From 738a6c64726d99eba7d755c5e043f85b43756898 Mon Sep 17 00:00:00 2001
From: Timothy Messier <tim.messier@gmail.com>
Date: Thu, 11 May 2023 20:41:18 +0000
Subject: [PATCH] feat(bsr/convert): Implement ToAsciicast

This adds support for converting a channel in a SSH BSR to an asciicast.
---
 internal/bsr/convert/convert.go | 58 +++++++++++++++++++++++++++++++--
 internal/bsr/convert/doc.go     |  5 +++
 2 files changed, 60 insertions(+), 3 deletions(-)
 create mode 100644 internal/bsr/convert/doc.go

diff --git a/internal/bsr/convert/convert.go b/internal/bsr/convert/convert.go
index da24d337a..2b2d7ec7b 100644
--- a/internal/bsr/convert/convert.go
+++ b/internal/bsr/convert/convert.go
@@ -5,16 +5,68 @@ package convert
 
 import (
 	"context"
+	"fmt"
 	"io"
 
 	"github.com/hashicorp/boundary/internal/bsr"
+	"github.com/hashicorp/boundary/internal/bsr/internal/is"
+	"github.com/hashicorp/boundary/internal/bsr/ssh"
 	"github.com/hashicorp/boundary/internal/storage"
 )
 
 // ToAsciicast accepts a bsr.Session and will convert the underlying BSR connection or channel file to an asciinema file.
 // The tempFs will be used to write the asciinema file to disk
 // It returns an io.Reader to the converted asciinema file
-// Supports WithChannelId() to indicate this conversion should occur on a chanel on a multiplexed session
-func ToAsciicast(ctx context.Context, session bsr.Session, tmp storage.TempFile, connectionId string, options ...Option) (io.ReadCloser, error) {
-	panic("not implemented")
+// Supports WithChannelId() to indicate this conversion should occur on a channel on a multiplexed session
+func ToAsciicast(ctx context.Context, session *bsr.Session, tmp storage.TempFile, connectionId string, options ...Option) (io.ReadCloser, error) {
+	const op = "convert.ToAsciicast"
+
+	switch {
+	case is.Nil(session):
+		return nil, fmt.Errorf("%s: missing session: %w", op, bsr.ErrInvalidParameter)
+	case is.Nil(session.Meta):
+		return nil, fmt.Errorf("%s: missing session meta: %w", op, bsr.ErrInvalidParameter)
+	case is.Nil(tmp):
+		return nil, fmt.Errorf("%s: missing temp file: %w", op, bsr.ErrInvalidParameter)
+	case connectionId == "":
+		return nil, fmt.Errorf("%s: missing connection id: %w", op, bsr.ErrInvalidParameter)
+	}
+
+	opts := getOpts(options...)
+
+	switch session.Meta.Protocol {
+	case ssh.Protocol:
+		chanId := opts.withChannelId
+		switch {
+		case chanId == "":
+			return nil, fmt.Errorf("%s: protocol %q requires channel id to convert: %w", op, ssh.Protocol, bsr.ErrInvalidParameter)
+		}
+
+		conn, err := session.OpenConnection(ctx, connectionId)
+		if err != nil {
+			return nil, fmt.Errorf("%s: %w", op, err)
+		}
+
+		ch, err := conn.OpenChannel(ctx, chanId)
+		if err != nil {
+			return nil, fmt.Errorf("%s: %w", op, err)
+		}
+
+		// TODO sanity checks before getting the data files:
+		// - check connection summary to see if there was an exec or shell request
+
+		reqScanner, err := ch.OpenRequestScanner(ctx, bsr.Inbound)
+		if err != nil {
+			return nil, fmt.Errorf("%s: %w", op, err)
+		}
+
+		msgScanner, err := ch.OpenMessageScanner(ctx, bsr.Outbound)
+		if err != nil {
+			return nil, fmt.Errorf("%s: %w", op, err)
+		}
+
+		return sshChannelToAsciicast(ctx, reqScanner, msgScanner, tmp)
+	default:
+		return nil, fmt.Errorf("%s: %w", op, ErrUnsupportedProtocol)
+	}
 }
diff --git a/internal/bsr/convert/doc.go b/internal/bsr/convert/doc.go
new file mode 100644
index 000000000..45dcb4a50
--- /dev/null
+++ b/internal/bsr/convert/doc.go
@@ -0,0 +1,5 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+// Package convert provides functions for converting BSR data into other formats.
+package convert