1 files changed, 129 insertions, 0 deletions
diff --git a/internal/taskproxy/run.go b/internal/taskproxy/run.go
new file mode 100644
index 0000000..7654b7b
--- /dev/null
+++ b/internal/taskproxy/run.go
@@ -0,0 +1,129 @@
+package taskproxy
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+type binaryFinder func() (string, error)
+
+type repoTopLevelDetector func(context.Context) (string, error)
+
+type commandRunner func(context.Context, string, []string, io.Reader, io.Writer, io.Writer) error
+
+type Runner struct {
+	CommandName    string
+	findTaskBinary binaryFinder
+	detectRepoRoot repoTopLevelDetector
+	runCommand     commandRunner
+}
+
+func NewRunner(commandName string) Runner {
+	return Runner{
+		CommandName:    strings.TrimSpace(commandName),
+		findTaskBinary: findTaskBinary,
+		detectRepoRoot: detectRepoRoot,
+		runCommand:     runTaskCommand,
+	}
+}
+
+func (r Runner) Run(ctx context.Context, args []string, stdin io.Reader, stdout, stderr io.Writer) (int, error) {
+	runner := normalizeRunner(r)
+	taskPath, err := runner.findTaskBinary()
+	if err != nil {
+		return 1, fmt.Errorf("%s: Taskwarrior binary lookup failed: %w", runner.commandLabel(), err)
+	}
+	repoRoot, err := runner.detectRepoRoot(ctx)
+	if err != nil {
+		return 1, fmt.Errorf("%s: must be run inside a git repository so project:<repo> can be derived: %w", runner.commandLabel(), err)
+	}
+	taskArgs, err := runner.taskArgs(repoRoot, args)
+	if err != nil {
+		return 1, fmt.Errorf("%s: %w", runner.commandLabel(), err)
+	}
+	if err := runner.runCommand(ctx, taskPath, taskArgs, stdin, stdout, stderr); err != nil {
+		return runner.exitCodeFor(err)
+	}
+	return 0, nil
+}
+
+func normalizeRunner(r Runner) Runner {
+	if r.CommandName == "" {
+		r.CommandName = "task"
+	}
+	if r.findTaskBinary == nil {
+		r.findTaskBinary = findTaskBinary
+	}
+	if r.detectRepoRoot == nil {
+		r.detectRepoRoot = detectRepoRoot
+	}
+	if r.runCommand == nil {
+		r.runCommand = runTaskCommand
+	}
+	return r
+}
+
+func (r Runner) commandLabel() string {
+	label := strings.TrimSpace(r.CommandName)
+	if label == "" {
+		return "task"
+	}
+	return label
+}
+
+func (r Runner) taskArgs(repoRoot string, args []string) ([]string, error) {
+	projectName, err := projectNameFromRoot(repoRoot)
+	if err != nil {
+		return nil, err
+	}
+	return append([]string{"project:" + projectName, "+agent"}, args...), nil
+}
+
+func (r Runner) exitCodeFor(err error) (int, error) {
+	var exitErr *exec.ExitError
+	if errors.As(err, &exitErr) {
+		return exitErr.ExitCode(), nil
+	}
+	return 1, fmt.Errorf("%s: failed to run Taskwarrior: %w", r.commandLabel(), err)
+}
+
+func projectNameFromRoot(repoRoot string) (string, error) {
+	projectName := filepath.Base(strings.TrimSpace(repoRoot))
+	if projectName == "" || projectName == "." || projectName == string(filepath.Separator) {
+		return "", fmt.Errorf("could not derive project name from git root %q", repoRoot)
+	}
+	return projectName, nil
+}
+
+func findTaskBinary() (string, error) {
+	path, err := exec.LookPath("task")
+	if err != nil {
+		return "", fmt.Errorf("Taskwarrior binary 'task' not found in PATH; install Taskwarrior and retry")
+	}
+	return path, nil
+}
+
+func detectRepoRoot(ctx context.Context) (string, error) {
+	out, err := exec.CommandContext(ctx, "git", "rev-parse", "--show-toplevel").Output()
+	if err != nil {
+		return "", fmt.Errorf("must be run inside a git repository so project:<repo> can be derived")
+	}
+	root := strings.TrimSpace(string(out))
+	if root == "" {
+		return "", fmt.Errorf("git returned an empty repository root")
+	}
+	return root, nil
+}
+
+func runTaskCommand(ctx context.Context, name string, args []string, stdin io.Reader, stdout, stderr io.Writer) error {
+	cmd := exec.CommandContext(ctx, name, args...)
+	cmd.Stdin = stdin
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+	return cmd.Run()
+}