#include <filezilla.h>
#include "local_path.h"
#ifndef __WXMSW__
#include <errno.h>
#endif

#include <deque>

#ifdef __WXMSW__
const wxChar CLocalPath::path_separator = '\\';
#else
const wxChar CLocalPath::path_separator = '/';
#endif

CLocalPath::CLocalPath(const wxString& path, wxString* file /*=0*/)
{
	SetPath(path, file);
}

bool CLocalPath::SetPath(const wxString& path, wxString* file /*=0*/)
{
	// This function ensures that the path is in canonical form on success.

	if (path.empty()) {
		m_path.clear();
		return false;
	}

	std::deque<wxChar*> segments; // List to store the beginnings of segments

	const wxChar* in = path.c_str();

	{
		wxStringBuffer start(m_path.Get(), path.Len() + 2);
		wxChar* out = start;

#ifdef __WXMSW__
		if (path == _T("\\"))
		{
			*out++ = '\\';
			*out++ = 0;
			if (file)
				file->clear();
			return true;
		}

		if (*in == '\\') {
			// possibly UNC

			in++;
			if (*in++ != '\\') {
				*start = 0;
				return false;
			}

			if (*in == '?') {
				// Could be \\?\c:\foo\bar
				// or \\?\UNC\server\sharee
				// or something else we do not support.
				if (*(++in) != '\\') {
					return false;
				}
				in++;
				if (((*in >= 'a' && *in <= 'z') || (*in >= 'A' || *in <= 'Z')) && *(in+1) == ':') {
					// It's \\?\c:\foo\bar
					goto parse_regular;
				}
				if (fz::strlen(in) < 5 || wxStrnicmp(in, _T("UNC\\"), 4)) {
					return false;
				}
				in += 4;
			}
			*out++ = '\\';
			*out++ = '\\';

			// UNC path
			while (*in)
			{
				if (*in == '/' || *in == '\\')
					break;
				*out++ = *in++;
			}
			*out++ = path_separator;

			if (out - start <= 3) {
				// not a valid UNC path
				*start = 0;
				return false;
			}

			segments.push_back(out);
		}
		else if ((*in >= 'a' && *in <= 'z') || (*in >= 'A' || *in <= 'Z'))
		{
parse_regular:
			// Regular path
			*out++ = *in++;

			if (*in++ != ':') {
				*start = 0;
				return false;
			}
			*out++ = ':';
			if (*in != '/' && *in != '\\' && *in) {
				*start = 0;
				return false;
			}
			*out++ = path_separator;
			segments.push_back(out);
		}
		else {
			*start = 0;
			return false;
		}
#else
		if (*in++ != '/')
		{
			// SetPath only accepts absolute paths
			*start = 0;
			return false;
		}

		*out++ = '/';
		segments.push_back(out);
#endif

		enum _last
		{
			separator,
			dot,
			dotdot,
			segment
		};
		enum _last last = separator;

		while (*in)
		{
			if (*in == '/'
	#ifdef __WXMSW__
				|| *in == '\\'
	#endif
				)
			{
				in++;
				if (last == separator)
				{
					// /foo//bar is equal to /foo/bar
					continue;
				}
				else if (last == dot)
				{
					// /foo/./bar is equal to /foo/bar
					last = separator;
					out = segments.back();
					continue;
				}
				else if (last == dotdot)
				{
					last = separator;

					// Go two segments back if possible
					if (segments.size() > 1)
						segments.pop_back();
					wxASSERT(!segments.empty());
					out = segments.back();
					continue;
				}

				// Ordinary segment just ended.
				*out++ = path_separator;
				segments.push_back(out);
				last = separator;
				continue;
			}
			else if (*in == '.')
			{
				if (last == separator)
					last = dot;
				else if (last == dot)
					last = dotdot;
				else if (last == dotdot)
					last = segment;
			}
			else
				last = segment;

			*out++ = *in++;
		}
		if (last == dot)
			out = segments.back();
		else if (last == dotdot)
		{
			if (segments.size() > 1)
				segments.pop_back();
			out = segments.back();
		}
		else if (last == segment)
		{
			if (file)
			{
				*out = 0;
				out = segments.back();
				*file = out;
			}
			else
				*out++ = path_separator;
		}

		*out = 0;
	}

	return true;
}

bool CLocalPath::empty() const
{
	return m_path->empty();
}

void CLocalPath::clear()
{
	m_path.clear();
}

bool CLocalPath::IsWriteable() const
{
	if (m_path->empty())
		return false;

#ifdef __WXMSW__
	if (m_path == _T("\\"))
		// List of drives not writeable
		return false;

	if (m_path->Left(2) == _T("\\\\")) {
		int pos = m_path->Mid(2).Find('\\');
		if (pos == -1 || pos + 3 == (int)m_path->Len())
			// List of shares on a computer not writeable
			return false;
	}
#endif

	return true;
}

bool CLocalPath::HasParent() const
{
#ifdef __WXMSW__
	// C:\f\ has parent
	// C:\ does not
	// \\x\y\ shortest UNC
	//   ^ min
	const int min = 2;
#else
	const int min = 0;
#endif
	for (int i = (int)m_path->Len() - 2; i >= min; --i) {
		if ((*m_path)[i] == path_separator)
			return true;
	}

	return false;
}

bool CLocalPath::HasLogicalParent() const
{
#ifdef __WXMSW__
	if (m_path->Len() == 3 && (*m_path)[0] != '\\') // Drive root
		return true;
#endif
	return HasParent();
}

CLocalPath CLocalPath::GetParent(wxString* last_segment /*=0*/) const
{
	CLocalPath parent;

#ifdef __WXMSW__
	if (m_path->Len() == 3 && (*m_path)[0] != '\\') // Drive root
	{
		if (last_segment)
			last_segment->clear();
		return CLocalPath(_T("\\"));
	}

	// C:\f\ has parent
	// C:\ does not
	// \\x\y\ shortest UNC
	//   ^ min
	const int min = 2;
#else
	const int min = 0;
#endif
	for (int i = (int)m_path->Len() - 2; i >= min; --i) {
		if ((*m_path)[i] == path_separator) {
			if (last_segment) {
				*last_segment = m_path->Mid(i + 1);
				last_segment->RemoveLast();
			}
			return CLocalPath(m_path->Left(i + 1));
		}
	}

	return CLocalPath();
}

bool CLocalPath::MakeParent(wxString* last_segment /*=0*/)
{
	wxString& path = m_path.Get();

#ifdef __WXMSW__
	if (path.Len() == 3 && path[0] != '\\') // Drive root
	{
		path = _T("\\");
		return true;
	}

	// C:\f\ has parent
	// C:\ does not
	// \\x\y\ shortest UNC
	//   ^ min
	const int min = 2;
#else
	const int min = 0;
#endif
	for (int i = (int)path.Len() - 2; i >= min; --i) {
		if (path[i] == path_separator) {
			if (last_segment) {
				*last_segment = path.Mid(i + 1);
				last_segment->RemoveLast();
			}
			path = path.Left(i + 1);
			return true;
		}
	}

	return false;
}

void CLocalPath::AddSegment(const wxString& segment)
{
	wxString& path = m_path.Get();

	wxASSERT(!path.empty());
	wxASSERT(segment.Find(_T("/")) == -1);
#ifdef __WXMSW__
	wxASSERT(segment.Find(_T("\\")) == -1);
#endif

	if (!segment.empty()) {
		path += segment;
		path += path_separator;
	}
}

bool CLocalPath::ChangePath(const wxString& new_path)
{
	if (new_path.empty())
		return false;

	wxString& path = m_path.Get();

#ifdef __WXMSW__
	if (new_path == _T("\\") || new_path == _T("/")) {
		path = _T("\\");
		return true;
	}

	if (new_path.Len() >= 2 && new_path[0] == '\\' && new_path[1] == '\\') {
		// Absolute UNC
		return SetPath(new_path);
	}
	if (new_path.Len() >= 2 && new_path[0] && new_path[1] == ':') {
		// Absolute new_path
		return SetPath(new_path);
	}

	// Relative new_path
	if (path.empty())
		return false;

	if (new_path.Len() >= 2 && (new_path[0] == '\\' || new_path[0] == '/') && path[1] == ':') {
		// Relative to drive root
		return SetPath(path.Left(2) + new_path);
	}
	else {
		// Relative to current directory
		return SetPath(path + new_path);
	}
#else
	if (!new_path.empty() && new_path[0] == path_separator) {
		// Absolute new_path
		return SetPath(new_path);
	}
	else
	{
		// Relative new_path

		if (path.empty())
			return false;

		return SetPath(path + new_path);
	}
#endif
}

bool CLocalPath::Exists(wxString *error /*=0*/) const
{
	wxASSERT(!m_path->empty());
	if (m_path->empty())
		return false;

#ifdef __WXMSW__
	if (m_path == _T("\\"))
	{
		// List of drives always exists
		return true;
	}

	if ((*m_path)[0] == '\\') {
		// \\server\share\ UNC path

		size_t pos;

		// Search for backslash separating server from share
		for (pos = 3; pos < m_path->Len(); pos++)
			if ((*m_path)[pos] == '\\')
				break;
		pos++;
		if (pos >= m_path->Len()) {
			// Partial UNC path
			return true;
		}
	}

	wxString path = *m_path;
	if (path.Len() > 3)
		path.RemoveLast();
	DWORD ret = ::GetFileAttributes(path.wc_str());
	if (ret == INVALID_FILE_ATTRIBUTES) {
		if (!error)
			return false;

		error->Printf(_("'%s' does not exist or cannot be accessed."), path);

		if ((*m_path)[0] == '\\')
			return false;

		// Check for removable drive, display a more specific error message in that case
		if (::GetLastError() != ERROR_NOT_READY)
			return false;
		int type = GetDriveType(m_path->Left(3).wc_str());
		if (type == DRIVE_REMOVABLE || type == DRIVE_CDROM)
			error->Printf(_("Cannot access '%s', no media inserted or drive not ready."), path);
		return false;
	}
	else if (!(ret & FILE_ATTRIBUTE_DIRECTORY)) {
		if (error)
			error->Printf(_("'%s' is not a directory."), path);
		return false;
	}

	return true;
#else
	wxString path = *m_path;
	if (path.Len() > 1)
		path.RemoveLast();

	const wxCharBuffer s = path.fn_str();

	struct stat buf;
	int result = stat(s, &buf);

	if (!result) {
		if (S_ISDIR(buf.st_mode))
			return true;

		if (error)
			error->Printf(_("'%s' is not a directory."), path);

		return false;
	}
	else if (result == ENOTDIR) {
		if (error)
			error->Printf(_("'%s' is not a directory."), path);
		return false;
	}
	else {
		if (error)
			error->Printf(_("'%s' does not exist or cannot be accessed."), path);
		return false;
	}
#endif
}

bool CLocalPath::operator==(const CLocalPath& op) const
{
#ifdef __WXMSW__
	return m_path->CmpNoCase(*op.m_path) == 0;
#else
	return m_path == op.m_path;
#endif
}

bool CLocalPath::operator!=(const CLocalPath& op) const
{
#ifdef __WXMSW__
	return m_path->CmpNoCase(*op.m_path) != 0;
#else
	return m_path != op.m_path;
#endif
}

bool CLocalPath::IsParentOf(const CLocalPath &path) const
{
	if (empty() || path.empty())
		return false;

	if (path.m_path->Len() < m_path->Len())
		return false;

#ifdef __WXMSW__
	if (m_path->CmpNoCase(path.m_path->Left(m_path->Len())))
		return false;
#else
	if (*m_path != path.m_path->Left(m_path->Len()))
		return false;
#endif

	return true;
}

bool CLocalPath::IsSubdirOf(const CLocalPath &path) const
{
	if (empty() || path.empty())
		return false;

	if (path.m_path->Len() > m_path->Len())
		return false;

#ifdef __WXMSW__
	if (path.m_path->CmpNoCase(m_path->Left(path.m_path->Len())))
		return false;
#else
	if (*path.m_path != m_path->Left(path.m_path->Len()))
		return false;
#endif

	return true;
}

wxString CLocalPath::GetLastSegment() const
{
	wxASSERT(HasParent());

#ifdef __WXMSW__
	// C:\f\ has parent
	// C:\ does not
	// \\x\y\ shortest UNC
	//   ^ min
	const int min = 2;
#else
	const int min = 0;
#endif
	for (int i = (int)m_path->Len() - 2; i >= min; i--) {
		if ((*m_path)[i] == path_separator) {
			wxString last = m_path->Mid(i + 1);
			last.RemoveLast();
			return last;
		}
	}

	return wxString();
}