cmd/get: add get command

For the moment, grabs c2 families.

Author: kmroz

cmd/get/get.go

@@ -0,0 +1,174 @@
+// Package get implements the get command.
+package get
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+	"text/tabwriter"
+	"time"
+
+	"github.com/alphasoc/flightsim/wisdom"
+)
+
+var Version string
+
+var usage = `usage: flightsim get [flags] element:category
+
+Available elements:
+
+	%s
+
+Available categories:
+
+	%s
+
+Available flags:
+`
+
+// printWelcome prints a basic welcome banner.
+func printWelcome() {
+	fmt.Printf(`
+AlphaSOC Network Flight Simulator™ %s (https://github.com/alphasoc/flightsim)
+The current time is %s
+`, Version, time.Now().Format("02-Jan-06 15:04:05"))
+}
+
+// printGoodbye prints a parting message.
+func printGoodbye() {
+	fmt.Printf("\nAll done!\n")
+}
+
+// printMsg prints msg, decorated with an info string and the current date/time.
+func printMsg(info string, msg string) {
+	if msg == "" {
+		return
+	}
+	fmt.Printf("%s [%s] %s\n", time.Now().Format("15:04:05"), info, msg)
+}
+
+// We only know how to get families for now.
+var supportedElementsMap = map[string]bool{
+	"families": true,
+}
+
+// supportedElements returns a slice of fetchable elements.
+func supportedElements() []string {
+	var elements []string
+	for e := range supportedElementsMap {
+		elements = append(elements, e)
+	}
+	return elements
+}
+
+// Taken from open-wisdom/server/entries/entries.go.
+// TODO: would be good to fetch these also.
+var supportedCategoriesMap = map[string]bool{
+	"c2": true,
+}
+
+// supportedCategories returns a slice of fetchable categories.
+func supportedCategories() []string {
+	var categories []string
+	for e := range supportedCategoriesMap {
+		categories = append(categories, e)
+	}
+	return categories
+}
+
+// computeFormatStr returns a format string to be used with column printing.
+func computeFormatStr(cols int) string {
+	fmtStr := "\n"
+	for i := 0; i < cols; i++ {
+		fmtStr += "%v\t"
+	}
+	return fmtStr
+}
+
+// printCol prints elements in cols columns.
+func printCol(elements []string, cols int) {
+	w := new(tabwriter.Writer)
+	// Min width, tab width, padding, pad char, flags.
+	w.Init(os.Stdout, 8, 8, 1, '\t', 0)
+	// Compute format string.
+	fmtStr := computeFormatStr(cols)
+	// Convert elements ([]string) to []interface{}.
+	elementsToPrint := make([]interface{}, len(elements))
+	for i, v := range elements {
+		elementsToPrint[i] = v
+	}
+	// Print.
+	i := 0
+	lenElementsToPrint := len(elementsToPrint)
+	for leftToPrint := lenElementsToPrint; leftToPrint > 0; {
+		// We don't have enough elements left to print to satisfy the format string,
+		// or the re-slice.  Thus, reset *cols and recompute the format string.
+		if leftToPrint < cols {
+			cols = leftToPrint
+			fmtStr = computeFormatStr(cols)
+		}
+		fmt.Fprintf(w, fmtStr, elementsToPrint[i:i+cols]...)
+		// Move by number of columns.
+		i += cols
+		leftToPrint = lenElementsToPrint - i
+	}
+	// Append a blank line.
+	fmt.Fprintf(w, "%v", "\n\n")
+	w.Flush()
+}
+
+// RunCmd runs the 'get' command and returns an error.
+func RunCmd(args []string) error {
+	printWelcome()
+	// Mirrors look of run command.
+	fmt.Println("")
+	cmdLine := flag.NewFlagSet("get", flag.ExitOnError)
+	// TODO: replace cols with -format (issue #45).
+	// cols := cmdLine.Int("cols", 0, "print elements in number of columns")
+	cmdLine.Usage = func() {
+		fmt.Fprintf(cmdLine.Output(), usage, strings.Join(supportedElements(), ", "), strings.Join(supportedCategories(), ", "))
+		cmdLine.PrintDefaults()
+	}
+	cmdLine.Parse(args)
+	// Next arg should be element:category (ie. families:c2)
+	toGet := cmdLine.Arg(0)
+	if len(toGet) == 0 {
+		return fmt.Errorf("nothing to get")
+	}
+	toGetArr := strings.Split(cmdLine.Arg(0), ":")
+	if len(toGetArr) != 2 {
+		return fmt.Errorf("unable to get '%v': invalid format", toGet)
+	}
+	elem := toGetArr[0]
+	cat := toGetArr[1]
+	// infoTag == "element:category" (ie. families:c2).  Mirrors the run command.
+	infoTag := cmdLine.Arg(0)
+	var elements []string
+	var err error
+	switch elem {
+	case "families":
+		printMsg(infoTag, fmt.Sprintf("Fetching %v %v", cat, elem))
+		elements, err = wisdom.Families(cat)
+		if err != nil {
+			return err
+		}
+	default:
+		return fmt.Errorf("unable to get '%v': unsupported element '%v'", toGet, elem)
+	}
+	// TODO: Leave quotes in for later cut/paste?
+	for i := 0; i < len(elements); i++ {
+		elements[i] = strings.Trim(elements[i], "\"")
+	}
+	// Default is to print in a single line.  Otherwise, column print.
+	// if *cols <= 0 {
+	// 	printMsg(infoTag, strings.Join(elements, ", "))
+	// } else {
+	// 	printCol(elements, *cols)
+	// }
+	printMsg(infoTag, strings.Join(elements, ", "))
+
+	printMsg(infoTag, fmt.Sprintf("Fetched %v %v %v", len(elements), cat, elem))
+	printGoodbye()
+	return nil
+}