finish up the documentation page

Signed-off-by: ngn <ngn@ngn.tf>

doc/src/docs.c

@@ -0,0 +1,106 @@
+#include <linux/limits.h>
+#include <dirent.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+
+#include "util.h"
+#include "docs.h"
+
+#define DOCS_LANG_CODE_LEN 2
+
+bool __docs_parse_name(docs_t *docs, char *ext) {
+  // check the extension
+  uint64_t ext_pos = util_endswith(docs->name, ext);
+
+  if (ext_pos == 0)
+    return false;
+
+  // example.en.json\0 => example.en\0json\0
+  docs->name[ext_pos] = 0;
+
+  // example.en\0json\0
+  //        |
+  //        `--- find this
+  for (docs->lang = docs->name; *docs->lang != 0 && *docs->lang != '.'; docs->lang++)
+    continue;
+
+  if (*docs->lang != '.')
+    return false;
+
+  // example.en\0json\0 => example.en\0json\0
+  *docs->lang++ = 0;
+
+  // example\0en\0json
+  // |        |   |
+  // |        |   `--- ext_pos
+  // |        `-- lang
+  // `-- name
+  return strlen(docs->lang) == DOCS_LANG_CODE_LEN && *docs->name != 0;
+}
+
+void __docs_clean(docs_t *docs) {
+  if (NULL == docs->file)
+    return;
+
+  util_file_free(docs->file);
+  docs->file = NULL;
+}
+
+bool docs_init(docs_t *docs, char *dir) {
+  if (NULL == docs || NULL == dir) {
+    errno = EINVAL;
+    return false;
+  }
+
+  bzero(docs, sizeof(*docs));
+  return NULL != (docs->dir = opendir(dir));
+}
+
+char *docs_next(docs_t *docs, char *name, bool content) {
+  if (NULL == docs) {
+    errno = EINVAL;
+    return false;
+  }
+
+  struct dirent *ent = NULL;
+  __docs_clean(docs);
+
+  while (NULL != (ent = readdir(docs->dir))) {
+    if (*ent->d_name == '.')
+      continue;
+
+    strcpy(docs->name, ent->d_name);
+
+    if (!__docs_parse_name(docs, content ? ".md" : ".json"))
+      continue;
+
+    if (NULL == name || strncmp(docs->name, name, NAME_MAX) == 0)
+      break;
+  }
+
+  if (NULL == ent) {
+    errno = ENOENT;
+    return NULL;
+  }
+
+  if (NULL == (docs->file = util_file_load(dirfd(docs->dir), ent->d_name)))
+    return NULL;
+
+  return docs->file->content;
+}
+
+void docs_reset(docs_t *docs) {
+  if (NULL != docs)
+    rewinddir(docs->dir);
+}
+
+void docs_free(docs_t *docs) {
+  if (NULL == docs)
+    return;
+
+  __docs_clean(docs);
+  closedir(docs->dir);
+
+  bzero(docs, sizeof(*docs));
+}