From 193020543bc9ca6ec57a08636f5b3f55c4dd78d7 Mon Sep 17 00:00:00 2001
From: Jeremy Kitchen <kitchen@kitchen.io>
Date: Sun, 7 Feb 2016 14:05:18 -0800
Subject: [PATCH] support for a pre_tweet_hook configuration parameter

---
 README.rst      |  5 ++++-
 config.example  |  1 +
 twtxt/cli.py    | 13 ++++++++++---
 twtxt/config.py |  5 +++++
 twtxt/helper.py |  8 ++++++++
 5 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/README.rst b/README.rst
index 45f6cd8..15ab547 100644
--- a/README.rst
+++ b/README.rst
@@ -125,6 +125,7 @@ Here’s an example ``conf`` file, showing every currently supported option:
     limit_timeline = 20
     timeout = 5.0
     sorting = descending
+    pre_tweet_hook = "scp buckket@example.org:~/public_html/twtxt.txt {twtfile}"
     post_tweet_hook = "scp {twtfile} buckket@example.org:~/public_html/twtxt.txt"
 
     [following]
@@ -151,10 +152,12 @@ Here’s an example ``conf`` file, showing every currently supported option:
 +-------------------+-------+------------+---------------------------------------------------+
 | sorting           | TEXT  | descending | sort timeline either descending or ascending      |
 +-------------------+-------+------------+---------------------------------------------------+
+| pre_tweet_hook    | TEXT  |            | command to be executed before tweeting            |
++-------------------+-------+------------+---------------------------------------------------+
 | post_tweet_hook   | TEXT  |            | command to be executed after tweeting             |
 +-------------------+-------+------------+---------------------------------------------------+
 
-``post_tweet_hook`` is very useful if you want to push your twtxt file to a remote (web) server. Check the example above tho see how it’s used with ``scp``.
+``pre_tweet_hook`` and ``post_tweet_hook`` are very useful if you want to push your twtxt file to a remote (web) server. Check the example above tho see how it’s used with ``scp``.
 
 [followings] section:
 =====================
diff --git a/config.example b/config.example
index 9fd7852..dff0c39 100644
--- a/config.example
+++ b/config.example
@@ -6,6 +6,7 @@ use_pager = False
 limit_timeline = 20
 timeout = 5.0
 sorting = descending
+pre_tweet_hook = "scp buckket@example.org:~/public_html/twtxt.txt {twtfile}"
 post_tweet_hook = "scp {twtfile} buckket@example.org:~/public_html/twtxt.txt"
 
 [following]
diff --git a/twtxt/cli.py b/twtxt/cli.py
index 64134c6..22e4da3 100644
--- a/twtxt/cli.py
+++ b/twtxt/cli.py
@@ -18,6 +18,7 @@
 from twtxt.config import Config
 from twtxt.file import get_local_tweets, add_local_tweet
 from twtxt.helper import run_post_tweet_hook
+from twtxt.helper import run_pre_tweet_hook
 from twtxt.helper import style_tweet, style_source, style_source_with_status
 from twtxt.helper import validate_created_at, validate_text
 from twtxt.helper import sort_and_truncate_tweets
@@ -69,12 +70,18 @@ def cli(ctx, config, verbose):
 def tweet(ctx, created_at, twtfile, text):
     """Append a new tweet to your twtxt file."""
     tweet = Tweet(text, created_at) if created_at else Tweet(text)
+
+    pre_tweet_hook = ctx.obj["conf"].pre_tweet_hook
+    if pre_tweet_hook:
+        if not run_pre_tweet_hook(pre_tweet_hook, ctx.obj["conf"].options):
+            raise Exception("✗ pre_tweet_hook returned non-zero")
+
     if not add_local_tweet(tweet, twtfile):
         click.echo("✗ Couldn’t write to file.")
     else:
-        hook = ctx.obj["conf"].post_tweet_hook
-        if hook:
-            run_post_tweet_hook(hook, ctx.obj["conf"].options)
+        post_tweet_hook = ctx.obj["conf"].post_tweet_hook
+        if post_tweet_hook:
+            run_post_tweet_hook(post_tweet_hook, ctx.obj["conf"].options)
 
 
 @cli.command()
diff --git a/twtxt/config.py b/twtxt/config.py
index 9a72ddd..796ec04 100644
--- a/twtxt/config.py
+++ b/twtxt/config.py
@@ -101,6 +101,11 @@ def nick(self):
         cfg = self.open_config()
         return cfg.get("twtxt", "nick", fallback=os.environ.get("USER", ""))
 
+    @property
+    def pre_tweet_hook(self):
+        cfg = self.open_config()
+        return cfg.get("twtxt", "pre_tweet_hook", fallback=None)
+
     @property
     def post_tweet_hook(self):
         cfg = self.open_config()
diff --git a/twtxt/helper.py b/twtxt/helper.py
index f0884b6..206706b 100644
--- a/twtxt/helper.py
+++ b/twtxt/helper.py
@@ -66,6 +66,14 @@ def validate_text(ctx, param, value):
         raise click.BadArgumentUsage("Text can’t be empty.")
 
 
+def run_pre_tweet_hook(hook, options):
+    try:
+        command = shlex.split(hook.format(**options))
+    except KeyError:
+        click.echo("✗ Invalid variables in pre_tweet_hook.")
+        return False
+    return not subprocess.call(command, shell=True, stdout=subprocess.PIPE)
+
 def run_post_tweet_hook(hook, options):
     try:
         command = shlex.split(hook.format(**options))