#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
#include "pkt-line.h"
#include "run-command.h"
#include "remote.h"
#include "send-pack.h"

static const char send_pack_usage[] =
"git-send-pack [--all] [--dry-run] [--force] [--receive-pack=<git-receive-pack>] [--verbose] [--thin] [<host>:]<directory> [<ref>...]\n"
"  --all and explicit <ref> specification are mutually exclusive.";

static struct send_pack_args args = {
        /* .receivepack = */ "git-receive-pack",
};

/*
 * Make a pack stream and spit it out into file descriptor fd
 */
static int pack_objects(int fd, struct ref *refs)
{
        /*
         * The child becomes pack-objects --revs; we feed
         * the revision parameters to it via its stdin and
         * let its stdout go back to the other end.
         */
        const char *argv[] = {
                "pack-objects",
                "--all-progress",
                "--revs",
                "--stdout",
                NULL,
                NULL,
        };
        struct child_process po;

        if (args.use_thin_pack)
                argv[4] = "--thin";
        memset(&po, 0, sizeof(po));
        po.argv = argv;
        po.in = -1;
        po.out = fd;
        po.git_cmd = 1;
        if (start_command(&po))
                die("git-pack-objects failed (%s)", strerror(errno));

        /*
         * We feed the pack-objects we just spawned with revision
         * parameters by writing to the pipe.
         */
        while (refs) {
                char buf[42];

                if (!is_null_sha1(refs->old_sha1) &&
                    has_sha1_file(refs->old_sha1)) {
                        memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
                        buf[0] = '^';
                        buf[41] = '\n';
                        if (!write_or_whine(po.in, buf, 42,
                                                "send-pack: send refs"))
                                break;
                }
                if (!is_null_sha1(refs->new_sha1)) {
                        memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
                        buf[40] = '\n';
                        if (!write_or_whine(po.in, buf, 41,
                                                "send-pack: send refs"))
                                break;
                }
                refs = refs->next;
        }

        if (finish_command(&po))
                return error("pack-objects died with strange error");
        return 0;
}

static void unmark_and_free(struct commit_list *list, unsigned int mark)
{
        while (list) {
                struct commit_list *temp = list;
                temp->item->object.flags &= ~mark;
                list = temp->next;
                free(temp);
        }
}

static int ref_newer(const unsigned char *new_sha1,
                     const unsigned char *old_sha1)
{
        struct object *o;
        struct commit *old, *new;
        struct commit_list *list, *used;
        int found = 0;

        /* Both new and old must be commit-ish and new is descendant of
         * old.  Otherwise we require --force.
         */
        o = deref_tag(parse_object(old_sha1), NULL, 0);
        if (!o || o->type != OBJ_COMMIT)
                return 0;
        old = (struct commit *) o;

        o = deref_tag(parse_object(new_sha1), NULL, 0);
        if (!o || o->type != OBJ_COMMIT)
                return 0;
        new = (struct commit *) o;

        if (parse_commit(new) < 0)
                return 0;

        used = list = NULL;
        commit_list_insert(new, &list);
        while (list) {
                new = pop_most_recent_commit(&list, 1);
                commit_list_insert(new, &used);
                if (new == old) {
                        found = 1;
                        break;
                }
        }
        unmark_and_free(list, 1);
        unmark_and_free(used, 1);
        return found;
}

static struct ref *local_refs, **local_tail;
static struct ref *remote_refs, **remote_tail;

static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
{
        struct ref *ref;
        int len = strlen(refname) + 1;
        ref = xcalloc(1, sizeof(*ref) + len);
        hashcpy(ref->new_sha1, sha1);
        memcpy(ref->name, refname, len);
        *local_tail = ref;
        local_tail = &ref->next;
        return 0;
}

static void get_local_heads(void)
{
        local_tail = &local_refs;
        for_each_ref(one_local_ref, NULL);
}

static int receive_status(int in)
{
        char line[1000];
        int ret = 0;
        int len = packet_read_line(in, line, sizeof(line));
        if (len < 10 || memcmp(line, "unpack ", 7)) {
                fprintf(stderr, "did not receive status back\n");
                return -1;
        }
        if (memcmp(line, "unpack ok\n", 10)) {
                fputs(line, stderr);
                ret = -1;
        }
        while (1) {
                len = packet_read_line(in, line, sizeof(line));
                if (!len)
                        break;
                if (len < 3 ||
                    (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
                        fprintf(stderr, "protocol error: %s\n", line);
                        ret = -1;
                        break;
                }
                if (!memcmp(line, "ok", 2))
                        continue;
                fputs(line, stderr);
                ret = -1;
        }
        return ret;
}

static void update_tracking_ref(struct remote *remote, struct ref *ref)
{
        struct refspec rs;
        int will_delete_ref;

        rs.src = ref->name;
        rs.dst = NULL;

        if (!ref->peer_ref)
                return;

        will_delete_ref = is_null_sha1(ref->peer_ref->new_sha1);

        if (!will_delete_ref &&
                        !hashcmp(ref->old_sha1, ref->peer_ref->new_sha1))
                return;

        if (!remote_find_tracking(remote, &rs)) {
                fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
                if (is_null_sha1(ref->peer_ref->new_sha1)) {
                        if (delete_ref(rs.dst, NULL))
                                error("Failed to delete");
                } else
                        update_ref("update by push", rs.dst,
                                        ref->new_sha1, NULL, 0, 0);
                free(rs.dst);
        }
}

static const char *prettify_ref(const char *name)
{
        return name + (
                !prefixcmp(name, "refs/heads/") ? 11 :
                !prefixcmp(name, "refs/tags/") ? 10 :
                !prefixcmp(name, "refs/remotes/") ? 13 :
                0);
}

#define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)

static int do_send_pack(int in, int out, struct remote *remote, const char *dest, int nr_refspec, const char **refspec)
{
        struct ref *ref;
        int new_refs;
        int ret = 0;
        int ask_for_status_report = 0;
        int allow_deleting_refs = 0;
        int expect_status_report = 0;
        int shown_dest = 0;

        /* No funny business with the matcher */
        remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
        get_local_heads();

        /* Does the other end support the reporting? */
        if (server_supports("report-status"))
                ask_for_status_report = 1;
        if (server_supports("delete-refs"))
                allow_deleting_refs = 1;

        /* match them up */
        if (!remote_tail)
                remote_tail = &remote_refs;
        if (match_refs(local_refs, remote_refs, &remote_tail,
                       nr_refspec, refspec, args.send_all))
                return -1;

        if (!remote_refs) {
                fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
                        "Perhaps you should specify a branch such as 'master'.\n");
                return 0;
        }

        /*
         * Finally, tell the other end!
         */
        new_refs = 0;
        for (ref = remote_refs; ref; ref = ref->next) {
                char old_hex[60], *new_hex;
                int will_delete_ref;
                const char *pretty_ref;
                const char *pretty_peer;

                if (!ref->peer_ref)
                        continue;

                if (!shown_dest) {
                        fprintf(stderr, "To %s\n", dest);
                        shown_dest = 1;
                }

                pretty_ref = prettify_ref(ref->name);
                pretty_peer = prettify_ref(ref->peer_ref->name);

                will_delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
                if (will_delete_ref && !allow_deleting_refs) {
                        fprintf(stderr, " ! %-*s %s (remote does not support deleting refs)\n",
                                        SUMMARY_WIDTH, "[rejected]", pretty_ref);
                        ret = -2;
                        continue;
                }
                if (!will_delete_ref &&
                    !hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
                        if (args.verbose)
                                fprintf(stderr, " = %-*s %s -> %s\n",
                                        SUMMARY_WIDTH, "[up to date]",
                                        pretty_peer, pretty_ref);
                        continue;
                }

                /* This part determines what can overwrite what.
                 * The rules are:
                 *
                 * (0) you can always use --force or +A:B notation to
                 *     selectively force individual ref pairs.
                 *
                 * (1) if the old thing does not exist, it is OK.
                 *
                 * (2) if you do not have the old thing, you are not allowed
                 *     to overwrite it; you would not know what you are losing
                 *     otherwise.
                 *
                 * (3) if both new and old are commit-ish, and new is a
                 *     descendant of old, it is OK.
                 *
                 * (4) regardless of all of the above, removing :B is
                 *     always allowed.
                 */

                if (!args.force_update &&
                    !will_delete_ref &&
                    !is_null_sha1(ref->old_sha1) &&
                    !ref->force) {
                        if (!has_sha1_file(ref->old_sha1) ||
                            !ref_newer(ref->peer_ref->new_sha1,
                                       ref->old_sha1)) {
                                /* We do not have the remote ref, or
                                 * we know that the remote ref is not
                                 * an ancestor of what we are trying to
                                 * push.  Either way this can be losing
                                 * commits at the remote end and likely
                                 * we were not up to date to begin with.
                                 */
                                fprintf(stderr, " ! %-*s %s -> %s (non-fast forward)\n",
                                                SUMMARY_WIDTH, "[rejected]",
                                                pretty_peer, pretty_ref);
                                ret = -2;
                                continue;
                        }
                }
                hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
                if (!will_delete_ref)
                        new_refs++;
                strcpy(old_hex, sha1_to_hex(ref->old_sha1));
                new_hex = sha1_to_hex(ref->new_sha1);

                if (!args.dry_run) {
                        if (ask_for_status_report) {
                                packet_write(out, "%s %s %s%c%s",
                                        old_hex, new_hex, ref->name, 0,
                                        "report-status");
                                ask_for_status_report = 0;
                                expect_status_report = 1;
                        }
                        else
                                packet_write(out, "%s %s %s",
                                        old_hex, new_hex, ref->name);
                }
                if (will_delete_ref)
                        fprintf(stderr, " - %-*s %s\n",
                                SUMMARY_WIDTH, "[deleting]",
                                pretty_ref);
                else if (is_null_sha1(ref->old_sha1)) {
                        const char *msg;

                        if (!prefixcmp(ref->name, "refs/tags/"))
                                msg = "[new tag]";
                        else
                                msg = "[new branch]";
                        fprintf(stderr, " * %-*s %s -> %s\n",
                                SUMMARY_WIDTH, msg,
                                pretty_peer, pretty_ref);
                }
                else {
                        char quickref[83];
                        char type = ' ';
                        const char *msg = "";

                        strcpy(quickref, find_unique_abbrev(ref->old_sha1, DEFAULT_ABBREV));
                        if (ref_newer(ref->peer_ref->new_sha1, ref->old_sha1))
                                strcat(quickref, "..");
                        else {
                                strcat(quickref, "...");
                                type = '+';
                                msg = " (forced update)";
                        }
                        strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));

                        fprintf(stderr, " %c %-*s %s -> %s%s\n",
                                type,
                                SUMMARY_WIDTH, quickref,
                                pretty_peer, pretty_ref,
                                msg);
                }
        }

        packet_flush(out);
        if (new_refs && !args.dry_run)
                ret = pack_objects(out, remote_refs);
        close(out);

        if (expect_status_report) {
                if (receive_status(in))
                        ret = -4;
        }

        if (!args.dry_run && remote && ret == 0) {
                for (ref = remote_refs; ref; ref = ref->next)
                        update_tracking_ref(remote, ref);
        }

        if (!new_refs && ret == 0)
                fprintf(stderr, "Everything up-to-date\n");
        return ret;
}

static void verify_remote_names(int nr_heads, const char **heads)
{
        int i;

        for (i = 0; i < nr_heads; i++) {
                const char *remote = strchr(heads[i], ':');

                remote = remote ? (remote + 1) : heads[i];
                switch (check_ref_format(remote)) {
                case 0: /* ok */
                case -2: /* ok but a single level -- that is fine for
                          * a match pattern.
                          */
                case -3: /* ok but ends with a pattern-match character */
                        continue;
                }
                die("remote part of refspec is not a valid name in %s",
                    heads[i]);
        }
}

int cmd_send_pack(int argc, const char **argv, const char *prefix)
{
        int i, nr_heads = 0;
        const char **heads = NULL;
        const char *remote_name = NULL;
        struct remote *remote = NULL;
        const char *dest = NULL;

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

                if (*arg == '-') {
                        if (!prefixcmp(arg, "--receive-pack=")) {
                                args.receivepack = arg + 15;
                                continue;
                        }
                        if (!prefixcmp(arg, "--exec=")) {
                                args.receivepack = arg + 7;
                                continue;
                        }
                        if (!prefixcmp(arg, "--remote=")) {
                                remote_name = arg + 9;
                                continue;
                        }
                        if (!strcmp(arg, "--all")) {
                                args.send_all = 1;
                                continue;
                        }
                        if (!strcmp(arg, "--dry-run")) {
                                args.dry_run = 1;
                                continue;
                        }
                        if (!strcmp(arg, "--force")) {
                                args.force_update = 1;
                                continue;
                        }
                        if (!strcmp(arg, "--verbose")) {
                                args.verbose = 1;
                                continue;
                        }
                        if (!strcmp(arg, "--thin")) {
                                args.use_thin_pack = 1;
                                continue;
                        }
                        usage(send_pack_usage);
                }
                if (!dest) {
                        dest = arg;
                        continue;
                }
                heads = (const char **) argv;
                nr_heads = argc - i;
                break;
        }
        if (!dest)
                usage(send_pack_usage);
        if (heads && args.send_all)
                usage(send_pack_usage);

        if (remote_name) {
                remote = remote_get(remote_name);
                if (!remote_has_url(remote, dest)) {
                        die("Destination %s is not a uri for %s",
                            dest, remote_name);
                }
        }

        return send_pack(&args, dest, remote, nr_heads, heads);
}

int send_pack(struct send_pack_args *my_args,
              const char *dest, struct remote *remote,
              int nr_heads, const char **heads)
{
        int fd[2], ret;
        struct child_process *conn;

        memcpy(&args, my_args, sizeof(args));

        verify_remote_names(nr_heads, heads);

        conn = git_connect(fd, dest, args.receivepack, args.verbose ? CONNECT_VERBOSE : 0);
        ret = do_send_pack(fd[0], fd[1], remote, dest, nr_heads, heads);
        close(fd[0]);
        close(fd[1]);
        ret |= finish_connect(conn);
        return !!ret;
}