#include "ipalloc.h"
#include "stralloc.h"
#include "dns.h"
#include "byte.h"
#include "uint16.h"
#include "curveresolve.h"
#include "error.h"
#include "dns_mxip.h"

static stralloc out = {0};
static stralloc out2 = {0};
static stralloc host = {0};
static stralloc key = {0};
static stralloc ext = {0};
static char *q = 0;

static void sort(ipalloc *ip){

    long long i, j;
    struct ip_mx ix;

    if (ip->len < 2) return;
    for (i = ip->len - 1; i > 0; --i) {
        for (j = 1; j <= i; ++j) {
            if (ip->ix[j-1].pref > ip->ix[j].pref) {
                byte_copy(&ix, sizeof(struct ip_mx), &ip->ix[j-1]);
                byte_copy(&ip->ix[j-1], sizeof(struct ip_mx), &ip->ix[j]);
                byte_copy(&ip->ix[j], sizeof(struct ip_mx), &ix);
            }
        }
    }
}

int dns_mxip(ipalloc *ia, stralloc *fqdn, int flagrelay) {

    long long i, j, k;
    uint16 pref;
    struct ip_mx ix;
    int temperr = 0;

    if (!ipalloc_readyplus(ia,0)) return -1;
    ia->len = 0;

    if (!stralloc_copys(&out, "")) return -1;
    if (!flagrelay) if (dns_mx(&out,fqdn) == -1) return -1;
    if (!out.len) {
        if (!stralloc_copyb(&out,"\0\0",2)) return -1;
        if (!dns_domain_fromdot(&q,fqdn->s, fqdn->len)) return -1;
        if (!dns_domain_todot_cat(&out,q)) return -1;
        dns_domain_free(&q);
        if (!stralloc_0(&out)) return -1;
    }

    i = 0;
    while (i + 2 < out.len) {
        byte_zero(&ix, sizeof(struct ip_mx));
        j = byte_chr(out.s + i + 2,out.len - i - 2,0);
        uint16_unpack_big(out.s + i, &pref);
        if (!stralloc_copyb(&host, out.s + i + 2,j)) return -1;
        if (curveresolve(&out2, &key, &ext, &host, 's') == -1) {
            if (errno == error_nomem) return -1;
            temperr = 1;
            i += j + 3;
            continue;
        }
        ix.pref = pref;
        if (key.len == 64 && ext.len == 32) {
            if (!stralloc_0(&key)) return -1;
            if (!stralloc_0(&ext)) return -1;
            /* XXX */
            ix.key  = key.s;  key.s  = 0; key.len  = 0; key.a  = 0;
            ix.ext  = ext.s;  ext.s  = 0; ext.len  = 0; ext.a  = 0;
            /* ix.name = host.s; host.s = 0; host.len = 0; host.a = 0; */
            ix.haskey = 1;
        }
        if (!stralloc_0(&host)) return -1;
        ix.name = host.s; host.s = 0; host.len = 0; host.a = 0;
        for (k = 0;k + 4 <= out2.len;k += 4) {
            byte_copy(ix.ip, 4, out2.s + k);
            if (!ipalloc_append(ia,&ix)) return -1;
        }
        i += j + 3;
    }
    if (temperr && ia->len <= 0) return -1;
    sort(ia);
    return 0;
}