1 files changed, 151 insertions, 0 deletions
diff --git a/src/main/completion/command.c b/src/main/completion/command.c
new file mode 100644
index 0000000..e4900ed
--- /dev/null
+++ b/src/main/completion/command.c
@@ -0,0 +1,151 @@
+#include "command.h"
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "dged/buffer.h"
+#include "dged/buffer_view.h"
+#include "dged/command.h"
+#include "dged/minibuffer.h"
+#include "dged/utf8.h"
+
+#include "main/completion.h"
+
+static bool is_space(const struct codepoint *c) {
+  // TODO: utf8 whitespace and other whitespace
+  return c->codepoint == ' ';
+}
+
+typedef void (*on_command_selected_cb)(struct command *);
+
+struct command_completion {
+  struct command *command;
+  on_command_selected_cb on_command_selected;
+};
+
+struct command_provider_data {
+  struct commands *commands;
+  on_command_selected_cb on_command_selected;
+};
+
+static void command_comp_selected(void *data, struct buffer_view *target) {
+  struct command_completion *cc = (struct command_completion *)data;
+  buffer_set_text(target->buffer, (uint8_t *)cc->command->name,
+                  strlen(cc->command->name));
+
+  abort_completion();
+  cc->on_command_selected(cc->command);
+}
+
+static struct region command_comp_render(void *data,
+                                         struct buffer *comp_buffer) {
+  struct command *command = ((struct command_completion *)data)->command;
+  struct location begin = buffer_end(comp_buffer);
+  buffer_add(comp_buffer, buffer_end(comp_buffer), (uint8_t *)command->name,
+             strlen(command->name));
+
+  struct location end = buffer_end(comp_buffer);
+  buffer_newline(comp_buffer, buffer_end(comp_buffer));
+
+  return region_new(begin, end);
+}
+
+static void command_comp_cleanup(void *data) {
+  struct command_completion *cc = (struct command_completion *)data;
+  free(cc);
+}
+
+struct needle_match_ctx {
+  const char *needle;
+  struct completion *completions;
+  uint32_t max_ncompletions;
+  uint32_t ncompletions;
+  on_command_selected_cb on_command_selected;
+};
+
+static void command_matches(struct command *command, void *userdata) {
+  struct needle_match_ctx *ctx = (struct needle_match_ctx *)userdata;
+
+  if (strncmp(ctx->needle, command->name, strlen(ctx->needle)) == 0 &&
+      ctx->ncompletions < ctx->max_ncompletions) {
+
+    struct command_completion *comp_data =
+        calloc(1, sizeof(struct command_completion));
+    comp_data->command = command;
+    comp_data->on_command_selected = ctx->on_command_selected;
+    ctx->completions[ctx->ncompletions] = (struct completion){
+        .render = command_comp_render,
+        .selected = command_comp_selected,
+        .cleanup = command_comp_cleanup,
+        .data = comp_data,
+    };
+    ++ctx->ncompletions;
+  }
+}
+
+static void command_complete(struct completion_context ctx, bool deletion,
+                             void *userdata) {
+  (void)deletion;
+  struct command_provider_data *pd = (struct command_provider_data *)userdata;
+  struct commands *commands = pd->commands;
+  if (commands == NULL) {
+    return;
+  }
+
+  struct text_chunk txt = {0};
+  if (ctx.buffer == minibuffer_buffer()) {
+    txt = minibuffer_content();
+  } else {
+    struct match_result start =
+        buffer_find_prev_in_line(ctx.buffer, ctx.location, is_space);
+    if (!start.found) {
+      start.at = (struct location){.line = ctx.location.line, .col = 0};
+      return;
+    }
+    txt = buffer_region(ctx.buffer, region_new(start.at, ctx.location));
+  }
+
+  char *needle = calloc(txt.nbytes + 1, sizeof(char));
+  memcpy(needle, txt.text, txt.nbytes);
+  needle[txt.nbytes] = '\0';
+
+  if (txt.allocated) {
+    free(txt.text);
+  }
+
+  struct completion *completions = calloc(50, sizeof(struct completion));
+
+  struct needle_match_ctx match_ctx = (struct needle_match_ctx){
+      .needle = needle,
+      .max_ncompletions = 50,
+      .completions = completions,
+      .ncompletions = 0,
+      .on_command_selected = pd->on_command_selected,
+  };
+
+  commands_for_each(commands, command_matches, &match_ctx);
+  ctx.add_completions(match_ctx.completions, match_ctx.ncompletions);
+  free(completions);
+  free(needle);
+}
+
+static void cleanup_provider(void *data) {
+  struct command_provider_data *cpd = (struct command_provider_data *)data;
+  free(cpd);
+}
+
+struct completion_provider
+create_commands_provider(struct commands *commands,
+                         on_command_selected_cb on_command_selected) {
+  struct command_provider_data *data =
+      calloc(1, sizeof(struct command_provider_data));
+  data->commands = commands;
+  data->on_command_selected = on_command_selected;
+
+  return (struct completion_provider){
+      .name = "commands",
+      .complete = command_complete,
+      .userdata = data,
+      .cleanup = cleanup_provider,
+  };
+}