/**
 * \file os_cygwin.cpp
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Ruurd A. Reitsma
 * \author Claus Hentschel
 * \author Angus Leeming
 * \author Enrico Forestieri
 *
 * Full author contact details are available in file CREDITS.
 *
 * Various OS specific functions
 */

#include <config.h>

#include "LyXRC.h"

#include "support/os.h"

#include "support/debug.h"
#include "support/environment.h"
#include "support/FileName.h"
#include "support/filetools.h"
#include "support/lassert.h"
#include "support/lstrings.h"

#include <windows.h>
#include <io.h>
#include <windef.h>
#include <shellapi.h>
#include <shlwapi.h>
#include <limits.h>
#include <stdlib.h>

#include <cygwin/version.h>
#include <sys/cygwin.h>

#include <ostream>

using namespace std;

namespace lyx {

void lyx_exit(int);

namespace support {
namespace os {

namespace {

int argc_ = 0;
char ** argv_ = 0;

bool windows_style_tex_paths_ = false;

// In both is_posix_path() and is_windows_path() it is assumed that
// a valid posix or pseudo-windows path is passed. They simply tell
// whether the path looks posix/pseudo-windows or not.

bool is_posix_path(string const & p)
{
	return  p.empty() ||
		(!contains(p, '\\') && (p.length() <= 1 || p[1] != ':'));
}

// This is a test for a win32 style path with forward slashes (pseudo-windows).

bool is_windows_path(string const & p)
{
	return p.empty() || (!contains(p, '\\') && p[0] != '/');
}


// Starting from Cygwin 1.7, new APIs for path conversions were introduced.
// The old ones are now deprecated, so avoid them if we detect a modern Cygwin.

#if CYGWIN_VERSION_DLL_MAJOR >= 1007

enum PathStyle {
	posix = CCP_WIN_A_TO_POSIX | CCP_RELATIVE,
	windows = CCP_POSIX_TO_WIN_A | CCP_RELATIVE
};


/// Convert a path to or from posix style.
/// \p p is encoded in local 8bit encoding or utf8.
/// The result is returned in the same encoding as \p p.
string convert_path(string const & p, PathStyle const & target)
{
	if ((target == posix && is_posix_path(p)) ||
	    (target == windows && is_windows_path(p)))
		return p;

	char path_buf[PATH_MAX];

	// cygwin_conv_path does not care about the encoding.
	if (cygwin_conv_path(target, p.c_str(), path_buf, sizeof(path_buf))) {
		lyxerr << "LyX: Cannot convert path: " << p << endl;
		return subst(p, '\\', '/');
	}
	return subst(path_buf, '\\', '/');
}


/// Convert a path list to or from posix style.
/// \p p is encoded in local 8bit encoding or utf8.
/// The result is returned in the same encoding as \p p.
string convert_path_list(string const & p, PathStyle const & target)
{
	if (p.empty())
		return p;

	char const * const pc = p.c_str();
	PathStyle const actual = cygwin_posix_path_list_p(pc) ? posix : windows;

	if (target != actual) {
		int const size = cygwin_conv_path_list(target, pc, NULL, 0);
		char * ptr = new char[size];
		if (ptr && cygwin_conv_path_list(target, pc, ptr, size) == 0) {
			string const path_list = subst(ptr, '\\', '/');
			delete [] ptr;
			return path_list;
		} else
			lyxerr << "LyX: Cannot convert path list: " << p << endl;
	}
	return subst(p, '\\', '/');
}

#else

enum PathStyle {
	posix,
	windows
};


/// Convert a path to or from posix style.
/// \p p is encoded in local 8bit encoding or utf8.
/// The result is returned in the same encoding as \p p.
string convert_path(string const & p, PathStyle const & target)
{
	char path_buf[PATH_MAX];

	if ((target == posix && is_posix_path(p)) ||
	    (target == windows && is_windows_path(p)))
		return p;

	path_buf[0] = '\0';

	// cygwin_conv_to_posix_path and cygwin_conv_to_win32_path do not
	// care about the encoding.
	if (target == posix)
		cygwin_conv_to_posix_path(p.c_str(), path_buf);
	else
		cygwin_conv_to_win32_path(p.c_str(), path_buf);

	return subst(path_buf[0] ? path_buf : p, '\\', '/');
}


/// Convert a path list to or from posix style.
/// \p p is encoded in local 8bit encoding or utf8.
/// The result is returned in the same encoding as \p p.
string convert_path_list(string const & p, PathStyle const & target)
{
	if (p.empty())
		return p;

	char const * const pc = p.c_str();
	PathStyle const actual = cygwin_posix_path_list_p(pc) ? posix : windows;

	if (target != actual) {
		int const target_size = (target == posix) ?
				cygwin_win32_to_posix_path_list_buf_size(pc) :
				cygwin_posix_to_win32_path_list_buf_size(pc);

		char * ptr = new char[target_size];

		if (ptr) {
			// FIXME: See comment in convert_path() above
			if (target == posix)
				cygwin_win32_to_posix_path_list(pc, ptr);
			else
				cygwin_posix_to_win32_path_list(pc, ptr);

			string path_list = subst(ptr, '\\', '/');
			delete [] ptr;
			return path_list;
		}
	}

	return subst(p, '\\', '/');
}

#endif


BOOL terminate_handler(DWORD event)
{
	if (event == CTRL_CLOSE_EVENT
	    || event == CTRL_LOGOFF_EVENT
	    || event == CTRL_SHUTDOWN_EVENT) {
		lyx::lyx_exit(1);
		return TRUE;
	}
	return FALSE;
}

} // namespace anon

void init(int argc, char * argv[])
{
	argc_ = argc;
	argv_ = argv;

	// Set environment's default locale
	setlocale(LC_ALL, "");
	setlocale(LC_NUMERIC, "C");

	// Make sure that the TEMP variable is set
	// and sync the Windows environment.
	setenv("TEMP", "/tmp", false);
	cygwin_internal(CW_SYNC_WINENV);

	// Catch shutdown events.
	SetConsoleCtrlHandler((PHANDLER_ROUTINE)terminate_handler, TRUE);
}


string utf8_argv(int i)
{
	LASSERT(i < argc_, return "");
	return to_utf8(from_local8bit(argv_[i]));
}


void remove_internal_args(int, int)
{}


string current_root()
{
	return string("/");
}


bool isFilesystemCaseSensitive()
{
	return false;
}


docstring::size_type common_path(docstring const & p1, docstring const & p2)
{
	docstring::size_type i = 0;
	docstring::size_type const p1_len = p1.length();
	docstring::size_type const p2_len = p2.length();
	while (i < p1_len && i < p2_len && uppercase(p1[i]) == uppercase(p2[i]))
		++i;
	if ((i < p1_len && i < p2_len)
	    || (i < p1_len && p1[i] != '/' && i == p2_len)
	    || (i < p2_len && p2[i] != '/' && i == p1_len))
	{
		if (i)
			--i;     // here was the last match
		while (i && p1[i] != '/')
			--i;
	}
	return i;
}


bool path_prefix_is(string const & path, string const & pre)
{
	return path_prefix_is(const_cast<string &>(path), pre, CASE_UNCHANGED);
}


bool path_prefix_is(string & path, string const & pre, path_case how)
{
	docstring const p1 = from_utf8(path);
	docstring const p2 = from_utf8(pre);
	docstring::size_type const p1_len = p1.length();
	docstring::size_type const p2_len = p2.length();
	docstring::size_type common_len = common_path(p1, p2);

	if (p2[p2_len - 1] == '/' && p1_len != p2_len)
		++common_len;

	if (common_len != p2_len)
		return false;

	if (how == CASE_ADJUSTED && !prefixIs(path, pre)) {
		if (p1_len < common_len)
			path = to_utf8(p2.substr(0, p1_len));
		else
			path = to_utf8(p2 + p1.substr(common_len,
							p1_len - common_len));
	}

	return true;
}


string external_path(string const & p)
{
	return convert_path(p, PathStyle(posix));
}


string internal_path(string const & p)
{
	return convert_path(p, PathStyle(posix));
}


string safe_internal_path(string const & p, file_access)
{
	return convert_path(p, PathStyle(posix));
}


string external_path_list(string const & p)
{
	return convert_path_list(p, PathStyle(posix));
}


string internal_path_list(string const & p)
{
	return convert_path_list(p, PathStyle(posix));
}


string latex_path(string const & p)
{
	// We may need a posix style path or a windows style path (depending
	// on windows_style_tex_paths_), but we use always forward slashes,
	// since it gets written into a .tex file.

	if (windows_style_tex_paths_ && FileName::isAbsolute(p)) {
		string dos_path = convert_path(p, PathStyle(windows));
		LYXERR(Debug::LATEX, "<Path correction for LaTeX> ["
			<< p << "]->>[" << dos_path << ']');
		return dos_path;
	}

	return convert_path(p, PathStyle(posix));
}


string latex_path_list(string const & p)
{
	// We may need a posix style path or a windows style path (depending
	// on windows_style_tex_paths_), but we use always forward slashes,
	// since this is standard for all tex engines.

	if (windows_style_tex_paths_)
		return convert_path_list(p, PathStyle(windows));

	return convert_path_list(p, PathStyle(posix));
}


bool is_valid_strftime(string const & p)
{
	string::size_type pos = p.find_first_of('%');
	while (pos != string::npos) {
		if (pos + 1 == string::npos)
			break;
		if (!containsOnly(p.substr(pos + 1, 1),
			"aAbBcCdDeEFgGhHIjklmMnOpPrRsStTuUVwWxXyYzZ%+"))
			return false;
		if (pos + 2 == string::npos)
		      break;
		pos = p.find_first_of('%', pos + 2);
	}
	return true;
}


// returns a string suitable to be passed to popen when
// reading a pipe
char const * popen_read_mode()
{
	return "r";
}


string const & nulldev()
{
	static string const nulldev_ = "/dev/null";
	return nulldev_;
}


shell_type shell()
{
	return UNIX;
}


char path_separator(path_type type)
{
	if (type == TEXENGINE)
		return windows_style_tex_paths_ ? ';' : ':';

	return ':';
}


void windows_style_tex_paths(bool use_windows_paths)
{
	windows_style_tex_paths_ = use_windows_paths;
}


bool canAutoOpenFile(string const & ext, auto_open_mode const mode)
{
	if (ext.empty())
		return false;

	string const full_ext = "." + ext;

	DWORD bufSize = MAX_PATH + 100;
	TCHAR buf[MAX_PATH + 100];
	// reference: http://msdn.microsoft.com/en-us/library/bb773471.aspx
	char const * action = (mode == VIEW) ? "open" : "edit";
	return S_OK == AssocQueryString(ASSOCF_INIT_IGNOREUNKNOWN,
		ASSOCSTR_EXECUTABLE, full_ext.c_str(), action, buf, &bufSize);
}


bool autoOpenFile(string const & filename, auto_open_mode const mode,
		  string const & path)
{
	string const texinputs = os::latex_path_list(
			replaceCurdirPath(path, lyxrc.texinputs_prefix));
	string const otherinputs = os::latex_path_list(path);
	string const sep = windows_style_tex_paths_ ? ";" : ":";
	string const oldtexinputs = getEnv("TEXINPUTS");
	string const newtexinputs = "." + sep + texinputs + sep + oldtexinputs;
	string const oldbibinputs = getEnv("BIBINPUTS");
	string const newbibinputs = "." + sep + otherinputs + sep + oldbibinputs;
	string const oldbstinputs = getEnv("BSTINPUTS");
	string const newbstinputs = "." + sep + otherinputs + sep + oldbstinputs;
	string const oldtexfonts = getEnv("TEXFONTS");
	string const newtexfonts = "." + sep + otherinputs + sep + oldtexfonts;
	if (!path.empty() && !lyxrc.texinputs_prefix.empty()) {
		setEnv("TEXINPUTS", newtexinputs);
		setEnv("BIBINPUTS", newbibinputs);
		setEnv("BSTINPUTS", newbstinputs);
		setEnv("TEXFONTS", newtexfonts);
		cygwin_internal(CW_SYNC_WINENV);
	}

	QString const win_path =
		toqstr(convert_path(filename, PathStyle(windows)));

	// reference: http://msdn.microsoft.com/en-us/library/bb762153.aspx
	wchar_t const * action = (mode == VIEW) ? L"open" : L"edit";
	bool success = reinterpret_cast<long>(ShellExecuteW(NULL, action,
			reinterpret_cast<wchar_t const *>(win_path.utf16()),
			NULL, NULL, 1)) > 32;

	if (!path.empty() && !lyxrc.texinputs_prefix.empty()) {
		setEnv("TEXINPUTS", oldtexinputs);
		setEnv("BIBINPUTS", oldbibinputs);
		setEnv("BSTINPUTS", oldbstinputs);
		setEnv("TEXFONTS", oldtexfonts);
		cygwin_internal(CW_SYNC_WINENV);
	}
	return success;
}


string real_path(string const & path)
{
	char rpath[PATH_MAX + 1];
	char * result = realpath(path.c_str(), rpath);
	return FileName::fromFilesystemEncoding(result ? rpath : path).absFileName();
}

} // namespace os
} // namespace support
} // namespace lyx