/*
 * "git rm" builtin command
 *
 * Copyright (C) Linus Torvalds 2006
 */
#include "cache.h"
#include "builtin.h"
#include "dir.h"
#include "cache-tree.h"
#include "tree-walk.h"
#include "parse-options.h"
#include "string-list.h"
#include "submodule.h"

static const char * const builtin_rm_usage[] = {
        N_("git rm [options] [--] <file>..."),
        NULL
};

static struct {
        int nr, alloc;
        struct {
                const char *name;
                char is_submodule;
        } *entry;
} list;

static int get_ours_cache_pos(const char *path, int pos)
{
        int i = -pos - 1;

        while ((i < active_nr) && !strcmp(active_cache[i]->name, path)) {
                if (ce_stage(active_cache[i]) == 2)
                        return i;
                i++;
        }
        return -1;
}

static void print_error_files(struct string_list *files_list,
                              const char *main_msg,
                              const char *hints_msg,
                              int *errs)
{
        if (files_list->nr) {
                int i;
                struct strbuf err_msg = STRBUF_INIT;

                strbuf_addstr(&err_msg, main_msg);
                for (i = 0; i < files_list->nr; i++)
                        strbuf_addf(&err_msg,
                                    "\n    %s",
                                    files_list->items[i].string);
                if (advice_rm_hints)
                        strbuf_addstr(&err_msg, hints_msg);
                *errs = error("%s", err_msg.buf);
                strbuf_release(&err_msg);
        }
}

static void error_removing_concrete_submodules(struct string_list *files, int *errs)
{
        print_error_files(files,
                          Q_("the following submodule (or one of its nested "
                             "submodules)\n"
                             "uses a .git directory:",
                             "the following submodules (or one of its nested "
                             "submodules)\n"
                             "use a .git directory:", files->nr),
                          _("\n(use 'rm -rf' if you really want to remove "
                            "it including all of its history)"),
                          errs);
        string_list_clear(files, 0);
}

static int check_submodules_use_gitfiles(void)
{
        int i;
        int errs = 0;
        struct string_list files = STRING_LIST_INIT_NODUP;

        for (i = 0; i < list.nr; i++) {
                const char *name = list.entry[i].name;
                int pos;
                const struct cache_entry *ce;
                struct stat st;

                pos = cache_name_pos(name, strlen(name));
                if (pos < 0) {
                        pos = get_ours_cache_pos(name, pos);
                        if (pos < 0)
                                continue;
                }
                ce = active_cache[pos];

                if (!S_ISGITLINK(ce->ce_mode) ||
                    (lstat(ce->name, &st) < 0) ||
                    is_empty_dir(name))
                        continue;

                if (!submodule_uses_gitfile(name))
                        string_list_append(&files, name);
        }

        error_removing_concrete_submodules(&files, &errs);

        return errs;
}

static int check_local_mod(unsigned char *head, int index_only)
{
        /*
         * Items in list are already sorted in the cache order,
         * so we could do this a lot more efficiently by using
         * tree_desc based traversal if we wanted to, but I am
         * lazy, and who cares if removal of files is a tad
         * slower than the theoretical maximum speed?
         */
        int i, no_head;
        int errs = 0;
        struct string_list files_staged = STRING_LIST_INIT_NODUP;
        struct string_list files_cached = STRING_LIST_INIT_NODUP;
        struct string_list files_submodule = STRING_LIST_INIT_NODUP;
        struct string_list files_local = STRING_LIST_INIT_NODUP;

        no_head = is_null_sha1(head);
        for (i = 0; i < list.nr; i++) {
                struct stat st;
                int pos;
                const struct cache_entry *ce;
                const char *name = list.entry[i].name;
                unsigned char sha1[20];
                unsigned mode;
                int local_changes = 0;
                int staged_changes = 0;

                pos = cache_name_pos(name, strlen(name));
                if (pos < 0) {
                        /*
                         * Skip unmerged entries except for populated submodules
                         * that could lose history when removed.
                         */
                        pos = get_ours_cache_pos(name, pos);
                        if (pos < 0)
                                continue;

                        if (!S_ISGITLINK(active_cache[pos]->ce_mode) ||
                            is_empty_dir(name))
                                continue;
                }
                ce = active_cache[pos];

                if (lstat(ce->name, &st) < 0) {
                        if (errno != ENOENT && errno != ENOTDIR)
                                warning("'%s': %s", ce->name, strerror(errno));
                        /* It already vanished from the working tree */
                        continue;
                }
                else if (S_ISDIR(st.st_mode)) {
                        /* if a file was removed and it is now a
                         * directory, that is the same as ENOENT as
                         * far as git is concerned; we do not track
                         * directories unless they are submodules.
                         */
                        if (!S_ISGITLINK(ce->ce_mode))
                                continue;
                }

                /*
                 * "rm" of a path that has changes need to be treated
                 * carefully not to allow losing local changes
                 * accidentally.  A local change could be (1) file in
                 * work tree is different since the index; and/or (2)
                 * the user staged a content that is different from
                 * the current commit in the index.
                 *
                 * In such a case, you would need to --force the
                 * removal.  However, "rm --cached" (remove only from
                 * the index) is safe if the index matches the file in
                 * the work tree or the HEAD commit, as it means that
                 * the content being removed is available elsewhere.
                 */

                /*
                 * Is the index different from the file in the work tree?
                 * If it's a submodule, is its work tree modified?
                 */
                if (ce_match_stat(ce, &st, 0) ||
                    (S_ISGITLINK(ce->ce_mode) &&
                     !ok_to_remove_submodule(ce->name)))
                        local_changes = 1;

                /*
                 * Is the index different from the HEAD commit?  By
                 * definition, before the very initial commit,
                 * anything staged in the index is treated by the same
                 * way as changed from the HEAD.
                 */
                if (no_head
                     || get_tree_entry(head, name, sha1, &mode)
                     || ce->ce_mode != create_ce_mode(mode)
                     || hashcmp(ce->sha1, sha1))
                        staged_changes = 1;

                /*
                 * If the index does not match the file in the work
                 * tree and if it does not match the HEAD commit
                 * either, (1) "git rm" without --cached definitely
                 * will lose information; (2) "git rm --cached" will
                 * lose information unless it is about removing an
                 * "intent to add" entry.
                 */
                if (local_changes && staged_changes) {
                        if (!index_only || !(ce->ce_flags & CE_INTENT_TO_ADD))
                                string_list_append(&files_staged, name);
                }
                else if (!index_only) {
                        if (staged_changes)
                                string_list_append(&files_cached, name);
                        if (local_changes) {
                                if (S_ISGITLINK(ce->ce_mode) &&
                                    !submodule_uses_gitfile(name))
                                        string_list_append(&files_submodule, name);
                                else
                                        string_list_append(&files_local, name);
                        }
                }
        }
        print_error_files(&files_staged,
                          Q_("the following file has staged content different "
                             "from both the\nfile and the HEAD:",
                             "the following files have staged content different"
                             " from both the\nfile and the HEAD:",
                             files_staged.nr),
                          _("\n(use -f to force removal)"),
                          &errs);
        string_list_clear(&files_staged, 0);
        print_error_files(&files_cached,
                          Q_("the following file has changes "
                             "staged in the index:",
                             "the following files have changes "
                             "staged in the index:", files_cached.nr),
                          _("\n(use --cached to keep the file,"
                            " or -f to force removal)"),
                          &errs);
        string_list_clear(&files_cached, 0);

        error_removing_concrete_submodules(&files_submodule, &errs);

        print_error_files(&files_local,
                          Q_("the following file has local modifications:",
                             "the following files have local modifications:",
                             files_local.nr),
                          _("\n(use --cached to keep the file,"
                            " or -f to force removal)"),
                          &errs);
        string_list_clear(&files_local, 0);

        return errs;
}

static struct lock_file lock_file;

static int show_only = 0, force = 0, index_only = 0, recursive = 0, quiet = 0;
static int ignore_unmatch = 0;

static struct option builtin_rm_options[] = {
        OPT__DRY_RUN(&show_only, N_("dry run")),
        OPT__QUIET(&quiet, N_("do not list removed files")),
        OPT_BOOLEAN( 0 , "cached",         &index_only, N_("only remove from the index")),
        OPT__FORCE(&force, N_("override the up-to-date check")),
        OPT_BOOLEAN('r', NULL,             &recursive,  N_("allow recursive removal")),
        OPT_BOOLEAN( 0 , "ignore-unmatch", &ignore_unmatch,
                                N_("exit with a zero status even if nothing matched")),
        OPT_END(),
};

int cmd_rm(int argc, const char **argv, const char *prefix)
{
        int i, newfd;
        const char **pathspec;
        char *seen;

        git_config(git_default_config, NULL);

        argc = parse_options(argc, argv, prefix, builtin_rm_options,
                             builtin_rm_usage, 0);
        if (!argc)
                usage_with_options(builtin_rm_usage, builtin_rm_options);

        if (!index_only)
                setup_work_tree();

        newfd = hold_locked_index(&lock_file, 1);

        if (read_cache() < 0)
                die(_("index file corrupt"));

        /*
         * Drop trailing directory separators from directories so we'll find
         * submodules in the index.
         */
        for (i = 0; i < argc; i++) {
                size_t pathlen = strlen(argv[i]);
                if (pathlen && is_dir_sep(argv[i][pathlen - 1]) &&
                    is_directory(argv[i])) {
                        do {
                                pathlen--;
                        } while (pathlen && is_dir_sep(argv[i][pathlen - 1]));
                        argv[i] = xmemdupz(argv[i], pathlen);
                }
        }

        pathspec = get_pathspec(prefix, argv);
        refresh_index(&the_index, REFRESH_QUIET, pathspec, NULL, NULL);

        seen = NULL;
        for (i = 0; pathspec[i] ; i++)
                /* nothing */;
        seen = xcalloc(i, 1);

        for (i = 0; i < active_nr; i++) {
                const struct cache_entry *ce = active_cache[i];
                if (!match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, seen))
                        continue;
                ALLOC_GROW(list.entry, list.nr + 1, list.alloc);
                list.entry[list.nr].name = ce->name;
                list.entry[list.nr++].is_submodule = S_ISGITLINK(ce->ce_mode);
        }

        if (pathspec) {
                const char *match;
                int seen_any = 0;
                for (i = 0; (match = pathspec[i]) != NULL ; i++) {
                        if (!seen[i]) {
                                if (!ignore_unmatch) {
                                        die(_("pathspec '%s' did not match any files"),
                                            match);
                                }
                        }
                        else {
                                seen_any = 1;
                        }
                        if (!recursive && seen[i] == MATCHED_RECURSIVELY)
                                die(_("not removing '%s' recursively without -r"),
                                    *match ? match : ".");
                }

                if (! seen_any)
                        exit(0);
        }

        /*
         * If not forced, the file, the index and the HEAD (if exists)
         * must match; but the file can already been removed, since
         * this sequence is a natural "novice" way:
         *
         *      rm F; git rm F
         *
         * Further, if HEAD commit exists, "diff-index --cached" must
         * report no changes unless forced.
         */
        if (!force) {
                unsigned char sha1[20];
                if (get_sha1("HEAD", sha1))
                        hashclr(sha1);
                if (check_local_mod(sha1, index_only))
                        exit(1);
        } else if (!index_only) {
                if (check_submodules_use_gitfiles())
                        exit(1);
        }

        /*
         * First remove the names from the index: we won't commit
         * the index unless all of them succeed.
         */
        for (i = 0; i < list.nr; i++) {
                const char *path = list.entry[i].name;
                if (!quiet)
                        printf("rm '%s'\n", path);

                if (remove_file_from_cache(path))
                        die(_("git rm: unable to remove %s"), path);
        }

        if (show_only)
                return 0;

        /*
         * Then, unless we used "--cached", remove the filenames from
         * the workspace. If we fail to remove the first one, we
         * abort the "git rm" (but once we've successfully removed
         * any file at all, we'll go ahead and commit to it all:
         * by then we've already committed ourselves and can't fail
         * in the middle)
         */
        if (!index_only) {
                int removed = 0;
                for (i = 0; i < list.nr; i++) {
                        const char *path = list.entry[i].name;
                        if (list.entry[i].is_submodule) {
                                if (is_empty_dir(path)) {
                                        if (!rmdir(path)) {
                                                removed = 1;
                                                continue;
                                        }
                                } else {
                                        struct strbuf buf = STRBUF_INIT;
                                        strbuf_addstr(&buf, path);
                                        if (!remove_dir_recursively(&buf, 0)) {
                                                removed = 1;
                                                strbuf_release(&buf);
                                                continue;
                                        }
                                        strbuf_release(&buf);
                                        /* Fallthrough and let remove_path() fail. */
                                }
                        }
                        if (!remove_path(path)) {
                                removed = 1;
                                continue;
                        }
                        if (!removed)
                                die_errno("git rm: '%s'", path);
                }
        }

        if (active_cache_changed) {
                if (write_cache(newfd, active_cache, active_nr) ||
                    commit_locked_index(&lock_file))
                        die(_("Unable to write new index file"));
        }

        return 0;
}