#include "cache.h"
#include "refs.h"

static const char *notnull(const char *arg, const char *name)
{
        if (!arg)
                die("%s required", name);
        return arg;
}

static unsigned int arg_flags(const char *arg, const char *name)
{
        return atoi(notnull(arg, name));
}

static const char **get_store(const char **argv, struct ref_store **refs)
{
        const char *gitdir;

        if (!argv[0]) {
                die("ref store required");
        } else if (!strcmp(argv[0], "main")) {
                *refs = get_main_ref_store();
        } else if (skip_prefix(argv[0], "submodule:", &gitdir)) {
                struct strbuf sb = STRBUF_INIT;
                int ret;

                ret = strbuf_git_path_submodule(&sb, gitdir, "objects/");
                if (ret)
                        die("strbuf_git_path_submodule failed: %d", ret);
                add_to_alternates_memory(sb.buf);
                strbuf_release(&sb);

                *refs = get_submodule_ref_store(gitdir);
        } else
                die("unknown backend %s", argv[0]);

        if (!*refs)
                die("no ref store");

        /* consume store-specific optional arguments if needed */

        return argv + 1;
}


static int cmd_pack_refs(struct ref_store *refs, const char **argv)
{
        unsigned int flags = arg_flags(*argv++, "flags");

        return refs_pack_refs(refs, flags);
}

static int cmd_peel_ref(struct ref_store *refs, const char **argv)
{
        const char *refname = notnull(*argv++, "refname");
        unsigned char sha1[20];
        int ret;

        ret = refs_peel_ref(refs, refname, sha1);
        if (!ret)
                puts(sha1_to_hex(sha1));
        return ret;
}

static int cmd_create_symref(struct ref_store *refs, const char **argv)
{
        const char *refname = notnull(*argv++, "refname");
        const char *target = notnull(*argv++, "target");
        const char *logmsg = *argv++;

        return refs_create_symref(refs, refname, target, logmsg);
}

static int cmd_delete_refs(struct ref_store *refs, const char **argv)
{
        unsigned int flags = arg_flags(*argv++, "flags");
        struct string_list refnames = STRING_LIST_INIT_NODUP;

        while (*argv)
                string_list_append(&refnames, *argv++);

        return refs_delete_refs(refs, &refnames, flags);
}

static int cmd_rename_ref(struct ref_store *refs, const char **argv)
{
        const char *oldref = notnull(*argv++, "oldref");
        const char *newref = notnull(*argv++, "newref");
        const char *logmsg = *argv++;

        return refs_rename_ref(refs, oldref, newref, logmsg);
}

static int each_ref(const char *refname, const struct object_id *oid,
                    int flags, void *cb_data)
{
        printf("%s %s 0x%x\n", oid_to_hex(oid), refname, flags);
        return 0;
}

static int cmd_for_each_ref(struct ref_store *refs, const char **argv)
{
        const char *prefix = notnull(*argv++, "prefix");

        return refs_for_each_ref_in(refs, prefix, each_ref, NULL);
}

static int cmd_resolve_ref(struct ref_store *refs, const char **argv)
{
        unsigned char sha1[20];
        const char *refname = notnull(*argv++, "refname");
        int resolve_flags = arg_flags(*argv++, "resolve-flags");
        int flags;
        const char *ref;

        ref = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
                                      sha1, &flags);
        printf("%s %s 0x%x\n", sha1_to_hex(sha1), ref, flags);
        return ref ? 0 : 1;
}

static int cmd_verify_ref(struct ref_store *refs, const char **argv)
{
        const char *refname = notnull(*argv++, "refname");
        struct strbuf err = STRBUF_INIT;
        int ret;

        ret = refs_verify_refname_available(refs, refname, NULL, NULL, &err);
        if (err.len)
                puts(err.buf);
        return ret;
}

static int cmd_for_each_reflog(struct ref_store *refs, const char **argv)
{
        return refs_for_each_reflog(refs, each_ref, NULL);
}

static int each_reflog(struct object_id *old_oid, struct object_id *new_oid,
                       const char *committer, unsigned long timestamp,
                       int tz, const char *msg, void *cb_data)
{
        printf("%s %s %s %lu %d %s\n",
               oid_to_hex(old_oid), oid_to_hex(new_oid),
               committer, timestamp, tz, msg);
        return 0;
}

static int cmd_for_each_reflog_ent(struct ref_store *refs, const char **argv)
{
        const char *refname = notnull(*argv++, "refname");

        return refs_for_each_reflog_ent(refs, refname, each_reflog, refs);
}

static int cmd_for_each_reflog_ent_reverse(struct ref_store *refs, const char **argv)
{
        const char *refname = notnull(*argv++, "refname");

        return refs_for_each_reflog_ent_reverse(refs, refname, each_reflog, refs);
}

static int cmd_reflog_exists(struct ref_store *refs, const char **argv)
{
        const char *refname = notnull(*argv++, "refname");

        return !refs_reflog_exists(refs, refname);
}

static int cmd_create_reflog(struct ref_store *refs, const char **argv)
{
        const char *refname = notnull(*argv++, "refname");
        int force_create = arg_flags(*argv++, "force-create");
        struct strbuf err = STRBUF_INIT;
        int ret;

        ret = refs_create_reflog(refs, refname, force_create, &err);
        if (err.len)
                puts(err.buf);
        return ret;
}

static int cmd_delete_reflog(struct ref_store *refs, const char **argv)
{
        const char *refname = notnull(*argv++, "refname");

        return refs_delete_reflog(refs, refname);
}

static int cmd_reflog_expire(struct ref_store *refs, const char **argv)
{
        die("not supported yet");
}

static int cmd_delete_ref(struct ref_store *refs, const char **argv)
{
        const char *msg = notnull(*argv++, "msg");
        const char *refname = notnull(*argv++, "refname");
        const char *sha1_buf = notnull(*argv++, "old-sha1");
        unsigned int flags = arg_flags(*argv++, "flags");
        unsigned char old_sha1[20];

        if (get_sha1_hex(sha1_buf, old_sha1))
                die("not sha-1");

        return refs_delete_ref(refs, msg, refname, old_sha1, flags);
}

static int cmd_update_ref(struct ref_store *refs, const char **argv)
{
        const char *msg = notnull(*argv++, "msg");
        const char *refname = notnull(*argv++, "refname");
        const char *new_sha1_buf = notnull(*argv++, "old-sha1");
        const char *old_sha1_buf = notnull(*argv++, "old-sha1");
        unsigned int flags = arg_flags(*argv++, "flags");
        unsigned char old_sha1[20];
        unsigned char new_sha1[20];

        if (get_sha1_hex(old_sha1_buf, old_sha1) ||
            get_sha1_hex(new_sha1_buf, new_sha1))
                die("not sha-1");

        return refs_update_ref(refs, msg, refname,
                               new_sha1, old_sha1,
                               flags, UPDATE_REFS_DIE_ON_ERR);
}

struct command {
        const char *name;
        int (*func)(struct ref_store *refs, const char **argv);
};

static struct command commands[] = {
        { "pack-refs", cmd_pack_refs },
        { "peel-ref", cmd_peel_ref },
        { "create-symref", cmd_create_symref },
        { "delete-refs", cmd_delete_refs },
        { "rename-ref", cmd_rename_ref },
        { "for-each-ref", cmd_for_each_ref },
        { "resolve-ref", cmd_resolve_ref },
        { "verify-ref", cmd_verify_ref },
        { "for-each-reflog", cmd_for_each_reflog },
        { "for-each-reflog-ent", cmd_for_each_reflog_ent },
        { "for-each-reflog-ent-reverse", cmd_for_each_reflog_ent_reverse },
        { "reflog-exists", cmd_reflog_exists },
        { "create-reflog", cmd_create_reflog },
        { "delete-reflog", cmd_delete_reflog },
        { "reflog-expire", cmd_reflog_expire },
        /*
         * backend transaction functions can't be tested separately
         */
        { "delete-ref", cmd_delete_ref },
        { "update-ref", cmd_update_ref },
        { NULL, NULL }
};

int cmd_main(int argc, const char **argv)
{
        struct ref_store *refs;
        const char *func;
        struct command *cmd;

        setup_git_directory();

        argv = get_store(argv + 1, &refs);

        func = *argv++;
        if (!func)
                die("ref function required");
        for (cmd = commands; cmd->name; cmd++) {
                if (!strcmp(func, cmd->name))
                        return cmd->func(refs, argv);
        }
        die("unknown function %s", func);
        return 0;
}