1 files changed, 101 insertions, 0 deletions
diff --git a/src/main/lsp/help.c b/src/main/lsp/help.c
new file mode 100644
index 0000000..e5bcc28
--- /dev/null
+++ b/src/main/lsp/help.c
@@ -0,0 +1,101 @@
+#include "help.h"
+
+#include "dged/binding.h"
+#include "dged/buffer.h"
+#include "dged/buffer_view.h"
+#include "dged/buffers.h"
+#include "dged/minibuffer.h"
+#include "dged/s8.h"
+#include "dged/window.h"
+
+#include "bindings.h"
+#include "lsp.h"
+
+static int32_t close_help(struct command_ctx ctx, int argc, const char **argv) {
+  (void)argc;
+  (void)argv;
+
+  if (window_has_prev_buffer_view(ctx.active_window)) {
+    window_set_buffer(ctx.active_window,
+                      window_prev_buffer_view(ctx.active_window)->buffer);
+  } else {
+    minibuffer_echo_timeout(4, "no previous buffer to go to");
+  }
+
+  return 0;
+}
+
+static void handle_help_response(struct lsp_server *server,
+                                 struct lsp_response *response,
+                                 void *userdata) {
+  (void)server;
+
+  struct buffers *buffers = (struct buffers *)userdata;
+  if (response->value.result.type == Json_Null) {
+    minibuffer_echo_timeout(4, "help: no help found");
+    return;
+  }
+
+  struct buffer *b = buffers_find(buffers, "*lsp-help*");
+  if (b == NULL) {
+    b = buffers_add(buffers, buffer_create("*lsp-help*"));
+    static struct command help_close = {
+        .name = "help_close",
+        .fn = close_help,
+    };
+
+    struct binding bindings[] = {
+        ANONYMOUS_BINDING(None, 'q', &help_close),
+    };
+    struct keymap km = keymap_create("help", 2);
+    keymap_bind_keys(&km, bindings, sizeof(bindings) / sizeof(bindings[0]));
+    buffer_add_keymap(b, km);
+  }
+
+  struct hover help = hover_from_json(&response->value.result);
+
+  buffer_set_readonly(b, false);
+  buffer_clear(b);
+  buffer_add(b, buffer_end(b), help.contents.s, help.contents.l);
+  buffer_set_readonly(b, true);
+
+  if (window_find_by_buffer(b) == NULL) {
+    window_set_buffer(windows_get_active(), b);
+  }
+  hover_free(&help);
+}
+
+void lsp_help(struct lsp_server *server, struct buffer *buffer,
+              struct location at, struct buffers *buffers) {
+  uint64_t id = new_pending_request(server, handle_help_response, buffers);
+  struct versioned_text_document_identifier doc =
+      versioned_identifier_from_buffer(buffer);
+
+  struct text_document_position pos = {
+      .uri = doc.uri,
+      .position = at,
+  };
+
+  struct s8 json_payload = document_position_to_json(&pos);
+  lsp_send(lsp_backend(server),
+           lsp_create_request(id, s8("textDocument/hover"), json_payload));
+
+  versioned_text_document_identifier_free(&doc);
+  s8delete(json_payload);
+}
+
+int32_t lsp_help_cmd(struct command_ctx ctx, int argc, const char **argv) {
+  (void)argc;
+  (void)argv;
+
+  struct buffer_view *bv = window_buffer_view(ctx.active_window);
+  struct lsp_server *server = lsp_server_for_lang_id(bv->buffer->lang.id);
+  if (server == NULL) {
+    minibuffer_echo_timeout(4, "no lsp server associated with %s",
+                            bv->buffer->name);
+    return 0;
+  }
+
+  lsp_help(server, bv->buffer, bv->dot, ctx.buffers);
+  return 0;
+}