/*
 * "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"

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

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

static void add_list(const char *name)
{
        if (list.nr >= list.alloc) {
                list.alloc = alloc_nr(list.alloc);
                list.name = xrealloc(list.name, list.alloc * sizeof(const char *));
        }
        list.name[list.nr++] = name;
}

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;

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

                pos = cache_name_pos(name, strlen(name));
                if (pos < 0)
                        continue; /* removing unmerged entry */
                ce = active_cache[pos];

                if (lstat(ce->name, &st) < 0) {
                        if (errno != ENOENT)
                                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.
                         */
                        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 (ce_match_stat(ce, &st, 0))
                        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))
                                errs = error("'%s' has staged content different "
                                             "from both the file and the HEAD\n"
                                             "(use -f to force removal)", name);
                }
                else if (!index_only) {
                        if (staged_changes)
                                errs = error("'%s' has changes staged in the index\n"
                                             "(use --cached to keep the file, "
                                             "or -f to force removal)", name);
                        if (local_changes)
                                errs = error("'%s' has local modifications\n"
                                             "(use --cached to keep the file, "
                                             "or -f to force removal)", name);
                }
        }
        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),
        OPT__QUIET(&quiet),
        OPT_BOOLEAN( 0 , "cached",         &index_only, "only remove from the index"),
        OPT_BOOLEAN('f', "force",          &force,      "override the up-to-date check"),
        OPT_BOOLEAN('r', NULL,             &recursive,  "allow recursive removal"),
        OPT_BOOLEAN( 0 , "ignore-unmatch", &ignore_unmatch,
                                "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, 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");
        refresh_cache(REFRESH_QUIET);

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

        for (i = 0; i < active_nr; i++) {
                struct cache_entry *ce = active_cache[i];
                if (!match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, seen))
                        continue;
                add_list(ce->name);
        }

        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);
        }

        /*
         * 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.name[i];
                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.name[i];
                        if (!remove_path(path)) {
                                removed = 1;
                                continue;
                        }
                        if (!removed)
                                die("git rm: %s: %s", path, strerror(errno));
                }
        }

        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;
}