/**
 * \file InsetBibtex.cpp
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Alejandro Aguilar Sierra
 * \author Richard Heck (BibTeX parser improvements)
 *
 * Full author contact details are available in file CREDITS.
 */

#include <config.h>

#include "InsetBibtex.h"

#include "Buffer.h"
#include "BufferParams.h"
#include "DispatchResult.h"
#include "Encoding.h"
#include "Format.h"
#include "FuncRequest.h"
#include "FuncStatus.h"
#include "LaTeXFeatures.h"
#include "MetricsInfo.h"
#include "OutputParams.h"
#include "TextClass.h"

#include "frontends/alert.h"

#include "support/convert.h"
#include "support/debug.h"
#include "support/docstream.h"
#include "support/ExceptionMessage.h"
#include "support/filetools.h"
#include "support/gettext.h"
#include "support/lstrings.h"
#include "support/os.h"
#include "support/Path.h"
#include "support/textutils.h"

#include <limits>

using namespace std;
using namespace lyx::support;

namespace lyx {

namespace Alert = frontend::Alert;
namespace os = support::os;


InsetBibtex::InsetBibtex(Buffer const & buf, InsetCommandParams const & p)
	: InsetCommand(p, "bibtex")
{
	Inset::setBuffer(const_cast<Buffer &>(buf));
	buffer_->invalidateBibinfoCache();
}


InsetBibtex::~InsetBibtex()
{
	if (isBufferValid())
		buffer_->invalidateBibinfoCache();
}


ParamInfo const & InsetBibtex::findInfo(string const & /* cmdName */)
{
	static ParamInfo param_info_;
	if (param_info_.empty()) {
		param_info_.add("btprint", ParamInfo::LATEX_OPTIONAL);
		param_info_.add("bibfiles", ParamInfo::LATEX_REQUIRED);
		param_info_.add("options", ParamInfo::LYX_INTERNAL);
	}
	return param_info_;
}


void InsetBibtex::doDispatch(Cursor & cur, FuncRequest & cmd)
{
	switch (cmd.action) {

	case LFUN_INSET_EDIT:
		editDatabases();
		break;

	case LFUN_INSET_MODIFY: {
		InsetCommandParams p(BIBTEX_CODE);
		try {
			if (!InsetCommand::string2params("bibtex", 
					to_utf8(cmd.argument()), p)) {
				cur.noUpdate();
				break;
			}
		} catch (ExceptionMessage const & message) {
			if (message.type_ == WarningException) {
				Alert::warning(message.title_, message.details_);
				cur.noUpdate();
			} else 
				throw message;
			break;
		}
		//
		setParams(p);
		buffer().updateBibfilesCache();
		break;
	}

	default:
		InsetCommand::doDispatch(cur, cmd);
		break;
	}
}


bool InsetBibtex::getStatus(Cursor & cur, FuncRequest const & cmd,
		FuncStatus & flag) const
{
	switch (cmd.action) {
	case LFUN_INSET_EDIT:
		flag.setEnabled(true);
		return true;

	default:
		return InsetCommand::getStatus(cur, cmd, flag);
	}
}


void InsetBibtex::editDatabases() const
{
	vector<docstring> bibfilelist = getVectorFromString(getParam("bibfiles"));

	if (bibfilelist.empty())
		return;

	int nr_databases = bibfilelist.size();
	if (nr_databases > 1) {
			docstring message = bformat(_("The BibTeX inset includes %1$s databases.\n"
						       "If you proceed, all of them will be opened."),
							convert<docstring>(nr_databases));
			int const ret = Alert::prompt(_("Open Databases?"),
				message, 0, 1, _("&Cancel"), _("&Proceed"));

			if (ret == 0)
				return;
	}

	vector<docstring>::const_iterator it = bibfilelist.begin();
	vector<docstring>::const_iterator en = bibfilelist.end();
	for (; it != en; ++it) {
		FileName bibfile = getBibTeXPath(*it, buffer());
		formats.edit(buffer(), bibfile,
		     formats.getFormatFromFile(bibfile));
	}
}


docstring InsetBibtex::screenLabel() const
{
	return _("BibTeX Generated Bibliography");
}


docstring InsetBibtex::toolTip(BufferView const & /*bv*/, int /*x*/, int /*y*/) const
{
	docstring item = from_ascii("* ");
	docstring tip = _("Databases:") + "\n";
	vector<docstring> bibfilelist = getVectorFromString(getParam("bibfiles"));

	if (bibfilelist.empty()) {
		tip += item;
		tip += _("none");
	} else {
		vector<docstring>::const_iterator it = bibfilelist.begin();
		vector<docstring>::const_iterator en = bibfilelist.end();
		for (; it != en; ++it) {
			tip += item;
			tip += *it + "\n";
		}
	}

	// Style-Options
	bool toc = false;
	docstring style = getParam("options"); // maybe empty! and with bibtotoc
	docstring bibtotoc = from_ascii("bibtotoc");
	if (prefixIs(style, bibtotoc)) {
		toc = true;
		if (contains(style, char_type(',')))
			style = split(style, bibtotoc, char_type(','));
	}

	tip += _("Style File:") +"\n";
	tip += item;
	if (!style.empty())
		tip += style;
	else
		tip += _("none");

	tip += "\n" + _("Lists:") + " ";
	docstring btprint = getParam("btprint");
		if (btprint == "btPrintAll")
			tip += _("all references");
		else if (btprint == "btPrintNotCited")
			tip += _("all uncited references");
		else
			tip += _("all cited references");
	
	if (toc) {
		tip += ", ";
		tip += _("included in TOC");
	}

	return tip;
}


static string normalizeName(Buffer const & buffer,
	OutputParams const & runparams, string const & name, string const & ext)
{
	string const fname = makeAbsPath(name, buffer.filePath()).absFilename();
	if (FileName(name).isAbsolute() || !FileName(fname + ext).isReadableFile())
		return name;
	if (!runparams.nice)
		return fname;

	// FIXME UNICODE
	return to_utf8(makeRelPath(from_utf8(fname),
					 from_utf8(buffer.masterBuffer()->filePath())));
}


int InsetBibtex::latex(odocstream & os, OutputParams const & runparams) const
{
	// the sequence of the commands:
	// 1. \bibliographystyle{style}
	// 2. \addcontentsline{...} - if option bibtotoc set
	// 3. \bibliography{database}
	// and with bibtopic:
	// 1. \bibliographystyle{style}
	// 2. \begin{btSect}{database}
	// 3. \btPrint{Cited|NotCited|All}
	// 4. \end{btSect}

	// Database(s)
	// If we are processing the LaTeX file in a temp directory then
	// copy the .bib databases to this temp directory, mangling their
	// names in the process. Store this mangled name in the list of
	// all databases.
	// (We need to do all this because BibTeX *really*, *really*
	// can't handle "files with spaces" and Windows users tend to
	// use such filenames.)
	// Otherwise, store the (maybe absolute) path to the original,
	// unmangled database name.
	vector<docstring> bibfilelist = getVectorFromString(getParam("bibfiles"));
	vector<docstring>::const_iterator it = bibfilelist.begin();
	vector<docstring>::const_iterator en = bibfilelist.end();
	odocstringstream dbs;
	bool didone = false;

	for (; it != en; ++it) {
		string utf8input = to_utf8(*it);
		string database =
			normalizeName(buffer(), runparams, utf8input, ".bib");
		FileName const try_in_file =
			makeAbsPath(database + ".bib", buffer().filePath());
		bool const not_from_texmf = try_in_file.isReadableFile();

		if (!runparams.inComment && !runparams.dryrun && !runparams.nice &&
		    not_from_texmf) {

			// mangledFilename() needs the extension
			DocFileName const in_file = DocFileName(try_in_file);
			database = removeExtension(in_file.mangledFilename());
			FileName const out_file = makeAbsPath(database + ".bib",
					buffer().masterBuffer()->temppath());

			bool const success = in_file.copyTo(out_file);
			if (!success) {
				lyxerr << "Failed to copy '" << in_file
				       << "' to '" << out_file << "'"
				       << endl;
			}
		} else if (!runparams.inComment && runparams.nice && not_from_texmf &&
			   !isValidLaTeXFilename(database)) {
				frontend::Alert::warning(_("Invalid filename"),
						         _("The following filename is likely to cause trouble "
							   "when running the exported file through LaTeX: ") +
							    from_utf8(database));
		}

		if (didone)
			dbs << ',';
		else 
			didone = true;
		// FIXME UNICODE
		dbs << from_utf8(latex_path(database));
	}
	docstring const db_out = dbs.str();

	// Post this warning only once.
	static bool warned_about_spaces = false;
	if (!warned_about_spaces &&
	    runparams.nice && db_out.find(' ') != docstring::npos) {
		warned_about_spaces = true;

		Alert::warning(_("Export Warning!"),
			       _("There are spaces in the paths to your BibTeX databases.\n"
					      "BibTeX will be unable to find them."));
	}
	// Style-Options
	string style = to_utf8(getParam("options")); // maybe empty! and with bibtotoc
	string bibtotoc;
	if (prefixIs(style, "bibtotoc")) {
		bibtotoc = "bibtotoc";
		if (contains(style, ','))
			style = split(style, bibtotoc, ',');
	}


	// line count
	int nlines = 0;

	if (!style.empty()) {
		string base = normalizeName(buffer(), runparams, style, ".bst");
		FileName const try_in_file = 
			makeAbsPath(base + ".bst", buffer().filePath());
		bool const not_from_texmf = try_in_file.isReadableFile();
		// If this style does not come from texmf and we are not
		// exporting to .tex copy it to the tmp directory.
		// This prevents problems with spaces and 8bit charcaters
		// in the file name.
		if (!runparams.inComment && !runparams.dryrun && !runparams.nice &&
		    not_from_texmf) {
			// use new style name
			DocFileName const in_file = DocFileName(try_in_file);
			base = removeExtension(in_file.mangledFilename());
			FileName const out_file = makeAbsPath(base + ".bst",
					buffer().masterBuffer()->temppath());
			bool const success = in_file.copyTo(out_file);
			if (!success) {
				lyxerr << "Failed to copy '" << in_file
				       << "' to '" << out_file << "'"
				       << endl;
			}
		}
		// FIXME UNICODE
		os << "\\bibliographystyle{"
		   << from_utf8(latex_path(normalizeName(buffer(), runparams, base, ".bst")))
		   << "}\n";
		nlines += 1;
	}

	// Post this warning only once.
	static bool warned_about_bst_spaces = false;
	if (!warned_about_bst_spaces && runparams.nice && contains(style, ' ')) {
		warned_about_bst_spaces = true;
		Alert::warning(_("Export Warning!"),
			       _("There are spaces in the path to your BibTeX style file.\n"
					      "BibTeX will be unable to find it."));
	}

	if (!db_out.empty() && buffer().params().use_bibtopic) {
		os << "\\begin{btSect}{" << db_out << "}\n";
		docstring btprint = getParam("btprint");
		if (btprint.empty())
			// default
			btprint = from_ascii("btPrintCited");
		os << "\\" << btprint << "\n"
		   << "\\end{btSect}\n";
		nlines += 3;
	}

	// bibtotoc-Option
	if (!bibtotoc.empty() && !buffer().params().use_bibtopic) {
		if (buffer().params().documentClass().hasLaTeXLayout("chapter")) {
			if (buffer().params().sides == OneSide) {
				// oneside
				os << "\\clearpage";
			} else {
				// twoside
				os << "\\cleardoublepage";
			}
			os << "\\addcontentsline{toc}{chapter}{\\bibname}";
		} else if (buffer().params().documentClass().hasLaTeXLayout("section"))
			os << "\\addcontentsline{toc}{section}{\\refname}";
	}

	if (!db_out.empty() && !buffer().params().use_bibtopic) {
		docstring btprint = getParam("btprint");
		if (btprint == "btPrintAll") {
			os << "\\nocite{*}\n";
			nlines += 1;
		}
		os << "\\bibliography{" << db_out << "}\n";
		nlines += 1;
	}

	return nlines;
}


support::FileNameList InsetBibtex::getBibFiles() const
{
	FileName path(buffer().filePath());
	support::PathChanger p(path);
	
	support::FileNameList vec;
	
	vector<docstring> bibfilelist = getVectorFromString(getParam("bibfiles"));
	vector<docstring>::const_iterator it = bibfilelist.begin();
	vector<docstring>::const_iterator en = bibfilelist.end();
	for (; it != en; ++it) {
		FileName const file = 
			findtexfile(changeExtension(to_utf8(*it), "bib"), "bib");

		if (!file.empty())
			vec.push_back(file);
		else
			LYXERR0("Couldn't find " + to_utf8(*it) + " in InsetBibtex::getBibFiles()!");
	}
	
	return vec;

}

namespace {

	// methods for parsing bibtex files

	typedef map<docstring, docstring> VarMap;

	/// remove whitespace characters, optionally a single comma,
	/// and further whitespace characters from the stream.
	/// @return true if a comma was found, false otherwise
	///
	bool removeWSAndComma(ifdocstream & ifs) {
		char_type ch;

		if (!ifs)
			return false;

		// skip whitespace
		do {
			ifs.get(ch);
		} while (ifs && isSpace(ch));

		if (!ifs)
			return false;

		if (ch != ',') {
			ifs.putback(ch);
			return false;
		}

		// skip whitespace
		do {
			ifs.get(ch);
		} while (ifs && isSpace(ch));

		if (ifs) {
			ifs.putback(ch);
		}

		return true;
	}


	enum charCase {
		makeLowerCase,
		keepCase
	};

	/// remove whitespace characters, read characer sequence
	/// not containing whitespace characters or characters in
	/// delimChars, and remove further whitespace characters.
	///
	/// @return true if a string of length > 0 could be read.
	///
	bool readTypeOrKey(docstring & val, ifdocstream & ifs,
		docstring const & delimChars, docstring const &illegalChars, 
		charCase chCase) {

		char_type ch;

		val.clear();

		if (!ifs)
			return false;

		// skip whitespace
		do {
			ifs.get(ch);
		} while (ifs && isSpace(ch));

		if (!ifs)
			return false;

		// read value
		bool legalChar = true;
		while (ifs && !isSpace(ch) && 
						 delimChars.find(ch) == docstring::npos &&
						 (legalChar = (illegalChars.find(ch) == docstring::npos))
					) 
		{
			if (chCase == makeLowerCase)
				val += lowercase(ch);
			else
				val += ch;
			ifs.get(ch);
		}
		
		if (!legalChar) {
			ifs.putback(ch);
			return false;
		}

		// skip whitespace
		while (ifs && isSpace(ch)) {
			ifs.get(ch);
		}

		if (ifs) {
			ifs.putback(ch);
		}

		return val.length() > 0;
	}

	/// read subsequent bibtex values that are delimited with a #-character.
	/// Concatenate all parts and replace names with the associated string in
	/// the variable strings.
	/// @return true if reading was successfull (all single parts were delimited
	/// correctly)
	bool readValue(docstring & val, ifdocstream & ifs, const VarMap & strings) {

		char_type ch;

		val.clear();

		if (!ifs)
			return false;

		do {
			// skip whitespace
			do {
				ifs.get(ch);
			} while (ifs && isSpace(ch));

			if (!ifs)
				return false;

			// check for field type
			if (isDigit(ch)) {

				// read integer value
				do {
					val += ch;
					ifs.get(ch);
				} while (ifs && isDigit(ch));

				if (!ifs)
					return false;

			} else if (ch == '"' || ch == '{') {
				// set end delimiter
				char_type delim = ch == '"' ? '"': '}';

				// Skip whitespace
				do {
					ifs.get(ch);
				} while (ifs && isSpace(ch));
				
				if (!ifs)
					return false;
				
				// We now have the first non-whitespace character
				// We'll collapse adjacent whitespace.
				bool lastWasWhiteSpace = false;
				
 				// inside this delimited text braces must match.
 				// Thus we can have a closing delimiter only
 				// when nestLevel == 0
				int nestLevel = 0;
 
				while (ifs && (nestLevel > 0 || ch != delim)) {
					if (isSpace(ch)) {
						lastWasWhiteSpace = true;
						ifs.get(ch);
						continue;
					}
					// We output the space only after we stop getting 
					// whitespace so as not to output any whitespace
					// at the end of the value.
					if (lastWasWhiteSpace) {
						lastWasWhiteSpace = false;
						val += ' ';
					}
					
					val += ch;

					// update nesting level
					switch (ch) {
						case '{':
							++nestLevel;
							break;
						case '}':
							--nestLevel;
							if (nestLevel < 0) return false;
							break;
					}

					ifs.get(ch);
				}

				if (!ifs)
					return false;

				ifs.get(ch);

				if (!ifs)
					return false;

			} else {

				// reading a string name
				docstring strName;

				while (ifs && !isSpace(ch) && ch != '#' && ch != ',' && ch != '}' && ch != ')') {
					strName += lowercase(ch);
					ifs.get(ch);
				}

				if (!ifs)
					return false;

				// replace the string with its assigned value or
				// discard it if it's not assigned
				if (strName.length()) {
					VarMap::const_iterator pos = strings.find(strName);
					if (pos != strings.end()) {
						val += pos->second;
					}
				}
			}

			// skip WS
			while (ifs && isSpace(ch)) {
				ifs.get(ch);
			}

			if (!ifs)
				return false;

			// continue reading next value on concatenate with '#'
		} while (ch == '#');

		ifs.putback(ch);

		return true;
	}
}


// This method returns a comma separated list of Bibtex entries
void InsetBibtex::fillWithBibKeys(BiblioInfo & keylist,
	InsetIterator const & /*di*/) const
{
	// This bibtex parser is a first step to parse bibtex files
	// more precisely.
	//
	// - it reads the whole bibtex entry and does a syntax check
	//   (matching delimiters, missing commas,...
	// - it recovers from errors starting with the next @-character
	// - it reads @string definitions and replaces them in the
	//   field values.
	// - it accepts more characters in keys or value names than
	//   bibtex does.
	//
	// Officially bibtex does only support ASCII, but in practice
	// you can use the encoding of the main document as long as
	// some elements like keys and names are pure ASCII. Therefore
	// we convert the file from the buffer encoding.
	// We don't restrict keys to ASCII in LyX, since our own
	// InsetBibitem can generate non-ASCII keys, and nonstandard
	// 8bit clean bibtex forks exist.
	support::FileNameList const files = getBibFiles();
	support::FileNameList::const_iterator it = files.begin();
	support::FileNameList::const_iterator en = files.end();
	for (; it != en; ++ it) {
		ifdocstream ifs(it->toFilesystemEncoding().c_str(),
			ios_base::in, buffer().params().encoding().iconvName());

		char_type ch;
		VarMap strings;

		while (ifs) {

			ifs.get(ch);
			if (!ifs)
				break;

			if (ch != '@')
				continue;

			docstring entryType;

			if (!readTypeOrKey(entryType, ifs, from_ascii("{("), docstring(), makeLowerCase)) {
				lyxerr << "InsetBibtex::fillWithBibKeys: Error reading entry type." << std::endl;
				continue;
			}

			if (!ifs) {
				lyxerr << "InsetBibtex::fillWithBibKeys: Unexpected end of file." << std::endl;
				continue;
			}

			if (entryType == from_ascii("comment")) {
				ifs.ignore(numeric_limits<int>::max(), '\n');
				continue;
			}

			ifs.get(ch);
			if (!ifs) {
				lyxerr << "InsetBibtex::fillWithBibKeys: Unexpected end of file." << std::endl;
				break;
			}

			if ((ch != '(') && (ch != '{')) {
				lyxerr << "InsetBibtex::fillWithBibKeys: Invalid entry delimiter." << std::endl;
				ifs.putback(ch);
				continue;
			}

			// process the entry
			if (entryType == from_ascii("string")) {

				// read string and add it to the strings map
				// (or replace it's old value)
				docstring name;
				docstring value;

				if (!readTypeOrKey(name, ifs, from_ascii("="), from_ascii("#{}(),"), makeLowerCase)) {
					lyxerr << "InsetBibtex::fillWithBibKeys: Error reading string name." << std::endl;
					continue;
				}

				if (!ifs) {
					lyxerr << "InsetBibtex::fillWithBibKeys: Unexpected end of file." << std::endl;
					continue;
				}

				// next char must be an equal sign
				ifs.get(ch);
				if (!ifs || ch != '=') {
					lyxerr << "InsetBibtex::fillWithBibKeys: No `=' after string name: " << 
							name << "." << std::endl;
					continue;
				}

				if (!readValue(value, ifs, strings)) {
					lyxerr << "InsetBibtex::fillWithBibKeys: Unable to read value for string: " << 
							name << "." << std::endl;
					continue;
				}

				strings[name] = value;

			} else if (entryType == from_ascii("preamble")) {

				// preamble definitions are discarded.
				// can they be of any use in lyx?
				docstring value;

				if (!readValue(value, ifs, strings)) {
					lyxerr << "InsetBibtex::fillWithBibKeys: Unable to read preamble value." << std::endl;
					continue;
				}

			} else {

				// Citation entry. Try to read the key.
				docstring key;

				if (!readTypeOrKey(key, ifs, from_ascii(","), from_ascii("}"), keepCase)) {
					lyxerr << "InsetBibtex::fillWithBibKeys: Unable to read key for entry type:" << 
							entryType << "." << std::endl;
					continue;
				}

				if (!ifs) {
					lyxerr << "InsetBibtex::fillWithBibKeys: Unexpected end of file." << std::endl;
					continue;
				}

				/////////////////////////////////////////////
				// now we have a key, so we will add an entry 
 				// (even if it's empty, as bibtex does)
				//
				// we now read the field = value pairs.
 				// all items must be separated by a comma. If
 				// it is missing the scanning of this entry is
 				// stopped and the next is searched.
				docstring fields;
				docstring name;
				docstring value;
				docstring commaNewline;
				docstring data;
				BibTeXInfo keyvalmap(key, entryType);
				
				bool readNext = removeWSAndComma(ifs);
 
				while (ifs && readNext) {

					// read field name
					if (!readTypeOrKey(name, ifs, from_ascii("="), 
					                   from_ascii("{}(),"), makeLowerCase) || !ifs)
						break;

					// next char must be an equal sign
					ifs.get(ch);
					if (!ifs) {
						lyxerr << "InsetBibtex::fillWithBibKeys: Unexpected end of file." << std::endl;
						break;
					}
					if (ch != '=') {
						lyxerr << "InsetBibtex::fillWithBibKeys: Missing `=' after field name: " <<
								name << ", for key: " << key << "." << std::endl;
						ifs.putback(ch);
						break;
					}

					// read field value
					if (!readValue(value, ifs, strings)) {
						lyxerr << "InsetBibtex::fillWithBibKeys: Unable to read value for field: " <<
								name << ", for key: " << key << "." << std::endl;
						break;
					}

					keyvalmap[name] = value;
					data += "\n\n" + value;
					keylist.addFieldName(name);
					readNext = removeWSAndComma(ifs);
				}

				// add the new entry
				keylist.addEntryType(entryType);
				keyvalmap.setAllData(data);
				keylist[key] = keyvalmap;
			} //< else (citation entry)
		} //< searching '@'
	} //< for loop over files
}


FileName InsetBibtex::getBibTeXPath(docstring const & filename, Buffer const & buf)
{
	string texfile = changeExtension(to_utf8(filename), "bib");
	// note that, if the filename can be found directly from the path, 
	// findtexfile will just return a FileName object for that path.
	FileName file(findtexfile(texfile, "bib"));
	if (file.empty())
		file = FileName(makeAbsPath(texfile, buf.filePath()));
	return file;
}
 

bool InsetBibtex::addDatabase(docstring const & db)
{
	docstring bibfiles = getParam("bibfiles");
	if (tokenPos(bibfiles, ',', db) != -1)
		return false;
	if (!bibfiles.empty())
		bibfiles += ',';
	setParam("bibfiles", bibfiles + db);
	return true;
}


bool InsetBibtex::delDatabase(docstring const & db)
{
	docstring bibfiles = getParam("bibfiles");
	if (contains(bibfiles, db)) {
		int const n = tokenPos(bibfiles, ',', db);
		docstring bd = db;
		if (n > 0) {
			// this is not the first database
			docstring tmp = ',' + bd;
			setParam("bibfiles", subst(bibfiles, tmp, docstring()));
		} else if (n == 0)
			// this is the first (or only) database
			setParam("bibfiles", split(bibfiles, bd, ','));
		else
			return false;
	}
	return true;
}


void InsetBibtex::validate(LaTeXFeatures & features) const
{
	if (features.bufferParams().use_bibtopic)
		features.require("bibtopic");
}


docstring InsetBibtex::contextMenu(BufferView const &, int, int) const
{
	return from_ascii("context-bibtex");
}


} // namespace lyx