sx-method-call rewritten and associated improvements in sx-request.

Now requires `'sx-auth` to account for authentication.

(sx-method-call) is now defined using `cl-defun` and uses keys rather
than positional arguments.

Authentication logic is performed in `sx-method-call` to ensure commands
are only passed on once they are needed.

When access token is available:
  - Filters will be used as provided
  - Methods will be called
When access token is unavailable:
  - Filters will downgrade to only request object that do not require
    auth.
  - Methods will instead use `sx-request-fallback` and return nil.

If auth is not specified but is required, `sx-method-call` will throw an
error.  If auth is specified as `'warn`, `user-error` will be called.

(sx-request--build-keyword-arguments) has been simplified.  It will
always pass an available access_token (api indicates doing so will use a
user/key quota rather than simply key quota).

(sx-request-make) now performs url retrieval directly.  Query
construction is all performed by `sx-method-call`.

2 files changed, 78 insertions, 61 deletions

diff --git a/sx-method.el b/sx-method.el
index e9c4f60..feebd84 100644
--- a/sx-method.el
+++ b/sx-method.el
@@ -25,32 +25,66 @@
 (require 'json)
 (require 'url)
 (require 'sx)
+(require 'sx-auth)
 (require 'sx-request)
 (require 'sx-filter)
 
-(defun sx-method-call
-    (method &optional keyword-arguments filter need-auth use-post silent)
-  "Call METHOD with KEYWORD-ARGUMENTS using FILTER.
+(cl-defun sx-method-call (method &key id
+                                      submethod
+                                      keywords
+                                      (filter 'none)
+                                      auth
+                                      (url-method "GET")
+                                      (site sx-site-default))
+    "Call METHOD with additional keys.
 
-If NEED-AUTH is non-nil, an auth-token is required.  If 'WARN,
-warn the user `(user-error ...)' if they do not have an AUTH
-token set.
-
-If USE-POST is non-nil, use `POST' rather than `GET' for passing
-arguments.
-
-If SILENT is non-nil, no messages will be printed.
+:ID is the id associated with a question, answer, comment, post or
+user.
+:SUBMETHOD is the additional segments of the method.
+:KEYWORDS are the api parameters.
+:FILTER is the set of filters to control the returned information
+:AUTH defines how to act if the method or filters require
+authentication.
+:URL-METHOD is either \"POST\" or \"GET\"
+:SITE is the api parameter specifying the site.
 
 Return the entire response as a complex alist."
-  (sx-request-make
-   method
-   (cons (cons 'filter
-               (sx-filter-get-var
-                (cond (filter filter)
-                      ((boundp 'stack-filter) stack-filter))))
-         keyword-arguments)
-   need-auth
-   use-post))
+    (let ((access-token (sx-cache-get 'auth))
+          (method-auth (sx-auth--method-p method submethod))
+          (filter-auth (sx-auth--filter-p filter))
+          (full-method (concat (format "%s" method)
+                               (when id
+                                 (format "/%s" id))
+                               (when submethod
+                                 (format "/%s" submethod))))
+          (call 'sx-request-make))
+      (lwarn "sx-call-method" :warning "A: %S T: %S. M: %S,%s. F: %S" (equal 'warn auth)
+	     access-token method-auth full-method filter-auth)
+      (unless access-token
+        (cond
+         ;; 1. Need auth and warn user (interactive use)
+         ((and method-auth (equal 'warn auth))
+          (user-error
+           "This request requires authentication.  Please run `M-x sx-auth-authenticate' and try again."))
+         ;; 2. Need auth to populate UI, cannot provide subset
+         ((and method-auth auth)
+          (setq call 'sx-request-fallback))
+         ;; 3. Need auth for type.  Use auth-less filter.
+         ((and filter-auth auth)
+          (setq filter filter-auth))
+         ;; 4. Requires auth but no value set for auth
+         ((and (or filter-auth method-auth) (not auth))
+          (error "This request requires authentication."))))
+      ;; Concatenate all parameters now that filter is ensured.
+      (setq parameters
+            (cons `(site . ,site)
+                  (cons (cons 'filter
+                              (sx-filter-get-var filter))
+                        keywords)))
+      (funcall call
+               full-method
+               parameters
+               url-method)))
 
 (provide 'sx-method)
 ;;; sx-method.el ends here
diff --git a/sx-request.el b/sx-request.el
index d982057..6673e48 100644
--- a/sx-request.el
+++ b/sx-request.el
@@ -71,19 +71,16 @@ number of requests left every time it finishes a call.")
 ;;; Making Requests
 
 (defun sx-request-make
-    (method &optional args need-auth use-post silent)
-  (let ((url-automatic-caching sx-request-cache-p)
-        (url-inhibit-uncompression t)
-        (silent (or silent sx-request-silent-p))
-        (request-method (if use-post "POST" "GET"))
-        (request-args
-         (sx-request--build-keyword-arguments args nil need-auth))
-        (request-url (concat sx-request-api-root method)))
-    (unless silent (sx-message "Request: %S" request-url))
-    (let ((response-buffer (sx-request--request request-url
-                                                request-args
-                                                request-method
-                                                silent)))
+    (method &optional args request-method)
+  (let* ((url-automatic-caching sx-request-cache-p)
+         (url-inhibit-uncompression t)
+         (url-request-data (sx-request--build-keyword-arguments args
+                                                            nil))
+         (request-url (concat sx-request-api-root method))
+         (url-request-method request-method)
+         (url-request-extra-headers
+          '(("Content-Type" . "application/x-www-form-urlencoded")))
+         (response-buffer (url-retrieve-synchronously request-url)))
       (if (not response-buffer)
           (error "Something went wrong in `url-retrieve-synchronously'")
         (with-current-buffer response-buffer
@@ -115,23 +112,21 @@ number of requests left every time it finishes a call.")
                        sx-request-remaining-api-requests-message-threshold)
                 (sx-message "%d API requests reamining"
                             sx-request-remaining-api-requests))
-              (sx-encoding-clean-content-deep .items))))))))
+              (sx-encoding-clean-content-deep .items)))))))
+
+(defun sx-request-fallback (method &optional args request-method)
+  "Fallback method when authentication is not available.
+This is for UI generation when the associated API call would
+require authentication.
+
+Currently returns nil."
+  nil)
 
 
 ;;; Support Functions
 
-(defun sx-request--request (url args method silent)
-  (let ((url-request-method method)
-        (url-request-extra-headers
-         '(("Content-Type" . "application/x-www-form-urlencoded")))
-        (url-request-data args))
-    (cond
-     ((equal '(24 . 4) (cons emacs-major-version emacs-minor-version))
-      (url-retrieve-synchronously url silent))
-     (t (url-retrieve-synchronously url)))))
-
 (defun sx-request--build-keyword-arguments (alist &optional
-                                                  kv-value-sep need-auth)
+                                                  kv-value-sep)
   "Build a \"key=value&key=value&...\"-style string with the elements
 of ALIST.  If any value in the alist is `nil', that pair will not
 be included in the return.  If you wish to pass a notion of
@@ -139,23 +134,11 @@ false, use the symbol `false'.  Each element is processed with
 `sx--thing-as-string'."
   ;; Add API key to list of arguments, this allows for increased quota
   ;; automatically.
-  (let* ((warn (equal need-auth 'warn))
-         (api-key (cons "key" sx-request-api-key))
-         (auth
-          (let ((auth (car (sx-cache-get 'auth))))
-            (cond
-             (auth)
-             ;; Pass user error when asking to warn
-             (warn
-              (user-error
-               "This query requires authentication.  Please run `M-x sx-auth-authenticate' and try again."))
-             ((not auth)
-              (lwarn "stack-mode" :debug
-                     "This query requires authentication")
-              nil)))))
+  (let ((api-key (cons "key" sx-request-api-key))
+         (auth (car (sx-cache-get 'auth))))
     (push api-key alist)
-    (if (and need-auth auth)
-        (push auth alist))
+    (when auth
+      (push auth alist))
     (mapconcat
      (lambda (pair)
        (concat