1 files changed, 297 insertions, 0 deletions
diff --git a/src/main/lsp/goto.c b/src/main/lsp/goto.c
new file mode 100644
index 0000000..7d2d228
--- /dev/null
+++ b/src/main/lsp/goto.c
@@ -0,0 +1,297 @@
+#include "goto.h"
+
+#include "dged/binding.h"
+#include "dged/buffer.h"
+#include "dged/buffer_view.h"
+#include "dged/buffers.h"
+#include "dged/location.h"
+#include "dged/minibuffer.h"
+#include "dged/window.h"
+#include "main/bindings.h"
+#include "main/lsp.h"
+
+#include "choice-buffer.h"
+
+static struct jump_stack {
+  buffer_keymap_id goto_keymap_id;
+  struct buffer_location *stack;
+  uint32_t top;
+  uint32_t size;
+  struct buffers *buffers;
+} g_jump_stack;
+
+static struct location_result g_location_result = {};
+
+struct buffer_location {
+  struct buffer *buffer;
+  struct location location;
+};
+
+void init_goto(size_t jump_stack_depth, struct buffers *buffers) {
+  g_jump_stack.size = jump_stack_depth;
+  g_jump_stack.top = 0;
+  g_jump_stack.goto_keymap_id = (buffer_keymap_id)-1;
+  g_jump_stack.stack = calloc(g_jump_stack.size, sizeof(struct jump_stack));
+  g_jump_stack.buffers = buffers;
+}
+
+void destroy_goto(void) {
+  free(g_jump_stack.stack);
+  g_jump_stack.stack = NULL;
+  g_jump_stack.top = 0;
+  g_jump_stack.size = 0;
+}
+
+void lsp_jump_to(struct text_document_location loc) {
+  if (s8startswith(loc.uri, s8("file://"))) {
+    const char *p = s8tocstr(loc.uri);
+    struct buffer *b = buffers_find_by_filename(g_jump_stack.buffers, &p[7]);
+
+    if (b == NULL) {
+      struct buffer new_buf = buffer_from_file(&p[7]);
+      b = buffers_add(g_jump_stack.buffers, new_buf);
+    }
+
+    free((void *)p);
+
+    struct window *w = windows_get_active();
+
+    struct buffer_view *old_bv = window_buffer_view(w);
+    g_jump_stack.stack[g_jump_stack.top] = (struct buffer_location){
+        .buffer = old_bv->buffer,
+        .location = old_bv->dot,
+    };
+    g_jump_stack.top = (g_jump_stack.top + 1) % g_jump_stack.size;
+
+    if (old_bv->buffer != b) {
+      struct window *tw = window_find_by_buffer(b);
+      if (tw == NULL) {
+        window_set_buffer(w, b);
+      } else {
+        w = tw;
+        windows_set_active(w);
+      }
+    }
+
+    struct buffer_view *bv = window_buffer_view(w);
+    buffer_view_goto(bv, loc.range.begin);
+  } else {
+    message("warning: unsupported LSP URI: %.*s", loc.uri.l, loc.uri.s);
+  }
+}
+
+static void location_selected(void *location, void *userdata) {
+  (void)userdata;
+  struct text_document_location *loc =
+      (struct text_document_location *)location;
+  lsp_jump_to(*loc);
+}
+
+static void location_buffer_close(void *userdata) {
+  (void)userdata;
+  location_result_free(&g_location_result);
+}
+
+static void handle_location_result(struct lsp_server *server,
+                                   struct lsp_response *response,
+                                   void *userdata) {
+  struct s8 title = s8((const char *)userdata);
+  struct location_result res =
+      location_result_from_json(&response->value.result);
+
+  if (res.type == Location_Null ||
+      (res.type == Location_Array && VEC_EMPTY(&res.location.array))) {
+    minibuffer_echo_timeout(2, "nothing found");
+    location_result_free(&res);
+    return;
+  }
+
+  if (res.type == Location_Single) {
+    lsp_jump_to(res.location.single);
+    location_result_free(&res);
+  } else if (res.type == Location_Array && VEC_SIZE(&res.location.array) == 1) {
+    lsp_jump_to(*VEC_FRONT(&res.location.array));
+    location_result_free(&res);
+  } else if (res.type == Location_Array) {
+
+    g_location_result = res;
+    struct choice_buffer *buf =
+        choice_buffer_create(title, g_jump_stack.buffers, location_selected,
+                             location_buffer_close, NULL, server);
+
+    VEC_FOR_EACH(&res.location.array, struct text_document_location * loc) {
+      choice_buffer_add_choice(buf,
+                               s8from_fmt("%.*s: %d, %d", loc->uri.l,
+                                          loc->uri.s, loc->range.begin.line,
+                                          loc->range.begin.col),
+                               loc);
+    }
+  }
+}
+
+int32_t lsp_goto_def_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 buffer *b = bv->buffer;
+  struct lsp_server *server = lsp_server_for_buffer(b);
+
+  if (server == NULL) {
+    minibuffer_echo_timeout(2, "buffer %s does not have lsp enabled", b->name);
+    return 0;
+  }
+
+  uint64_t id = new_pending_request(server, handle_location_result,
+                                    (void *)"Definitions");
+  struct versioned_text_document_identifier doc =
+      versioned_identifier_from_buffer(b);
+  struct text_document_position params = {
+      .uri = doc.uri,
+      .position = bv->dot,
+  };
+
+  struct s8 json_payload = document_position_to_json(&params);
+  lsp_send(lsp_backend(server),
+           lsp_create_request(id, s8("textDocument/definition"), json_payload));
+
+  versioned_text_document_identifier_free(&doc);
+  s8delete(json_payload);
+
+  return 0;
+}
+
+int32_t lsp_goto_decl_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 buffer *b = bv->buffer;
+  struct lsp_server *server = lsp_server_for_buffer(b);
+
+  if (server == NULL) {
+    minibuffer_echo_timeout(2, "buffer %s does not have lsp enabled", b->name);
+    return 0;
+  }
+
+  uint64_t id = new_pending_request(server, handle_location_result,
+                                    (void *)"Declarations");
+  struct versioned_text_document_identifier doc =
+      versioned_identifier_from_buffer(b);
+  struct text_document_position params = {
+      .uri = doc.uri,
+      .position = bv->dot,
+  };
+
+  struct s8 json_payload = document_position_to_json(&params);
+  lsp_send(
+      lsp_backend(server),
+      lsp_create_request(id, s8("textDocument/declaration"), json_payload));
+
+  versioned_text_document_identifier_free(&doc);
+  s8delete(json_payload);
+
+  return 0;
+}
+
+int32_t lsp_goto_impl_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 buffer *b = bv->buffer;
+  struct lsp_server *server = lsp_server_for_buffer(b);
+
+  if (server == NULL) {
+    minibuffer_echo_timeout(2, "buffer %s does not have lsp enabled", b->name);
+    return 0;
+  }
+
+  uint64_t id = new_pending_request(server, handle_location_result,
+                                    (void *)"Implementations");
+  struct versioned_text_document_identifier doc =
+      versioned_identifier_from_buffer(b);
+  struct text_document_position params = {
+      .uri = doc.uri,
+      .position = bv->dot,
+  };
+
+  struct s8 json_payload = document_position_to_json(&params);
+  lsp_send(
+      lsp_backend(server),
+      lsp_create_request(id, s8("textDocument/implementation"), json_payload));
+
+  versioned_text_document_identifier_free(&doc);
+  s8delete(json_payload);
+
+  return 0;
+}
+
+static int32_t handle_lsp_goto_key(struct command_ctx ctx, int argc,
+                                   const char **argv) {
+  (void)argc;
+  (void)argv;
+
+  buffer_remove_keymap(g_jump_stack.goto_keymap_id);
+  minibuffer_abort_prompt();
+
+  struct command *cmd = lookup_command(ctx.commands, (char *)ctx.userdata);
+  if (cmd == NULL) {
+    return 0;
+  }
+
+  return execute_command(cmd, ctx.commands, windows_get_active(), ctx.buffers,
+                         0, NULL);
+}
+
+COMMAND_FN("lsp-goto-definition", goto_d_pressed, handle_lsp_goto_key,
+           "lsp-goto-definition");
+COMMAND_FN("lsp-goto-declaration", goto_f_pressed, handle_lsp_goto_key,
+           "lsp-goto-declaration");
+
+int32_t lsp_goto_cmd(struct command_ctx ctx, int argc, const char **argv) {
+  (void)argc;
+  (void)argv;
+
+  struct binding bindings[] = {
+      ANONYMOUS_BINDING(None, 'd', &goto_d_pressed_command),
+      ANONYMOUS_BINDING(None, 'f', &goto_f_pressed_command),
+  };
+  struct keymap m = keymap_create("lsp-goto", 8);
+  keymap_bind_keys(&m, bindings, sizeof(bindings) / sizeof(bindings[0]));
+  g_jump_stack.goto_keymap_id = buffer_add_keymap(minibuffer_buffer(), m);
+  return minibuffer_keymap_prompt(ctx, "lsp-goto: ", &m);
+}
+
+int32_t lsp_goto_previous_cmd(struct command_ctx ctx, int argc,
+                              const char **argv) {
+  (void)ctx;
+  (void)argc;
+  (void)argv;
+
+  uint32_t index =
+      g_jump_stack.top == 0 ? g_jump_stack.size - 1 : g_jump_stack.top - 1;
+
+  struct buffer_location *loc = &g_jump_stack.stack[index];
+  if (loc->buffer == NULL) {
+    return 0;
+  }
+
+  struct window *w = windows_get_active();
+  if (window_buffer(w) != loc->buffer) {
+    struct window *tw = window_find_by_buffer(loc->buffer);
+    if (tw == NULL) {
+      window_set_buffer(w, loc->buffer);
+    } else {
+      w = tw;
+      windows_set_active(w);
+    }
+  }
+
+  buffer_view_goto(window_buffer_view(w), loc->location);
+
+  loc->buffer = NULL;
+  g_jump_stack.top = index;
+
+  return 0;
+}