Begin trying to integrate the transpiler

cmd/mothd/puzzlecmd.go

@@ -0,0 +1,124 @@
+// Provides a Puzzle interface that runs a command for each request
+package main
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// PuzzleCommand specifies a command to run for the puzzle API
+type PuzzleCommand struct {
+	Path string
+	Args []string
+}
+
+// Inventory runs with "action=inventory", and parses the output into a category list.
+func (pc PuzzleCommand) Inventory() (inv []Category) {
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, pc.Path, pc.Args...)
+	cmd.Env = os.Environ()
+	cmd.Env = append(cmd.Env, "action=inventory")
+
+	stdout, err := cmd.Output()
+	if err != nil {
+		log.Print(err)
+		return
+	}
+
+	for _, line := range strings.Split(string(stdout), "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+		parts := strings.Split(line, " ")
+		if len(parts) < 2 {
+			log.Println("Skipping misformatted line:", line)
+			continue
+		}
+		name := parts[0]
+		puzzles := make([]int, 0, 10)
+		for _, pointsString := range parts[1:] {
+			points, err := strconv.Atoi(pointsString)
+			if err != nil {
+				log.Println(err)
+				continue
+			}
+			puzzles = append(puzzles, points)
+		}
+		inv = append(inv, Category{name, puzzles})
+	}
+	return
+}
+
+type NullReadSeekCloser struct {
+	io.ReadSeeker
+}
+
+func (f NullReadSeekCloser) Close() error {
+	return nil
+}
+
+// Open passes its arguments to the command with "action=open".
+func (pc PuzzleCommand) Open(cat string, points int, path string) (ReadSeekCloser, time.Time, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, pc.Path, pc.Args...)
+	cmd.Env = os.Environ()
+	cmd.Env = append(cmd.Env, "action=open")
+	cmd.Env = append(cmd.Env, "cat="+cat)
+	cmd.Env = append(cmd.Env, "points="+strconv.Itoa(points))
+	cmd.Env = append(cmd.Env, "path="+path)
+
+	stdoutBytes, err := cmd.Output()
+	stdout := NullReadSeekCloser{bytes.NewReader(stdoutBytes)}
+	now := time.Now()
+	return stdout, now, err
+}
+
+// CheckAnswer passes its arguments to the command with "action=answer".
+// If the command exits successfully and sends "correct" to stdout,
+// nil is returned.
+func (pc PuzzleCommand) CheckAnswer(cat string, points int, answer string) error {
+	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, pc.Path, pc.Args...)
+	cmd.Env = os.Environ()
+	cmd.Env = append(cmd.Env, "action=answer")
+	cmd.Env = append(cmd.Env, "cat="+cat)
+	cmd.Env = append(cmd.Env, "points="+strconv.Itoa(points))
+	cmd.Env = append(cmd.Env, "answer="+answer)
+
+	stdout, err := cmd.Output()
+	if ee, ok := err.(*exec.ExitError); ok {
+		log.Printf("%s: %s", pc.Path, string(ee.Stderr))
+		return err
+	} else if err != nil {
+		return err
+	}
+	result := strings.TrimSpace(string(stdout))
+
+	if result != "correct" {
+		if result == "" {
+			result = "Nothing written to stdout"
+		}
+		return fmt.Errorf("Wrong answer: %s", result)
+	}
+
+	return nil
+}
+
+// Maintain does nothing: a command puzzle provider has no housekeeping
+func (pc PuzzleCommand) Maintain(updateInterval time.Duration) {
+}

cmd/mothd/puzzlecmd_test.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"io/ioutil"
+	"os/exec"
+	"testing"
+)
+
+func TestPuzzleCommand(t *testing.T) {
+	pc := PuzzleCommand{
+		Path: "testdata/testpiler.sh",
+	}
+
+	inv := pc.Inventory()
+	if len(inv) != 2 {
+		t.Errorf("Wrong length for inventory")
+	}
+	for _, cat := range inv {
+		switch cat.Name {
+		case "pategory":
+			if len(cat.Puzzles) != 8 {
+				t.Errorf("pategory wrong number of puzzles: %d", len(cat.Puzzles))
+			}
+			if cat.Puzzles[5] != 10 {
+				t.Errorf("pategory puzzles[5] wrong value: %d", cat.Puzzles[5])
+			}
+		case "nealegory":
+			if len(cat.Puzzles) != 3 {
+				t.Errorf("nealegoy wrong number of puzzles: %d", len(cat.Puzzles))
+			}
+		}
+	}
+
+	if err := pc.CheckAnswer("pategory", 1, "answer"); err != nil {
+		t.Errorf("Correct answer for pategory: %v", err)
+	}
+	if err := pc.CheckAnswer("pategory", 1, "wrong"); err == nil {
+		t.Errorf("Wrong answer for pategory judged correct")
+	}
+
+	if err := pc.CheckAnswer("pategory", 2, "answer"); err == nil {
+		t.Errorf("Internal error not returned")
+	} else if ee, ok := err.(*exec.ExitError); ok {
+		if string(ee.Stderr) != "Internal error\n" {
+			t.Errorf("Unexpected error returned: %#v", string(ee.Stderr))
+		}
+	} else if err.Error() != "moo" {
+		t.Error(err)
+	}
+
+	if f, _, err := pc.Open("pategory", 1, "moo.txt"); err != nil {
+		t.Error(err)
+	} else if buf, err := ioutil.ReadAll(f); err != nil {
+		f.Close()
+		t.Error(err)
+	} else if string(buf) != "Moo.\n" {
+		f.Close()
+		t.Errorf("Wrong contents: %#v", string(buf))
+	} else {
+		f.Close()
+	}
+}

cmd/mothd/testdata/testpiler.sh

@@ -0,0 +1,30 @@
+#! /bin/sh -e
+
+case "$action:$cat:$points" in
+    inventory::)
+        echo "pategory 1 2 3 4 5 10 20 300"
+        echo "nealegory 1 2 3"
+        ;;
+    open:*:*)
+        if [ "$path" = "moo.txt" ]; then
+            echo "Moo."
+        else
+            cat $cat_$points_$path
+        fi
+        ;;
+    answer:pategory:1)
+        if [ "$answer" = "answer" ]; then
+            echo "correct"
+        else
+            echo "Sorry, wrong answer."
+        fi
+        ;;
+    answer:pategory:2)
+        echo "Internal error" 1>&2
+        exit 1
+        ;;
+    *)
+        echo "ERROR: Unknown action: $action" 1>&2
+        exit 1
+        ;;
+esac