/*
    Copyright (C) 2006-2009 Paul Davis

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <vector>

#include <sys/time.h>
#include <sys/stat.h>
#include <stdio.h> // for rename(), sigh
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#include "pbd/convert.h"
#include "pbd/basename.h"
#include "pbd/mountpoint.h"
#include "pbd/stl_delete.h"
#include "pbd/strsplit.h"
#include "pbd/shortpath.h"
#include "pbd/enumwriter.h"

#include <glibmm/miscutils.h>
#include <glibmm/fileutils.h>
#include <glibmm/thread.h>

#include "ardour/file_source.h"
#include "ardour/directory_names.h"
#include "ardour/session.h"
#include "ardour/session_directory.h"
#include "ardour/source_factory.h"
#include "ardour/filename_extensions.h"

#include "i18n.h"

using namespace std;
using namespace ARDOUR;
using namespace PBD;
using namespace Glib;

PBD::Signal3<int,std::string,std::string,std::vector<std::string> > FileSource::AmbiguousFileName;

FileSource::FileSource (Session& session, DataType type, const string& path, const string& origin, Source::Flag flag)
	: Source(session, type, path, flag)
	, _path(path)
	, _file_is_new(true)
	, _channel (0)
        , _origin (origin)
        , _open (false)
{
	set_within_session_from_path (path);

        prevent_deletion ();
}

FileSource::FileSource (Session& session, const XMLNode& node, bool /*must_exist*/)
	: Source (session, node)
	, _file_is_new (false)
{
	/* this setting of _path is temporary - we expect derived classes
	   to call ::init() which will actually locate the file
	   and reset _path and _within_session correctly.
	*/

	_path = _name;
	_within_session = true;

        prevent_deletion ();
}

void
FileSource::prevent_deletion ()
{
        /* if this file already exists, it cannot be removed, ever
         */

        if (Glib::file_test (_path, Glib::FILE_TEST_EXISTS)) {
                if (!(_flags & Destructive)) {
                        mark_immutable ();
                } else {
                        _flags = Flag (_flags & ~(Removable|RemovableIfEmpty|RemoveAtDestroy));
                }
        }
}

bool
FileSource::removable () const
{
        bool r = ((_flags & Removable)
                  && ((_flags & RemoveAtDestroy) ||
                      ((_flags & RemovableIfEmpty) && empty() == 0)));

        return r;
}

int
FileSource::init (const string& pathstr, bool must_exist)
{
	_timeline_position = 0;

        if (Stateful::loading_state_version < 3000) {
                if (!find_2X (_session, _type, pathstr, must_exist, _file_is_new, _channel, _path)) {
                        throw MissingSource (pathstr, _type);
                }
        } else {
                if (!find (_session, _type, pathstr, must_exist, _file_is_new, _channel, _path)) {
                        throw MissingSource (pathstr, _type);
                }
        }

	set_within_session_from_path (_path);

        if (!within_session()) {
                _session.ensure_search_path_includes (Glib::path_get_dirname (_path), _type);
        }

        _name = Glib::path_get_basename (_path);

	if (_file_is_new && must_exist) {
		return -1;
	}

	return 0;
}

int
FileSource::set_state (const XMLNode& node, int /*version*/)
{
	const XMLProperty* prop;

	if ((prop = node.property (X_("channel"))) != 0) {
		_channel = atoi (prop->value());
	} else {
		_channel = 0;
	}

        if ((prop = node.property (X_("origin"))) != 0) {
                _origin = prop->value();
        }

	return 0;
}

void
FileSource::mark_take (const string& id)
{
	if (writable ()) {
		_take_id = id;
	}
}

int
FileSource::move_to_trash (const string& trash_dir_name)
{
	if (!within_session() || !writable()) {
		return -1;
	}

	/* don't move the file across filesystems, just stick it in the
	   trash_dir_name directory on whichever filesystem it was already on
	*/

        vector<string> v;
	v.push_back (Glib::path_get_dirname (Glib::path_get_dirname (_path)));
        v.push_back (trash_dir_name);
	v.push_back (Glib::path_get_basename (_path));

	string newpath = Glib::build_filename (v);

	/* the new path already exists, try versioning */

	if (Glib::file_test (newpath.c_str(), Glib::FILE_TEST_EXISTS)) {
		char buf[PATH_MAX+1];
		int version = 1;
		string newpath_v;

		snprintf (buf, sizeof (buf), "%s.%d", newpath.c_str(), version);
		newpath_v = buf;

		while (Glib::file_test (newpath_v, Glib::FILE_TEST_EXISTS) && version < 999) {
			snprintf (buf, sizeof (buf), "%s.%d", newpath.c_str(), ++version);
			newpath_v = buf;
		}

		if (version == 999) {
			PBD::error << string_compose (
					_("there are already 1000 files with names like %1; versioning discontinued"),
					newpath) << endmsg;
		} else {
			newpath = newpath_v;
		}
	}

	if (::rename (_path.c_str(), newpath.c_str()) != 0) {
		PBD::error << string_compose (
				_("cannot rename file source from %1 to %2 (%3)"),
				_path, newpath, strerror (errno)) << endmsg;
		return -1;
	}

	if (move_dependents_to_trash() != 0) {
		/* try to back out */
		rename (newpath.c_str(), _path.c_str());
		return -1;
	}

	_path = newpath;

	/* file can not be removed twice, since the operation is not idempotent */
	_flags = Flag (_flags & ~(RemoveAtDestroy|Removable|RemovableIfEmpty));

	return 0;
}

/** Find the actual source file based on \a filename.
 *
 * If the source is within the session tree, \a filename should be a simple filename (no slashes).
 * If the source is external, \a filename should be a full path.
 * In either case, found_path is set to the complete absolute path of the source file.
 * \return true iff the file was found.
 */
bool
FileSource::find (Session& s, DataType type, const string& path, bool must_exist,
		  bool& isnew, uint16_t& chan, string& found_path)
{
	bool ret = false;
        string keeppath;

	isnew = false;

        if (!Glib::path_is_absolute (path)) {
                vector<string> dirs;
                vector<string> hits;
                int cnt;
                string fullpath;

                string search_path = s.source_search_path (type);

                if (search_path.length() == 0) {
                        error << _("FileSource: search path not set") << endmsg;
                        goto out;
                }

                split (search_path, dirs, ':');

                cnt = 0;
                hits.clear ();

                for (vector<string>::iterator i = dirs.begin(); i != dirs.end(); ++i) {

                        fullpath = Glib::build_filename (*i, path);

                        if (Glib::file_test (fullpath, Glib::FILE_TEST_EXISTS|Glib::FILE_TEST_IS_REGULAR)) {
                                keeppath = fullpath;
                                hits.push_back (fullpath);
                                ++cnt;
                        }
                }

                if (cnt > 1) {

                        int which = FileSource::AmbiguousFileName (path, search_path, hits).get_value_or (-1);

                        if (which < 0) {
                                goto out;
                        } else {
                                keeppath = hits[which];
                        }

                } else if (cnt == 0) {

                        if (must_exist) {
                                error << string_compose(
                                        _("Filesource: cannot find required file (%1): while searching %2"),
                                        path, search_path) << endmsg;
                                goto out;
                        } else {
                                isnew = true;
                        }
                }
        } else {
                keeppath = path;
        }

        /* Current find() is unable to parse relative path names to yet non-existant
           sources. QuickFix(tm)
        */
        if (keeppath == "") {
                if (must_exist) {
                        error << "FileSource::find(), keeppath = \"\", but the file must exist" << endl;
                } else {
                        keeppath = path;
                }
        }

        found_path = keeppath;

        ret = true;

  out:
	return ret;
}

/** Find the actual source file based on \a filename.
 *
 * If the source is within the session tree, \a filename should be a simple filename (no slashes).
 * If the source is external, \a filename should be a full path.
 * In either case, found_path is set to the complete absolute path of the source file.
 * \return true iff the file was found.
 */
bool
FileSource::find_2X (Session& s, DataType type, const string& path, bool must_exist,
                     bool& isnew, uint16_t& chan, string& found_path)
{
	string search_path = s.source_search_path (type);

	string pathstr = path;
	string::size_type pos;
	bool ret = false;

	isnew = false;

	if (!Glib::path_is_absolute (pathstr)) {

		/* non-absolute pathname: find pathstr in search path */

		vector<string> dirs;
		int cnt;
		string fullpath;
		string keeppath;

		if (search_path.length() == 0) {
			error << _("FileSource: search path not set") << endmsg;
			goto out;
		}

		split (search_path, dirs, ':');

		cnt = 0;

		for (vector<string>::iterator i = dirs.begin(); i != dirs.end(); ++i) {

                        fullpath = Glib::build_filename (*i, pathstr);

			/* i (paul) made a nasty design error by using ':' as a special character in
			   Ardour 0.99 .. this hack tries to make things sort of work.
			*/

			if ((pos = pathstr.find_last_of (':')) != string::npos) {

				if (Glib::file_test (fullpath, Glib::FILE_TEST_EXISTS|Glib::FILE_TEST_IS_REGULAR)) {

					/* its a real file, no problem */

					keeppath = fullpath;
					++cnt;

				} else {

					if (must_exist) {

						/* might be an older session using file:channel syntax. see if the version
						   without the :suffix exists
						 */

						string shorter = pathstr.substr (0, pos);
                                                fullpath = Glib::build_filename (*i, shorter);

						if (Glib::file_test (pathstr, Glib::FILE_TEST_EXISTS|Glib::FILE_TEST_IS_REGULAR)) {
							chan = atoi (pathstr.substr (pos+1));
							pathstr = shorter;
							keeppath = fullpath;
							++cnt;
						}

					} else {

						/* new derived file (e.g. for timefx) being created in a newer session */

					}
				}

			} else {

				if (Glib::file_test (fullpath, Glib::FILE_TEST_EXISTS|Glib::FILE_TEST_IS_REGULAR)) {
					keeppath = fullpath;
					++cnt;
				}
			}
		}

		if (cnt > 1) {

			error << string_compose (
					_("FileSource: \"%1\" is ambigous when searching %2\n\t"),
					pathstr, search_path) << endmsg;
			goto out;

		} else if (cnt == 0) {

			if (must_exist) {
				error << string_compose(
						_("Filesource: cannot find required file (%1): while searching %2"),
						pathstr, search_path) << endmsg;
				goto out;
			} else {
				isnew = true;
			}
		}

		/* Current find() is unable to parse relative path names to yet non-existant
		   sources. QuickFix(tm) */
		if (keeppath == "") {
			if (must_exist) {
				error << "FileSource::find(), keeppath = \"\", but the file must exist" << endl;
			} else {
				keeppath = pathstr;
			}
		}

		found_path = keeppath;

		ret = true;

	} else {

		/* external files and/or very very old style sessions include full paths */

		/* ugh, handle ':' situation */

		if ((pos = pathstr.find_last_of (':')) != string::npos) {

			string shorter = pathstr.substr (0, pos);

			if (Glib::file_test (shorter, Glib::FILE_TEST_EXISTS|Glib::FILE_TEST_IS_REGULAR)) {
				chan = atoi (pathstr.substr (pos+1));
				pathstr = shorter;
			}
		}

		found_path = pathstr;

		if (!Glib::file_test (pathstr, Glib::FILE_TEST_EXISTS|Glib::FILE_TEST_IS_REGULAR)) {

			/* file does not exist or we cannot read it */

			if (must_exist) {
				error << string_compose(
						_("Filesource: cannot find required file (%1): %2"),
						path, strerror (errno)) << endmsg;
				goto out;
			}

			if (errno != ENOENT) {
				error << string_compose(
						_("Filesource: cannot check for existing file (%1): %2"),
						path, strerror (errno)) << endmsg;
				goto out;
			}

			/* a new file */
			isnew = true;
			ret = true;

		} else {

			/* already exists */
			ret = true;
		}
	}

out:
	return ret;
}

int
FileSource::set_source_name (const string& newname, bool destructive)
{
	Glib::Mutex::Lock lm (_lock);
	string oldpath = _path;
	string newpath = _session.change_source_path_by_name (oldpath, _name, newname, destructive);

	if (newpath.empty()) {
		error << string_compose (_("programming error: %1"), "cannot generate a changed file path") << endmsg;
		return -1;
	}

	// Test whether newpath exists, if yes notify the user but continue.
	if (Glib::file_test (newpath, Glib::FILE_TEST_EXISTS)) {
		error << string_compose (_("Programming error! %1 tried to rename a file over another file! It's safe to continue working, but please report this to the developers."), PROGRAM_NAME) << endmsg;
		return -1;
	}

        if (::rename (oldpath.c_str(), newpath.c_str()) != 0) {
                error << string_compose (_("cannot rename file %1 to %2 (%3)"), oldpath, newpath, strerror(errno)) << endmsg;
                return -1;
        }

	_name = Glib::path_get_basename (newpath);
	_path = newpath;

	return 0;
}

void
FileSource::mark_immutable ()
{
	/* destructive sources stay writable, and their other flags don't change.  */
	if (!(_flags & Destructive)) {
		_flags = Flag (_flags & ~(Writable|Removable|RemovableIfEmpty|RemoveAtDestroy|CanRename));
	}
}

void
FileSource::mark_nonremovable ()
{
        _flags = Flag (_flags & ~(Removable|RemovableIfEmpty|RemoveAtDestroy));
}

void
FileSource::set_within_session_from_path (const std::string& path)
{
	_within_session = _session.path_is_within_session (path);
}

void
FileSource::set_path (const std::string& newpath)
{
        _path = newpath;
}

void
FileSource::inc_use_count ()
{
        Source::inc_use_count ();
}