.png": Mainboard,
	"nvidia.png":    GpuNvidia,
	"ram.png":       RAM,
	"computer.png":  Computer,
}

var sensorToType = map[string]Sensor{
	"Clocks":       Clock,
	"Controls":     Control,
	"Data":         Data,
	"Factors":      Factor,
	"Fans":         Fan,
	"Flows":        Flow,
	"Levels":       Level,
	"Load":         Load,
	"Powers":       Power,
	"Temperatures": Temperature,
	"Voltages":     Voltage,
}

func (s Sensor) String() string {
	switch s {
	case Clock:
		return "Clock"
	case Control:
		return "Control"
	case Data:
		return "Data"
	case Factor:
		return "Factor"
	case Fan:
		return "Fan"
	case Flow:
		return "Flow"
	case Level:
		return "Level"
	case Load:
		return "Load"
	case Power:
		return "Power"
	case SmallData:
		return "SmallData"
	case Temperature:
		return "Temperature"
	case Voltage:
		return "Voltage"
	}
	return "Unknown"
}

func (h HardwareType) String() string {
	switch h {
	case UnknownHardware:
		return "Unknown"
	case Mainboard:
		return "Mainboard"
	case SuperIO:
		return "SuperIO"
	case CPU:
		return "CPU"
	case RAM:
		return "RAM"
	case GpuNvidia:
		return "GpuNvidia"
	case GpuAti:
		return "GpuAti"
	case TBalancer:
		return "TBalancer"
	case Heatmaster:
		return "Heatmaster"
	case HDD:
		return "HDD"
	case Controller:
		return "Controller"
	case Computer:
		return "Computer"
	}
	return "Unknown"
}

// Value from ohwm
type Value struct {
	Hardware []Hardware
	Unit     Sensor
	Label    string
	Value    string
}

// Float64 gets value as float64
func (v *Value) Float64() float64 {
	val := strings.Split(v.Value, " ")
	if len(val) == 0 {
		return 0
	}
	ret, err := strconv.ParseFloat(val[0], 64)
	if err != nil {
		return 0
	}
	return ret
}

// MetricName returns value as a metric name
func (v *Value) MetricName() string {
	segments := []string{"ohwm"}
	for _, hw := range v.Hardware {
		metricname, ok := hardwareToMetric[hw.Type]
		if !ok {
			metricname = hardwareToMetric[UnknownHardware]
		}
		segments = append(segments, metricname)
		if hw.TypeCount > 1 {
			segments = append(segments, fmt.Sprintf("%d", hw.TypeIndex))
		}
	}

	sensorname, ok := sensorToMetric[v.Unit]
	if !ok {
		sensorname = sensorToMetric[UnknownSensor]
	}
	segments = append(segments, sensorname)

	sluglabel := slug.Make(v.Label)
	segments = append(segments, sluglabel)

	ret := strings.Join(segments, "_")
	return strings.ReplaceAll(ret, "-", "_")
}

// IsValue true if node has children
func (n *Node) IsValue() bool {
	if n.Children == nil {
		return false
	}
	return len(n.Children) == 0
}

// IsRoot returns true if json is a root node
func (n *Node) IsRoot() bool {
	return n.ID == 0
}

// IsSensor returns true if json node is for a sensor type
func (n *Node) IsSensor() bool {
	if n.ImageURL == "" || n.Text == "" {
		return false
	}
	_, ok := sensorToType[n.Text]
	return ok
}

// SensorType returns type of sensor
func (n *Node) SensorType() Sensor {
	st, _ := sensorToType[n.Text]
	// Figure out if data is in GB (Data) or MB (SmallData)
	if st == Data {
		if len(n.Children) > 0 {
			val := n.Children[0]
			if strings.HasSuffix(val.Value, "MB") {
				st = SmallData
			}
		}
	}
	return st
}

// IsHardware returns true if json node is for hardware
func (n *Node) IsHardware() bool {
	if n.ImageURL == "" || n.Text == "" {
		return false
	}
	_, ok := imageToHardware[path.Base(n.ImageURL)]
	return ok
}

// HardwareType returns HardwareType of node
func (n *Node) HardwareType() HardwareType {
	ht, _ := imageToHardware[path.Base(n.ImageURL)]
	return ht
}

// Visitor callback function
type Visitor func(v Value) error

// Walk from json root
func (n *Node) Walk(fn Visitor) error {
	return n.walk(fn, Value{Hardware: []Hardware{}}, 0, 0)
}

func (n *Node) childDeviceTotals() map[HardwareType]int {
	totals := map[HardwareType]int{}
	for _, child := range n.Children {
		totals[child.HardwareType()]++
	}
	return totals
}

func (n *Node) walk(fn Visitor, ctx Value, hwIndex, hwTotal int) error {
	if n.IsValue() {
		ctx.Label = n.Text
		ctx.Value = n.Value
		return fn(ctx)
	}
	if n.IsSensor() {
		ctx.Unit = n.SensorType()
	}
	if n.IsHardware() {
		ctx.Hardware = append(ctx.Hardware, Hardware{
			Type:      n.HardwareType(),
			Value:     n.Text,
			TypeIndex: hwIndex,
			TypeCount: hwTotal,
		})
	}
	totals := n.childDeviceTotals()
	deviceIndex := map[HardwareType]int{}
	for _, child := range n.Children {
		deviceType := child.HardwareType()
		index := deviceIndex[deviceType]
		if err := child.walk(fn, ctx, index, totals[deviceType]); err != nil {
			return err
		}
		deviceIndex[deviceType]++
	}
	return nil
}

// Values from json root
func (n *Node) Values() ([]Value, error) {
	ret := []Value{}
	err := n.Walk(func(val Value) error {
		ret = append(ret, val)
		return nil
	})
	if err != nil {
		return nil, err
	}
	return ret, nil
}

// Node from data
type Node struct {
	ID       int `json:"id"`
	ImageURL string
	Max      string
	Min      string
	Text     string
	Value    string
	Children []Node
}

// Client for open hardware monitor
type Client struct {
	Timeout time.Duration
	URL     url.URL
}

// Fetch requests
func (c *Client) Fetch() (*Node, error) {
	client := http.Client{Timeout: c.Timeout}
	resp, err := client.Get(c.URL.String())
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	return c.Decode(resp.Body)
}

// Decode json
func (c *Client) Decode(r io.Reader) (*Node, error) {
	node := &Node{}
	decoder := json.NewDecoder(r)
	if err := decoder.Decode(node); err != nil {
		return nil, err
	}
	return node, nil
}

// Stringify tree
func (n *Node) Stringify() string {
	return n.stringify(0)
}

func (n *Node) stringify(indent int) string {
	prefix := ""
	for i := 0; i < indent; i++ {
		prefix += "  "
	}

	ret := prefix + n.Text
	if n.Value != "" {
		ret += ": " + n.Value
	}
	if n.Max != "" && n.Min != "" && n.Max != "-" && n.Min != "-" {
		ret += fmt.Sprintf(" (%s - %s)", n.Min, n.Max)
	}
	ret += "\n"
	for _, child := range n.Children {
		ret += child.stringify(indent + 1)
	}

	return ret
}