/*
 * "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"

static const char builtin_rm_usage[] =
"git-rm [-n] [-f] [--cached] <filepattern>...";

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 remove_file(const char *name)
{
        int ret;
        char *slash;

        ret = unlink(name);
        if (ret && errno == ENOENT)
                /* The user has removed it from the filesystem by hand */
                ret = errno = 0;

        if (!ret && (slash = strrchr(name, '/'))) {
                char *n = xstrdup(name);
                do {
                        n[slash - name] = 0;
                        name = n;
                } while (!rmdir(name) && (slash = strrchr(name, '/')));
        }
        return ret;
}

static int check_local_mod(unsigned char *head)
{
        /* 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;

                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)
                                fprintf(stderr, "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;
                }
                if (ce_match_stat(ce, &st, 0))
                        errs = error("'%s' has local modifications "
                                     "(hint: try -f)", ce->name);
                if (no_head)
                        continue;
                /*
                 * It is Ok to remove a newly added path, as long as
                 * it is cache-clean.
                 */
                if (get_tree_entry(head, name, sha1, &mode))
                        continue;
                /*
                 * Otherwise make sure the version from the HEAD
                 * matches the index.
                 */
                if (ce->ce_mode != create_ce_mode(mode) ||
                    hashcmp(ce->sha1, sha1))
                        errs = error("'%s' has changes staged in the index "
                                     "(hint: try -f)", name);
        }
        return errs;
}

static struct lock_file lock_file;

int cmd_rm(int argc, const char **argv, const char *prefix)
{
        int i, newfd;
        int show_only = 0, force = 0, index_only = 0, recursive = 0;
        const char **pathspec;
        char *seen;

        git_config(git_default_config);

        newfd = hold_lock_file_for_update(&lock_file, get_index_file(), 1);

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

        for (i = 1 ; i < argc ; i++) {
                const char *arg = argv[i];

                if (*arg != '-')
                        break;
                else if (!strcmp(arg, "--")) {
                        i++;
                        break;
                }
                else if (!strcmp(arg, "-n"))
                        show_only = 1;
                else if (!strcmp(arg, "--cached"))
                        index_only = 1;
                else if (!strcmp(arg, "-f"))
                        force = 1;
                else if (!strcmp(arg, "-r"))
                        recursive = 1;
                else
                        usage(builtin_rm_usage);
        }
        if (argc <= i)
                usage(builtin_rm_usage);

        pathspec = get_pathspec(prefix, argv + i);
        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;
                for (i = 0; (match = pathspec[i]) != NULL ; i++) {
                        if (!seen[i])
                                die("pathspec '%s' did not match any files",
                                    match);
                        if (!recursive && seen[i] == MATCHED_RECURSIVELY)
                                die("not removing '%s' recursively without -r",
                                    *match ? match : ".");
                }
        }

        /*
         * 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 fm 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))
                        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];
                printf("rm '%s'\n", path);

                if (remove_file_from_cache(path))
                        die("git-rm: unable to remove %s", path);
                cache_tree_invalidate_path(active_cache_tree, 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_file(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) ||
                    close(newfd) || commit_lock_file(&lock_file))
                        die("Unable to write new index file");
        }

        return 0;
}