package main

import (
	"bufio"
	"flag"
	"fmt"
	"os"
	"reflect"
)

func main() {
	filename := flag.String("f", "", "Candump filename")
	canbus := flag.String("c", "", "CAN bus interface")
	all := flag.Bool("a", false, "Show all packets")
	flag.Parse()

	var frames <-chan *CanFrame
	last := make(map[interface{}]interface{})

	switch {
	case len(*filename) > 0:
		fmt.Printf("Open file %v\n", *filename)
		frames = readfile(filename)
	case len(*canbus) > 0:
		fmt.Printf("Open device %v\n", canbus)
		var err error
		frames, err = StartCan(*canbus)
		if err != nil {
			fmt.Println(err)
			return
		}

	default:
		flag.Usage()
	}

	if frames == nil {
		fmt.Println("Get no data")
		os.Exit(0)
	}

	events := FromCanFrames(frames)

	for event := range events {

		eventType := reflect.TypeOf(event)

		lastValue := last[eventType]
		value, date := event.GetValue()

		if lastValue != value || *all {
			fmt.Printf("%v | %s = %v\n", *date, eventType, value)
			last[eventType] = value
		}

		//if msg, isType := event.(MaximumBatteryVoltage); isType {
		//	fmt.Printf("MaximumBatteryVoltage: %v\n", msg.GetMaxBattVoltage())
		//}
	}
}

func readfile(filename *string) <-chan *CanFrame {
	c := make(chan *CanFrame)

	go func() {
		defer close(c)

		file, err := os.Open(*filename)
		if err != nil {
			fmt.Println(err)
			return
		}
		defer file.Close()

		scanner := bufio.NewScanner(file)
		for scanner.Scan() {
			text := scanner.Text()
			c <- FromString(&text)
		}

		if err := scanner.Err(); err != nil {
			fmt.Println(err)
		}
	}()

	return c
}