#include "aes67_sdp_sap.h"

#include <stdio.h>
#include <string.h>

#include "aes67_cfg.h"
#include "aes67_net.h"
#include "aes67_ptp.h"
#include "aes67_web.h"
#include "esp_netif.h"

#define SDP_MAX 1024

// Same lines, in the same order, as the SDP preview in web/index.html.
size_t aes67_sdp_build(char *buf, size_t size)
{
    cJSON *a = cfg_get("aes67");
    cJSON *p = cfg_get("ptp");
    if (!a || !p) {
        cJSON_Delete(a);
        cJSON_Delete(p);
        return 0;
    }
#define NUM(o, k) cJSON_GetObjectItemCaseSensitive(o, k)->valuedouble
#define STR(o, k) cJSON_GetObjectItemCaseSensitive(o, k)->valuestring
    char ip[16] = "0.0.0.0";
    esp_netif_ip_info_t info;
    esp_netif_t *netif = aes67_net_netif();
    if (netif && esp_netif_get_ip_info(netif, &info) == ESP_OK && info.ip.addr) {
        snprintf(ip, sizeof(ip), IPSTR, IP2STR(&info.ip));
    }
    char gm[24];
    if (!aes67_ptp_gm_id(gm)) {
        strcpy(gm, "00-00-00-00-00-00-00-00");
    }
    int ch = (int)NUM(a, "channels");
    char info_ch[16];
    snprintf(info_ch, sizeof(info_ch), ch == 1 ? "mono" : ch == 2 ? "stereo" : "%d ch", ch);
    int dom = (int)NUM(p, "domain");
    int pt = (int)NUM(a, "pt");

    int n = snprintf(buf, size,
                     "v=0\r\n"
                     "o=- %.0f %.0f IN IP4 %s\r\n"
                     "s=%s\r\n"
                     "c=IN IP4 %s/%d\r\n"
                     "t=0 0\r\n"
                     "a=clock-domain:PTPv2 %d\r\n"
                     "m=audio %d RTP/AVP %d\r\n"
                     "i=%s\r\n"
                     "a=rtpmap:%d %s/%d/%d\r\n"
                     "a=recvonly\r\n"
                     "a=ptime:%g\r\n"
                     "a=ts-refclk:ptp=IEEE1588-2008:%s:%d\r\n"
                     "a=mediaclk:direct=%.0f\r\n",
                     NUM(a, "session_id"), NUM(a, "session_ver"), ip,
                     STR(a, "name"),
                     STR(a, "mcast"), (int)NUM(a, "ttl"),
                     dom,
                     (int)NUM(a, "port"), pt,
                     info_ch,
                     pt, STR(a, "encoding"), (int)NUM(a, "rate"), ch,
                     NUM(a, "ptime"),
                     gm, dom,
                     NUM(a, "clk_offset"));
#undef NUM
#undef STR
    cJSON_Delete(a);
    cJSON_Delete(p);
    return n > 0 && (size_t)n < size ? (size_t)n : 0;
}

static esp_err_t sdp_get(httpd_req_t *req)
{
    char buf[SDP_MAX];
    size_t len = aes67_sdp_build(buf, sizeof(buf));
    if (!len) {
        return httpd_resp_send_err(req, HTTPD_500_INTERNAL_SERVER_ERROR, "SDP build failed");
    }
    httpd_resp_set_type(req, "application/sdp");
    httpd_resp_set_hdr(req, "Cache-Control", "no-store");
    return httpd_resp_send(req, buf, len);
}

esp_err_t aes67_sdp_sap_init(void)
{
    static const httpd_uri_t uri = { .uri = "/stream.sdp", .method = HTTP_GET, .handler = sdp_get };
    return web_register_uri(&uri);
}