piem: Sketch a base

This does nothing useful, but the idea is that it never will do much
of anything on its own.  Different libraries---piem-notmuch,
piem-elfeed, piem-gnus, and so on---will populate its hooks, teaching
it how to extract information.

1 files changed, 109 insertions, 1 deletions

diff --git a/piem.el b/piem.el
index 886643d..979f944 100644
--- a/piem.el
+++ b/piem.el
@@ -1,4 +1,112 @@
-;;; piem.el --- Emacs tools for working with public-index
+;;; piem.el --- Emacs tools for working with public-index  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2020  Kyle Meyer
+
+;; Author: Kyle Meyer <kyle@kyleam.com>
+;; Keywords: vc, tools
+;; Version: 0.0.0
+;; Package-Requires: ((emacs "26.3"))
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU 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 General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+
+(require 'subr-x)
+
+(defgroup piem ()
+  "Emacs tools for working with public-inbox archives."
+  :link '(info-link "(piem)Top")
+  :group 'tools)
+
+;; TODO: These intentionally follow public-inbox's configuration
+;; names.  Eventually reading values from there as well should be
+;; supported.
+;;
+;; TODO: Decide how to deal with inboxes that map to more than one
+;; coderepos.  This is important to support for people that want to
+;; use a catchall inbox for small projects which they don't think
+;; (yet) need a dedicated address.
+(defcustom piem-inboxes nil
+  "List of public-inbox-archived projects.
+
+Elements have the form (NAME . INFO), where INFO is a property
+list that supports the following properties:
+
+  :address
+  :listid
+      The email address and List-ID for the inbox.
+  :coderepo
+      Local path of the code repository associated with the inbox.
+  :url
+      A URL hosting HTTPS archives.
+
+Here's an example for the public-inbox project itself:
+
+    (\"public-inbox\" .
+     (:coderepo
+      \"~/src/public-inbox/\"
+      :address
+      \"meta@public-inbox.org\"
+      :listid
+      \"meta.public-inbox.org\"
+      :url
+      \"https://public-inbox.org/meta/\"))"
+  :type '(alist :key-type string
+                :value-type
+                (plist :value-type string)))
+
+(defcustom piem-get-inbox-functions nil
+  "Functions tried to get the inbox of the current buffer.
+Each function should accept no arguments and return the name of
+the inbox associated with the current buffer or nil."
+  :type 'hook)
+
+(defcustom piem-get-mid-functions nil
+  "Functions tried to get the message ID of the current buffer.
+Each function should accept no arguments and return the
+message ID associated with the current buffer or nil."
+  :type 'hook)
+
+(defcustom piem-mid-to-thread-functions nil
+  "Functions tried to create an mbox from a message ID.
+Each function should accept one argument, the message ID.  If the
+function knows how to create an mbox for the message ID, it
+should return a function that takes no arguments and inserts the
+mbox's contents in the current buffer."
+  :type 'hook)
+
+;;;###autoload
+(defun piem-inbox ()
+  "Return the current buffer's inbox."
+  (run-hook-with-args-until-success 'piem-get-inbox-functions))
+
+;;;###autoload
+(defun piem-inbox-coderepo ()
+  "Return the code repository of current buffer's inbox."
+  (when-let ((p (piem-inbox))
+             (repo (plist-get
+                    (alist-get p piem-inboxes) :coderepo)))
+    (expand-file-name repo)))
+
+;;;###autoload
+(defun piem-mid ()
+  "Return the current buffer's message ID."
+  (run-hook-with-args-until-success 'piem-get-mid-functions))
 
 (defun piem-please ()
   "How I wish I could intersect my emails, feeds, and repos")