#include "git2/ignore.h"

#include "common.h"

#include "ignore.h"

#include "attrcache.h"

#include "path.h"

#include "config.h"

#include "fnmatch.h"

#define GIT_IGNORE_INTERNAL		"[internal]exclude"

#define GIT_IGNORE_DEFAULT_RULES ".\n..\n.git\n"

/**

 * A negative ignore pattern can negate a positive one without

 * wildcards if it is a basename only and equals the basename of

 * the positive pattern. Thus

 *

 * foo/bar

 * !bar

 *

 * would result in foo/bar being unignored again while

 *

 * moo/foo/bar

 * !foo/bar

 *

 * would do nothing. The reverse also holds true: a positive

 * basename pattern can be negated by unignoring the basename in

 * subdirectories. Thus

 *

 * bar

 * !foo/bar

 *

 * would result in foo/bar being unignored again. As with the

 * first case,

 *

 * foo/bar

 * !moo/foo/bar

 *

 * would do nothing, again.

 */

static int does_negate_pattern(git_attr_fnmatch *rule, git_attr_fnmatch *neg)

{

	int (*cmp)(const char *, const char *, size_t);

	git_attr_fnmatch *longer, *shorter;

	char *p;

	if ((rule->flags & GIT_ATTR_FNMATCH_NEGATIVE) != 0

	    || (neg->flags & GIT_ATTR_FNMATCH_NEGATIVE) == 0)

		return false;

	if (neg->flags & GIT_ATTR_FNMATCH_ICASE)

		cmp = git__strncasecmp;

	else

		cmp = git__strncmp;

	/* If lengths match we need to have an exact match */

	if (rule->length == neg->length) {

		return cmp(rule->pattern, neg->pattern, rule->length) == 0;

	} else if (rule->length < neg->length) {

		shorter = rule;

		longer = neg;

	} else {

		shorter = neg;

		longer = rule;

	}

	/* Otherwise, we need to check if the shorter

	 * rule is a basename only (that is, it contains

	 * no path separator) and, if so, if it

	 * matches the tail of the longer rule */

	p = longer->pattern + longer->length - shorter->length;

	if (p[-1] != '/')

		return false;

	if (memchr(shorter->pattern, '/', shorter->length) != NULL)

		return false;

	return cmp(p, shorter->pattern, shorter->length) == 0;

}

/**

 * A negative ignore can only unignore a file which is given explicitly before, thus

 *

 *    foo

 *    !foo/bar

 *

 * does not unignore 'foo/bar' as it's not in the list. However

 *

 *    foo/<star>

 *    !foo/bar

 *

 * does unignore 'foo/bar', as it is contained within the 'foo/<star>' rule.

 */

static int does_negate_rule(int *out, git_vector *rules, git_attr_fnmatch *match)

{

	int error = 0, fnflags;

	size_t i;

	git_attr_fnmatch *rule;

	char *path;

	git_buf buf = GIT_BUF_INIT;

	*out = 0;

	fnflags = FNM_PATHNAME;

	if (match->flags & GIT_ATTR_FNMATCH_ICASE)

		fnflags |= FNM_IGNORECASE;

	/* path of the file relative to the workdir, so we match the rules in subdirs */

	if (match->containing_dir) {

		git_buf_puts(&buf, match->containing_dir);

	}

	if (git_buf_puts(&buf, match->pattern) < 0)

		return -1;

	path = git_buf_detach(&buf;;

	git_vector_foreach(rules, i, rule) {

		if (!(rule->flags & GIT_ATTR_FNMATCH_HASWILD)) {

			if (does_negate_pattern(rule, match)) {

				error = 0;

				*out = 1;

				goto out;

			}

			else

				continue;

		}

		/*

		 * When dealing with a directory, we add '/<star>' so

		 * p_fnmatch() honours FNM_PATHNAME. Checking for LEADINGDIR

		 * alone isn't enough as that's also set for nagations, so we

		 * need to check that NEGATIVE is off.

		 */

		git_buf_clear(&buf;;

		if (rule->containing_dir) {

			git_buf_puts(&buf, rule->containing_dir);

		}

		error = git_buf_puts(&buf, rule->pattern);

		if ((rule->flags & (GIT_ATTR_FNMATCH_LEADINGDIR | GIT_ATTR_FNMATCH_NEGATIVE)) == GIT_ATTR_FNMATCH_LEADINGDIR)

			error = git_buf_PUTS(&buf, "/*");

		if (error < 0)

			goto out;

		if ((error = p_fnmatch(git_buf_cstr(&buf), path, fnflags)) < 0) {

			giterr_set(GITERR_INVALID, "error matching pattern");

			goto out;

		}

		/* if we found a match, we want to keep this rule */

		if (error != FNM_NOMATCH) {

			*out = 1;

			error = 0;

			goto out;

		}

	}

	error = 0;

out:

	git__free(path);

	git_buf_free(&buf;;

	return error;

}

static int parse_ignore_file(

	git_repository *repo, git_attr_file *attrs, const char *data)

{

	int error = 0;

	int ignore_case = false;

	const char *scan = data, *context = NULL;

	git_attr_fnmatch *match = NULL;

	if (git_repository__cvar(&ignore_case, repo, GIT_CVAR_IGNORECASE) < 0)

		giterr_clear();

	/* if subdir file path, convert context for file paths */

	if (attrs->entry &&

		git_path_root(attrs->entry->path) < 0 &&

		!git__suffixcmp(attrs->entry->path, "/" GIT_IGNORE_FILE))

		context = attrs->entry->path;

	if (git_mutex_lock(&attrs->lock) < 0) {

		giterr_set(GITERR_OS, "failed to lock ignore file");

		return -1;

	}

	while (!error && *scan) {

		int valid_rule = 1;

		if (!match && !(match = git__calloc(1, sizeof(*match)))) {

			error = -1;

			break;

		}

		match->flags = GIT_ATTR_FNMATCH_ALLOWSPACE | GIT_ATTR_FNMATCH_ALLOWNEG;

		if (!(error = git_attr_fnmatch__parse(

			match, &attrs->pool, context, &scan)))

		{

			match->flags |= GIT_ATTR_FNMATCH_IGNORE;

			if (ignore_case)

				match->flags |= GIT_ATTR_FNMATCH_ICASE;

			while (match->length > 0) {

				if (match->pattern[match->length - 1] == ' ' ||

				    match->pattern[match->length - 1] == '\t') {

					match->pattern[match->length - 1] = 0;

					match->length --;

				} else {

					break;

				}

			}

			scan = git__next_line(scan);

			/*

			 * If a negative match doesn't actually do anything,

			 * throw it away. As we cannot always verify whether a

			 * rule containing wildcards negates another rule, we

			 * do not optimize away these rules, though.

			 * */

			if (match->flags & GIT_ATTR_FNMATCH_NEGATIVE

			    && !(match->flags & GIT_ATTR_FNMATCH_HASWILD))

				error = does_negate_rule(&valid_rule, &attrs->rules, match);

			if (!error && valid_rule)

				error = git_vector_insert(&attrs->rules, match);

		}

		if (error != 0 || !valid_rule) {

			match->pattern = NULL;

			if (error == GIT_ENOTFOUND)

				error = 0;

		} else {

			match = NULL; /* vector now "owns" the match */

		}

	}

	git_mutex_unlock(&attrs->lock);

	git__free(match);

	return error;

}

static int push_ignore_file(

	git_ignores *ignores,

	git_vector *which_list,

	const char *base,

	const char *filename)

{

	int error = 0;

	git_attr_file *file = NULL;

	error = git_attr_cache__get(

		&file, ignores->repo, NULL, GIT_ATTR_FILE__FROM_FILE,

		base, filename, parse_ignore_file);

	if (error < 0)

		return error;

	if (file != NULL) {

		if ((error = git_vector_insert(which_list, file)) < 0)

			git_attr_file__free(file);

	}

	return error;

}

static int push_one_ignore(void *payload, const char *path)

{

	git_ignores *ign = payload;

	ign->depth++;

	return push_ignore_file(ign, &ign->ign_path, path, GIT_IGNORE_FILE);

}

static int get_internal_ignores(git_attr_file **out, git_repository *repo)

{

	int error;

	if ((error = git_attr_cache__init(repo)) < 0)

		return error;

	error = git_attr_cache__get(

		out, repo, NULL, GIT_ATTR_FILE__IN_MEMORY, NULL, GIT_IGNORE_INTERNAL, NULL);

	/* if internal rules list is empty, insert default rules */

	if (!error && !(*out)->rules.length)

		error = parse_ignore_file(repo, *out, GIT_IGNORE_DEFAULT_RULES);

	return error;

}

int git_ignore__for_path(

	git_repository *repo,

	const char *path,

	git_ignores *ignores)

{

	int error = 0;

	const char *workdir = git_repository_workdir(repo);

	git_buf infopath = GIT_BUF_INIT;

	assert(repo && ignores && path);

	memset(ignores, 0, sizeof(*ignores));

	ignores->repo = repo;

	/* Read the ignore_case flag */

	if ((error = git_repository__cvar(

			&ignores->ignore_case, repo, GIT_CVAR_IGNORECASE)) < 0)

		goto cleanup;

	if ((error = git_attr_cache__init(repo)) < 0)

		goto cleanup;

	/* given a unrooted path in a non-bare repo, resolve it */

	if (workdir && git_path_root(path) < 0) {

		git_buf local = GIT_BUF_INIT;

		if ((error = git_path_dirname_r(&local, path)) < 0 ||

		    (error = git_path_resolve_relative(&local, 0)) < 0 ||

		    (error = git_path_to_dir(&local)) < 0 ||

		    (error = git_buf_joinpath(&ignores->dir, workdir, local.ptr)) < 0)

		{;} /* Nothing, we just want to stop on the first error */

		git_buf_free(&local);

	} else {

		error = git_buf_joinpath(&ignores->dir, path, "");

	}

	if (error < 0)

		goto cleanup;

	if (workdir && !git__prefixcmp(ignores->dir.ptr, workdir))

		ignores->dir_root = strlen(workdir);

	/* set up internals */

	if ((error = get_internal_ignores(&ignores->ign_internal, repo)) < 0)

		goto cleanup;

	/* load .gitignore up the path */

	if (workdir != NULL) {

		error = git_path_walk_up(

			&ignores->dir, workdir, push_one_ignore, ignores);

		if (error < 0)

			goto cleanup;

	}

	if ((error = git_repository_item_path(&infopath,

			repo, GIT_REPOSITORY_ITEM_INFO)) < 0)

		goto cleanup;

	/* load .git/info/exclude */

	error = push_ignore_file(

		ignores, &ignores->ign_global,

		infopath.ptr, GIT_IGNORE_FILE_INREPO);

	if (error < 0)

		goto cleanup;

	/* load core.excludesfile */

	if (git_repository_attr_cache(repo)->cfg_excl_file != NULL)

		error = push_ignore_file(

			ignores, &ignores->ign_global, NULL,

			git_repository_attr_cache(repo)->cfg_excl_file);

cleanup:

	git_buf_free(&infopath);

	if (error < 0)

		git_ignore__free(ignores);

	return error;

}

int git_ignore__push_dir(git_ignores *ign, const char *dir)

{

	if (git_buf_joinpath(&ign->dir, ign->dir.ptr, dir) < 0)

		return -1;

	ign->depth++;

	return push_ignore_file(

		ign, &ign->ign_path, ign->dir.ptr, GIT_IGNORE_FILE);

}

int git_ignore__pop_dir(git_ignores *ign)

{

	if (ign->ign_path.length > 0) {

		git_attr_file *file = git_vector_last(&ign->ign_path);

		const char *start = file->entry->path, *end;

		/* - ign->dir looks something like "/home/user/a/b/" (or "a/b/c/d/")

		 * - file->path looks something like "a/b/.gitignore

		 *

		 * We are popping the last directory off ign->dir.  We also want

		 * to remove the file from the vector if the popped directory

		 * matches the ignore path.  We need to test if the "a/b" part of

		 * the file key matches the path we are about to pop.

		 */

		if ((end = strrchr(start, '/')) != NULL) {

			size_t dirlen = (end - start) + 1;

			const char *relpath = ign->dir.ptr + ign->dir_root;

			size_t pathlen = ign->dir.size - ign->dir_root;

			if (pathlen == dirlen && !memcmp(relpath, start, dirlen)) {

				git_vector_pop(&ign->ign_path);

				git_attr_file__free(file);

			}

		}

	}

	if (--ign->depth > 0) {

		git_buf_rtruncate_at_char(&ign->dir, '/');

		git_path_to_dir(&ign->dir);

	}

	return 0;

}

void git_ignore__free(git_ignores *ignores)

{

	unsigned int i;

	git_attr_file *file;

	git_attr_file__free(ignores->ign_internal);

	git_vector_foreach(&ignores->ign_path, i, file) {

		git_attr_file__free(file);

		ignores->ign_path.contents[i] = NULL;

	}

	git_vector_free(&ignores->ign_path);

	git_vector_foreach(&ignores->ign_global, i, file) {

		git_attr_file__free(file);

		ignores->ign_global.contents[i] = NULL;

	}

	git_vector_free(&ignores->ign_global);

	git_buf_free(&ignores->dir);

}

static bool ignore_lookup_in_rules(

	int *ignored, git_attr_file *file, git_attr_path *path)

{

	size_t j;

	git_attr_fnmatch *match;

	git_vector_rforeach(&file->rules, j, match) {

		if (git_attr_fnmatch__match(match, path)) {

			*ignored = ((match->flags & GIT_ATTR_FNMATCH_NEGATIVE) == 0) ?

				GIT_IGNORE_TRUE : GIT_IGNORE_FALSE;

			return true;

		}

	}

	return false;

}

int git_ignore__lookup(

	int *out, git_ignores *ignores, const char *pathname, git_dir_flag dir_flag)

{

	unsigned int i;

	git_attr_file *file;

	git_attr_path path;

	*out = GIT_IGNORE_NOTFOUND;

	if (git_attr_path__init(

		&path, pathname, git_repository_workdir(ignores->repo), dir_flag) < 0)

		return -1;

	/* first process builtins - success means path was found */

	if (ignore_lookup_in_rules(out, ignores->ign_internal, &path))

		goto cleanup;

	/* next process files in the path */

	git_vector_foreach(&ignores->ign_path, i, file) {

		if (ignore_lookup_in_rules(out, file, &path))

			goto cleanup;

	}

	/* last process global ignores */

	git_vector_foreach(&ignores->ign_global, i, file) {

		if (ignore_lookup_in_rules(out, file, &path))

			goto cleanup;

	}

cleanup:

	git_attr_path__free(&path);

	return 0;

}

int git_ignore_add_rule(git_repository *repo, const char *rules)

{

	int error;

	git_attr_file *ign_internal = NULL;

	if ((error = get_internal_ignores(&ign_internal, repo)) < 0)

		return error;

	error = parse_ignore_file(repo, ign_internal, rules);

	git_attr_file__free(ign_internal);

	return error;

}

int git_ignore_clear_internal_rules(git_repository *repo)

{

	int error;

	git_attr_file *ign_internal;

	if ((error = get_internal_ignores(&ign_internal, repo)) < 0)

		return error;

	if (!(error = git_attr_file__clear_rules(ign_internal, true)))

		error = parse_ignore_file(

			repo, ign_internal, GIT_IGNORE_DEFAULT_RULES);

	git_attr_file__free(ign_internal);

	return error;

}

int git_ignore_path_is_ignored(

	int *ignored,

	git_repository *repo,

	const char *pathname)

{

	int error;

	const char *workdir;

	git_attr_path path;

	git_ignores ignores;

	unsigned int i;

	git_attr_file *file;

	assert(repo && ignored && pathname);

	workdir = git_repository_workdir(repo);

	memset(&path, 0, sizeof(path));

	memset(&ignores, 0, sizeof(ignores));

	if ((error = git_attr_path__init(&path, pathname, workdir, GIT_DIR_FLAG_UNKNOWN)) < 0 ||

		(error = git_ignore__for_path(repo, path.path, &ignores)) < 0)

		goto cleanup;

	while (1) {

		/* first process builtins - success means path was found */

		if (ignore_lookup_in_rules(ignored, ignores.ign_internal, &path))

			goto cleanup;

		/* next process files in the path */

		git_vector_foreach(&ignores.ign_path, i, file) {

			if (ignore_lookup_in_rules(ignored, file, &path))

				goto cleanup;

		}

		/* last process global ignores */

		git_vector_foreach(&ignores.ign_global, i, file) {

			if (ignore_lookup_in_rules(ignored, file, &path))

				goto cleanup;

		}

		/* move up one directory */

		if (path.basename == path.path)

			break;

		path.basename[-1] = '\0';

		while (path.basename > path.path && *path.basename != '/')

			path.basename--;

		if (path.basename > path.path)

			path.basename++;

		path.is_dir = 1;

		if ((error = git_ignore__pop_dir(&ignores)) < 0)

			break;

	}

	*ignored = 0;

cleanup:

	git_attr_path__free(&path);

	git_ignore__free(&ignores);

	return error;

}

int git_ignore__check_pathspec_for_exact_ignores(

	git_repository *repo,

	git_vector *vspec,

	bool no_fnmatch)

{

	int error = 0;

	size_t i;

	git_attr_fnmatch *match;

	int ignored;

	git_buf path = GIT_BUF_INIT;

	const char *wd, *filename;

	git_index *idx;

	if ((error = git_repository__ensure_not_bare(

			repo, "validate pathspec")) < 0 ||

		(error = git_repository_index(&idx, repo)) < 0)

		return error;

	wd = git_repository_workdir(repo);

	git_vector_foreach(vspec, i, match) {

		/* skip wildcard matches (if they are being used) */

		if ((match->flags & GIT_ATTR_FNMATCH_HASWILD) != 0 &&

			!no_fnmatch)

			continue;

		filename = match->pattern;

		/* if file is already in the index, it's fine */

		if (git_index_get_bypath(idx, filename, 0) != NULL)

			continue;

		if ((error = git_buf_joinpath(&path, wd, filename)) < 0)

			break;

		/* is there a file on disk that matches this exactly? */

		if (!git_path_isfile(path.ptr))

			continue;

		/* is that file ignored? */

		if ((error = git_ignore_path_is_ignored(&ignored, repo, filename)) < 0)

			break;

		if (ignored) {

			giterr_set(GITERR_INVALID, "pathspec contains ignored file '%s'",

				filename);

			error = GIT_EINVALIDSPEC;

			break;

		}

	}

	git_index_free(idx);

	git_buf_free(&path);

	return error;

}