From cbbc18c3a35457135d500264cc56a8ab26424760 Mon Sep 17 00:00:00 2001
From: nick black <dankamongmen@gmail.com>
Date: Wed, 4 Dec 2019 23:15:52 -0500
Subject: [PATCH] build and destroy input sequence trie #78

---
 src/lib/input.c     | 72 +++++++++++++++++++++++++++++++++++++++++++--
 src/lib/internal.h  |  8 +++++
 src/lib/notcurses.c |  2 ++
 3 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/src/lib/input.c b/src/lib/input.c
index 30a8bf714..6ed29e8e7 100644
--- a/src/lib/input.c
+++ b/src/lib/input.c
@@ -8,7 +8,7 @@ sig_atomic_t resize_seen = 0;
 static inline int
 pop_input_keypress(notcurses* nc){
   int candidate = nc->inputbuf[nc->inputbuf_valid_starts];
-fprintf(stderr, "DEOCCUPY: %u@%u read: %d\n", nc->inputbuf_occupied, nc->inputbuf_valid_starts, nc->inputbuf[nc->inputbuf_valid_starts]);
+// fprintf(stderr, "DEOCCUPY: %u@%u read: %d\n", nc->inputbuf_occupied, nc->inputbuf_valid_starts, nc->inputbuf[nc->inputbuf_valid_starts]);
   if(++nc->inputbuf_valid_starts == sizeof(nc->inputbuf) / sizeof(*nc->inputbuf)){
     nc->inputbuf_valid_starts = 0;
   }
@@ -16,17 +16,83 @@ fprintf(stderr, "DEOCCUPY: %u@%u read: %d\n", nc->inputbuf_occupied, nc->inputbu
   return candidate;
 }
 
+// we assumed escapes can only be composed of 7-bit chars
+typedef struct esctrie {
+  ncspecial_key special; // escape terminating here
+  struct esctrie** trie;  // if non-NULL, next level of radix-128 trie
+} esctrie;
+
+static esctrie*
+create_esctrie_node(ncspecial_key special){
+  esctrie* e = malloc(sizeof(*e));
+  if(e){
+    e->special = special;
+    e->trie = NULL;
+  }
+  return e;
+}
+
+void input_free_esctrie(esctrie** eptr){
+  esctrie* e;
+  if( (e = *eptr) ){
+    if(e->trie){
+      int z;
+      for(z = 0 ; z < 0x80 ; ++z){
+        if(e->trie[z]){
+          input_free_esctrie(&e->trie[z]);
+        }
+      }
+      free(e->trie);
+    }
+    free(e);
+  }
+}
+
+int input_add_escape(notcurses* nc, const char* esc, ncspecial_key special){
+  esctrie** cur;
+  fprintf(stderr, "ADDING: %s for %d\n", esc, special);
+  if(esc[0] != ESC || strlen(esc) < 2){ // assume ESC prefix + content
+    return -1;
+  }
+  do{
+    ++esc;
+    int validate = *esc;
+    if(validate < 0 || validate >= 0x80){
+      return -1;
+    }
+    if(nc->inputescapes == NULL){
+      cur = &nc->inputescapes;
+    }else if(validate){
+      if((*cur)->trie == NULL){
+        const size_t tsize = sizeof((*cur)->trie) * 0x80;
+        (*cur)->trie = malloc(tsize);
+        memset((*cur)->trie, 0, tsize);
+      }
+      cur = &(*cur)->trie[validate];
+    }
+    if(*cur == NULL){
+      if((*cur = create_esctrie_node(NCKEY_INVALID)) == NULL){
+        return -1;
+      }
+    }
+  }while(*esc);
+  if((*cur)->special){ // already had one here!
+    return -1;
+  }
+  (*cur)->special = special;
+  return 0;
+}
+
 // add the keypress we just read to our input queue (assuming there is room).
 // if there is a full UTF8 codepoint or keystroke (composed or otherwise),
 // return it, and pop it from the queue.
 static int
 handle_getc(notcurses* nc, cell* c, int kpress, ncspecial_key* special){
-fprintf(stderr, "KEYPRESS: %d\n", kpress);
+// fprintf(stderr, "KEYPRESS: %d\n", kpress);
   if(kpress < 0){
     return -1;
   }
   if(kpress == ESC){
-fprintf(stderr, "ESCAPE OH SHIT\n");
     // FIXME delay a little waiting for more?
     while(nc->inputbuf_occupied){
       int candidate = pop_input_keypress(nc);
diff --git a/src/lib/internal.h b/src/lib/internal.h
index 03279b75d..6cff13b7b 100644
--- a/src/lib/internal.h
+++ b/src/lib/internal.h
@@ -23,6 +23,7 @@ struct AVCodec;
 struct AVCodecParameters;
 struct AVPacket;
 struct SwsContext;
+struct esctrie;
 
 // A plane is memory for some rectilinear virtual window, plus current cursor
 // state for that window. A notcurses context describes a single terminal, and
@@ -121,10 +122,17 @@ typedef struct notcurses {
   unsigned inputbuf_occupied;
   unsigned inputbuf_valid_starts;
   unsigned inputbuf_write_at;
+  struct esctrie* inputescapes; // trie of input escapes -> ncspecial_keys
 } notcurses;
 
 extern sig_atomic_t resize_seen;
 
+// add this escape sequence to the trie, resolving to the specified specialkey
+int input_add_escape(notcurses* nc, const char* esc, ncspecial_key special);
+
+// free up the input escapes trie
+void input_free_esctrie(struct esctrie** trie);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/lib/notcurses.c b/src/lib/notcurses.c
index f258b4dbf..728e14202 100644
--- a/src/lib/notcurses.c
+++ b/src/lib/notcurses.c
@@ -607,6 +607,7 @@ notcurses* notcurses_init(const notcurses_options* opts){
   ret->stats.render_min_bytes = ~0UL;
   ret->ttyfp = opts->outfp;
   ret->renderfp = opts->renderfp;
+  ret->inputescapes = NULL;
   ret->ttyinfp = stdin; // FIXME
   if(make_nonblocking(ret->ttyinfp)){
     free(ret);
@@ -729,6 +730,7 @@ int notcurses_stop(notcurses* nc){
       nc->top = p->z;
       free_plane(p);
     }
+    input_free_esctrie(&nc->inputescapes);
     ret |= pthread_mutex_destroy(&nc->lock);
     free(nc);
   }