Implement configuration files

1 files changed, 53 insertions, 10 deletions

diff --git a/brisket.hy b/brisket.hy
index 7d45d36..7e14926 100644
--- a/brisket.hy
+++ b/brisket.hy
@@ -1,4 +1,6 @@
-(import [os.path [expanduser]])
+(import [configparser [ConfigParser]])
+(import [os [getenv makedirs]])
+(import [os.path [dirname expanduser]])
 (import [sys [argv exit stderr]])
 (import re)
 (import [nntplib [NNTP-SSL]])
@@ -7,6 +9,7 @@
 (require [hy.contrib.walk [let]])
 
 (setv *auth-source* (expanduser "~/.authinfo.gpg"))
+(setv *config-path* (expanduser "~/.config/brisket/config.ini"))
 (setv *recognized-commands* ["describe-group"
                              "help"
                              "list-group"
@@ -26,6 +29,40 @@
     (let [handler (get (globals) (.replace command "-" "_"))]
       (print (. handler __doc__)))))
 
+(defn make-config []
+  "Create a default configuration file.
+
+Creates the configuration directory if it does not exist, as well as an INI file
+populated with default configuration values."
+  (let [config (ConfigParser)]
+    (assoc config "Server" {})
+    (assoc (get config "Server") "Host" "news.eternal-september.org")
+    (makedirs (dirname *config-path*))
+    (with [out (open *config-path* "w+")]
+      (.write config out))
+    config))
+
+(defn load-config []
+  "Load the configuration file for Brisket.
+
+Returns a default configuration, written to `*config-path*`, if a configuration
+file cannot be found."
+  (let [config (ConfigParser)]
+    (if (= 1 (len (.read config *config-path*)))
+        config
+        (make-config))))
+
+(defn find-host [config]
+  "Returns the host that Brisket should connect to.
+
+The lookup order is:
+  - NNTPSERVER environment variable.
+  - 'Host' in the 'Server' section of the configuration file."
+  (or (getenv "NNTPSERVER")
+      (if (and (in "Server" config)
+               (in "Host" (get config "Server")))
+          (get (get config "Server") "Host"))))
+
 (defn get-user-info [host]
   (let [process (Popen ["gpg" "-q" "-d" *auth-source*] :stdout PIPE)
         output (first (.communicate process))]
@@ -45,7 +82,13 @@
       (err (.format "  - {}" command)))
     (exit 1))
 
-  (let [command (nth argv 1)]
+  (let [config (load-config)
+        host (find-host config)
+        command (nth argv 1)]
+    (when (is host None)
+      (err (.format "no host specified"))
+      (exit 1))
+
     (unless (in command *recognized-commands*)
       (err (.format "unrecognized command: {}" command))
       (exit 1))
@@ -64,31 +107,31 @@
 ;;
 ;; def list_groups(n, *args):
 ;;     pattern = args[0] if len(args) >= 1 else None
-;; 
+;;
 ;;     _, groups = n.list()
-;; 
+;;
 ;;     for group in groups:
 ;;         if pattern is None or re.match(pattern, group.group):
 ;;             print(group.group)
-;; 
+;;
 ;; def describe_group(n, *args):
 ;;     if len(args) < 1:
 ;;         err("usage: describe-group [group]")
 ;;         return
-;; 
+;;
 ;;     _, descs = n.descriptions(args[0])
-;; 
+;;
 ;;     for desc in descs:
 ;;         print(desc)
-;; 
+;;
 ;; def list_group(n, *args):
 ;;     if len(args) < 1:
 ;;         err("usage: list-group [group]")
 ;;         return
-;; 
+;;
 ;;     _, _, first, last, _ = n.group(args[0])
 ;;     _, overviews = n.over((first, last))
-;; 
+;;
 ;;     for article_num, overview in overviews:
 ;;         print("\"{}\" by {} on {}".format(
 ;;             overview.get("subject"),