/////////////////////////////////////////////////////////////////////////////
// Name:        url.cpp
// Purpose:     URL parser
// Author:      Guilhem Lavaux
// Modified by:
// Created:     20/07/1997
// RCS-ID:      $Id$
// Copyright:   (c) 1997, 1998 Guilhem Lavaux
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

#ifdef __GNUG__
#pragma implementation "url.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#include <string.h>
#include <ctype.h>

#include "wx/string.h"
#include "wx/list.h"
#include "wx/utils.h"
#include "wx/module.h"
#include "wx/url.h"

IMPLEMENT_CLASS(wxProtoInfo, wxObject)
IMPLEMENT_CLASS(wxURL, wxObject)

// Protocols list
wxProtoInfo *wxURL::ms_protocols = NULL;

#if wxUSE_SOCKETS
    wxHTTP *wxURL::ms_proxyDefault = NULL;
    bool wxURL::ms_useDefaultProxy = FALSE;
#endif

// --------------------------------------------------------------
// wxURL
// --------------------------------------------------------------

// --------------------------------------------------------------
// --------- wxURL CONSTRUCTOR DESTRUCTOR -----------------------
// --------------------------------------------------------------

wxURL::wxURL(const wxString& url)
{
    m_protocol = NULL;
    m_error = wxURL_NOERR;
    m_url = url;

#if wxUSE_SOCKETS
    if ( ms_useDefaultProxy && !ms_proxyDefault )
    {
        SetDefaultProxy(getenv("HTTP_PROXY"));

        if ( !ms_proxyDefault )
        {
            // don't try again
            ms_useDefaultProxy = FALSE;
        }
    }

    m_useProxy = ms_proxyDefault != NULL;
    m_proxy = ms_proxyDefault;
#endif // wxUSE_SOCKETS

    ParseURL();
}

bool wxURL::ParseURL()
{
  wxString last_url = m_url;

  // If the URL was already parsed (m_protocol != NULL), pass this section.
  if (!m_protocol)
  {
    // Clean up
    CleanData();

    // Extract protocol name
    if (!PrepProto(last_url))
    {
      m_error = wxURL_SNTXERR;
      return FALSE;
    }

    // Find and create the protocol object
    if (!FetchProtocol())
    {
      m_error = wxURL_NOPROTO;
      return FALSE;
    }

    // Do we need a host name ?
    if (m_protoinfo->m_needhost)
    {
      // Extract it
      if (!PrepHost(last_url))
      {
        m_error = wxURL_SNTXERR;
        return FALSE;
      }
    }

    // Extract full path
    if (!PrepPath(last_url))
    {
      m_error = wxURL_NOPATH;
      return FALSE;
    }
  }
  // URL parse finished.

#if wxUSE_SOCKETS
  if (m_useProxy)
  {
    // We destroy the newly created protocol.
    CleanData();

    // Third, we rebuild the URL.
    m_url = m_protoname + wxT(":");
    if (m_protoinfo->m_needhost)
      m_url = m_url + wxT("//") + m_hostname;

    m_url += m_path;

    // We initialize specific variables.
    m_protocol = m_proxy; // FIXME: we should clone the protocol
  }
#endif

  m_error = wxURL_NOERR;
  return TRUE;
}

void wxURL::CleanData()
{
#if wxUSE_SOCKETS
  if (!m_useProxy)
#endif
    delete m_protocol;
}

wxURL::~wxURL()
{
  CleanData();
#if wxUSE_SOCKETS
  if (m_proxy && m_proxy != ms_proxyDefault)
    delete m_proxy;
#endif
}

// --------------------------------------------------------------
// --------- wxURL urls decoders --------------------------------
// --------------------------------------------------------------

bool wxURL::PrepProto(wxString& url)
{
  int pos;

  // Find end
  pos = url.Find(wxT(':'));
  if (pos == -1)
    return FALSE;

  m_protoname = url(0, pos);

  url = url(pos+1, url.Length());

  return TRUE;
}

bool wxURL::PrepHost(wxString& url)
{
  wxString temp_url;
  int pos, pos2;

  if ((url.GetChar(0) != wxT('/')) || (url.GetChar(1) != wxT('/')))
    return FALSE;

  url = url(2, url.Length());

  pos = url.Find(wxT('/'));
  if (pos == -1)
    pos = url.Length();

  if (pos == 0)
    return FALSE;

  temp_url = url(0, pos);
  url = url(url.Find(wxT('/')), url.Length());

  // Retrieve service number
  pos2 = temp_url.Find(wxT(':'), TRUE);
  if (pos2 != -1 && pos2 < pos)
  {
    m_servname = temp_url(pos2+1, pos);
    if (!m_servname.IsNumber())
      return FALSE;
    temp_url = temp_url(0, pos2);
  }

  // Retrieve user and password.
  pos2 = temp_url.Find(wxT('@'));
  // Even if pos2 equals -1, this code is right.
  m_hostname = temp_url(pos2+1, temp_url.Length());

  m_user = wxT("");
  m_password = wxT("");

  if (pos2 == -1)
    return TRUE;

  temp_url = temp_url(0, pos2);
  pos2 = temp_url.Find(wxT(':'));

  if (pos2 == -1)
    return FALSE;

  m_user = temp_url(0, pos2);
  m_password = temp_url(pos2+1, url.Length());

  return TRUE;
}

bool wxURL::PrepPath(wxString& url)
{
  if (url.Length() != 0)
    m_path = ConvertToValidURI(url);
  else
    m_path = wxT("/");
  return TRUE;
}

bool wxURL::FetchProtocol()
{
  wxProtoInfo *info = ms_protocols;

  while (info)
  {
    if (m_protoname == info->m_protoname)
    {
      if (m_servname.IsNull())
        m_servname = info->m_servname;

      m_protoinfo = info;
      m_protocol = (wxProtocol *)m_protoinfo->m_cinfo->CreateObject();
      return TRUE;
    }
    info = info->next;
  }
  return FALSE;
}

// --------------------------------------------------------------
// --------- wxURL get ------------------------------------------
// --------------------------------------------------------------

wxInputStream *wxURL::GetInputStream()
{
  wxInputStream *the_i_stream = NULL;

  if (!m_protocol)
  {
    m_error = wxURL_NOPROTO;
    return NULL;
  }

  m_error = wxURL_NOERR;
  if (m_user != wxT(""))
  {
    m_protocol->SetUser(m_user);
    m_protocol->SetPassword(m_password);
  }

#if wxUSE_SOCKETS
    wxIPV4address addr;

  // m_protoinfo is NULL when we use a proxy
  if (!m_useProxy && m_protoinfo->m_needhost)
  {
    if (!addr.Hostname(m_hostname))
    {
      m_error = wxURL_NOHOST;
      return NULL;
    }

    addr.Service(m_servname);

    if (!m_protocol->Connect(addr, TRUE)) // Watcom needs the 2nd arg for some reason
    {
      m_error = wxURL_CONNERR;
      return NULL;
    }
  }
#endif

  // When we use a proxy, we have to pass the whole URL to it.
  if (m_useProxy)
    the_i_stream = m_protocol->GetInputStream(m_url);
  else
    the_i_stream = m_protocol->GetInputStream(m_path);

  if (!the_i_stream)
  {
    m_error = wxURL_PROTOERR;
    return NULL;
  }

  return the_i_stream;
}

#if wxUSE_SOCKETS
void wxURL::SetDefaultProxy(const wxString& url_proxy)
{
  if ( !url_proxy )
  {
      if ( ms_proxyDefault )
      {
          ms_proxyDefault->Close();
          delete ms_proxyDefault;
          ms_proxyDefault = NULL;
      }
  }
  else
  {
      wxString tmp_str = url_proxy;
      int pos = tmp_str.Find(wxT(':'));
      if (pos == -1)
          return;

      wxString hostname = tmp_str(0, pos),
      port = tmp_str(pos+1, tmp_str.Length()-pos);
      wxIPV4address addr;

      if (!addr.Hostname(hostname))
          return;
      if (!addr.Service(port))
          return;

      if (ms_proxyDefault)
          // Finally, when all is right, we connect the new proxy.
          ms_proxyDefault->Close();
      else
          ms_proxyDefault = new wxHTTP();
      ms_proxyDefault->Connect(addr, TRUE); // Watcom needs the 2nd arg for some reason
  }
}

void wxURL::SetProxy(const wxString& url_proxy)
{
    if ( !url_proxy )
    {
        if ( m_proxy && m_proxy != ms_proxyDefault )
        {
            m_proxy->Close();
            delete m_proxy;
        }

        m_useProxy = FALSE;
    }
    else
    {
        wxString tmp_str;
        wxString hostname, port;
        int pos;
        wxIPV4address addr;

        tmp_str = url_proxy;
        pos = tmp_str.Find(wxT(':'));
        // This is an invalid proxy name.
        if (pos == -1)
            return;

        hostname = tmp_str(0, pos);
        port = tmp_str(pos, tmp_str.Length()-pos);

        addr.Hostname(hostname);
        addr.Service(port);

        // Finally, create the whole stuff.
        if (m_proxy && m_proxy != ms_proxyDefault)
            delete m_proxy;
        m_proxy = new wxHTTP();
        m_proxy->Connect(addr, TRUE); // Watcom needs the 2nd arg for some reason

        CleanData();
        // Reparse url.
        m_useProxy = TRUE;
        ParseURL();
    }
}
#endif // wxUSE_SOCKETS

wxString wxURL::ConvertToValidURI(const wxString& uri, const wxChar* delims)
{
  wxString out_str;
  wxString hexa_code;
  size_t i;

  for (i = 0; i < uri.Len(); i++)
  {
    wxChar c = uri.GetChar(i);

    if (c == wxT(' '))
    {
      // GRG, Apr/2000: changed to "%20" instead of '+'

      out_str += wxT("%20");
    }
    else
    {
      // GRG, Apr/2000: modified according to the URI definition (RFC 2396)
      // 
      // - Alphanumeric characters are never escaped
      // - Unreserved marks are never escaped
      // - Delimiters must be escaped if they appear within a component
      //     but not if they are used to separate components. Here we have
      //     no clear way to distinguish between these two cases, so they
      //     are escaped unless they are passed in the 'delims' parameter
      //     (allowed delimiters).

      static const wxChar marks[] = wxT("-_.!~*()'");

      if ( !wxIsalnum(c) && !wxStrchr(marks, c) && !wxStrchr(delims, c) )
      {
        hexa_code.Printf(wxT("%%%02X"), c);
        out_str += hexa_code;
      }
      else
      {
        out_str += c;
      }
    }
  }

  return out_str;
}

wxString wxURL::ConvertFromURI(const wxString& uri)
{
  wxString new_uri;

  size_t i = 0;
  while (i < uri.Len())
  {
    int code;
    if (uri[i] == wxT('%'))
    {
      i++;
      if (uri[i] >= wxT('A') && uri[i] <= wxT('F'))
        code = (uri[i] - wxT('A') + 10) * 16;
      else
        code = (uri[i] - wxT('0')) * 16;

      i++;
      if (uri[i] >= wxT('A') && uri[i] <= wxT('F'))
        code += (uri[i] - wxT('A')) + 10;
      else
        code += (uri[i] - wxT('0'));

      i++;
      new_uri += (wxChar)code;
      continue;
    }
    new_uri += uri[i];
    i++;
  }
  return new_uri;
}

// ----------------------------------------------------------------------
// A module which deletes the default proxy if we created it
// ----------------------------------------------------------------------

#if wxUSE_SOCKETS

class wxURLModule : public wxModule
{
public:
    virtual bool OnInit();
    virtual void OnExit();

private:
    DECLARE_DYNAMIC_CLASS(wxURLModule)
};

IMPLEMENT_DYNAMIC_CLASS(wxURLModule, wxModule)

bool wxURLModule::OnInit()
{
    // env var HTTP_PROXY contains the address of the default proxy to use if
    // set, but don't try to create this proxy right now because it will slow
    // down the program startup (especially if there is no DNS server
    // available, in which case it may take up to 1 minute)

    if ( getenv("HTTP_PROXY") )
    {
        wxURL::ms_useDefaultProxy = TRUE;
    }

    return TRUE;
}

void wxURLModule::OnExit()
{
    delete wxURL::ms_proxyDefault;
    wxURL::ms_proxyDefault = NULL;
}

#endif // wxUSE_SOCKETS
