Add skeleton for configuration prompter

cli.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// ReadInput reads the next line from a Reader. It will return 'def' if nothing
+// was input, or it will return the response.
+func ReadInput(r *bufio.Reader, def string) string {
+	resp, err := r.ReadString('\n')
+	if err != nil {
+		panic(err)
+	}
+
+	if resp == "\n" {
+		return def
+	}
+
+	return resp[:len(resp)-1]
+}
+
+// ParsePort returns the port number from a listen address
+func ParsePort(addr string) (uint16, error) {
+	parts := strings.Split(addr, ":")
+
+	port, err := strconv.ParseUint(parts[len(parts)-1], 10, 16)
+
+	if err != nil {
+		return 0, err
+	}
+
+	return uint16(port), nil
+}
+
+// PromptForConfiguration walks a user through configuration
+func PromptForConfiguration() Config {
+	reader := bufio.NewReader(os.Stdin)
+
+	var config Config
+
+	fmt.Printf("TempGopher v%s\n", Version)
+	fmt.Println("You will now be asked a series of questions to help configure your thermostat.")
+	fmt.Println("Don't worry, it will all be over quickly.")
+	fmt.Println("\nDefault values will be in brackets. Just press enter if they look good.")
+	fmt.Println("=====")
+
+	fmt.Print("Listen address?\n[:8080]: ")
+	config.ListenAddr = ReadInput(reader, ":8080")
+
+	port, err := ParsePort(config.ListenAddr)
+	if err != nil {
+		panic(err)
+	}
+	hostname, err := os.Hostname()
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println("Base URL? (This is what you type into your browser to get to the web UI)")
+	defURL := fmt.Sprintf("http://%s:%d", hostname, port)
+	fmt.Printf("[%s]: ", defURL)
+	config.BaseURL = ReadInput(reader, defURL)
+
+	fmt.Println("Display temperatures in fahrenheit? (Otherwise uses celsius)")
+	fmt.Print("[true]: ")
+
+	config.DisplayFahrenheit, err = strconv.ParseBool(ReadInput(reader, "true"))
+	if err != nil {
+		panic(err)
+	}
+
+	return config
+}
+
+// ConfigCLI prompts the user for configuration and writes to a config file
+func ConfigCLI(path string) {
+	config := PromptForConfiguration()
+
+	SaveConfig(path, config)
+}

main.go

@@ -12,13 +12,18 @@ const Version = "0.2.0-dev"
 
 func main() {
 	var args struct {
-		Action     string `arg:"required,positional" help:"run"`
+		Action     string `arg:"required,positional" help:"run config"`
 		ConfigFile string `arg:"-c,required" help:"path to config file"`
 	}
 
 	p := arg.MustParse(&args)
-	if args.Action != "run" {
-		p.Fail("ACTION must be run")
+	if args.Action != "run" && args.Action != "config" {
+		p.Fail("ACTION must be run or config")
+	}
+
+	if args.Action == "config" {
+		ConfigCLI(args.ConfigFile)
+		return
 	}
 
 	// Create a channel for receiving of state