From 6e75e155262d3d268d5ab6bf764910b96621c588 Mon Sep 17 00:00:00 2001
From: drewcassidy <drewcassidy@me.com>
Date: Wed, 21 Apr 2021 01:20:08 -0700
Subject: [PATCH] `yaclog init` command

---
 yaclog/changelog.py    | 28 +++++++++++++----------
 yaclog/cli/__init__.py |  0
 yaclog/cli/__main__.py | 52 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+), 12 deletions(-)
 create mode 100644 yaclog/cli/__init__.py
 create mode 100644 yaclog/cli/__main__.py

diff --git a/yaclog/changelog.py b/yaclog/changelog.py
index 18ca4c5..464b293 100644
--- a/yaclog/changelog.py
+++ b/yaclog/changelog.py
@@ -29,6 +29,8 @@ under2_regex = re.compile(r'^-+\s*$')
 bullet_regex = re.compile(r'^[-+*]')
 linkid_regex = re.compile(r'^\[(?P<link_id>\S*)]:\s*(?P<link>.*)')
 
+default_header = '# Changelog\n\nAll notable changes to this project will be documented in this file'
+
 
 def _strip_link(token):
     if link_literal := re.fullmatch(r'\[(.*?)]\((.*?)\)', token):
@@ -112,26 +114,28 @@ class VersionEntry:
 
 
 class Changelog:
-    def __init__(self, path: os.PathLike):
+    def __init__(self, path: os.PathLike = None):
         self.path = path
         self.header = ''
         self.versions = []
+        self.links = {}
+
+        if not os.path.exists(path):
+            self.header = default_header
+            return
 
         # Read file
         with open(path, 'r') as fp:
-            self.lines = fp.readlines()
+            lines = fp.readlines()
 
         section = ''
         in_block = False
         in_code = False
 
-        self.links = {}
-
-        links = {}
         segments: List[Tuple[int, List[str], str]] = []
         header_segments = []
 
-        for line_no, line in enumerate(self.lines):
+        for line_no, line in enumerate(lines):
             if in_code:
                 # this is the contents of a code block
                 segments[-1][1].append(line)
@@ -168,7 +172,7 @@ class Changelog:
 
             elif match := linkid_regex.match(line):
                 # this is a link definition in the form '[id]: link', so add it to the link table
-                links[match['link_id'].lower()] = match['link']
+                self.links[match['link_id'].lower()] = match['link']
 
             elif line.isspace():
                 # skip empty lines
@@ -241,18 +245,18 @@ class Changelog:
             if match := re.fullmatch(r'\[(.*)]', version.name):
                 # ref-matched link
                 link_id = match[1].lower()
-                if link_id in links:
-                    version.link = links.pop(link_id)
+                if link_id in self.links:
+                    version.link = self.links.pop(link_id)
                     version.link_id = None
                     version.name = match[1]
 
-            elif version.link_id in links:
+            elif version.link_id in self.links:
                 # id-matched link
-                version.link = links.pop(version.link_id)
+                version.link = self.links.pop(version.link_id)
 
         # strip whitespace from header
         self.header = _join_markdown(header_segments)
-        self.links = links
+        self.links = self.links
 
     def write(self, path: os.PathLike = None):
         if path is None:
diff --git a/yaclog/cli/__init__.py b/yaclog/cli/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/yaclog/cli/__main__.py b/yaclog/cli/__main__.py
new file mode 100644
index 0000000..20d5c04
--- /dev/null
+++ b/yaclog/cli/__main__.py
@@ -0,0 +1,52 @@
+#  yaclog: yet another changelog tool
+#  Copyright (c) 2021. Andrew Cassidy
+#
+#  This program is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU Affero General Public License as
+#  published by the Free Software Foundation, either version 3 of the
+#  License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU Affero General Public License for more details.
+#
+#  You should have received a copy of the GNU Affero General Public License
+#  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+import click
+import yaclog
+import os.path
+
+
+@click.group()
+@click.option('--path', envvar='YACLOG_PATH', default='CHANGELOG.md',
+              type=click.Path(dir_okay=False, writable=True, readable=True))
+@click.version_option()
+@click.pass_context
+def cli(ctx, path):
+    ctx.obj = path
+
+    if not (ctx.invoked_subcommand == 'init' or os.path.exists(path)):
+        # if the path doesnt exist, then ask if we can create it
+        if click.confirm(f'Changelog file {path} does not exist. Would you like to create it?'):
+            ctx.invoke('init')
+        else:
+            return
+
+
+@cli.command('init')
+@click.pass_context
+def init(ctx):
+    path = ctx.parent.params['path']
+
+    if os.path.exists(path) and not click.confirm(
+            f'Changelog file {path} already exists. Would you like to overwrite it?'):
+        return
+
+    yaclog.Changelog(path).write()
+    print(f'Created new changelog file at {path}')
+
+
+if __name__ == '__main__':
+    cli()