Merge branch 'rewrite'

1 files changed, 207 insertions, 0 deletions

diff --git a/edit.c b/edit.c
new file mode 100644
index 0000000..d90d558
--- /dev/null
+++ b/edit.c
@@ -0,0 +1,207 @@
+/* Copyright (C) 2020  C. McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <wchar.h>
+#include <wctype.h>
+
+#include "chat.h"
+
+enum { Cap = 512 };
+static wchar_t buf[Cap];
+static size_t len;
+static size_t pos;
+
+char *editBuffer(size_t *mbsPos) {
+	static char mbs[MB_LEN_MAX * Cap];
+
+	const wchar_t *ptr = buf;
+	size_t mbsLen = wcsnrtombs(mbs, &ptr, pos, sizeof(mbs) - 1, NULL);
+	assert(mbsLen != (size_t)-1);
+	if (mbsPos) *mbsPos = mbsLen;
+
+	ptr = &buf[pos];
+	size_t n = wcsnrtombs(
+		&mbs[mbsLen], &ptr, len - pos, sizeof(mbs) - mbsLen - 1, NULL
+	);
+	assert(n != (size_t)-1);
+	mbsLen += n;
+
+	mbs[mbsLen] = '\0';
+	return mbs;
+}
+
+static struct {
+	wchar_t buf[Cap];
+	size_t len;
+} cut;
+
+static bool reserve(size_t index, size_t count) {
+	if (len + count > Cap) return false;
+	memmove(&buf[index + count], &buf[index], sizeof(*buf) * (len - index));
+	len += count;
+	return true;
+}
+
+static void delete(size_t index, size_t count) {
+	if (index + count > len) return;
+	if (count > 1) {
+		memcpy(cut.buf, &buf[index], sizeof(*buf) * count);
+		cut.len = count;
+	}
+	memmove(
+		&buf[index], &buf[index + count], sizeof(*buf) * (len - index - count)
+	);
+	len -= count;
+}
+
+static struct {
+	size_t pos;
+	size_t pre;
+	size_t len;
+} tab;
+
+static void tabComplete(size_t id) {
+	if (!tab.len) {
+		tab.pos = pos;
+		while (tab.pos && buf[tab.pos - 1] != L' ') tab.pos--;
+		if (tab.pos == pos) return;
+		tab.pre = pos - tab.pos;
+		tab.len = tab.pre;
+	}
+
+	char mbs[MB_LEN_MAX * Cap];
+	const wchar_t *ptr = &buf[tab.pos];
+	size_t n = wcsnrtombs(mbs, &ptr, tab.pre, sizeof(mbs) - 1, NULL);
+	assert(n != (size_t)-1);
+	mbs[n] = '\0';
+
+	const char *comp = complete(id, mbs);
+	if (!comp) comp = complete(id, mbs);
+	if (!comp) {
+		tab.len = 0;
+		return;
+	}
+
+	wchar_t wcs[Cap];
+	n = mbstowcs(wcs, comp, sizeof(wcs));
+	assert(n != (size_t)-1);
+	if (tab.pos + n + 2 > Cap) {
+		completeReject();
+		tab.len = 0;
+		return;
+	}
+
+	delete(tab.pos, tab.len);
+	if (wcs[0] != L'/' && !tab.pos) {
+		tab.len = n + 2;
+		reserve(tab.pos, tab.len);
+		buf[tab.pos + n + 0] = L':';
+		buf[tab.pos + n + 1] = L' ';
+	} else if (
+		tab.pos >= 2 && (buf[tab.pos - 2] == L':' || buf[tab.pos - 2] == L',')
+	) {
+		tab.len = n + 2;
+		reserve(tab.pos, tab.len);
+		buf[tab.pos - 2] = L',';
+		buf[tab.pos + n + 0] = L':';
+		buf[tab.pos + n + 1] = L' ';
+	} else {
+		tab.len = n + 1;
+		reserve(tab.pos, tab.len);
+		buf[tab.pos + n] = L' ';
+	}
+	memcpy(&buf[tab.pos], wcs, sizeof(*wcs) * n);
+	pos = tab.pos + tab.len;
+}
+
+static void tabAccept(void) {
+	completeAccept();
+	tab.len = 0;
+}
+
+static void tabReject(void) {
+	completeReject();
+	tab.len = 0;
+}
+
+void edit(size_t id, enum Edit op, wchar_t ch) {
+	size_t init = pos;
+	switch (op) {
+		break; case EditHead: pos = 0;
+		break; case EditTail: pos = len;
+		break; case EditPrev: if (pos) pos--;
+		break; case EditNext: if (pos < len) pos++;
+		break; case EditPrevWord: {
+			if (pos) pos--;
+			while (pos && !iswspace(buf[pos - 1])) pos--;
+		}
+		break; case EditNextWord: {
+			if (pos < len) pos++;
+			while (pos < len && !iswspace(buf[pos])) pos++;
+		}
+
+		break; case EditDeleteHead: delete(0, pos); pos = 0;
+		break; case EditDeleteTail: delete(pos, len - pos);
+		break; case EditDeletePrev: if (pos) delete(--pos, 1);
+		break; case EditDeleteNext: delete(pos, 1);
+		break; case EditDeletePrevWord: {
+			if (!pos) break;
+			size_t word = pos - 1;
+			while (word && !iswspace(buf[word - 1])) word--;
+			delete(word, pos - word);
+			pos = word;
+		}
+		break; case EditDeleteNextWord: {
+			if (pos == len) break;
+			size_t word = pos + 1;
+			while (word < len && !iswspace(buf[word])) word++;
+			delete(pos, word - pos);
+		}
+		break; case EditPaste: {
+			if (reserve(pos, cut.len)) {
+				memcpy(&buf[pos], cut.buf, sizeof(*buf) * cut.len);
+				pos += cut.len;
+			}
+		}
+
+		break; case EditInsert: {
+			if (reserve(pos, 1)) {
+				buf[pos++] = ch;
+			}
+		}
+		break; case EditComplete: {
+			tabComplete(id);
+			return;
+		}
+		break; case EditEnter: {
+			tabAccept();
+			command(id, editBuffer(NULL));
+			len = pos = 0;
+			return;
+		}
+	}
+
+	if (pos < init) {
+		tabReject();
+	} else {
+		tabAccept();
+	}
+}