#include "cache.h"
#include "parse-options.h"
#include "transport.h"
#include "remote.h"
#include "string-list.h"
#include "strbuf.h"
#include "run-command.h"
#include "refs.h"

static const char * const builtin_remote_usage[] = {
        "git remote [-v | --verbose]",
        "git remote add [-t <branch>] [-m <master>] [-f] [--mirror] <name> <url>",
        "git remote rename <old> <new>",
        "git remote rm <name>",
        "git remote show [-n] <name>",
        "git remote prune [-n | --dry-run] <name>",
        "git remote [-v | --verbose] update [group]",
        NULL
};

static int verbose;

static int show_all(void);

static inline int postfixcmp(const char *string, const char *postfix)
{
        int len1 = strlen(string), len2 = strlen(postfix);
        if (len1 < len2)
                return 1;
        return strcmp(string + len1 - len2, postfix);
}

static int opt_parse_track(const struct option *opt, const char *arg, int not)
{
        struct string_list *list = opt->value;
        if (not)
                string_list_clear(list, 0);
        else
                string_list_append(arg, list);
        return 0;
}

static int fetch_remote(const char *name)
{
        const char *argv[] = { "fetch", name, NULL, NULL };
        if (verbose) {
                argv[1] = "-v";
                argv[2] = name;
        }
        printf("Updating %s\n", name);
        if (run_command_v_opt(argv, RUN_GIT_CMD))
                return error("Could not fetch %s", name);
        return 0;
}

static int add(int argc, const char **argv)
{
        int fetch = 0, mirror = 0;
        struct string_list track = { NULL, 0, 0 };
        const char *master = NULL;
        struct remote *remote;
        struct strbuf buf = STRBUF_INIT, buf2 = STRBUF_INIT;
        const char *name, *url;
        int i;

        struct option options[] = {
                OPT_GROUP("add specific options"),
                OPT_BOOLEAN('f', "fetch", &fetch, "fetch the remote branches"),
                OPT_CALLBACK('t', "track", &track, "branch",
                        "branch(es) to track", opt_parse_track),
                OPT_STRING('m', "master", &master, "branch", "master branch"),
                OPT_BOOLEAN(0, "mirror", &mirror, "no separate remotes"),
                OPT_END()
        };

        argc = parse_options(argc, argv, options, builtin_remote_usage, 0);

        if (argc < 2)
                usage_with_options(builtin_remote_usage, options);

        name = argv[0];
        url = argv[1];

        remote = remote_get(name);
        if (remote && (remote->url_nr > 1 || strcmp(name, remote->url[0]) ||
                        remote->fetch_refspec_nr))
                die("remote %s already exists.", name);

        strbuf_addf(&buf2, "refs/heads/test:refs/remotes/%s/test", name);
        if (!valid_fetch_refspec(buf2.buf))
                die("'%s' is not a valid remote name", name);

        strbuf_addf(&buf, "remote.%s.url", name);
        if (git_config_set(buf.buf, url))
                return 1;

        strbuf_reset(&buf);
        strbuf_addf(&buf, "remote.%s.fetch", name);

        if (track.nr == 0)
                string_list_append("*", &track);
        for (i = 0; i < track.nr; i++) {
                struct string_list_item *item = track.items + i;

                strbuf_reset(&buf2);
                strbuf_addch(&buf2, '+');
                if (mirror)
                        strbuf_addf(&buf2, "refs/%s:refs/%s",
                                        item->string, item->string);
                else
                        strbuf_addf(&buf2, "refs/heads/%s:refs/remotes/%s/%s",
                                        item->string, name, item->string);
                if (git_config_set_multivar(buf.buf, buf2.buf, "^$", 0))
                        return 1;
        }

        if (mirror) {
                strbuf_reset(&buf);
                strbuf_addf(&buf, "remote.%s.mirror", name);
                if (git_config_set(buf.buf, "true"))
                        return 1;
        }

        if (fetch && fetch_remote(name))
                return 1;

        if (master) {
                strbuf_reset(&buf);
                strbuf_addf(&buf, "refs/remotes/%s/HEAD", name);

                strbuf_reset(&buf2);
                strbuf_addf(&buf2, "refs/remotes/%s/%s", name, master);

                if (create_symref(buf.buf, buf2.buf, "remote add"))
                        return error("Could not setup master '%s'", master);
        }

        strbuf_release(&buf);
        strbuf_release(&buf2);
        string_list_clear(&track, 0);

        return 0;
}

struct branch_info {
        char *remote_name;
        struct string_list merge;
};

static struct string_list branch_list;

static const char *abbrev_ref(const char *name, const char *prefix)
{
        const char *abbrev = skip_prefix(name, prefix);
        if (abbrev)
                return abbrev;
        return name;
}
#define abbrev_branch(name) abbrev_ref((name), "refs/heads/")

static int config_read_branches(const char *key, const char *value, void *cb)
{
        if (!prefixcmp(key, "branch.")) {
                char *name;
                struct string_list_item *item;
                struct branch_info *info;
                enum { REMOTE, MERGE } type;

                key += 7;
                if (!postfixcmp(key, ".remote")) {
                        name = xstrndup(key, strlen(key) - 7);
                        type = REMOTE;
                } else if (!postfixcmp(key, ".merge")) {
                        name = xstrndup(key, strlen(key) - 6);
                        type = MERGE;
                } else
                        return 0;

                item = string_list_insert(name, &branch_list);

                if (!item->util)
                        item->util = xcalloc(sizeof(struct branch_info), 1);
                info = item->util;
                if (type == REMOTE) {
                        if (info->remote_name)
                                warning("more than one branch.%s", key);
                        info->remote_name = xstrdup(value);
                } else {
                        char *space = strchr(value, ' ');
                        value = abbrev_branch(value);
                        while (space) {
                                char *merge;
                                merge = xstrndup(value, space - value);
                                string_list_append(merge, &info->merge);
                                value = abbrev_branch(space + 1);
                                space = strchr(value, ' ');
                        }
                        string_list_append(xstrdup(value), &info->merge);
                }
        }
        return 0;
}

static void read_branches(void)
{
        if (branch_list.nr)
                return;
        git_config(config_read_branches, NULL);
}

struct ref_states {
        struct remote *remote;
        struct string_list new, stale, tracked;
};

static int handle_one_branch(const char *refname,
        const unsigned char *sha1, int flags, void *cb_data)
{
        struct ref_states *states = cb_data;
        struct refspec refspec;

        memset(&refspec, 0, sizeof(refspec));
        refspec.dst = (char *)refname;
        if (!remote_find_tracking(states->remote, &refspec)) {
                struct string_list_item *item;
                const char *name = abbrev_branch(refspec.src);
                /* symbolic refs pointing nowhere were handled already */
                if ((flags & REF_ISSYMREF) ||
                                unsorted_string_list_has_string(&states->tracked,
                                        name) ||
                                unsorted_string_list_has_string(&states->new,
                                        name))
                        return 0;
                item = string_list_append(name, &states->stale);
                item->util = xstrdup(refname);
        }
        return 0;
}

static int get_ref_states(const struct ref *remote_refs, struct ref_states *states)
{
        struct ref *fetch_map = NULL, **tail = &fetch_map;
        struct ref *ref;
        int i;

        for (i = 0; i < states->remote->fetch_refspec_nr; i++)
                if (get_fetch_map(remote_refs, states->remote->fetch + i, &tail, 1))
                        die("Could not get fetch map for refspec %s",
                                states->remote->fetch_refspec[i]);

        states->new.strdup_strings = states->tracked.strdup_strings = 1;
        for (ref = fetch_map; ref; ref = ref->next) {
                unsigned char sha1[20];
                if (!ref->peer_ref || read_ref(ref->peer_ref->name, sha1))
                        string_list_append(abbrev_branch(ref->name), &states->new);
                else
                        string_list_append(abbrev_branch(ref->name), &states->tracked);
        }
        free_refs(fetch_map);

        for_each_ref(handle_one_branch, states);
        sort_string_list(&states->stale);

        return 0;
}

struct known_remote {
        struct known_remote *next;
        struct remote *remote;
};

struct known_remotes {
        struct remote *to_delete;
        struct known_remote *list;
};

static int add_known_remote(struct remote *remote, void *cb_data)
{
        struct known_remotes *all = cb_data;
        struct known_remote *r;

        if (!strcmp(all->to_delete->name, remote->name))
                return 0;

        r = xmalloc(sizeof(*r));
        r->remote = remote;
        r->next = all->list;
        all->list = r;
        return 0;
}

struct branches_for_remote {
        struct remote *remote;
        struct string_list *branches, *skipped;
        struct known_remotes *keep;
};

static int add_branch_for_removal(const char *refname,
        const unsigned char *sha1, int flags, void *cb_data)
{
        struct branches_for_remote *branches = cb_data;
        struct refspec refspec;
        struct string_list_item *item;
        struct known_remote *kr;

        memset(&refspec, 0, sizeof(refspec));
        refspec.dst = (char *)refname;
        if (remote_find_tracking(branches->remote, &refspec))
                return 0;

        /* don't delete a branch if another remote also uses it */
        for (kr = branches->keep->list; kr; kr = kr->next) {
                memset(&refspec, 0, sizeof(refspec));
                refspec.dst = (char *)refname;
                if (!remote_find_tracking(kr->remote, &refspec))
                        return 0;
        }

        /* don't delete non-remote refs */
        if (prefixcmp(refname, "refs/remotes")) {
                /* advise user how to delete local branches */
                if (!prefixcmp(refname, "refs/heads/"))
                        string_list_append(abbrev_branch(refname),
                                           branches->skipped);
                /* silently skip over other non-remote refs */
                return 0;
        }

        /* make sure that symrefs are deleted */
        if (flags & REF_ISSYMREF)
                return unlink(git_path("%s", refname));

        item = string_list_append(refname, branches->branches);
        item->util = xmalloc(20);
        hashcpy(item->util, sha1);

        return 0;
}

struct rename_info {
        const char *old;
        const char *new;
        struct string_list *remote_branches;
};

static int read_remote_branches(const char *refname,
        const unsigned char *sha1, int flags, void *cb_data)
{
        struct rename_info *rename = cb_data;
        struct strbuf buf = STRBUF_INIT;
        struct string_list_item *item;
        int flag;
        unsigned char orig_sha1[20];
        const char *symref;

        strbuf_addf(&buf, "refs/remotes/%s", rename->old);
        if(!prefixcmp(refname, buf.buf)) {
                item = string_list_append(xstrdup(refname), rename->remote_branches);
                symref = resolve_ref(refname, orig_sha1, 1, &flag);
                if (flag & REF_ISSYMREF)
                        item->util = xstrdup(symref);
                else
                        item->util = NULL;
        }

        return 0;
}

static int migrate_file(struct remote *remote)
{
        struct strbuf buf = STRBUF_INIT;
        int i;
        char *path = NULL;

        strbuf_addf(&buf, "remote.%s.url", remote->name);
        for (i = 0; i < remote->url_nr; i++)
                if (git_config_set_multivar(buf.buf, remote->url[i], "^$", 0))
                        return error("Could not append '%s' to '%s'",
                                        remote->url[i], buf.buf);
        strbuf_reset(&buf);
        strbuf_addf(&buf, "remote.%s.push", remote->name);
        for (i = 0; i < remote->push_refspec_nr; i++)
                if (git_config_set_multivar(buf.buf, remote->push_refspec[i], "^$", 0))
                        return error("Could not append '%s' to '%s'",
                                        remote->push_refspec[i], buf.buf);
        strbuf_reset(&buf);
        strbuf_addf(&buf, "remote.%s.fetch", remote->name);
        for (i = 0; i < remote->fetch_refspec_nr; i++)
                if (git_config_set_multivar(buf.buf, remote->fetch_refspec[i], "^$", 0))
                        return error("Could not append '%s' to '%s'",
                                        remote->fetch_refspec[i], buf.buf);
        if (remote->origin == REMOTE_REMOTES)
                path = git_path("remotes/%s", remote->name);
        else if (remote->origin == REMOTE_BRANCHES)
                path = git_path("branches/%s", remote->name);
        if (path && unlink(path))
                warning("failed to remove '%s'", path);
        return 0;
}

static int mv(int argc, const char **argv)
{
        struct option options[] = {
                OPT_END()
        };
        struct remote *oldremote, *newremote;
        struct strbuf buf = STRBUF_INIT, buf2 = STRBUF_INIT, buf3 = STRBUF_INIT;
        struct string_list remote_branches = { NULL, 0, 0, 0 };
        struct rename_info rename;
        int i;

        if (argc != 3)
                usage_with_options(builtin_remote_usage, options);

        rename.old = argv[1];
        rename.new = argv[2];
        rename.remote_branches = &remote_branches;

        oldremote = remote_get(rename.old);
        if (!oldremote)
                die("No such remote: %s", rename.old);

        if (!strcmp(rename.old, rename.new) && oldremote->origin != REMOTE_CONFIG)
                return migrate_file(oldremote);

        newremote = remote_get(rename.new);
        if (newremote && (newremote->url_nr > 1 || newremote->fetch_refspec_nr))
                die("remote %s already exists.", rename.new);

        strbuf_addf(&buf, "refs/heads/test:refs/remotes/%s/test", rename.new);
        if (!valid_fetch_refspec(buf.buf))
                die("'%s' is not a valid remote name", rename.new);

        strbuf_reset(&buf);
        strbuf_addf(&buf, "remote.%s", rename.old);
        strbuf_addf(&buf2, "remote.%s", rename.new);
        if (git_config_rename_section(buf.buf, buf2.buf) < 1)
                return error("Could not rename config section '%s' to '%s'",
                                buf.buf, buf2.buf);

        strbuf_reset(&buf);
        strbuf_addf(&buf, "remote.%s.fetch", rename.new);
        if (git_config_set_multivar(buf.buf, NULL, NULL, 1))
                return error("Could not remove config section '%s'", buf.buf);
        for (i = 0; i < oldremote->fetch_refspec_nr; i++) {
                char *ptr;

                strbuf_reset(&buf2);
                strbuf_addstr(&buf2, oldremote->fetch_refspec[i]);
                ptr = strstr(buf2.buf, rename.old);
                if (ptr)
                        strbuf_splice(&buf2, ptr-buf2.buf, strlen(rename.old),
                                        rename.new, strlen(rename.new));
                if (git_config_set_multivar(buf.buf, buf2.buf, "^$", 0))
                        return error("Could not append '%s'", buf.buf);
        }

        read_branches();
        for (i = 0; i < branch_list.nr; i++) {
                struct string_list_item *item = branch_list.items + i;
                struct branch_info *info = item->util;
                if (info->remote_name && !strcmp(info->remote_name, rename.old)) {
                        strbuf_reset(&buf);
                        strbuf_addf(&buf, "branch.%s.remote", item->string);
                        if (git_config_set(buf.buf, rename.new)) {
                                return error("Could not set '%s'", buf.buf);
                        }
                }
        }

        /*
         * First remove symrefs, then rename the rest, finally create
         * the new symrefs.
         */
        for_each_ref(read_remote_branches, &rename);
        for (i = 0; i < remote_branches.nr; i++) {
                struct string_list_item *item = remote_branches.items + i;
                int flag = 0;
                unsigned char sha1[20];
                const char *symref;

                symref = resolve_ref(item->string, sha1, 1, &flag);
                if (!(flag & REF_ISSYMREF))
                        continue;
                if (delete_ref(item->string, NULL, REF_NODEREF))
                        die("deleting '%s' failed", item->string);
        }
        for (i = 0; i < remote_branches.nr; i++) {
                struct string_list_item *item = remote_branches.items + i;

                if (item->util)
                        continue;
                strbuf_reset(&buf);
                strbuf_addstr(&buf, item->string);
                strbuf_splice(&buf, strlen("refs/remotes/"), strlen(rename.old),
                                rename.new, strlen(rename.new));
                strbuf_reset(&buf2);
                strbuf_addf(&buf2, "remote: renamed %s to %s",
                                item->string, buf.buf);
                if (rename_ref(item->string, buf.buf, buf2.buf))
                        die("renaming '%s' failed", item->string);
        }
        for (i = 0; i < remote_branches.nr; i++) {
                struct string_list_item *item = remote_branches.items + i;

                if (!item->util)
                        continue;
                strbuf_reset(&buf);
                strbuf_addstr(&buf, item->string);
                strbuf_splice(&buf, strlen("refs/remotes/"), strlen(rename.old),
                                rename.new, strlen(rename.new));
                strbuf_reset(&buf2);
                strbuf_addstr(&buf2, item->util);
                strbuf_splice(&buf2, strlen("refs/remotes/"), strlen(rename.old),
                                rename.new, strlen(rename.new));
                strbuf_reset(&buf3);
                strbuf_addf(&buf3, "remote: renamed %s to %s",
                                item->string, buf.buf);
                if (create_symref(buf.buf, buf2.buf, buf3.buf))
                        die("creating '%s' failed", buf.buf);
        }
        return 0;
}

static int remove_branches(struct string_list *branches)
{
        int i, result = 0;
        for (i = 0; i < branches->nr; i++) {
                struct string_list_item *item = branches->items + i;
                const char *refname = item->string;
                unsigned char *sha1 = item->util;

                if (delete_ref(refname, sha1, 0))
                        result |= error("Could not remove branch %s", refname);
        }
        return result;
}

static int rm(int argc, const char **argv)
{
        struct option options[] = {
                OPT_END()
        };
        struct remote *remote;
        struct strbuf buf = STRBUF_INIT;
        struct known_remotes known_remotes = { NULL, NULL };
        struct string_list branches = { NULL, 0, 0, 1 };
        struct string_list skipped = { NULL, 0, 0, 1 };
        struct branches_for_remote cb_data = {
                NULL, &branches, &skipped, &known_remotes
        };
        int i, result;

        if (argc != 2)
                usage_with_options(builtin_remote_usage, options);

        remote = remote_get(argv[1]);
        if (!remote)
                die("No such remote: %s", argv[1]);

        known_remotes.to_delete = remote;
        for_each_remote(add_known_remote, &known_remotes);

        strbuf_addf(&buf, "remote.%s", remote->name);
        if (git_config_rename_section(buf.buf, NULL) < 1)
                return error("Could not remove config section '%s'", buf.buf);

        read_branches();
        for (i = 0; i < branch_list.nr; i++) {
                struct string_list_item *item = branch_list.items + i;
                struct branch_info *info = item->util;
                if (info->remote_name && !strcmp(info->remote_name, remote->name)) {
                        const char *keys[] = { "remote", "merge", NULL }, **k;
                        for (k = keys; *k; k++) {
                                strbuf_reset(&buf);
                                strbuf_addf(&buf, "branch.%s.%s",
                                                item->string, *k);
                                if (git_config_set(buf.buf, NULL)) {
                                        strbuf_release(&buf);
                                        return -1;
                                }
                        }
                }
        }

        /*
         * We cannot just pass a function to for_each_ref() which deletes
         * the branches one by one, since for_each_ref() relies on cached
         * refs, which are invalidated when deleting a branch.
         */
        cb_data.remote = remote;
        result = for_each_ref(add_branch_for_removal, &cb_data);
        strbuf_release(&buf);

        if (!result)
                result = remove_branches(&branches);
        string_list_clear(&branches, 1);

        if (skipped.nr) {
                fprintf(stderr, skipped.nr == 1 ?
                        "Note: A non-remote branch was not removed; "
                        "to delete it, use:\n" :
                        "Note: Non-remote branches were not removed; "
                        "to delete them, use:\n");
                for (i = 0; i < skipped.nr; i++)
                        fprintf(stderr, "  git branch -d %s\n",
                                skipped.items[i].string);
        }
        string_list_clear(&skipped, 0);

        return result;
}

static void show_list(const char *title, struct string_list *list,
                      const char *extra_arg)
{
        int i;

        if (!list->nr)
                return;

        printf(title, list->nr > 1 ? "es" : "", extra_arg);
        printf("\n");
        for (i = 0; i < list->nr; i++)
                printf("    %s\n", list->items[i].string);
}

static void free_remote_ref_states(struct ref_states *states)
{
        string_list_clear(&states->new, 0);
        string_list_clear(&states->stale, 0);
        string_list_clear(&states->tracked, 0);
}

static int append_ref_to_tracked_list(const char *refname,
        const unsigned char *sha1, int flags, void *cb_data)
{
        struct ref_states *states = cb_data;
        struct refspec refspec;

        memset(&refspec, 0, sizeof(refspec));
        refspec.dst = (char *)refname;
        if (!remote_find_tracking(states->remote, &refspec))
                string_list_append(abbrev_branch(refspec.src), &states->tracked);

        return 0;
}

static int get_remote_ref_states(const char *name,
                                 struct ref_states *states,
                                 int query)
{
        struct transport *transport;
        const struct ref *remote_refs;

        states->remote = remote_get(name);
        if (!states->remote)
                return error("No such remote: %s", name);

        read_branches();

        if (query) {
                transport = transport_get(NULL, states->remote->url_nr > 0 ?
                        states->remote->url[0] : NULL);
                remote_refs = transport_get_remote_refs(transport);
                transport_disconnect(transport);

                get_ref_states(remote_refs, states);
        } else
                for_each_ref(append_ref_to_tracked_list, states);

        return 0;
}

static int show(int argc, const char **argv)
{
        int no_query = 0, result = 0;
        struct option options[] = {
                OPT_GROUP("show specific options"),
                OPT_BOOLEAN('n', NULL, &no_query, "do not query remotes"),
                OPT_END()
        };
        struct ref_states states;

        argc = parse_options(argc, argv, options, builtin_remote_usage, 0);

        if (argc < 1)
                return show_all();

        memset(&states, 0, sizeof(states));
        for (; argc; argc--, argv++) {
                int i;

                get_remote_ref_states(*argv, &states, !no_query);

                printf("* remote %s\n  URL: %s\n", *argv,
                        states.remote->url_nr > 0 ?
                                states.remote->url[0] : "(no URL)");

                for (i = 0; i < branch_list.nr; i++) {
                        struct string_list_item *branch = branch_list.items + i;
                        struct branch_info *info = branch->util;
                        int j;

                        if (!info->merge.nr || strcmp(*argv, info->remote_name))
                                continue;
                        printf("  Remote branch%s merged with 'git pull' "
                                "while on branch %s\n   ",
                                info->merge.nr > 1 ? "es" : "",
                                branch->string);
                        for (j = 0; j < info->merge.nr; j++)
                                printf(" %s", info->merge.items[j].string);
                        printf("\n");
                }

                if (!no_query) {
                        show_list("  New remote branch%s (next fetch "
                                "will store in remotes/%s)",
                                &states.new, states.remote->name);
                        show_list("  Stale tracking branch%s (use 'git remote "
                                "prune')", &states.stale, "");
                }

                show_list("  Tracked remote branch%s", &states.tracked, "");

                if (states.remote->push_refspec_nr) {
                        printf("  Local branch%s pushed with 'git push'\n",
                                states.remote->push_refspec_nr > 1 ?
                                        "es" : "");
                        for (i = 0; i < states.remote->push_refspec_nr; i++) {
                                struct refspec *spec = states.remote->push + i;
                                printf("    %s%s%s%s\n",
                                       spec->force ? "+" : "",
                                       abbrev_branch(spec->src),
                                       spec->dst ? ":" : "",
                                       spec->dst ? abbrev_branch(spec->dst) : "");
                        }
                }

                free_remote_ref_states(&states);
        }

        return result;
}

static int prune(int argc, const char **argv)
{
        int dry_run = 0, result = 0;
        struct option options[] = {
                OPT_GROUP("prune specific options"),
                OPT__DRY_RUN(&dry_run),
                OPT_END()
        };
        struct ref_states states;
        const char *dangling_msg;

        argc = parse_options(argc, argv, options, builtin_remote_usage, 0);

        if (argc < 1)
                usage_with_options(builtin_remote_usage, options);

        dangling_msg = (dry_run
                        ? " %s will become dangling!\n"
                        : " %s has become dangling!\n");

        memset(&states, 0, sizeof(states));
        for (; argc; argc--, argv++) {
                int i;

                get_remote_ref_states(*argv, &states, 1);

                if (states.stale.nr) {
                        printf("Pruning %s\n", *argv);
                        printf("URL: %s\n",
                               states.remote->url_nr
                               ? states.remote->url[0]
                               : "(no URL)");
                }

                for (i = 0; i < states.stale.nr; i++) {
                        const char *refname = states.stale.items[i].util;

                        if (!dry_run)
                                result |= delete_ref(refname, NULL, 0);

                        printf(" * [%s] %s\n", dry_run ? "would prune" : "pruned",
                               abbrev_ref(refname, "refs/remotes/"));
                        warn_dangling_symref(dangling_msg, refname);
                }

                free_remote_ref_states(&states);
        }

        return result;
}

static int get_one_remote_for_update(struct remote *remote, void *priv)
{
        struct string_list *list = priv;
        if (!remote->skip_default_update)
                string_list_append(remote->name, list);
        return 0;
}

struct remote_group {
        const char *name;
        struct string_list *list;
} remote_group;

static int get_remote_group(const char *key, const char *value, void *cb)
{
        if (!prefixcmp(key, "remotes.") &&
                        !strcmp(key + 8, remote_group.name)) {
                /* split list by white space */
                int space = strcspn(value, " \t\n");
                while (*value) {
                        if (space > 1)
                                string_list_append(xstrndup(value, space),
                                                remote_group.list);
                        value += space + (value[space] != '\0');
                        space = strcspn(value, " \t\n");
                }
        }

        return 0;
}

static int update(int argc, const char **argv)
{
        int i, result = 0;
        struct string_list list = { NULL, 0, 0, 0 };
        static const char *default_argv[] = { NULL, "default", NULL };

        if (argc < 2) {
                argc = 2;
                argv = default_argv;
        }

        remote_group.list = &list;
        for (i = 1; i < argc; i++) {
                remote_group.name = argv[i];
                result = git_config(get_remote_group, NULL);
        }

        if (!result && !list.nr  && argc == 2 && !strcmp(argv[1], "default"))
                result = for_each_remote(get_one_remote_for_update, &list);

        for (i = 0; i < list.nr; i++)
                result |= fetch_remote(list.items[i].string);

        /* all names were strdup()ed or strndup()ed */
        list.strdup_strings = 1;
        string_list_clear(&list, 0);

        return result;
}

static int get_one_entry(struct remote *remote, void *priv)
{
        struct string_list *list = priv;

        if (remote->url_nr > 0) {
                int i;

                for (i = 0; i < remote->url_nr; i++)
                        string_list_append(remote->name, list)->util = (void *)remote->url[i];
        } else
                string_list_append(remote->name, list)->util = NULL;

        return 0;
}

static int show_all(void)
{
        struct string_list list = { NULL, 0, 0 };
        int result = for_each_remote(get_one_entry, &list);

        if (!result) {
                int i;

                sort_string_list(&list);
                for (i = 0; i < list.nr; i++) {
                        struct string_list_item *item = list.items + i;
                        if (verbose)
                                printf("%s\t%s\n", item->string,
                                        item->util ? (const char *)item->util : "");
                        else {
                                if (i && !strcmp((item - 1)->string, item->string))
                                        continue;
                                printf("%s\n", item->string);
                        }
                }
        }
        return result;
}

int cmd_remote(int argc, const char **argv, const char *prefix)
{
        struct option options[] = {
                OPT__VERBOSE(&verbose),
                OPT_END()
        };
        int result;

        argc = parse_options(argc, argv, options, builtin_remote_usage,
                PARSE_OPT_STOP_AT_NON_OPTION);

        if (argc < 1)
                result = show_all();
        else if (!strcmp(argv[0], "add"))
                result = add(argc, argv);
        else if (!strcmp(argv[0], "rename"))
                result = mv(argc, argv);
        else if (!strcmp(argv[0], "rm"))
                result = rm(argc, argv);
        else if (!strcmp(argv[0], "show"))
                result = show(argc, argv);
        else if (!strcmp(argv[0], "prune"))
                result = prune(argc, argv);
        else if (!strcmp(argv[0], "update"))
                result = update(argc, argv);
        else {
                error("Unknown subcommand: %s", argv[0]);
                usage_with_options(builtin_remote_usage, options);
        }

        return result ? 1 : 0;
}