1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 
19 #include <errno.h>
20 #include <curses.h>
21 #include <panel.h>
22 #include <locale.h>
23 #include <stdlib.h>
24 #include <stdio.h>
25 #include <getopt.h>
26 #include <string.h>
27 #include <err.h>
28 #include <unistd.h>
29 #include <util.h>
30 #include <limits.h>
31 
32 #include "got_error.h"
33 #include "got_object.h"
34 #include "got_reference.h"
35 #include "got_repository.h"
36 #include "got_diff.h"
37 #include "got_opentemp.h"
38 
39 #ifndef MIN
40 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
41 #endif
42 
43 #ifndef nitems
44 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
45 #endif
46 
47 enum tog_view_id {
48 	TOG_VIEW_LOG,
49 	TOG_VIEW_DIFF,
50 	TOG_VIEW_BLAME,
51 };
52 
53 struct tog_cmd {
54 	const char *name;
55 	const struct got_error *(*cmd_main)(int, char *[]);
56 	void (*cmd_usage)(void);
57 	enum tog_view_id view;
58 	const char *descr;
59 };
60 
61 __dead void	usage(void);
62 __dead void	usage_log(void);
63 __dead void	usage_diff(void);
64 __dead void	usage_blame(void);
65 
66 const struct got_error*	cmd_log(int, char *[]);
67 const struct got_error*	cmd_diff(int, char *[]);
68 const struct got_error*	cmd_blame(int, char *[]);
69 
70 struct tog_cmd tog_commands[] = {
71 	{ "log",	cmd_log,	usage_log,	TOG_VIEW_LOG,
72 	    "show repository history" },
73 	{ "diff",	cmd_diff,	usage_diff,	TOG_VIEW_DIFF,
74 	    "compare files and directories" },
75 	{ "blame",	cmd_blame,	usage_blame,	TOG_VIEW_BLAME,
76 	    "show line-by-line file history" },
77 };
78 
79 /* globals */
80 static struct tog_view {
81 	WINDOW *window;
82 	PANEL *panel;
83 } tog_log_view, tog_diff_view;
84 
85 __dead void
86 usage_log(void)
87 {
88 	endwin();
89 	fprintf(stderr, "usage: %s log [-c commit] [repository-path]\n",
90 	    getprogname());
91 	exit(1);
92 }
93 
94 static const struct got_error *
95 draw_commit(struct got_commit_object *commit, struct got_object_id *id)
96 {
97 	const struct got_error *err = NULL;
98 	char *logmsg0 = NULL, *logmsg = NULL;
99 	char *author0 = NULL, *author = NULL;
100 	char *newline, *smallerthan;
101 	char *line = NULL;
102 	char *id_str = NULL;
103 	const size_t id_display_len = 8;
104 	const size_t author_display_len = 16;
105 	size_t id_len, author_len, logmsg_len, avail;
106 	int i, col;
107 
108 	err = got_object_id_str(&id_str, id);
109 	if (err)
110 		return err;
111 	id_len = strlen(id_str);
112 
113 	logmsg0 = strdup(commit->logmsg);
114 	if (logmsg0 == NULL) {
115 		err = got_error_from_errno();
116 		goto done;
117 	}
118 	logmsg = logmsg0;
119 	while (*logmsg == '\n')
120 		logmsg++;
121 	newline = strchr(logmsg, '\n');
122 	if (newline)
123 		*newline = '\0';
124 	logmsg_len = strlen(logmsg);
125 
126 	author0 = strdup(commit->author);
127 	if (author0 == NULL) {
128 		err = got_error_from_errno();
129 		goto done;
130 	}
131 	author = author0;
132 	smallerthan = strchr(author, '<');
133 	if (smallerthan)
134 		*smallerthan = '\0';
135 	else {
136 		char *at = strchr(author, '@');
137 		if (at)
138 			*at = '\0';
139 	}
140 	author_len = strlen(author);
141 
142 	avail = COLS - 1;
143 	line = calloc(avail + 1, sizeof(*line));
144 	if (line == NULL) {
145 		err = got_error_from_errno();
146 		goto done;
147 	}
148 
149 	col = 0;
150 	for (i = 0; i < MIN(id_display_len, id_len); i++) {
151 		if (col >= avail)
152 			goto draw;
153 		line[col++] = id_str[i];
154 	}
155 	while (i < id_display_len) {
156 		if (col >= avail)
157 			goto draw;
158 		line[col++] = ' ';
159 		i++;
160 	}
161 	if (col >= avail)
162 		goto draw;
163 	line[col++] = ' ';
164 	for (i = 0; i < MIN(author_display_len, author_len); i++) {
165 		if (col >= avail)
166 			goto draw;
167 		line[col++] = author[i];
168 	}
169 	while (i < author_display_len) {
170 		if (col >= avail)
171 			goto draw;
172 		line[col++] = ' ';
173 		i++;
174 	}
175 	if (col >= avail)
176 		goto draw;
177 	line[col++] = ' ';
178 
179 	while (col < avail && *logmsg)
180 		line[col++] = *logmsg++;
181 	while (col < avail)
182 		line[col++] = ' ';
183 draw:
184 	waddstr(tog_log_view.window, line);
185 	waddch(tog_log_view.window, '\n');
186 done:
187 	free(logmsg0);
188 	free(author0);
189 	free(line);
190 	free(id_str);
191 	return err;
192 }
193 
194 struct commit_queue_entry {
195 	TAILQ_ENTRY(commit_queue_entry) entry;
196 	struct got_object_id *id;
197 	struct got_commit_object *commit;
198 };
199 TAILQ_HEAD(commit_queue, commit_queue_entry);
200 
201 static struct commit_queue_entry *
202 alloc_commit_queue_entry(struct got_commit_object *commit,
203     struct got_object_id *id)
204 {
205 	struct commit_queue_entry *entry;
206 
207 	entry = calloc(1, sizeof(*entry));
208 	if (entry == NULL)
209 		return NULL;
210 
211 	entry->id = id;
212 	entry->commit = commit;
213 	return entry;
214 }
215 
216 static void
217 pop_commit(struct commit_queue *commits)
218 {
219 	struct commit_queue_entry *entry;
220 
221 	entry = TAILQ_FIRST(commits);
222 	TAILQ_REMOVE(commits, entry, entry);
223 	got_object_commit_close(entry->commit);
224 	free(entry->id);
225 	free(entry);
226 }
227 
228 static void
229 free_commits(struct commit_queue *commits)
230 {
231 	while (!TAILQ_EMPTY(commits))
232 		pop_commit(commits);
233 }
234 
235 
236 static const struct got_error *
237 fetch_parent_commit(struct commit_queue_entry **pentry,
238     struct commit_queue_entry *entry, struct got_repository *repo)
239 {
240 	const struct got_error *err = NULL;
241 	struct got_object *obj = NULL;
242 	struct got_commit_object *commit;
243 	struct got_object_id *id;
244 	struct got_parent_id *pid;
245 
246 	*pentry = NULL;
247 
248 	/* Follow the first parent (TODO: handle merge commits). */
249 	pid = SIMPLEQ_FIRST(&entry->commit->parent_ids);
250 	if (pid == NULL)
251 		return NULL;
252 	err = got_object_open(&obj, repo, pid->id);
253 	if (err)
254 		return err;
255 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_COMMIT) {
256 		err = got_error(GOT_ERR_OBJ_TYPE);
257 		got_object_close(obj);
258 		return err;
259 	}
260 
261 	err = got_object_commit_open(&commit, repo, obj);
262 	got_object_close(obj);
263 	if (err)
264 		return err;
265 
266 	id = got_object_id_dup(pid->id);
267 	if (id == NULL) {
268 		err = got_error_from_errno();
269 		got_object_commit_close(commit);
270 		return err;;
271 	}
272 
273 	*pentry = alloc_commit_queue_entry(commit, id);
274 	if (*pentry == NULL) {
275 		err = got_error_from_errno();
276 		got_object_commit_close(commit);
277 	}
278 
279 	return err;;
280 }
281 
282 static const struct got_error *
283 get_head_commit_id(struct got_object_id **head_id, struct got_repository *repo)
284 {
285 	const struct got_error *err = NULL;
286 	struct got_reference *head_ref;
287 
288 	*head_id = NULL;
289 
290 	err = got_ref_open(&head_ref, repo, GOT_REF_HEAD);
291 	if (err)
292 		return err;
293 
294 	err = got_ref_resolve(head_id, repo, head_ref);
295 	got_ref_close(head_ref);
296 	if (err) {
297 		*head_id = NULL;
298 		return err;
299 	}
300 
301 	return NULL;
302 }
303 
304 static const struct got_error *
305 prepend_commits(int *ncommits, struct commit_queue *commits,
306     struct got_object_id *first_id, struct got_object_id *last_id,
307     int limit, struct got_repository *repo)
308 {
309 	const struct got_error *err = NULL;
310 	struct got_object *first_obj = NULL, *last_obj = NULL;
311 	struct got_commit_object *commit = NULL;
312 	struct got_object_id *id = NULL;
313 	struct commit_queue_entry *entry, *old_head_entry;
314 
315 	*ncommits = 0;
316 
317 	err = got_object_open(&first_obj, repo, first_id);
318 	if (err)
319 		goto done;
320 	if (got_object_get_type(first_obj) != GOT_OBJ_TYPE_COMMIT) {
321 		err = got_error(GOT_ERR_OBJ_TYPE);
322 		goto done;
323 	}
324 	err = got_object_open(&last_obj, repo, last_id);
325 	if (err)
326 		goto done;
327 	if (got_object_get_type(last_obj) != GOT_OBJ_TYPE_COMMIT) {
328 		err = got_error(GOT_ERR_OBJ_TYPE);
329 		goto done;
330 	}
331 
332 	err = got_object_commit_open(&commit, repo, first_obj);
333 	if (err)
334 		goto done;
335 
336 	id = got_object_id_dup(first_id);
337 	if (id == NULL) {
338 		err = got_error_from_errno();
339 		goto done;
340 	}
341 
342 	entry = alloc_commit_queue_entry(commit, id);
343 	if (entry == NULL)
344 		return got_error_from_errno();
345 
346 	old_head_entry = TAILQ_FIRST(commits);
347 	if (old_head_entry)
348 		TAILQ_INSERT_BEFORE(old_head_entry, entry, entry);
349 	else
350 		TAILQ_INSERT_HEAD(commits, entry, entry);
351 
352 	*ncommits = 1;
353 
354 	/*
355 	 * Fetch parent commits.
356 	 * XXX If first and last commit aren't ancestrally related this loop
357 	 * we will keep iterating until a root commit is encountered.
358 	 */
359 	while (1) {
360 		struct commit_queue_entry *pentry;
361 
362 		err = fetch_parent_commit(&pentry, entry, repo);
363 		if (err)
364 			goto done;
365 		if (pentry == NULL)
366 			break;
367 
368 		/*
369 		 * Fill up to old HEAD commit if commit queue was not empty.
370 		 * We must not leave a gap in history.
371 		 */
372 		if (old_head_entry &&
373 		    got_object_id_cmp(pentry->id, old_head_entry->id) == 0)
374 			break;
375 
376 		TAILQ_INSERT_AFTER(commits, entry, pentry, entry);
377 		(*ncommits)++;
378 		if (*ncommits >= limit)
379 			break;
380 
381 		/* Fill up to last requested commit if queue was empty. */
382 		if (old_head_entry == NULL &&
383 		    got_object_id_cmp(pentry->id, last_id) == 0)
384 			break;
385 
386 		entry = pentry;
387 	}
388 
389 done:
390 	if (first_obj)
391 		got_object_close(first_obj);
392 	if (last_obj)
393 		got_object_close(last_obj);
394 	return err;
395 }
396 
397 static const struct got_error *
398 fetch_commits(struct commit_queue_entry **start_entry,
399     struct got_object_id *start_id, struct commit_queue *commits,
400     int limit, struct got_repository *repo)
401 {
402 	const struct got_error *err;
403 	struct commit_queue_entry *entry;
404 	int ncommits = 0;
405 	struct got_object_id *head_id = NULL;
406 
407 	*start_entry = NULL;
408 
409 	err = get_head_commit_id(&head_id, repo);
410 	if (err)
411 		return err;
412 
413 	/* Prepend HEAD commit and all ancestors up to start commit. */
414 	err = prepend_commits(&ncommits, commits, head_id, start_id, limit,
415 	    repo);
416 	if (err)
417 		return err;
418 
419 	if (got_object_id_cmp(head_id, start_id) == 0)
420 		*start_entry = TAILQ_FIRST(commits);
421 	else
422 		*start_entry = TAILQ_LAST(commits, commit_queue);
423 
424 	if (ncommits >= limit)
425 		return NULL;
426 
427 	/* Append more commits from start commit up to the requested limit. */
428 	entry = TAILQ_LAST(commits, commit_queue);
429 	while (entry && ncommits < limit) {
430 		struct commit_queue_entry *pentry;
431 
432 		err = fetch_parent_commit(&pentry, entry, repo);
433 		if (err)
434 			break;
435 		if (pentry)
436 			TAILQ_INSERT_TAIL(commits, pentry, entry);
437 		entry = pentry;
438 		ncommits++;
439 	}
440 
441 	if (err)
442 		*start_entry = NULL;
443 	return err;
444 }
445 
446 static const struct got_error *
447 draw_commits(struct commit_queue_entry **last, struct commit_queue_entry *first,
448     int selected, int limit)
449 {
450 	const struct got_error *err = NULL;
451 	struct commit_queue_entry *entry;
452 	int ncommits = 0;
453 
454 	wclear(tog_log_view.window);
455 
456 	entry = first;
457 	*last = first;
458 	while (entry) {
459 		if (ncommits == limit)
460 			break;
461 		if (ncommits == selected)
462 			wstandout(tog_log_view.window);
463 		err = draw_commit(entry->commit, entry->id);
464 		if (ncommits == selected)
465 			wstandend(tog_log_view.window);
466 		if (err)
467 			break;
468 		ncommits++;
469 		*last = entry;
470 		entry = TAILQ_NEXT(entry, entry);
471 	}
472 
473 	update_panels();
474 	doupdate();
475 
476 	return err;
477 }
478 
479 static void
480 scroll_up(struct commit_queue_entry **first_displayed_entry, int n,
481     struct commit_queue *commits)
482 {
483 	struct commit_queue_entry *entry;
484 	int nscrolled = 0;
485 
486 	entry = TAILQ_FIRST(commits);
487 	if (*first_displayed_entry == entry)
488 		return;
489 
490 	entry = *first_displayed_entry;
491 	while (entry && nscrolled < n) {
492 		entry = TAILQ_PREV(entry, commit_queue, entry);
493 		if (entry) {
494 			*first_displayed_entry = entry;
495 			nscrolled++;
496 		}
497 	}
498 }
499 
500 static const struct got_error *
501 scroll_down(struct commit_queue_entry **first_displayed_entry, int n,
502     struct commit_queue_entry *last_displayed_entry,
503     struct commit_queue *commits, struct got_repository *repo)
504 {
505 	const struct got_error *err = NULL;
506 	struct commit_queue_entry *entry;
507 	int nscrolled = 0;
508 
509 	if (last_displayed_entry->commit->nparents == 0)
510 		return NULL;
511 
512 	entry = *first_displayed_entry;
513 	do {
514 		struct commit_queue_entry *pentry;
515 
516 		pentry = TAILQ_NEXT(entry, entry);
517 		if (pentry == NULL) {
518 			err = fetch_parent_commit(&pentry, entry, repo);
519 			if (err)
520 				break;
521 			if (pentry == NULL) {
522 				*first_displayed_entry = entry;
523 				return NULL;
524 			}
525 			TAILQ_INSERT_TAIL(commits, pentry, entry);
526 			last_displayed_entry = pentry;
527 		}
528 
529 		*first_displayed_entry = pentry;
530 		entry = pentry;
531 
532 		if (TAILQ_LAST(commits, commit_queue) == last_displayed_entry) {
533 			err = fetch_parent_commit(&pentry, last_displayed_entry,
534 			    repo);
535 			if (err)
536 				break;
537 			if (pentry) {
538 				TAILQ_INSERT_TAIL(commits, pentry, entry);
539 				last_displayed_entry = pentry;
540 			}
541 		}
542 	} while (++nscrolled < n);
543 
544 	return NULL;
545 }
546 
547 static int
548 num_parents(struct commit_queue_entry *entry)
549 {
550 	int nparents = 0;
551 
552 	while (entry) {
553 		entry = TAILQ_NEXT(entry, entry);
554 		nparents++;
555 	}
556 
557 	return nparents;
558 }
559 
560 static const struct got_error *
561 show_log_view(struct got_object_id *start_id, struct got_repository *repo)
562 {
563 	const struct got_error *err = NULL;
564 	struct got_object_id *id;
565 	int ch, done = 0, selected = 0, nparents;
566 	struct commit_queue commits;
567 	struct commit_queue_entry *first_displayed_entry = NULL;
568 	struct commit_queue_entry *last_displayed_entry = NULL;
569 
570 	id = got_object_id_dup(start_id);
571 	if (id == NULL)
572 		return got_error_from_errno();
573 
574 	if (tog_log_view.window == NULL) {
575 		tog_log_view.window = newwin(0, 0, 0, 0);
576 		if (tog_log_view.window == NULL)
577 			return got_error_from_errno();
578 		keypad(tog_log_view.window, TRUE);
579 	}
580 	if (tog_log_view.panel == NULL) {
581 		tog_log_view.panel = new_panel(tog_log_view.window);
582 		if (tog_log_view.panel == NULL)
583 			return got_error_from_errno();
584 	}
585 
586 	TAILQ_INIT(&commits);
587 	err = fetch_commits(&first_displayed_entry, id, &commits, LINES, repo);
588 	if (err)
589 		goto done;
590 	while (!done) {
591 		err = draw_commits(&last_displayed_entry, first_displayed_entry,
592 		    selected, LINES);
593 		if (err)
594 			goto done;
595 
596 		nodelay(stdscr, FALSE);
597 		ch = wgetch(tog_log_view.window);
598 		switch (ch) {
599 			case ERR:
600 				if (errno) {
601 					err = got_error_from_errno();
602 					goto done;
603 				}
604 				break;
605 			case 'q':
606 				done = 1;
607 				break;
608 			case 'k':
609 			case KEY_UP:
610 				if (selected > 0)
611 					selected--;
612 				if (selected > 0)
613 					break;
614 				scroll_up(&first_displayed_entry, 1, &commits);
615 				break;
616 			case KEY_PPAGE:
617 				if (TAILQ_FIRST(&commits) ==
618 				    first_displayed_entry) {
619 					selected = 0;
620 					break;
621 				}
622 				scroll_up(&first_displayed_entry, LINES,
623 				    &commits);
624 				break;
625 			case 'j':
626 			case KEY_DOWN:
627 				nparents = num_parents(first_displayed_entry);
628 				if (selected < LINES - 1 &&
629 				    selected < nparents - 1)
630 					selected++;
631 				if (selected < LINES - 1 &&
632 				    selected < nparents - 1)
633 					break;
634 				err = scroll_down(&first_displayed_entry, 1,
635 				    last_displayed_entry, &commits, repo);
636 				if (err)
637 					goto done;
638 				break;
639 			case KEY_NPAGE:
640 				nparents = num_parents(first_displayed_entry);
641 				if (nparents < LINES - 1 &&
642 				    selected < nparents - 1) {
643 					selected = nparents - 1;
644 					break;
645 				}
646 				err = scroll_down(&first_displayed_entry, LINES,
647 				    last_displayed_entry, &commits, repo);
648 				if (err)
649 					goto done;
650 				nparents = num_parents(first_displayed_entry);
651 				if (selected > nparents)
652 					selected = nparents - 1;
653 				break;
654 			case KEY_RESIZE:
655 				if (selected > LINES)
656 					selected = LINES - 1;
657 				break;
658 			default:
659 				break;
660 		}
661 		nodelay(stdscr, TRUE);
662 	}
663 done:
664 	free_commits(&commits);
665 	return err;
666 }
667 
668 const struct got_error *
669 cmd_log(int argc, char *argv[])
670 {
671 	const struct got_error *error;
672 	struct got_repository *repo;
673 	struct got_object_id *start_id = NULL;
674 	char *repo_path = NULL;
675 	char *start_commit = NULL;
676 	int ch;
677 
678 #ifndef PROFILE
679 	if (pledge("stdio rpath wpath cpath flock proc tty", NULL) == -1)
680 		err(1, "pledge");
681 #endif
682 
683 	while ((ch = getopt(argc, argv, "c:")) != -1) {
684 		switch (ch) {
685 		case 'c':
686 			start_commit = optarg;
687 			break;
688 		default:
689 			usage();
690 			/* NOTREACHED */
691 		}
692 	}
693 
694 	argc -= optind;
695 	argv += optind;
696 
697 	if (argc == 0) {
698 		repo_path = getcwd(NULL, 0);
699 		if (repo_path == NULL)
700 			return got_error_from_errno();
701 	} else if (argc == 1) {
702 		repo_path = realpath(argv[0], NULL);
703 		if (repo_path == NULL)
704 			return got_error_from_errno();
705 	} else
706 		usage_log();
707 
708 	error = got_repo_open(&repo, repo_path);
709 	free(repo_path);
710 	if (error != NULL)
711 		return error;
712 
713 	if (start_commit == NULL) {
714 		error = get_head_commit_id(&start_id, repo);
715 		if (error != NULL)
716 			return error;
717 	} else {
718 		struct got_object *obj;
719 		error = got_object_open_by_id_str(&obj, repo, start_commit);
720 		if (error == NULL) {
721 			start_id = got_object_get_id(obj);
722 			if (start_id == NULL)
723 				error = got_error_from_errno();
724 		}
725 	}
726 	if (error != NULL)
727 		return error;
728 	error = show_log_view(start_id, repo);
729 	free(start_id);
730 	got_repo_close(repo);
731 	return error;
732 }
733 
734 __dead void
735 usage_diff(void)
736 {
737 	endwin();
738 	fprintf(stderr, "usage: %s diff [repository-path] object1 object2\n",
739 	    getprogname());
740 	exit(1);
741 }
742 
743 const struct got_error *
744 draw_diff(FILE *f, int *first_displayed_line, int *last_displayed_line,
745     int *eof, int max_lines)
746 {
747 	int nlines = 0, nprinted = 0;
748 
749 	rewind(f);
750 	wclear(tog_diff_view.window);
751 
752 	*eof = 0;
753 	while (nprinted < max_lines) {
754 		char *line;
755 		size_t lineno;
756 		size_t linelen;
757 		const char delim[3] = { '\0', '\0', '\0'};
758 
759 		line = fparseln(f, &linelen, &lineno, delim, 0);
760 		if (line == NULL) {
761 			*eof = 1;
762 			break;
763 		}
764 		if (++nlines < *first_displayed_line) {
765 			free(line);
766 			continue;
767 		}
768 
769 		if (linelen > COLS - 1)
770 			line[COLS - 1] = '\0';
771 		waddstr(tog_diff_view.window, line);
772 		waddch(tog_diff_view.window, '\n');
773 		if (++nprinted == 1)
774 			*first_displayed_line = nlines;
775 		free(line);
776 	}
777 	*last_displayed_line = nlines;
778 
779 	update_panels();
780 	doupdate();
781 
782 	return NULL;
783 }
784 
785 const struct got_error *
786 show_diff_view(struct got_object *obj1, struct got_object *obj2,
787     struct got_repository *repo)
788 {
789 	const struct got_error *err;
790 	FILE *f;
791 	int ch, done = 0, first_displayed_line = 1, last_displayed_line = LINES;
792 	int eof;
793 
794 	if (got_object_get_type(obj1) != got_object_get_type(obj2))
795 		return got_error(GOT_ERR_OBJ_TYPE);
796 
797 	f = got_opentemp();
798 	if (f == NULL)
799 		return got_error_from_errno();
800 
801 	switch (got_object_get_type(obj1)) {
802 	case GOT_OBJ_TYPE_BLOB:
803 		err = got_diff_objects_as_blobs(obj1, obj2, repo, f);
804 		break;
805 	case GOT_OBJ_TYPE_TREE:
806 		err = got_diff_objects_as_trees(obj1, obj2, repo, f);
807 		break;
808 	case GOT_OBJ_TYPE_COMMIT:
809 		err = got_diff_objects_as_commits(obj1, obj2, repo, f);
810 		break;
811 	default:
812 		return got_error(GOT_ERR_OBJ_TYPE);
813 	}
814 
815 	fflush(f);
816 
817 	if (tog_diff_view.window == NULL) {
818 		tog_diff_view.window = newwin(0, 0, 0, 0);
819 		if (tog_diff_view.window == NULL)
820 			return got_error_from_errno();
821 		keypad(tog_diff_view.window, TRUE);
822 	}
823 	if (tog_diff_view.panel == NULL) {
824 		tog_diff_view.panel = new_panel(tog_diff_view.window);
825 		if (tog_diff_view.panel == NULL)
826 			return got_error_from_errno();
827 	} else
828 		show_panel(tog_diff_view.panel);
829 
830 	while (!done) {
831 		err = draw_diff(f, &first_displayed_line, &last_displayed_line,
832 		    &eof, LINES);
833 		if (err)
834 			break;
835 		nodelay(stdscr, FALSE);
836 		ch = wgetch(tog_diff_view.window);
837 		switch (ch) {
838 			case 'q':
839 				done = 1;
840 				break;
841 			case 'k':
842 			case KEY_UP:
843 				if (first_displayed_line > 1)
844 					first_displayed_line--;
845 				break;
846 			case 'j':
847 			case KEY_DOWN:
848 				if (!eof)
849 					first_displayed_line++;
850 				break;
851 			default:
852 				break;
853 		}
854 		nodelay(stdscr, TRUE);
855 	}
856 	fclose(f);
857 	return err;
858 }
859 
860 const struct got_error *
861 cmd_diff(int argc, char *argv[])
862 {
863 	const struct got_error *error = NULL;
864 	struct got_repository *repo = NULL;
865 	struct got_object *obj1 = NULL, *obj2 = NULL;
866 	char *repo_path = NULL;
867 	char *obj_id_str1 = NULL, *obj_id_str2 = NULL;
868 	int ch;
869 
870 #ifndef PROFILE
871 	if (pledge("stdio rpath wpath cpath flock proc tty", NULL) == -1)
872 		err(1, "pledge");
873 #endif
874 
875 	while ((ch = getopt(argc, argv, "")) != -1) {
876 		switch (ch) {
877 		default:
878 			usage();
879 			/* NOTREACHED */
880 		}
881 	}
882 
883 	argc -= optind;
884 	argv += optind;
885 
886 	if (argc == 0) {
887 		usage_diff(); /* TODO show local worktree changes */
888 	} else if (argc == 2) {
889 		repo_path = getcwd(NULL, 0);
890 		if (repo_path == NULL)
891 			return got_error_from_errno();
892 		obj_id_str1 = argv[0];
893 		obj_id_str2 = argv[1];
894 	} else if (argc == 3) {
895 		repo_path = realpath(argv[0], NULL);
896 		if (repo_path == NULL)
897 			return got_error_from_errno();
898 		obj_id_str1 = argv[1];
899 		obj_id_str2 = argv[2];
900 	} else
901 		usage_diff();
902 
903 	error = got_repo_open(&repo, repo_path);
904 	free(repo_path);
905 	if (error)
906 		goto done;
907 
908 	error = got_object_open_by_id_str(&obj1, repo, obj_id_str1);
909 	if (error)
910 		goto done;
911 
912 	error = got_object_open_by_id_str(&obj2, repo, obj_id_str2);
913 	if (error)
914 		goto done;
915 
916 	error = show_diff_view(obj1, obj2, repo);
917 done:
918 	got_repo_close(repo);
919 	if (obj1)
920 		got_object_close(obj1);
921 	if (obj2)
922 		got_object_close(obj2);
923 	return error;
924 }
925 
926 __dead void
927 usage_blame(void)
928 {
929 	endwin();
930 	fprintf(stderr, "usage: %s blame [repository-path] blob-object\n",
931 	    getprogname());
932 	exit(1);
933 }
934 
935 const struct got_error *
936 cmd_blame(int argc, char *argv[])
937 {
938 	return got_error(GOT_ERR_NOT_IMPL);
939 }
940 
941 static void
942 init_curses(void)
943 {
944 	initscr();
945 	cbreak();
946 	noecho();
947 	nonl();
948 	intrflush(stdscr, FALSE);
949 	keypad(stdscr, TRUE);
950 	curs_set(0);
951 }
952 
953 __dead void
954 usage(void)
955 {
956 	int i;
957 
958 	fprintf(stderr, "usage: %s [-h] [command] [arg ...]\n\n"
959 	    "Available commands:\n", getprogname());
960 	for (i = 0; i < nitems(tog_commands); i++) {
961 		struct tog_cmd *cmd = &tog_commands[i];
962 		fprintf(stderr, "    %s: %s\n", cmd->name, cmd->descr);
963 	}
964 	exit(1);
965 }
966 
967 static char **
968 make_argv(const char *arg0, const char *arg1)
969 {
970 	char **argv;
971 	int argc = (arg1 == NULL ? 1 : 2);
972 
973 	argv = calloc(argc, sizeof(char *));
974 	if (argv == NULL)
975 		err(1, "calloc");
976 	argv[0] = strdup(arg0);
977 	if (argv[0] == NULL)
978 		err(1, "calloc");
979 	if (arg1) {
980 		argv[1] = strdup(arg1);
981 		if (argv[1] == NULL)
982 			err(1, "calloc");
983 	}
984 
985 	return argv;
986 }
987 
988 int
989 main(int argc, char *argv[])
990 {
991 	const struct got_error *error = NULL;
992 	struct tog_cmd *cmd = NULL;
993 	int ch, hflag = 0;
994 	char **cmd_argv = NULL;
995 
996 	setlocale(LC_ALL, "");
997 
998 	while ((ch = getopt(argc, argv, "h")) != -1) {
999 		switch (ch) {
1000 		case 'h':
1001 			hflag = 1;
1002 			break;
1003 		default:
1004 			usage();
1005 			/* NOTREACHED */
1006 		}
1007 	}
1008 
1009 	argc -= optind;
1010 	argv += optind;
1011 	optind = 0;
1012 	optreset = 1;
1013 
1014 	if (argc == 0) {
1015 		/* Build an argument vector which runs a default command. */
1016 		cmd = &tog_commands[0];
1017 		cmd_argv = make_argv(cmd->name, NULL);
1018 		argc = 1;
1019 	} else {
1020 		int i;
1021 
1022 		/* Did the user specific a command? */
1023 		for (i = 0; i < nitems(tog_commands); i++) {
1024 			if (strncmp(tog_commands[i].name, argv[0],
1025 			    strlen(argv[0])) == 0) {
1026 				cmd = &tog_commands[i];
1027 				if (hflag)
1028 					tog_commands[i].cmd_usage();
1029 				break;
1030 			}
1031 		}
1032 		if (cmd == NULL) {
1033 			/* Did the user specify a repository? */
1034 			char *repo_path = realpath(argv[0], NULL);
1035 			if (repo_path) {
1036 				struct got_repository *repo;
1037 				error = got_repo_open(&repo, repo_path);
1038 				if (error == NULL)
1039 					got_repo_close(repo);
1040 			} else
1041 				error = got_error_from_errno();
1042 			if (error) {
1043 				fprintf(stderr, "%s: '%s' is neither a known "
1044 				    "command nor a path to a repository\n",
1045 				    getprogname(), argv[0]);
1046 				free(repo_path);
1047 				return 1;
1048 			}
1049 			cmd = &tog_commands[0];
1050 			cmd_argv = make_argv(cmd->name, repo_path);
1051 			argc = 2;
1052 			free(repo_path);
1053 		}
1054 	}
1055 
1056 	init_curses();
1057 
1058 	error = cmd->cmd_main(argc, cmd_argv ? cmd_argv : argv);
1059 	if (error)
1060 		goto done;
1061 done:
1062 	endwin();
1063 	free(cmd_argv);
1064 	if (error)
1065 		fprintf(stderr, "%s: %s\n", getprogname(), error->msg);
1066 	return 0;
1067 }