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

static const char * const builtin_remote_usage[] = {
        "git remote",
        "git remote add <name> <url>",
        "git remote rm <name>",
        "git remote show <name>",
        "git remote prune <name>",
        "git remote update [group]",
        NULL
};

static int verbose;

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 inline const char *skip_prefix(const char *name, const char *prefix)
{
        return !name ? "" :
                prefixcmp(name, prefix) ?  name : name + strlen(prefix);
}

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

static int fetch_remote(const char *name)
{
        const char *argv[] = { "fetch", name, NULL };
        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 path_list track = { NULL, 0, 0 };
        const char *master = NULL;
        struct remote *remote;
        struct strbuf buf, buf2;
        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_init(&buf, 0);
        strbuf_init(&buf2, 0);

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

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

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

                strbuf_reset(&buf2);
                if (mirror)
                        strbuf_addf(&buf2, "refs/%s:refs/%s",
                                        item->path, item->path);
                else
                        strbuf_addf(&buf2, "refs/heads/%s:refs/remotes/%s/%s",
                                        item->path, name, item->path);
                if (git_config_set_multivar(buf.buf, buf2.buf, "^$", 0))
                        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);
        path_list_clear(&track, 0);

        return 0;
}

struct branch_info {
        char *remote;
        struct path_list merge;
};

static struct path_list branch_list;

static int config_read_branches(const char *key, const char *value)
{
        if (!prefixcmp(key, "branch.")) {
                char *name;
                struct path_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 = path_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)
                                warning("more than one branch.%s", key);
                        info->remote = xstrdup(value);
                } else {
                        char *space = strchr(value, ' ');
                        value = skip_prefix(value, "refs/heads/");
                        while (space) {
                                char *merge;
                                merge = xstrndup(value, space - value);
                                path_list_append(merge, &info->merge);
                                value = skip_prefix(space + 1, "refs/heads/");
                                space = strchr(value, ' ');
                        }
                        path_list_append(xstrdup(value), &info->merge);
                }
        }
        return 0;
}

static void read_branches(void)
{
        if (branch_list.nr)
                return;
        git_config(config_read_branches);
        sort_path_list(&branch_list);
}

struct ref_states {
        struct remote *remote;
        struct strbuf remote_prefix;
        struct path_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 path_list_item *item;
                const char *name = skip_prefix(refspec.src, "refs/heads/");
                /* symbolic refs pointing nowhere were handled already */
                if ((flags & REF_ISSYMREF) ||
                                unsorted_path_list_has_path(&states->tracked,
                                        name) ||
                                unsorted_path_list_has_path(&states->new,
                                        name))
                        return 0;
                item = path_list_append(name, &states->stale);
                item->util = xstrdup(refname);
        }
        return 0;
}

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

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

        states->new.strdup_paths = states->tracked.strdup_paths = 1;
        for (ref = fetch_map; ref; ref = ref->next) {
                struct path_list *target = &states->tracked;
                unsigned char sha1[20];
                void *util = NULL;

                if (!ref->peer_ref || read_ref(ref->peer_ref->name, sha1))
                        target = &states->new;
                else {
                        target = &states->tracked;
                        if (hashcmp(sha1, ref->new_sha1))
                                util = &states;
                }
                path_list_append(skip_prefix(ref->name, "refs/heads/"),
                                target)->util = util;
        }
        free_refs(fetch_map);

        strbuf_addf(&states->remote_prefix,
                "refs/remotes/%s/", states->remote->name);
        for_each_ref(handle_one_branch, states);
        sort_path_list(&states->stale);

        return 0;
}

struct branches_for_remote {
        const char *prefix;
        struct path_list *branches;
};

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;

        if (!prefixcmp(refname, branches->prefix)) {
                struct path_list_item *item;

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

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

        return 0;
}

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

                if (delete_ref(refname, sha1))
                        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;
        struct path_list branches = { NULL, 0, 0, 1 };
        struct branches_for_remote cb_data = { NULL, &branches };
        int i;

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

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

        strbuf_init(&buf, 0);
        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 path_list_item *item = branch_list.items + i;
                struct branch_info *info = item->util;
                if (info->remote && !strcmp(info->remote, remote->name)) {
                        const char *keys[] = { "remote", "merge", NULL }, **k;
                        for (k = keys; *k; k++) {
                                strbuf_reset(&buf);
                                strbuf_addf(&buf, "branch.%s.%s",
                                                item->path, *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.
         */
        strbuf_reset(&buf);
        strbuf_addf(&buf, "refs/remotes/%s/", remote->name);
        cb_data.prefix = buf.buf;
        i = for_each_ref(add_branch_for_removal, &cb_data);
        strbuf_release(&buf);

        if (!i)
                i = remove_branches(&branches);
        path_list_clear(&branches, 1);

        return i;
}

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

        if (!list->nr)
                return;

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

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

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

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

        memset(&states, 0, sizeof(states));
        for (; argc; argc--, argv++) {
                struct transport *transport;
                const struct ref *ref;
                struct strbuf buf;
                int i, got_states;

                states.remote = remote_get(*argv);
                if (!states.remote)
                        return error("No such remote: %s", *argv);
                transport = transport_get(NULL, states.remote->url_nr > 0 ?
                        states.remote->url[0] : NULL);
                ref = transport_get_remote_refs(transport);
                transport_disconnect(transport);

                read_branches();
                got_states = get_ref_states(ref, &states);
                if (got_states)
                        result = error("Error getting local info for '%s'",
                                        states.remote->name);

                if (prune) {
                        struct strbuf buf;
                        int prefix_len;

                        strbuf_init(&buf, 0);
                        if (states.remote->fetch_refspec_nr == 1 &&
                                        states.remote->fetch->pattern &&
                                        !strcmp(states.remote->fetch->src,
                                                states.remote->fetch->dst))
                                /* handle --mirror remote */
                                strbuf_addstr(&buf, "refs/heads/");
                        else
                                strbuf_addf(&buf, "refs/remotes/%s/", *argv);
                        prefix_len = buf.len;

                        for (i = 0; i < states.stale.nr; i++) {
                                strbuf_setlen(&buf, prefix_len);
                                strbuf_addstr(&buf, states.stale.items[i].path);
                                result |= delete_ref(buf.buf, NULL);
                        }

                        strbuf_release(&buf);
                        goto cleanup_states;
                }

                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 path_list_item *branch = branch_list.items + i;
                        struct branch_info *info = branch->util;
                        int j;

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

                if (got_states)
                        continue;
                strbuf_init(&buf, 0);
                strbuf_addf(&buf, "  New remote branch%%s (next fetch will "
                        "store in remotes/%s)", states.remote->name);
                show_list(buf.buf, &states.new);
                strbuf_release(&buf);
                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", spec->force ? "+" : "",
                                        skip_prefix(spec->src, "refs/heads/"),
                                        spec->dst ? ":" : "",
                                        skip_prefix(spec->dst, "refs/heads/"));
                        }
                        printf("\n");
                }
cleanup_states:
                /* NEEDSWORK: free remote */
                path_list_clear(&states.new, 0);
                path_list_clear(&states.stale, 0);
                path_list_clear(&states.tracked, 0);
        }

        return result;
}

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

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

static int get_remote_group(const char *key, const char *value)
{
        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)
                                path_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 path_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);
        }

        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].path);

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

        return result;
}

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

        path_list_append(remote->name, list)->util = remote->url_nr ?
                (void *)remote->url[0] : NULL;
        if (remote->url_nr > 1)
                warning("Remote %s has more than one URL", remote->name);

        return 0;
}

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

        if (!result) {
                int i;

                sort_path_list(&list);
                for (i = 0; i < list.nr; i++) {
                        struct path_list_item *item = list.items + i;
                        printf("%s%s%s\n", item->path,
                                verbose ? "\t" : "",
                                verbose && item->util ?
                                        (const char *)item->util : "");
                }
        }
        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], "rm"))
                result = rm(argc, argv);
        else if (!strcmp(argv[0], "show"))
                result = show_or_prune(argc, argv, 0);
        else if (!strcmp(argv[0], "prune"))
                result = show_or_prune(argc, argv, 1);
        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;
}