emacs: Add Hydra interface.

* emacs/guix-utils.el (guix-hexify, guix-number->bool): New procedures.
  (guix-while-null): New macro.
* emacs/guix-hydra.el: New file.
* emacs/guix-hydra-build.el: New file.
* emacs/guix-hydra-jobset.el: New file.
* emacs.am (ELFILES): Add them.
* doc/emacs.texi (Emacs Hydra): New node.
  (Emacs Interface): Add it.
* doc/guix.texi (Top): Add it.
  (Substitutes): Mention Emacs interface.

1 files changed, 363 insertions, 0 deletions

diff --git a/emacs/guix-hydra.el b/emacs/guix-hydra.el
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+++ b/emacs/guix-hydra.el
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+;;; guix-hydra.el --- Common code for interacting with Hydra  -*- lexical-binding: t -*-
+
+;; Copyright © 2015 Alex Kost <alezost@gmail.com>
+
+;; This file is part of GNU Guix.
+
+;; GNU Guix 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.
+
+;; GNU Guix 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 <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This file provides some general code for 'list'/'info' interfaces for
+;; Hydra (Guix build farm).
+
+;;; Code:
+
+(require 'json)
+(require 'guix-buffer)
+(require 'guix-entry)
+(require 'guix-utils)
+(require 'guix-help-vars)
+
+(guix-define-groups hydra)
+
+(defvar guix-hydra-job-regexp
+  (concat ".*\\." (regexp-opt guix-help-system-types) "\\'")
+  "Regexp matching a full name of Hydra job (including system).")
+
+(defun guix-hydra-message (entries search-type &rest _)
+  "Display a message after showing Hydra ENTRIES."
+  ;; XXX Add more messages maybe.
+  (when (null entries)
+    (if (eq search-type 'fake)
+        (message "The update is impossible due to lack of Hydra API.")
+      (message "Hydra has returned no results."))))
+
+(defun guix-hydra-list-describe (ids)
+  "Describe 'hydra' entries with IDS (list of identifiers)."
+  (guix-buffer-display-entries
+   (guix-entries-by-ids ids (guix-buffer-current-entries))
+   'info (guix-buffer-current-entry-type)
+   ;; Hydra does not provide an API to receive builds/jobsets by
+   ;; IDs/names, so we use a 'fake' search type.
+   '(fake)
+   'add))
+
+
+;;; Readers
+
+(defvar guix-hydra-projects
+  '("gnu" "guix")
+  "List of available Hydra projects.")
+
+(guix-define-readers
+ :completions-var guix-hydra-projects
+ :single-reader guix-hydra-read-project
+ :single-prompt "Project: ")
+
+(guix-define-readers
+ :single-reader guix-hydra-read-jobset
+ :single-prompt "Jobset: ")
+
+(guix-define-readers
+ :single-reader guix-hydra-read-job
+ :single-prompt "Job: ")
+
+(guix-define-readers
+ :completions-var guix-help-system-types
+ :single-reader guix-hydra-read-system
+ :single-prompt "System: ")
+
+
+;;; Defining URLs
+
+(defvar guix-hydra-url "http://hydra.gnu.org"
+  "URL of the Hydra build farm.")
+
+(defun guix-hydra-url (&rest url-parts)
+  "Return Hydra URL."
+  (apply #'concat guix-hydra-url "/" url-parts))
+
+(defun guix-hydra-api-url (type args)
+  "Return URL for receiving data using Hydra API.
+TYPE is the name of an allowed method.
+ARGS is alist of (KEY . VALUE) pairs.
+Skip ARG, if VALUE is nil or an empty string."
+  (declare (indent 1))
+  (let* ((fields (mapcar
+                  (lambda (arg)
+                    (pcase arg
+                      (`(,key . ,value)
+                       (unless (or (null value)
+                                   (equal "" value))
+                         (concat (guix-hexify key) "="
+                                 (guix-hexify value))))
+                      (_ (error "Wrong argument '%s'" arg))))
+                  args))
+         (fields (mapconcat #'identity (delq nil fields) "&")))
+    (guix-hydra-url "api/" type "?" fields)))
+
+
+;;; Receiving data from Hydra
+
+(defun guix-hydra-receive-data (url)
+  "Return output received from URL and processed with `json-read'."
+  (with-temp-buffer
+    (url-insert-file-contents url)
+    (goto-char (point-min))
+    (let ((json-key-type 'symbol)
+          (json-array-type 'list)
+          (json-object-type 'alist))
+      (json-read))))
+
+(defun guix-hydra-get-entries (entry-type search-type &rest args)
+  "Receive ENTRY-TYPE entries from Hydra.
+SEARCH-TYPE is one of the types defined by `guix-hydra-define-interface'."
+  (unless (eq search-type 'fake)
+    (let* ((url         (apply #'guix-hydra-search-url
+                               entry-type search-type args))
+           (raw-entries (guix-hydra-receive-data url))
+           (entries     (guix-hydra-filter-entries
+                         raw-entries
+                         (guix-hydra-filters entry-type))))
+      entries)))
+
+
+;;; Filters for processing raw entries
+
+(defun guix-hydra-filter-entries (entries filters)
+  "Filter ENTRIES using FILTERS.
+Call `guix-modify' on each entry from ENTRIES."
+  (mapcar (lambda (entry)
+            (guix-modify entry filters))
+          entries))
+
+(defun guix-hydra-filter-names (entry name-alist)
+  "Replace names of ENTRY parameters using NAME-ALIST.
+Each element of NAME-ALIST is (OLD-NAME . NEW-NAME) pair."
+  (mapcar (lambda (param)
+            (pcase param
+              (`(,name . ,val)
+               (let ((new-name (guix-assq-value name-alist name)))
+                 (if new-name
+                     (cons new-name val)
+                   param)))))
+          entry))
+
+(defun guix-hydra-filter-boolean (entry params)
+  "Convert number PARAMS (0/1) of ENTRY to boolean values (nil/t)."
+  (mapcar (lambda (param)
+            (pcase param
+              (`(,name . ,val)
+               (if (memq name params)
+                   (cons name (guix-number->bool val))
+                 param))))
+          entry))
+
+
+;;; Wrappers for defined variables
+
+(defvar guix-hydra-entry-type-data nil
+  "Alist with hydra entry type data.
+This alist is filled by `guix-hydra-define-entry-type' macro.")
+
+(defun guix-hydra-entry-type-value (entry-type symbol)
+  "Return SYMBOL's value for ENTRY-TYPE from `guix-hydra'."
+  (symbol-value (guix-assq-value guix-hydra-entry-type-data
+                                 entry-type symbol)))
+
+(defun guix-hydra-search-url (entry-type search-type &rest args)
+  "Return URL to receive ENTRY-TYPE entries from Hydra."
+  (apply (guix-assq-value (guix-hydra-entry-type-value
+                           entry-type 'search-types)
+                          search-type)
+         args))
+
+(defun guix-hydra-filters (entry-type)
+  "Return a list of filters for ENTRY-TYPE."
+  (guix-hydra-entry-type-value entry-type 'filters))
+
+
+;;; Interface definers
+
+(defmacro guix-hydra-define-entry-type (entry-type &rest args)
+  "Define general code for ENTRY-TYPE.
+Remaining arguments (ARGS) should have a form [KEYWORD VALUE] ...
+
+Required keywords:
+
+  - `:search-types' - default value of the generated
+    `guix-ENTRY-TYPE-search-types' variable.
+
+Optional keywords:
+
+  - `:filters' - default value of the generated
+    `guix-ENTRY-TYPE-filters' variable.
+
+  - `:filter-names' - if specified, a generated
+    `guix-ENTRY-TYPE-filter-names' function for filtering these
+    names will be added to `guix-ENTRY-TYPE-filters' variable.
+
+  - `:filter-boolean-params' - if specified, a generated
+    `guix-ENTRY-TYPE-filter-boolean' function for filtering these
+    names will be added to `guix-ENTRY-TYPE-filters' variable.
+
+The rest keyword arguments are passed to
+`guix-define-entry-type' macro."
+  (declare (indent 1))
+  (let* ((entry-type-str     (symbol-name entry-type))
+         (prefix             (concat "guix-" entry-type-str))
+         (search-types-var   (intern (concat prefix "-search-types")))
+         (filters-var        (intern (concat prefix "-filters")))
+         (get-fun            (intern (concat prefix "-get-entries"))))
+    (guix-keyword-args-let args
+        ((search-types-val   :search-types)
+         (filters-val        :filters)
+         (filter-names-val   :filter-names)
+         (filter-bool-val    :filter-boolean-params))
+      `(progn
+         (defvar ,search-types-var ,search-types-val
+           ,(format "\
+Alist of search types and according URL functions.
+Functions are used to define URL to receive '%s' entries."
+                    entry-type-str))
+
+         (defvar ,filters-var ,filters-val
+           ,(format "\
+List of filters for '%s' parameters.
+Each filter is a function that should take an entry as a single
+argument, and should also return an entry."
+                    entry-type-str))
+
+         ,(when filter-bool-val
+            (let ((filter-bool-var (intern (concat prefix
+                                                   "-filter-boolean-params")))
+                  (filter-bool-fun (intern (concat prefix
+                                                   "-filter-boolean"))))
+              `(progn
+                 (defvar ,filter-bool-var ,filter-bool-val
+                   ,(format "\
+List of '%s' parameters that should be transformed to boolean values."
+                            entry-type-str))
+
+                 (defun ,filter-bool-fun (entry)
+                   ,(format "\
+Run `guix-hydra-filter-boolean' with `%S' variable."
+                            filter-bool-var)
+                   (guix-hydra-filter-boolean entry ,filter-bool-var))
+
+                 (setq ,filters-var
+                       (cons ',filter-bool-fun ,filters-var)))))
+
+         ;; Do not move this clause up!: name filtering should be
+         ;; performed before any other filtering, so this filter should
+         ;; be consed after the boolean filter.
+         ,(when filter-names-val
+            (let* ((filter-names-var (intern (concat prefix
+                                                     "-filter-names")))
+                   (filter-names-fun filter-names-var))
+              `(progn
+                 (defvar ,filter-names-var ,filter-names-val
+                   ,(format "\
+Alist of '%s' parameter names returned by Hydra API and names
+used internally by the elisp code of this package."
+                            entry-type-str))
+
+                 (defun ,filter-names-fun (entry)
+                   ,(format "\
+Run `guix-hydra-filter-names' with `%S' variable."
+                            filter-names-var)
+                   (guix-hydra-filter-names entry ,filter-names-var))
+
+                 (setq ,filters-var
+                       (cons ',filter-names-fun ,filters-var)))))
+
+         (defun ,get-fun (search-type &rest args)
+           ,(format "\
+Receive '%s' entries.
+See `guix-hydra-get-entries' for details."
+                    entry-type-str)
+           (apply #'guix-hydra-get-entries
+                  ',entry-type search-type args))
+
+         (guix-alist-put!
+          '((search-types . ,search-types-var)
+            (filters      . ,filters-var))
+          'guix-hydra-entry-type-data ',entry-type)
+
+         (guix-define-entry-type ,entry-type
+           :parent-group guix-hydra
+           :parent-faces-group guix-hydra-faces
+           ,@%foreign-args)))))
+
+(defmacro guix-hydra-define-interface (buffer-type entry-type &rest args)
+  "Define BUFFER-TYPE interface for displaying ENTRY-TYPE entries.
+
+This macro should be called after calling
+`guix-hydra-define-entry-type' with the same ENTRY-TYPE.
+
+ARGS are passed to `guix-BUFFER-TYPE-define-interface' macro."
+  (declare (indent 2))
+  (let* ((entry-type-str  (symbol-name entry-type))
+         (buffer-type-str (symbol-name buffer-type))
+         (get-fun         (intern (concat "guix-" entry-type-str
+                                          "-get-entries")))
+         (definer         (intern (concat "guix-" buffer-type-str
+                                          "-define-interface"))))
+    `(,definer ,entry-type
+       :get-entries-function ',get-fun
+       :message-function 'guix-hydra-message
+       ,@args)))
+
+(defmacro guix-hydra-info-define-interface (entry-type &rest args)
+  "Define 'info' interface for displaying ENTRY-TYPE entries.
+See `guix-hydra-define-interface'."
+  (declare (indent 1))
+  `(guix-hydra-define-interface info ,entry-type
+     ,@args))
+
+(defmacro guix-hydra-list-define-interface (entry-type &rest args)
+  "Define 'list' interface for displaying ENTRY-TYPE entries.
+Remaining arguments (ARGS) should have a form [KEYWORD VALUE] ...
+
+Optional keywords:
+
+  - `:describe-function' - default value of the generated
+    `guix-ENTRY-TYPE-list-describe-function' variable (if not
+    specified, use `guix-hydra-list-describe').
+
+The rest keyword arguments are passed to
+`guix-hydra-define-interface' macro."
+  (declare (indent 1))
+  (guix-keyword-args-let args
+      ((describe-val :describe-function))
+    `(guix-hydra-define-interface list ,entry-type
+       :describe-function ,(or describe-val ''guix-hydra-list-describe)
+       ,@args)))
+
+
+(defvar guix-hydra-font-lock-keywords
+  (eval-when-compile
+    `((,(rx "(" (group (or "guix-hydra-define-entry-type"
+                           "guix-hydra-define-interface"
+                           "guix-hydra-info-define-interface"
+                           "guix-hydra-list-define-interface"))
+            symbol-end)
+       . 1))))
+
+(font-lock-add-keywords 'emacs-lisp-mode guix-hydra-font-lock-keywords)
+
+(provide 'guix-hydra)
+
+;;; guix-hydra.el ends here