registry: Create an abstraction for registries.

Author: nouwaarom

Makefile

@@ -23,7 +23,7 @@ MAKEFILES = $(wildcard deps/*/Makefile)
 export CC
 
 ifdef STATIC
-	CFLAGS  += -DCURL_STATICLIB -std=c99 -Ideps -Wall -Wno-unused-function -U__STRICT_ANSI__ $(shell deps/curl/bin/curl-config --cflags)
+	CFLAGS  += -DCURL_STATICLIB -std=c99 -Ideps -Wall -Werror=return-type -Wno-unused-function -U__STRICT_ANSI__ $(shell deps/curl/bin/curl-config --cflags)
 	LDFLAGS += -static $(shell deps/curl/bin/curl-config --static-libs)
 else
 	CFLAGS  += -std=c99 -Ideps -Wall -Wno-unused-function -U__STRICT_ANSI__ $(shell curl-config --cflags)

deps/wiki-registry/github-registry.c

@@ -0,0 +1,131 @@
+//
+// github-registry.c
+//
+// Copyright (c) 2020 Elbert van de Put
+// Based on work by Stephen Mathieson
+// MIT licensed
+//
+#include <string.h>
+#include "github-registry.h"
+#include "gumbo-text-content/gumbo-text-content.h"
+#include "gumbo-get-element-by-id/get-element-by-id.h"
+#include "gumbo-get-elements-by-tag-name/get-elements-by-tag-name.h"
+#include "http-get/http-get.h"
+#include <curl/curl.h>
+#include "substr/substr.h"
+#include "strdup/strdup.h"
+#include "case/case.h"
+#include "trim/trim.h"
+#include "wiki-registry-internal.h"
+
+/**
+ * Add `href` to the given `package`.
+ */
+static void add_package_href(wiki_package_ptr_t self) {
+    size_t len = strlen(self->repo) + 20; // https://github.com/ \0
+    self->href = malloc(len);
+    if (self->href)
+        sprintf(self->href, "https://github.com/%s", self->repo);
+}
+
+/**
+ * Parse the given wiki `li` into a package.
+ */
+static wiki_package_ptr_t parse_li(GumboNode *li) {
+    wiki_package_ptr_t self = wiki_package_new();
+    char *text = NULL;
+
+    if (!self) goto cleanup;
+
+    text = gumbo_text_content(li);
+    if (!text) goto cleanup;
+
+    // TODO support unicode dashes
+    char *tok = strstr(text, " - ");
+    if (!tok) goto cleanup;
+
+    int pos = tok - text;
+    self->repo = substr(text, 0, pos);
+    self->description = substr(text, pos + 3, -1);
+    if (!self->repo || !self->description) goto cleanup;
+    trim(self->description);
+    trim(self->repo);
+
+    add_package_href(self);
+
+    cleanup:
+    free(text);
+    return self;
+}
+
+/**
+ * Parse a list of packages from the given `html`
+ */
+list_t *wiki_registry_parse(const char *html) {
+    GumboOutput *output = gumbo_parse(html);
+    list_t *pkgs = list_new();
+
+    GumboNode *body = gumbo_get_element_by_id("wiki-body", output->root);
+    if (body) {
+        // grab all category `<h2 />`s
+        list_t *h2s = gumbo_get_elements_by_tag_name("h2", body);
+        list_node_t *heading_node;
+        list_iterator_t *heading_iterator = list_iterator_new(h2s, LIST_HEAD);
+        while ((heading_node = list_iterator_next(heading_iterator))) {
+            GumboNode *heading = (GumboNode *) heading_node->val;
+            char *category = gumbo_text_content(heading);
+            // die if we failed to parse a category, as it's
+            // almost certinaly a malloc error
+            if (!category) break;
+            trim(case_lower(category));
+            GumboVector *siblings = &heading->parent->v.element.children;
+            size_t pos = heading->index_within_parent;
+
+            // skip elements until the UL
+            // TODO: don't hardcode position here
+            // 2:
+            //   1 - whitespace
+            //   2 - actual node
+            GumboNode *ul = siblings->data[pos + 2];
+            if (GUMBO_TAG_UL != ul->v.element.tag) {
+                free(category);
+                continue;
+            }
+
+            list_t *lis = gumbo_get_elements_by_tag_name("li", ul);
+            list_iterator_t *li_iterator = list_iterator_new(lis, LIST_HEAD);
+            list_node_t *li_node;
+            while ((li_node = list_iterator_next(li_iterator))) {
+                wiki_package_ptr_t package = parse_li(li_node->val);
+                if (package && package->description) {
+                    package->category = strdup(category);
+                    list_rpush(pkgs, list_node_new(package));
+                } else {
+                    // failed to parse package
+                    if (package) wiki_package_free(package);
+                }
+            }
+            list_iterator_destroy(li_iterator);
+            list_destroy(lis);
+            free(category);
+        }
+        list_iterator_destroy(heading_iterator);
+        list_destroy(h2s);
+    }
+
+    gumbo_destroy_output(&kGumboDefaultOptions, output);
+    return pkgs;
+}
+
+/**
+ * Get a list of packages from the given GitHub wiki `url`.
+ */
+list_t *github_registry_fetch(const char *url) {
+    http_get_response_t *res = http_get(url);
+    if (!res->ok) return NULL;
+
+    list_t *list = wiki_registry_parse(res->data);
+    http_get_free(res);
+    return list;
+}
+

deps/wiki-registry/github-registry.h

@@ -0,0 +1,8 @@
+#ifndef CLIB_GITHUB_REGISTRY_H
+#define CLIB_GITHUB_REGISTRY_H
+
+#include "list/list.h"
+
+list_t* github_registry_fetch(const char *url);
+
+#endif //CLIB_GITHUB_REGISTRY_H

deps/wiki-registry/gitlab-registry.c

@@ -0,0 +1,12 @@
+//
+// gitlab-registry.c
+//
+// Copyright (c) 2020 Elbert van de Put
+// MIT licensed
+//
+#include "gitlab-registry.h"
+
+list_t* gitlab_registry_fetch(const char *url) {
+    return NULL;
+}
+

deps/wiki-registry/gitlab-registry.h

@@ -0,0 +1,8 @@
+#ifndef CLIB_GITLAB_REGISTRY_H
+#define CLIB_GITLAB_REGISTRY_H
+
+#include "list/list.h"
+
+list_t* gitlab_registry_fetch(const char *url);
+
+#endif //CLIB_GITLAB_REGISTRY_H

deps/wiki-registry/wiki-registry-internal.h

@@ -0,0 +1,17 @@
+#ifndef WIKI_REGISTRY_HELPER_H
+#define WIKI_REGISTRY_HELPER_H
+// DO NOT INCLUDE. THIS HEADER IS INTERNAL ONLY
+#include "wiki-registry.h"
+
+struct wiki_package_t {
+    char *repo;
+    char *href;
+    char *description;
+    char *category;
+};
+
+wiki_package_ptr_t wiki_package_new();
+
+void wiki_package_free(wiki_package_ptr_t pkg);
+
+#endif //WIKI_REGISTRY_HELPER_H