From d36c6f93d8dde634a1232495944a6f6adbce2ea4 Mon Sep 17 00:00:00 2001
From: Shrikant Sharat <shrikantsharat.k@gmail.com>
Date: Fri, 21 Sep 2012 17:17:09 +0530
Subject: [PATCH] Implemented `antigen-snapshot` command.

Creates a snapshot file with some basic metadata information and pairs of repo
urls and their version hashes. Tests included.
---
 antigen.zsh       | 37 +++++++++++++++++++++++++++++++++++++
 tests/snapshots.t | 22 ++++++++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 tests/snapshots.t

diff --git a/antigen.zsh b/antigen.zsh
index c71d4d1..87af785 100644
--- a/antigen.zsh
+++ b/antigen.zsh
@@ -349,6 +349,43 @@ antigen-list () {
     fi
 }
 
+antigen-snapshot () {
+
+    local snapshot_file="${1:-antigen-shapshot}"
+
+    # The snapshot content lines are pairs of repo-url and git version hash, in
+    # the form:
+    #   <version-hash> <repo-url>
+    local snapshot_content="$(-antigen-echo-record | sed 's/ .*$//' | sort -u |
+        while read url; do
+            dir="$(-antigen-get-clone-dir "$url")"
+            version_hash="$(cd "$dir" && git rev-parse HEAD)"
+            echo "$version_hash $dir"
+        done)"
+
+    {
+        # The first line in the snapshot file is for metadata, in the form:
+        #   key='value'; key='value'; key='value';
+        # Where `key`s are valid shell variable names.
+
+        # Snapshot version. Has no relation to antigen version. If the snapshot
+        # file format changes, this number can be incremented.
+        echo -n "version='1';"
+
+        # Snapshot creation date+time.
+        echo -n " created_on='$(date)';"
+
+        # Add a checksum with the md5 checksum of all the snapshot lines.
+        local checksum="$(echo "$snapshot_content" | md5sum)"
+        echo -n " checksum='${checksum%% *}';"
+
+        # A newline after the metadata and then the snapshot lines.
+        echo "\n$snapshot_content"
+
+    } > "$snapshot_file"
+
+}
+
 antigen-help () {
     cat <<EOF
 Antigen is a plugin management system for zsh. It makes it easy to grab awesome
diff --git a/tests/snapshots.t b/tests/snapshots.t
new file mode 100644
index 0000000..5dd1295
--- /dev/null
+++ b/tests/snapshots.t
@@ -0,0 +1,22 @@
+Load a couple of plugins.
+
+  $ antigen-bundle $PLUGIN_DIR
+  Cloning into '*'... (glob)
+  done.
+  $ antigen-bundle $PLUGIN_DIR2
+  Cloning into '*'... (glob)
+  done.
+
+Create a snapshot file.
+
+  $ test -f snapshot-file
+  [1]
+  $ antigen-snapshot snapshot-file
+  $ test -f snapshot-file
+
+See the contents of the snapshot file.
+
+  $ cat snapshot-file
+  version='1'; created_on='*'; checksum='*'; (glob)
+  .{40} .*-test-plugin (re)
+  .{40} .*-test-plugin2 (re)
-- 
2.0.0