1 files changed, 160 insertions, 0 deletions
diff --git a/src/lang.c b/src/lang.c
new file mode 100644
index 0000000..6919780
--- /dev/null
+++ b/src/lang.c
@@ -0,0 +1,160 @@
+#include "lang.h"
+#include "minibuffer.h"
+#include "settings.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void define_lang(const char *name, const char *id, const char *extensions,
+                 uint32_t tab_width, const char *lang_srv) {
+  char namebuf[128] = {0};
+
+  size_t offs = snprintf(namebuf, 128, "languages.%s.", id);
+
+  char *b = namebuf + offs;
+  snprintf(b, 128 - offs, "%s", "extensions");
+  settings_register_setting(
+      namebuf, (struct setting_value){.type = Setting_String,
+                                      .string_value = (char *)extensions});
+
+  snprintf(b, 128 - offs, "%s", "tab-width");
+  settings_register_setting(namebuf,
+                            (struct setting_value){.type = Setting_Number,
+                                                   .number_value = tab_width});
+
+  snprintf(b, 128 - offs, "%s", "lang-srv");
+  settings_register_setting(
+      namebuf, (struct setting_value){.type = Setting_String,
+                                      .string_value = (char *)lang_srv});
+
+  snprintf(b, 128 - offs, "%s", "name");
+  settings_register_setting(
+      namebuf, (struct setting_value){.type = Setting_String,
+                                      .string_value = (char *)name});
+}
+
+static struct language g_fundamental = {
+    .name = "Fundamental",
+    .tab_width = 4,
+    .lang_srv = NULL,
+};
+
+void languages_init(bool register_default) {
+  if (register_default) {
+    define_lang("C", "c", "c h", 2, "clangd");
+    define_lang("C++", "cxx", "cpp cxx cc c++ hh h", 2, "clangd");
+    define_lang("Rust", "rs", "rs", 4, "rust-analyzer");
+    define_lang("Nix", "nix", "nix", 4, "rnix-lsp");
+  }
+}
+
+struct language lang_from_settings(const char *lang_path) {
+  char setting_name_buf[128] = {0};
+  size_t offs = snprintf(setting_name_buf, 128, "%s.", lang_path);
+  char *b = setting_name_buf + offs;
+
+  struct language l;
+
+  snprintf(b, 128 - offs, "%s", "name");
+  struct setting *name = settings_get(setting_name_buf);
+  l.name = name != NULL ? name->value.string_value : "Unknown";
+
+  snprintf(b, 128 - offs, "%s", "tab-width");
+  struct setting *tab_width = settings_get(setting_name_buf);
+
+  // fall back to global value
+  if (tab_width == NULL) {
+    tab_width = settings_get("editor.tab-width");
+  }
+  l.tab_width = tab_width != NULL ? tab_width->value.number_value : 4;
+
+  snprintf(b, 128 - offs, "%s", "lang-srv");
+  struct setting *lang_srv = settings_get(setting_name_buf);
+  l.lang_srv = lang_srv->value.string_value;
+
+  return l;
+}
+
+void next_ext(const char *curr, const char **nxt, const char **end) {
+  if (curr == NULL) {
+    *nxt = *end = NULL;
+    return;
+  }
+
+  *nxt = curr;
+  *end = curr + strlen(curr);
+
+  const char *spc = strchr(curr, ' ');
+  if (spc != NULL) {
+    *end = spc;
+  }
+}
+
+struct language lang_from_extension(const char *ext) {
+
+  uint32_t extlen = strlen(ext);
+  if (extlen == 0) {
+    return g_fundamental;
+  }
+
+  // get "languages.*" settings
+  struct setting **settings = NULL;
+  uint32_t nsettings = 0;
+  settings_get_prefix("languages.", &settings, &nsettings);
+
+  // find the first one with a matching extension list
+  for (uint32_t i = 0; i < nsettings; ++i) {
+    struct setting *setting = settings[i];
+    char *setting_name = strrchr(setting->path, '.');
+    if (setting_name != NULL &&
+        strncmp(setting_name + 1, "extensions", 10) == 0) {
+      const char *val = setting->value.string_value;
+
+      // go over extensions
+      const char *cext = val, *nxt = NULL, *end = NULL;
+      next_ext(cext, &nxt, &end);
+      while (nxt != end) {
+        if (extlen == (end - nxt) && strncmp(ext, nxt, (end - nxt)) == 0) {
+          char lang_path[128] = {0};
+          strncpy(lang_path, setting->path, setting_name - setting->path);
+
+          free(settings);
+          return lang_from_settings(lang_path);
+        }
+
+        cext = end + 1;
+        next_ext(cext, &nxt, &end);
+      }
+    }
+  }
+
+  free(settings);
+
+  // fall back to fundamental
+  return g_fundamental;
+}
+
+struct language lang_from_id(const char *id) {
+  if (id == NULL || (strlen(id) == 3 && strncmp(id, "fnd", 3) == 0) ||
+      strlen(id) == 0) {
+    return g_fundamental;
+  }
+
+  char lang_path[128] = {0};
+  snprintf(lang_path, 128, "languages.%s", id);
+
+  // check that it exists
+  struct setting **settings = NULL;
+  uint32_t nsettings = 0;
+
+  settings_get_prefix(lang_path, &settings, &nsettings);
+  free(settings);
+
+  if (nsettings > 0) {
+    return lang_from_settings(lang_path);
+  } else {
+    minibuffer_echo_timeout(4, "failed to find language \"%s\"", id);
+    return lang_from_settings("languages.fnd");
+  }
+}