#include "barev_xml.h"

#include <string.h>

static int append_str(char *out, size_t out_size, size_t *pos, const char *s) {
  size_t i;
  if (!out || !s || !pos || out_size == 0) return 0;
  for (i = 0; s[i] != '\0'; ++i) {
    if (*pos + 1 >= out_size) return 0;
    out[*pos] = s[i];
    *pos = *pos + 1;
  }
  out[*pos] = '\0';
  return 1;
}

int barev_xml_escape(const char *in, char *out, size_t out_size) {
  size_t i;
  size_t pos;
  const char *rep;
  if (!in || !out || out_size == 0) return 0;
  pos = 0;
  out[0] = '\0';
  for (i = 0; in[i] != '\0'; ++i) {
    rep = 0;
    if (in[i] == '&') rep = "&amp;";
    else if (in[i] == '<') rep = "&lt;";
    else if (in[i] == '>') rep = "&gt;";
    else if (in[i] == '"') rep = "&quot;";
    else if (in[i] == '\'') rep = "&apos;";

    if (rep) {
      if (!append_str(out, out_size, &pos, rep)) return 0;
    } else {
      if (pos + 1 >= out_size) return 0;
      out[pos++] = in[i];
      out[pos] = '\0';
    }
  }
  return 1;
}

int barev_build_stream_header(const char *from_jid, const char *to_jid, char *out, size_t out_size) {
  size_t pos;
  char from_e[512], to_e[512];
  if (!from_jid || !to_jid || !out || out_size == 0) return 0;
  if (!barev_xml_escape(from_jid, from_e, sizeof(from_e))) return 0;
  if (!barev_xml_escape(to_jid, to_e, sizeof(to_e))) return 0;
  pos = 0;
  out[0] = '\0';
  if (!append_str(out, out_size, &pos, "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n")) return 0;
  if (!append_str(out, out_size, &pos, "<stream:stream xmlns=\"jabber:client\" xmlns:stream=\"http://etherx.jabber.org/streams\" from=\"")) return 0;
  if (!append_str(out, out_size, &pos, from_e)) return 0;
  if (!append_str(out, out_size, &pos, "\" to=\"")) return 0;
  if (!append_str(out, out_size, &pos, to_e)) return 0;
  if (!append_str(out, out_size, &pos, "\">")) return 0;
  return 1;
}

int barev_build_stream_end(char *out, size_t out_size) {
  size_t pos;
  if (!out || out_size == 0) return 0;
  pos = 0;
  out[0] = '\0';
  return append_str(out, out_size, &pos, "</stream:stream>");
}

int barev_build_presence(const char *to_jid, int status, const char *status_msg, char *out, size_t out_size) {
  size_t pos;
  char to_e[512], msg_e[1024];
  const char *show = 0;
  if (!out || out_size == 0) return 0;
  pos = 0;
  out[0] = '\0';

  if (!append_str(out, out_size, &pos, "<presence")) return 0;
  if (to_jid && to_jid[0] != '\0') {
    if (!barev_xml_escape(to_jid, to_e, sizeof(to_e))) return 0;
    if (!append_str(out, out_size, &pos, " to=\"")) return 0;
    if (!append_str(out, out_size, &pos, to_e)) return 0;
    if (!append_str(out, out_size, &pos, "\"")) return 0;
  }
  if (!append_str(out, out_size, &pos, ">")) return 0;

  if (status == 2) show = "away";
  else if (status == 3) show = "xa";
  else if (status == 4) show = "dnd";
  else if (status == 0) show = "offline";

  if (show) {
    if (!append_str(out, out_size, &pos, "<show>")) return 0;
    if (!append_str(out, out_size, &pos, show)) return 0;
    if (!append_str(out, out_size, &pos, "</show>")) return 0;
  }

  if (status_msg && status_msg[0] != '\0') {
    if (!barev_xml_escape(status_msg, msg_e, sizeof(msg_e))) return 0;
    if (!append_str(out, out_size, &pos, "<status>")) return 0;
    if (!append_str(out, out_size, &pos, msg_e)) return 0;
    if (!append_str(out, out_size, &pos, "</status>")) return 0;
  }

  if (!append_str(out, out_size, &pos, "</presence>")) return 0;
  return 1;
}

int barev_build_message(const char *from_jid, const char *to_jid, const char *body, char *out, size_t out_size) {
  size_t pos;
  char from_e[512], to_e[512], body_e[2048];
  if (!from_jid || !to_jid || !body || !out || out_size == 0) return 0;
  if (!barev_xml_escape(from_jid, from_e, sizeof(from_e))) return 0;
  if (!barev_xml_escape(to_jid, to_e, sizeof(to_e))) return 0;
  if (!barev_xml_escape(body, body_e, sizeof(body_e))) return 0;

  pos = 0;
  out[0] = '\0';
  if (!append_str(out, out_size, &pos, "<message to=\"")) return 0;
  if (!append_str(out, out_size, &pos, to_e)) return 0;
  if (!append_str(out, out_size, &pos, "\" from=\"")) return 0;
  if (!append_str(out, out_size, &pos, from_e)) return 0;
  if (!append_str(out, out_size, &pos, "\" type=\"chat\"><body>")) return 0;
  if (!append_str(out, out_size, &pos, body_e)) return 0;
  if (!append_str(out, out_size, &pos, "</body></message>")) return 0;
  return 1;
}

int barev_build_ping(const char *from_jid, const char *to_jid, const char *ping_id, char *out, size_t out_size) {
  size_t pos;
  char from_e[512], to_e[512], id_e[256];
  if (!from_jid || !to_jid || !ping_id || !out || out_size == 0) return 0;
  if (!barev_xml_escape(from_jid, from_e, sizeof(from_e))) return 0;
  if (!barev_xml_escape(to_jid, to_e, sizeof(to_e))) return 0;
  if (!barev_xml_escape(ping_id, id_e, sizeof(id_e))) return 0;
  pos = 0;
  out[0] = '\0';
  if (!append_str(out, out_size, &pos, "<iq type=\"get\" id=\"")) return 0;
  if (!append_str(out, out_size, &pos, id_e)) return 0;
  if (!append_str(out, out_size, &pos, "\" from=\"")) return 0;
  if (!append_str(out, out_size, &pos, from_e)) return 0;
  if (!append_str(out, out_size, &pos, "\" to=\"")) return 0;
  if (!append_str(out, out_size, &pos, to_e)) return 0;
  if (!append_str(out, out_size, &pos, "\"><ping xmlns=\"urn:xmpp:ping\"/></iq>")) return 0;
  return 1;
}

int barev_build_pong(const char *to_jid, const char *ping_id, char *out, size_t out_size) {
  size_t pos;
  char to_e[512], id_e[256];
  if (!to_jid || !ping_id || !out || out_size == 0) return 0;
  if (!barev_xml_escape(to_jid, to_e, sizeof(to_e))) return 0;
  if (!barev_xml_escape(ping_id, id_e, sizeof(id_e))) return 0;
  pos = 0;
  out[0] = '\0';
  if (!append_str(out, out_size, &pos, "<iq type=\"result\" to=\"")) return 0;
  if (!append_str(out, out_size, &pos, to_e)) return 0;
  if (!append_str(out, out_size, &pos, "\" id=\"")) return 0;
  if (!append_str(out, out_size, &pos, id_e)) return 0;
  if (!append_str(out, out_size, &pos, "\"/>")) return 0;
  return 1;
}

int barev_build_chatstate(const char *to_jid, const char *state_name, char *out, size_t out_size) {
  size_t pos;
  char to_e[512], st_e[64];
  if (!to_jid || !state_name || !out || out_size == 0) return 0;
  if (!barev_xml_escape(to_jid, to_e, sizeof(to_e))) return 0;
  if (!barev_xml_escape(state_name, st_e, sizeof(st_e))) return 0;
  pos = 0;
  out[0] = '\0';
  if (!append_str(out, out_size, &pos, "<message type=\"chat\" to=\"")) return 0;
  if (!append_str(out, out_size, &pos, to_e)) return 0;
  if (!append_str(out, out_size, &pos, "\" id=\"chat-1\"><")) return 0;
  if (!append_str(out, out_size, &pos, st_e)) return 0;
  if (!append_str(out, out_size, &pos, " xmlns=\"http://jabber.org/protocol/chatstates\"/></message>")) return 0;
  return 1;
}

int barev_build_vcard_get(const char *to_jid, const char *id, char *out, size_t out_size) {
  size_t pos;
  char to_e[512], id_e[128];
  if (!to_jid || !id || !out || out_size == 0) return 0;
  if (!barev_xml_escape(to_jid, to_e, sizeof(to_e))) return 0;
  if (!barev_xml_escape(id, id_e, sizeof(id_e))) return 0;
  pos = 0;
  out[0] = '\0';
  if (!append_str(out, out_size, &pos, "<iq type=\"get\" to=\"")) return 0;
  if (!append_str(out, out_size, &pos, to_e)) return 0;
  if (!append_str(out, out_size, &pos, "\" id=\"")) return 0;
  if (!append_str(out, out_size, &pos, id_e)) return 0;
  if (!append_str(out, out_size, &pos, "\"><vCard xmlns=\"vcard-temp\"/></iq>")) return 0;
  return 1;
}

int barev_build_vcard_result(const char *to_jid, const char *id, const char *vcard_inner, char *out, size_t out_size) {
  size_t pos;
  char to_e[512], id_e[128];
  if (!to_jid || !id || !vcard_inner || !out || out_size == 0) return 0;
  if (!barev_xml_escape(to_jid, to_e, sizeof(to_e))) return 0;
  if (!barev_xml_escape(id, id_e, sizeof(id_e))) return 0;
  pos = 0;
  out[0] = '\0';
  if (!append_str(out, out_size, &pos, "<iq type=\"result\" to=\"")) return 0;
  if (!append_str(out, out_size, &pos, to_e)) return 0;
  if (!append_str(out, out_size, &pos, "\" id=\"")) return 0;
  if (!append_str(out, out_size, &pos, id_e)) return 0;
  if (!append_str(out, out_size, &pos, "\">")) return 0;
  if (!append_str(out, out_size, &pos, vcard_inner)) return 0;
  if (!append_str(out, out_size, &pos, "</iq>")) return 0;
  return 1;
}

int barev_extract_attribute(const char *xml, const char *attr_name, char *out, size_t out_size) {
  const char *p;
  const char *q;
  size_t n;
  char pat[128];
  if (!xml || !attr_name || !out || out_size == 0) return 0;
  out[0] = '\0';
  if (strlen(attr_name) + 3 >= sizeof(pat)) return 0;
  strcpy(pat, attr_name);
  strcat(pat, "='");
  p = strstr(xml, pat);
  if (!p) {
    strcpy(pat, attr_name);
    strcat(pat, "=\"");
    p = strstr(xml, pat);
    if (!p) return 0;
  }
  p += strlen(pat);
  q = p;
  while (*q && *q != '\'' && *q != '"') q++;
  n = (size_t)(q - p);
  if (n + 1 > out_size) return 0;
  memcpy(out, p, n);
  out[n] = '\0';
  return 1;
}

int barev_extract_element_content(const char *xml, const char *element, char *out, size_t out_size) {
  char open[128], close[128];
  const char *p;
  const char *q;
  size_t n;
  if (!xml || !element || !out || out_size == 0) return 0;
  out[0] = '\0';
  if (strlen(element) + 3 >= sizeof(open)) return 0;
  strcpy(open, "<"); strcat(open, element); strcat(open, ">");
  strcpy(close, "</"); strcat(close, element); strcat(close, ">");
  p = strstr(xml, open);
  if (!p) return 0;
  p += strlen(open);
  q = strstr(p, close);
  if (!q) return 0;
  n = (size_t)(q - p);
  if (n + 1 > out_size) return 0;
  memcpy(out, p, n);
  out[n] = '\0';
  return 1;
}