Add completion to execute

Completes on the command, not on following arguments if written
directly at the prompt.

6 files changed, 108 insertions, 6 deletions

diff --git a/src/dged/command.c b/src/dged/command.c
index 9144058..2775286 100644
--- a/src/dged/command.c
+++ b/src/dged/command.c
@@ -63,6 +63,14 @@ int32_t execute_command(struct command *command, struct commands *commands,
       argc, argv);
 }
 
+void commands_for_each(struct commands *commands,
+                       void (*callback)(struct command *, void *),
+                       void *userdata) {
+  HASHMAP_FOR_EACH(&commands->commands, struct command_entry * entry) {
+    callback(&entry->value, userdata);
+  }
+}
+
 void command_ctx_push_arg(struct command_ctx *ctx, const char *argv) {
   if (ctx->saved_argc < 64) {
     ctx->saved_argv[ctx->saved_argc] = strdup(argv);
diff --git a/src/dged/command.h b/src/dged/command.h
index 956c10a..2b0f074 100644
--- a/src/dged/command.h
+++ b/src/dged/command.h
@@ -183,6 +183,10 @@ struct command *lookup_command(struct commands *commands, const char *name);
 struct command *lookup_command_by_hash(struct commands *commands,
                                        uint32_t hash);
 
+void commands_for_each(struct commands *commands,
+                       void (*callback)(struct command *, void *),
+                       void *userdata);
+
 void command_ctx_push_arg(struct command_ctx *ctx, const char *argv);
 void command_ctx_free(struct command_ctx *ctx);
 
diff --git a/src/main/cmds.c b/src/main/cmds.c
index d28924b..4dc84ed 100644
--- a/src/main/cmds.c
+++ b/src/main/cmds.c
@@ -54,11 +54,23 @@ int32_t write_file(struct command_ctx ctx, int argc, const char *argv[]) {
   return 0;
 }
 
+static void run_interactive_comp_inserted() { minibuffer_execute(); }
+
 int32_t run_interactive(struct command_ctx ctx, int argc, const char *argv[]) {
   if (argc == 0) {
+    struct completion_provider providers[] = {commands_provider()};
+    enable_completion(minibuffer_buffer(),
+                      ((struct completion_trigger){
+                          .kind = CompletionTrigger_Input,
+                          .input =
+                              (struct completion_trigger_input){
+                                  .nchars = 0, .trigger_initially = false}}),
+                      providers, 1, run_interactive_comp_inserted);
+
     return minibuffer_prompt(ctx, "execute: ");
   }
 
+  disable_completion(minibuffer_buffer());
   struct command *cmd = lookup_command(ctx.commands, argv[0]);
   if (cmd != NULL) {
     return execute_command(cmd, ctx.commands, ctx.active_window, ctx.buffers,
diff --git a/src/main/completion.c b/src/main/completion.c
index 4735c87..b2170e7 100644
--- a/src/main/completion.c
+++ b/src/main/completion.c
@@ -54,6 +54,14 @@ static struct completion_provider g_buffer_provider = {
     .userdata = NULL,
 };
 
+static uint32_t complete_commands(struct completion_context ctx,
+                                  void *userdata);
+static struct completion_provider g_commands_provider = {
+    .name = "commands",
+    .complete = complete_commands,
+    .userdata = NULL,
+};
+
 struct completion_provider path_provider() {
   return g_path_provider;
 }
@@ -62,6 +70,10 @@ struct completion_provider buffer_provider() {
   return g_buffer_provider;
 }
 
+struct completion_provider commands_provider() {
+  return g_commands_provider;
+}
+
 struct active_completion {
   struct buffer *buffer;
   uint32_t insert_hook_id;
@@ -267,13 +279,14 @@ static void update_completion_buffer(struct buffer *buffer, void *userdata) {
                              }});
 }
 
-void init_completion(struct buffers *buffers) {
+void init_completion(struct buffers *buffers, struct commands *commands) {
   if (g_target_buffer == NULL) {
     g_target_buffer = buffers_add(buffers, buffer_create("*completions*"));
     buffer_add_update_hook(g_target_buffer, update_completion_buffer, NULL);
   }
 
   g_buffer_provider.userdata = buffers;
+  g_commands_provider.userdata = commands;
   VEC_INIT(&g_active_completions, 32);
 }
 
@@ -511,7 +524,7 @@ done:
   return n;
 }
 
-struct buffer_match_ctx {
+struct needle_match_ctx {
   const char *needle;
   struct completion *completions;
   uint32_t max_ncompletions;
@@ -519,7 +532,7 @@ struct buffer_match_ctx {
 };
 
 static void buffer_matches(struct buffer *buffer, void *userdata) {
-  struct buffer_match_ctx *ctx = (struct buffer_match_ctx *)userdata;
+  struct needle_match_ctx *ctx = (struct needle_match_ctx *)userdata;
 
   if (strncmp(ctx->needle, buffer->name, strlen(ctx->needle)) == 0 &&
       ctx->ncompletions < ctx->max_ncompletions) {
@@ -568,7 +581,7 @@ static uint32_t complete_buffers(struct completion_context ctx,
     free(txt.text);
   }
 
-  struct buffer_match_ctx match_ctx = (struct buffer_match_ctx){
+  struct needle_match_ctx match_ctx = (struct needle_match_ctx){
       .needle = needle,
       .max_ncompletions = ctx.max_ncompletions,
       .completions = ctx.completions,
@@ -579,3 +592,66 @@ static uint32_t complete_buffers(struct completion_context ctx,
   free(needle);
   return match_ctx.ncompletions;
 }
+
+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) {
+    ctx->completions[ctx->ncompletions] = (struct completion){
+        .display = strdup(command->name),
+        .insert = strdup(command->name + strlen(ctx->needle)),
+        .complete = true,
+    };
+    ++ctx->ncompletions;
+  }
+}
+
+static uint32_t complete_commands(struct completion_context ctx,
+                                  void *userdata) {
+
+  struct commands *commands = (struct commands *)userdata;
+  if (commands == NULL) {
+    return 0;
+  }
+
+  struct text_chunk txt = {0};
+  uint32_t start_idx = 0;
+  if (ctx.buffer == minibuffer_buffer()) {
+    txt = minibuffer_content();
+  } else {
+    txt = buffer_line(ctx.buffer, ctx.location.line);
+    uint32_t end_idx = text_col_to_byteindex(
+        ctx.buffer->text, ctx.location.line, ctx.location.col);
+    for (uint32_t bytei = end_idx; bytei > 0; --bytei) {
+      if (txt.text[bytei] == ' ') {
+        start_idx = bytei + 1;
+        break;
+      }
+    }
+
+    if (start_idx >= end_idx) {
+      return 0;
+    }
+
+    txt.nbytes = end_idx - start_idx;
+  }
+
+  char *needle = calloc(txt.nbytes + 1, sizeof(uint8_t));
+  memcpy(needle, txt.text + start_idx, txt.nbytes);
+
+  if (txt.allocated) {
+    free(txt.text);
+  }
+
+  struct needle_match_ctx match_ctx = (struct needle_match_ctx){
+      .needle = needle,
+      .max_ncompletions = ctx.max_ncompletions,
+      .completions = ctx.completions,
+      .ncompletions = 0,
+  };
+  commands_for_each(commands, command_matches, &match_ctx);
+
+  free(needle);
+  return match_ctx.ncompletions;
+}
diff --git a/src/main/completion.h b/src/main/completion.h
index b53c942..776ef9b 100644
--- a/src/main/completion.h
+++ b/src/main/completion.h
@@ -5,6 +5,7 @@
 
 struct buffer;
 struct buffers;
+struct commands;
 
 struct completion {
   const char *display;
@@ -46,7 +47,7 @@ struct completion_trigger {
   };
 };
 
-void init_completion(struct buffers *buffers);
+void init_completion(struct buffers *buffers, struct commands *commands);
 void destroy_completion();
 
 typedef void (*insert_cb)();
@@ -65,6 +66,7 @@ void enable_completion(struct buffer *source, struct completion_trigger trigger,
 
 struct completion_provider path_provider();
 struct completion_provider buffer_provider();
+struct completion_provider commands_provider();
 
 /**
  * Abort any active completion.
diff --git a/src/main/main.c b/src/main/main.c
index 6048b63..a020b9f 100644
--- a/src/main/main.c
+++ b/src/main/main.c
@@ -310,7 +310,7 @@ int main(int argc, char *argv[]) {
   struct keymap *current_keymap = NULL;
   init_bindings();
 
-  init_completion(&buflist);
+  init_completion(&buflist, &commands);
   timers_init();
 
   float frame_time = 0.f;