/*
 * Copyright (c) 2003-2007, John Wiegley.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of New Artisans LLC nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "xml.h"
#include "journal.h"

namespace ledger {
namespace xml {

const std::size_t document_t::ledger_builtins_size = 12;
const char *      document_t::ledger_builtins[] = {
  "account",
  "account-path",
  "amount",
  "code",
  "commodity",
  "entries",
  "entry",
  "journal",
  "name",
  "note",
  "payee",
  "transaction"
};

document_t::document_t(node_t * _top)
  : stub(this), top(_top ? _top : &stub) {
  TRACE_CTOR(xml::document_t, "node_t *, const char **, const int");
}

document_t::~document_t()
{
  TRACE_DTOR(xml::document_t);
  if (top && top != &stub)
    checked_delete(top);
}

void document_t::set_top(node_t * _top)
{
  if (top && top != &stub)
    checked_delete(top);
  top = _top;
}

int document_t::register_name(const string& name)
{
  int index = lookup_name_id(name);
  if (index != -1)
    return index;

  names.push_back(name);
  index = names.size() - 1;

  DEBUG("xml.lookup", this << " Inserting name: " << names.back());

  std::pair<names_map::iterator, bool> result =
    names_index.insert(names_map::value_type(names.back(), index));
  assert(result.second);

  return index + 1000;
}

int document_t::lookup_name_id(const string& name) const
{
  int id;
  if ((id = lookup_builtin_id(name)) != -1)
    return id;

  DEBUG("xml.lookup", this << " Finding name: " << name);

  names_map::const_iterator i = names_index.find(name);
  if (i != names_index.end())
    return (*i).second + 1000;

  return -1;
}

int document_t::lookup_builtin_id(const string& name)
{
  int first = 0;
  int last  = (int)ledger_builtins_size;

  while (first <= last) {
    int mid = (first + last) / 2; // compute mid point.

    int result;
    if ((result = (int)name[0] - (int)ledger_builtins[mid][0]) == 0)
      result = std::strcmp(name.c_str(), ledger_builtins[mid]);

    if (result > 0)
      first = mid + 1;		// repeat search in top half.
    else if (result < 0)
      last = mid - 1;		// repeat search in bottom half.
    else
      return mid + 10;
  }

  return -1;
}

const char * document_t::lookup_name(int id) const
{
  if (id < 1000) {
    switch (id) {
    case CURRENT:
      return "CURRENT";
    case PARENT:
      return "PARENT";
    case ROOT:
      return "ROOT";
    case ALL:
      return "ALL";
    default:
      assert(id >= 10);
      return ledger_builtins[id - 10];
    }
  } else {
    return names[id - 1000].c_str();
  }
}

void document_t::print(std::ostream& out) const
{
  if (top) {
    out << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
    top->print(out);
  }
}

#ifndef THREADSAFE
document_t * node_t::document;
#endif

node_t::node_t(document_t * _document, parent_node_t * _parent,
	       flags_t _flags)
  : supports_flags<>(_flags),
    name_id(0), parent(_parent), next(NULL), prev(NULL), attrs(NULL)
{
  TRACE_CTOR(node_t, "document_t *, node_t *");
  document = _document;
  if (document && ! document->top)
    document->set_top(this);
  if (parent)
    parent->add_child(this);
}

void node_t::extract()
{
  if (prev)
    prev->next = next;

  if (parent) {
    if (parent->_children == this)
      parent->_children = next;

    if (parent->_last_child == this)
      parent->_last_child = prev;

    parent = NULL;
  }

  if (next)
    next->prev = prev;

  next = NULL;
  prev = NULL;
}

const char * node_t::name() const
{
  return document->lookup_name(name_id);
}

int node_t::set_name(const char * _name)
{
  name_id = document->register_name(_name);
  return name_id;
}

node_t * node_t::lookup_child(const char * _name) const
{
  int id = document->lookup_name_id(_name);
  return lookup_child(id);
}

node_t * node_t::lookup_child(const string& _name) const
{
  int id = document->lookup_name_id(_name);
  return lookup_child(id);
}

void parent_node_t::clear()
{
  node_t * child = _children;
  while (child) {
    node_t * tnext = child->next;
    checked_delete(child);
    child = tnext;
  }
}

void parent_node_t::add_child(node_t * node)
{
  // It is important that this node is not called before children(),
  // otherwise, this node will not get auto-populated.
  if (_children == NULL) {
    assert(_last_child == NULL);
    _children = node;
    node->prev = NULL;
  } else {
    assert(_last_child != NULL);
    _last_child->next = node;
    node->prev = _last_child;
  }

  node->parent = this;

  while (node->next) {
    node_t * next_node = node->next;
    assert(next_node->prev == node);
    next_node->parent = this;
    node = next_node;
  }

  _last_child = node;
}

void parent_node_t::print(std::ostream& out, int depth) const
{
  for (int i = 0; i < depth; i++) out << "  ";
  out << '<' << name() << ">\n";

  for (node_t * child = children(); child; child = child->next)
    child->print(out, depth + 1);

  for (int i = 0; i < depth; i++) out << "  ";
  out << "</" << name() << ">\n";
}

void terminal_node_t::print(std::ostream& out, int depth) const
{
  for (int i = 0; i < depth; i++) out << "  ";

  if (data.empty()) {
    out << '<' << name() << " />\n";
  } else {
    out << '<' << name() << ">"
	<< text()
	<< "</" << name() << ">\n";
  }
}

#if defined(HAVE_EXPAT) || defined(HAVE_XMLPARSE)

template <typename T>
inline T * create_node(document_t::parser_t * parser)
{
  T * node = new T(parser->document, parser->node_stack.empty() ?
		   NULL : parser->node_stack.front());

  node->set_name(parser->pending);
  node->attrs = parser->pending_attrs;

  parser->pending	= NULL;
  parser->pending_attrs = NULL;

  return node;
}

static void startElement(void *userData, const char *name, const char **attrs)
{
  document_t::parser_t * parser = static_cast<document_t::parser_t *>(userData);

  DEBUG("xml.parse", "startElement(" << name << ")");

  if (parser->pending) {
    parent_node_t * node = create_node<parent_node_t>(parser);
    if (parser->node_stack.empty())
      parser->document->top = node;
    parser->node_stack.push_front(node);
  }

  parser->pending = name;

  if (attrs) {
    for (const char ** p = attrs; *p; p += 2) {
      if (! parser->pending_attrs)
	parser->pending_attrs = new node_t::attrs_map;

      std::pair<node_t::attrs_map::iterator, bool> result
	= parser->pending_attrs->insert
	    (node_t::attrs_map::value_type(*p, *(p + 1)));
      assert(result.second);
    }
  }
}

static void endElement(void *userData, const char *name)
{
  document_t::parser_t * parser = static_cast<document_t::parser_t *>(userData);

  DEBUG("xml.parse", "endElement(" << name << ")");

  if (parser->pending) {
    terminal_node_t * node = create_node<terminal_node_t>(parser);
    if (parser->node_stack.empty()) {
      parser->document->top = node;
      return;
    }
  }
  else if (! parser->handled_data) {
    assert(! parser->node_stack.empty());
    parser->node_stack.pop_front();
  }
  else {
    parser->handled_data = false;
  }
}

static void dataHandler(void *userData, const char *s, int len)
{
  document_t::parser_t * parser = static_cast<document_t::parser_t *>(userData);

  DEBUG("xml.parse", "dataHandler(" << string(s, len) << ")");

  bool all_whitespace = true;
  for (int i = 0; i < len; i++) {
    if (! std::isspace(s[i])) {
      all_whitespace = false;
      break;
    }
  }

  // jww (2006-09-28): I currently do not support text nodes within a
  // node that has children.

  if (! all_whitespace) {
    terminal_node_t * node = create_node<terminal_node_t>(parser);

    node->set_text(string(s, len));
    parser->handled_data = true;

    if (parser->node_stack.empty()) {
      parser->document->top = node;
      return;
    }
  }
}

bool document_t::parser_t::test(std::istream& in) const
{
  char buf[80];

  in.getline(buf, 79);
  if (std::strncmp(buf, "<?xml", 5) != 0) {
    in.clear();
    in.seekg(0, std::ios::beg);
    return false;
  }

  in.clear();
  in.seekg(0, std::ios::beg);
  return true;
}

document_t * document_t::parser_t::parse(std::istream& in)
{
  std::auto_ptr<document_t> doc(new document_t);

  document = doc.get();

  parser = XML_ParserCreate(NULL);

  XML_SetElementHandler(parser, startElement, endElement);
  XML_SetCharacterDataHandler(parser, dataHandler);
  XML_SetUserData(parser, this);

  char buf[BUFSIZ];
  while (! in.eof()) {
    in.getline(buf, BUFSIZ - 1);
    std::strcat(buf, "\n");
    bool result;
    try {
      result = XML_Parse(parser, buf, std::strlen(buf), in.eof());
    }
    catch (const std::exception& err) {
      //unsigned long line = XML_GetCurrentLineNumber(parser) - offset++;
      XML_ParserFree(parser);
      throw_(parse_error, err.what());
    }

    if (! have_error.empty()) {
      //unsigned long line = XML_GetCurrentLineNumber(parser) - offset++;
#if 0
      // jww (2007-04-26): What is this doing??
      parse_error err(have_error);
      std::cerr << "Error: " << err.what() << std::endl;
#endif
      have_error = "";
    }

    if (! result) {
      //unsigned long line = XML_GetCurrentLineNumber(parser) - offset++;
      const char * err = XML_ErrorString(XML_GetErrorCode(parser));
      XML_ParserFree(parser);
      throw_(parse_error, err);
    }
  }

  XML_ParserFree(parser);

  document = NULL;
  return doc.release();
}

node_t * commodity_node_t::children() const
{
  // jww (2007-04-19): Need to report the commodity and its details
  return NULL;
}

node_t * amount_node_t::children() const
{
  // jww (2007-04-19): Need to report the quantity and commodity
  return NULL;
}

node_t * transaction_node_t::children() const
{
  return parent_node_t::children();
}

node_t * transaction_node_t::lookup_child(int _name_id) const
{
  switch (_name_id) {
  case document_t::PAYEE:
    payee_virtual_node = new terminal_node_t(document);
    payee_virtual_node->set_text(transaction->entry->payee);
    return payee_virtual_node;

  case document_t::ACCOUNT:
    return new account_node_t(document, transaction->account,
			      const_cast<transaction_node_t *>(this));
  }
  return NULL;
}

value_t transaction_node_t::to_value() const
{
  if (transaction->amount)
    return *transaction->amount;
  else
    return value_t();
}

node_t * entry_node_t::children() const
{
  if (! _children)
    for (transactions_list::iterator i = entry->transactions.begin();
	 i != entry->transactions.end();
	 i++)
      new transaction_node_t(document, *i, const_cast<entry_node_t *>(this));

  return parent_node_t::children();
}

node_t * entry_node_t::lookup_child(int _name_id) const
{
  switch (_name_id) {
  case document_t::CODE: {
    if (! entry->code)
      break;

    // jww (2007-04-20): I have to save this and then delete it later
    terminal_node_t * code_node =
      new terminal_node_t(document, const_cast<entry_node_t *>(this));
    code_node->set_name(document_t::CODE);
    code_node->set_text(*entry->code);
    return code_node;
  }

  case document_t::PAYEE: {
    // jww (2007-04-20): I have to save this and then delete it later
    terminal_node_t * payee_node =
      new terminal_node_t(document, const_cast<entry_node_t *>(this));
    payee_node->set_name(document_t::PAYEE);
    payee_node->set_text(entry->payee);
    return payee_node;
  }
  }
  return NULL;
}

node_t * account_node_t::children() const
{
  if (! _children) {
    if (! account->name.empty()) {
      terminal_node_t * name_node =
	new terminal_node_t(document, const_cast<account_node_t *>(this));
      name_node->set_name(document_t::NAME);
      name_node->set_text(account->name);
    }

    if (account->note) {
      terminal_node_t * note_node =
	new terminal_node_t(document, const_cast<account_node_t *>(this));
      note_node->set_name(document_t::NOTE);
      note_node->set_text(*account->note);
    }

    for (accounts_map::iterator i = account->accounts.begin();
	 i != account->accounts.end();
	 i++)
      new account_node_t(document, (*i).second, const_cast<account_node_t *>(this));
  }
  return parent_node_t::children();
}

node_t * journal_node_t::children() const
{
  if (! _children) {
#if 0
    account_node_t * master_account =
      new account_node_t(document, journal->master, const_cast<journal_node_t *>(this));
#endif

    parent_node_t * entries =
      new parent_node_t(document, const_cast<journal_node_t *>(this));
    entries->set_name(document_t::ENTRIES);

    for (entries_list::iterator i = journal->entries.begin();
	 i != journal->entries.end();
	 i++)
      new entry_node_t(document, *i, const_cast<journal_node_t *>(this));
  }
  return parent_node_t::children();
}

#endif // defined(HAVE_EXPAT) || defined(HAVE_XMLPARSE)

void output_xml_string(std::ostream& out, const string& str)
{
  for (const char * s = str.c_str(); *s; s++) {
    switch (*s) {
    case '<':
      out << "&lt;";
      break;
    case '>':
      out << "&rt;";
      break;
    case '&':
      out << "&amp;";
      break;
    default:
      out << *s;
      break;
    }
  }
}

} // namespace xml
} // namespace ledger