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

static struct refspec_item s_tag_refspec = {
        0,
        1,
        0,
        0,
        "refs/tags/*",
        "refs/tags/*"
};

/* See TAG_REFSPEC for the string version */
const struct refspec_item *tag_refspec = &s_tag_refspec;

static struct refspec_item *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
{
        int i;
        struct refspec_item *rs = xcalloc(nr_refspec, sizeof(*rs));

        for (i = 0; i < nr_refspec; i++) {
                size_t llen;
                int is_glob;
                const char *lhs, *rhs;
                int flags;

                is_glob = 0;

                lhs = refspec[i];
                if (*lhs == '+') {
                        rs[i].force = 1;
                        lhs++;
                }

                rhs = strrchr(lhs, ':');

                /*
                 * Before going on, special case ":" (or "+:") as a refspec
                 * for pushing matching refs.
                 */
                if (!fetch && rhs == lhs && rhs[1] == '\0') {
                        rs[i].matching = 1;
                        continue;
                }

                if (rhs) {
                        size_t rlen = strlen(++rhs);
                        is_glob = (1 <= rlen && strchr(rhs, '*'));
                        rs[i].dst = xstrndup(rhs, rlen);
                }

                llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
                if (1 <= llen && memchr(lhs, '*', llen)) {
                        if ((rhs && !is_glob) || (!rhs && fetch))
                                goto invalid;
                        is_glob = 1;
                } else if (rhs && is_glob) {
                        goto invalid;
                }

                rs[i].pattern = is_glob;
                rs[i].src = xstrndup(lhs, llen);
                flags = REFNAME_ALLOW_ONELEVEL | (is_glob ? REFNAME_REFSPEC_PATTERN : 0);

                if (fetch) {
                        struct object_id unused;

                        /* LHS */
                        if (!*rs[i].src)
                                ; /* empty is ok; it means "HEAD" */
                        else if (llen == GIT_SHA1_HEXSZ && !get_oid_hex(rs[i].src, &unused))
                                rs[i].exact_sha1 = 1; /* ok */
                        else if (!check_refname_format(rs[i].src, flags))
                                ; /* valid looking ref is ok */
                        else
                                goto invalid;
                        /* RHS */
                        if (!rs[i].dst)
                                ; /* missing is ok; it is the same as empty */
                        else if (!*rs[i].dst)
                                ; /* empty is ok; it means "do not store" */
                        else if (!check_refname_format(rs[i].dst, flags))
                                ; /* valid looking ref is ok */
                        else
                                goto invalid;
                } else {
                        /*
                         * LHS
                         * - empty is allowed; it means delete.
                         * - when wildcarded, it must be a valid looking ref.
                         * - otherwise, it must be an extended SHA-1, but
                         *   there is no existing way to validate this.
                         */
                        if (!*rs[i].src)
                                ; /* empty is ok */
                        else if (is_glob) {
                                if (check_refname_format(rs[i].src, flags))
                                        goto invalid;
                        }
                        else
                                ; /* anything goes, for now */
                        /*
                         * RHS
                         * - missing is allowed, but LHS then must be a
                         *   valid looking ref.
                         * - empty is not allowed.
                         * - otherwise it must be a valid looking ref.
                         */
                        if (!rs[i].dst) {
                                if (check_refname_format(rs[i].src, flags))
                                        goto invalid;
                        } else if (!*rs[i].dst) {
                                goto invalid;
                        } else {
                                if (check_refname_format(rs[i].dst, flags))
                                        goto invalid;
                        }
                }
        }
        return rs;

 invalid:
        if (verify) {
                /*
                 * nr_refspec must be greater than zero and i must be valid
                 * since it is only possible to reach this point from within
                 * the for loop above.
                 */
                free_refspec(i+1, rs);
                return NULL;
        }
        die("Invalid refspec '%s'", refspec[i]);
}

int valid_fetch_refspec(const char *fetch_refspec_str)
{
        struct refspec_item *refspec;

        refspec = parse_refspec_internal(1, &fetch_refspec_str, 1, 1);
        free_refspec(1, refspec);
        return !!refspec;
}

struct refspec_item *parse_fetch_refspec(int nr_refspec, const char **refspec)
{
        return parse_refspec_internal(nr_refspec, refspec, 1, 0);
}

struct refspec_item *parse_push_refspec(int nr_refspec, const char **refspec)
{
        return parse_refspec_internal(nr_refspec, refspec, 0, 0);
}

void free_refspec(int nr_refspec, struct refspec_item *refspec)
{
        int i;

        if (!refspec)
                return;

        for (i = 0; i < nr_refspec; i++) {
                free(refspec[i].src);
                free(refspec[i].dst);
        }
        free(refspec);
}