#!/usr/bin/env python3
from __future__ import print_function#defaults to Python 3, but should also work in 2.7
"""Functions for checking fgdata for various problems (and one for creating smaller/split versions of it)

By Rebecca Palmer"""
import os
import os.path
import re
from collections import defaultdict
import subprocess
import multiprocessing
import math
import tarfile
import tempfile
import gzip
import shutil
import time
try:
    devnull=subprocess.DEVNULL#hide annoying nvcompress messages
except (AttributeError,NameError):#pre-3.3 Python
    devnull=None
def path_join(*args):
    """Unlike plain os.path.join, this always uses forward slashes, and doesn't add a trailing / if the last component is empty"""
    return os.path.normpath(os.path.join(*args)).replace('\\','/')
def rfilelist(path,exclude_dirs=[]):
    """Dict of files/sizes in path, including those in any subdirectories (as relative paths)"""
    files=defaultdict(int)
    if not os.path.exists(path):
        return files
    dirs=[""]
    while dirs:
        cdir=dirs.pop()
        cdirfiles=os.listdir(path_join(path,cdir))
        for file in cdirfiles:
            if os.path.isdir(path_join(path,cdir,file)):
                if path_join(cdir,file) not in exclude_dirs:
                    dirs.append(path_join(cdir,file))
            else:
                files[path_join(cdir,file)]=os.path.getsize(path_join(path,cdir,file))
    return files
def strip_comments(text,comment_types=None,filename=None):
    """Remove comments from text
    Assumes comments don't nest (including different types of comments: will be wrong for e.g. /* aaa // bbb */ will-remove-this in C++ if // are removed first)
    Doesn't check for being inside a string literal, and doesn't check for line-start * in C /* ... */"""
    if comment_types is None:
        if filename is None:
            raise TypeError("must give either filename or comment_types")
        if os.path.splitext(filename)[1] in (".xml",".eff"):
            comment_types=(("<!--","-->",""),)
        elif os.path.splitext(filename)[1] in (".c",".cpp",".cxx",".h",".hpp",".hxx",".frag",".vert"):
            comment_types=(("//","\n","\n"),("/*","*/",""))
        elif os.path.splitext(filename)[1] in (".nas",):
            comment_types=(("#","\n","\n"),)
        else:
            comment_types=[]
    if type(text) in (bytes,bytearray):
        comment_types=[[bytes(c,encoding="ascii") for c in ct] for ct in comment_types]
    for comment_type in comment_types:
        text=text.split(comment_type[0],maxsplit=1)[0]+comment_type[2].join(s.split(comment_type[1],maxsplit=1)[1] for s in text.split(comment_type[0])[1:] if comment_type[1] in s)
    return text
def files_used(pattern,path,exclude_dirs=[],filelist=None,filetypes=None,relative_path=False):
    """Files used by an element matching pattern, in a file in path or filelist"""
    textures=[]
    if filelist is None:
        filelist=rfilelist(path,exclude_dirs).keys()
    if filetypes is not None:
        filelist=[f for f in filelist if os.path.splitext(f)[1] in filetypes]
    texfind=re.compile(pattern)
    for file in filelist:
        try:
            f=open(path_join(path,file),'r',errors='replace')
        except FileNotFoundError:
            continue
        for line in f:
            tex=texfind.search(line)
            if tex:
                if relative_path:
                    textures.append(os.path.normpath(path_join(os.path.dirname(file),tex.group(1).replace('\\','/'))).replace('\\','/'))
                else:
                    textures.append(os.path.normpath(tex.group(1).replace('\\','/')).replace('\\','/'))
    return textures
def find_unused_textures(basedir,output_lists=True,grep_check=False,output_rsync_rules=False,output_comparison_strips=False, output_removal_commands=False,return_used_noregions=False):
    """Checks if any textures are unused (wasting space), and if any textures are only available as .dds (not recommended in the source repository, as it is a lossy-compressed format)

Set basedir to your fg-root, and enable the kind(s) of output you want:
output_lists prints lists of unused textures, and of dds-only textures
grep_check checks for possible use outside the normal directories; requires Unix shell and assumes side-by-side fgdata,flightgear,simgear
output_rsync_rules prints rsync rules for excluding unused textures from the release flightgear-data.  Warning: if you use this, re-run this script regularly, in case they start being used
output_comparison_strips creates thumbnail strips, unused_duplicate.png/unused_dds.png/high_low.png, for visually checking whether same-name textures are the same (remove the unused one entirely) or different (move it to Unused); requires imagemagick or graphicsmagick
output_removal_commands creates another script, delete_unused_textures.sh, which will remove unused textures when run in a Unix shell"""

    false_positives=set(['buildings-lightmap.png','buildings.png','Credits','Globe/00README.txt', 'Globe/01READMEocean_depth_1png.txt', 'Globe/world.topo.bathy.200407.3x4096x2048.png','Trees/convert.pl','Splash1.png','Splash2.png','Splash3.png','Splash4.png','Splash5.png'])#these either aren't textures, or are used where we don't check; 'unknown.rgb','Terrain/unknown.rgb' are also referenced, but already don't exist
    used_textures=set(files_used(path=path_join(basedir,'Materials'),pattern=r'<(?:texture|object-mask|tree-texture).*?>(\S+?)</(texture|object-mask|tree-texture)'))|false_positives
    used_textures_noregions=set(files_used(path=path_join(basedir,'Materials'),exclude_dirs=['regions'],pattern=r'<(?:texture|object-mask|tree-texture).*?>(\S+?)</(texture|object-mask|tree-texture)'))|false_positives#this pattern matches a <texture> (possibly with number), <tree-texture> or <object-mask> element
    used_effectslow=set(files_used(path=path_join(basedir,'Effects'),pattern=r'image.*?>[\\/]?Textures[\\/](\S+?)</.*?image'))|set(files_used(path=path_join(basedir,'Materials'),pattern=r'<building-(?:texture|lightmap).*?>Textures[\\/](\S+?)</building-(?:texture|lightmap)'))#Effects (<image>), and Materials <building-texture>/<building-lightmap>, explicitly includes the Textures/ or Textures.high/
    used_effectshigh=set(files_used(path=path_join(basedir,'Effects'),pattern=r'image.*?>[\\/]?Textures.high[\\/](\S+?)</.*?image'))|set(files_used(path=path_join(basedir,'Materials'),pattern=r'<building-(?:texture|lightmap).*?>Textures.high[\\/](\S+?)</building-(?:texture|lightmap)'))
    high_tsizes=rfilelist(path_join(basedir,'Textures.high'))
    high_textures=set(high_tsizes.keys())
    low_tsizes=rfilelist(path_join(basedir,'Textures'),exclude_dirs=['Sky','Unused'])#sky textures are used where we don't check
    low_textures=set(low_tsizes.keys())
    only_high=high_textures-low_textures
    used_noreg_onlyhigh=(only_high&used_textures_noregions)|used_effectshigh
    used_noreg_onlyhighsize=sum(high_tsizes[t] for t in used_noreg_onlyhigh)
    used_noreg_low=(low_textures&used_textures_noregions)|used_effectslow
    used_noregions=used_textures_noregions|used_effectshigh|used_effectslow
    used_noreg_lowsize=sum(low_tsizes[t] for t in used_noreg_low)
    used_noreg_defsize=sum(low_tsizes[t] for t in (used_textures_noregions-high_textures)|used_effectslow)+sum(high_tsizes[t] for t in used_textures_noregions|used_effectshigh)
    used_defsize=sum(low_tsizes[t] for t in (used_textures-high_textures)|used_effectslow)+sum(high_tsizes[t] for t in used_textures|used_effectshigh)
    unused=(high_textures|low_textures)-used_textures-used_effectslow-used_effectshigh
    t_size=lambda tset: sum(high_tsizes[t] for t in tset)+sum(low_tsizes[t] for t in tset)
    missing=(used_textures-(high_textures|low_textures))|(used_effectslow-low_textures)|(used_effectshigh-high_textures)
    if missing:
        raise ValueError("Some used textures not found: "+repr(missing))
    sourceless=[f for f in (high_textures|low_textures) if (f[-4:]==".dds" and f[:-4]+".png" not in high_textures and (f in high_textures or f[:-4]+".png" not in low_textures) )]+['Terrain/airport.dds']#airport.dds isn't the same as airport.png; crop-colors.dds/cropgrass-colors.dds/rock-colors.dds/forest-colors.dds also differ but only in strip width, which doesn't matter as they are 1D color strips
    sourceless_used=set(sourceless)-unused
    needed_as_source=[f for f in unused if (f[-4:]!=".dds" and f[:-4]+".png" in (used_textures|used_effectslow|used_effectshigh) or f[:-4]+".dds" in (used_textures|used_effectslow|used_effectshigh))]+['Runway/designation_letters.svg']
    known_non_duplicates=['deciduous.png','drycrop.png','irrcrop.png','marsh1.png','gravel.png','Town.png','grass.png','mixedcrop.png','resgrid.png']+['glacier.png','rock.png','cropgrass.png']#first group real winter textures, second group unrelated textures
    unused_duplicate=[f for f in unused if (f[0:14]=="Terrain.winter" and "Terrain"+f[14:] in (high_textures|low_textures) and f[15:] not in known_non_duplicates)]
    unused_dds=set(f for f in (unused-set(unused_duplicate)) if (f[-4:]==".dds" and f[:-4]+".png" in (high_textures|low_textures) and f!='Terrain/airport.dds'))#airport.dds isn't the same as airport.png; crop-colors.dds/cropgrass-colors.dds/rock-colors.dds/forest-colors.dds also differ but only in strip width, which doesn't matter as they are 1D color strips
    unused_other=unused-set(unused_duplicate)-set(unused_dds)-set(needed_as_source)
    known_highlow_mismatch=set(['Terrain.winter/mixedcrop4.png','Terrain.winter/cropgrass3.png','Terrain.winter/drycrop4.png','Terrain.winter/irrcrop2.png','Terrain.winter/drycrop1.png','Terrain.winter/drycrop3.png','Terrain.winter/mixedcrop1.png','Terrain.winter/ mixedforest2.png','Terrain.winter/cropgrass2.png','Terrain.winter/cropgrass1.png','Terrain.winter/tundra.png','Terrain.winter/mixedforest3.png','Terrain.winter/shrub2.png','Terrain.winter/drycrop2.png','Terrain.winter/deciduous1.png','Terrain.winter/ mixedcrop3.png','Terrain.winter/naturalcrop1.png']+['Terrain.winter/tundra3.png','Terrain.winter/forest1c.png','Terrain.winter/herbtundra.png']+['Terrain/grass_rwy.dds','Terrain/cropwood.dds','Terrain/herbtundra.dds','Terrain/irrcrop.dds','Terrain/shrub.dds','Terrain.winter/mixedforest.png','Runway/pa_taxiway.png','Runway/pc_taxiway.png'])#first group are different degrees of snow cover on the same base texture, last group unrelated textures, middle group hard to tell; p{a,c}_taxiway (only low-res has side lines) are also mismatched in .dds, but as each .dds matches its size .png, only the .png needs to be kept in Unused
    lowres_maybe_source=['Terrain/lava1.png','Terrain/lava2.png','Terrain/lava3.png','Terrain/sand4.png','Terrain/sand5.png','Terrain/sand6.png']#these are clearly related, but the high-res version has unnatural-looking high-frequency noise, suggesting that the low-res version might be the original: keep it
    unused_dds_matchhigh=set(f for f in (unused_dds&known_highlow_mismatch) if f[:-4]+".png" not in low_textures)
    unused_dds_matchlow=set(f for f in (unused_dds&known_highlow_mismatch) if f[:-4]+".png" not in high_textures)
    low_unneeded=(high_textures&low_textures)-used_effectslow-unused-set(lowres_maybe_source)
    low_unneeded_duplicate=low_unneeded-set(known_highlow_mismatch)
    low_unneeded_nondup=low_unneeded&set(known_highlow_mismatch)
    def image_check_strip(basedir,index_fname,ilist1,ilist2=None,size=128):
        """Generate two rows of thumbnails, for easy visual comparison (between the two lists given, or if a single list is given, between low and high resolution)"""
        if not ilist1:
            print(index_fname," empty, skipping")
            return
        if ilist2 is None:
            ipairs=[[path_join(basedir,'Textures',f),path_join(basedir,'Textures.high',f)] for f in ilist1]
        else:
            ipairs=[]
            for f1,f2 in zip(ilist1,ilist2):
                if f1 in low_textures:
                    ipairs.append([path_join(basedir,'Textures',f1),path_join(basedir,'Textures',f2) if f2 in low_textures else path_join(basedir,'Textures.high',f2)])
                if f1 in high_textures:
                    ipairs.append([path_join(basedir,'Textures.high',f1),path_join(basedir,'Textures.high',f2) if f2 in high_textures else path_join(basedir,'Textures',f2)])
        ilist_f=[f[0] for f in ipairs]+[f[1] for f in ipairs]
        subprocess.call(['montage','-label',"'%f'"]+ilist_f+['-tile','x2','-geometry',str(size)+'x'+str(size)]+[index_fname])
    def rsync_rules(basedir,flist,include=False,high=None):
        """Output rsync rules to exclude/include the specified textures from high/low/both (high=True/False/None) resolutions"""
        for f in flist:
            if high!=True and f in low_textures:
                print("+" if include else "-",path_join('/fgdata/Textures',f))
            if high!=False and f in high_textures:
                print("+" if include else "-",path_join('/fgdata/Textures.high',f))
    def removal_command(basedir,flist,high=None):
        """Return command to delete the specified textures from high/low/both (high=True/False/None) resolutions"""
        if not flist:
            return ""
        a="rm"
        for f in flist:
            if high!=True and f in low_textures:
                a=a+" "+path_join('Textures',f)
            if high!=False and f in high_textures:
                a=a+" "+path_join('Textures.high',f)
        a=a+"\n"
        return a
    def move_command(basedir,flist,high=None,comment=False):
        """Return command to move the specified textures to Unused from high/low/both (high=True/False/None) resolutions"""
        if not flist:
            return ""
        dirset_low=set() if high==True else set(os.path.dirname(f) for f in set(flist)&low_textures)
        dirset_high=set() if high==False else set(os.path.dirname(f) for f in set(flist)&high_textures)
        a=""
        for d in dirset_low:
            a=a+("#" if comment else "")+"mv --target-directory="+path_join("Textures/Unused",d)+" "+(" ".join(path_join("Textures",f) for f in flist if (os.path.dirname(f)==d and f in low_textures)))+"\n"
        for d in dirset_high:
            a=a+("#" if comment else "")+"mv --target-directory="+path_join("Textures/Unused",d+".high")+" "+(" ".join(path_join("Textures.high",f) for f in flist if (os.path.dirname(f)==d and f in high_textures)))+"\n"
        return a
    if output_comparison_strips:
        image_check_strip(basedir,"unused_duplicate.png",unused_duplicate,["Terrain"+f[14:] for f in unused_duplicate])
        image_check_strip(basedir,"unused_dds.png",unused_dds,[f[:-4]+".png" for f in unused_dds])
        dds_skip=set(['Runway/rwy-normalmap.dds','Water/perlin-noise-nm.dds','Water/water_sine_nmap.dds','Water/waves-ver10-nm.dds'])
        used_dds_withpng=set(f for f in (high_textures|low_textures) if (f[-4:]==".dds" and f[:-4]+".png" in (high_textures|low_textures)))-unused_dds-dds_skip
        print(".dds omitted from comparison strip (normal maps etc): ",dds_skip)
        #used_dds_withpng different: p{a,c}_taxiway.dds and possibly more runway markings (darker),sand{4,5,6}.dds(less high-freq noise),water.dds(more high-freq noise),grass_rwy.dds (has stripes),cropwood.dds,irrcrop.dds,shrub.dds,herbtundra.dds,cropgrass.dds(unrelated)
        #water-reflection.{png,dds} really are plain white (so do match), not an alpha map
        image_check_strip(basedir,"used_dds.png",used_dds_withpng,[f[:-4]+".png" for f in used_dds_withpng])
        image_check_strip(basedir,"high_low.png",high_textures&low_textures)
        #image_check_strip(basedir,"high_low2.png",[f for f in high_textures&low_textures if (f[0:14]=="Terrain.winter" or "_taxiway." in f or "lava" in f or "sand" in f)],size=512)#closer look at the doubtful cases
    if output_lists:
        print("\n\nunused-winter same as normal:",sorted(unused_duplicate),"\nsize=",t_size(unused_duplicate),"\n\nunused-dds with matching png:",sorted(unused_dds),"\nsize=",t_size(unused_dds),"\n\nunused-unique:",sorted(unused_other),"\nsize=",t_size(unused_other),"\n\nnot directly used but keep as source:",sorted(needed_as_source),"\nsize=",t_size(needed_as_source),"\n\nunused low, matches high:",sorted(low_unneeded_duplicate),"\nsize=",sum(low_tsizes[f] for f in low_unneeded_duplicate),"\n\nunused low, unique:",sorted(low_unneeded_nondup),"\nsize=",sum(low_tsizes[f] for f in low_unneeded_nondup),"\n\nall non-sky textures size=",sum(high_tsizes.values())+sum(low_tsizes.values()),"used size=",used_defsize,"used no-regions size=",used_noreg_defsize,"\n\nnot found:",sorted(missing),"\n\n.dds only/highest-res:",sorted(sourceless),"\n\n.dds only/highest-res, used:",sorted(sourceless_used))
        #not really meaningful after removing low-res duplicates: ,"\n\nused high-only, not regions:",sorted(used_noreg_onlyhigh),"\nsize=",used_noreg_onlyhighsize,"these+used low (i.e. minimal flightgear-data) size=",used_noreg_onlyhighsize+used_noreg_lowsize
    if grep_check:
        unused_f=[os.path.basename(f) for f in unused]
        all_f=[os.path.basename(f) for f in (high_textures|low_textures)]
        print("\n\nPossible use outside main search:")#used to set false_positives
        subprocess.call(["grep","-r","-E","--exclude-dir=Aircraft","--exclude-dir=.git","-e","("+")|(".join(unused)+")",basedir,path_join(basedir,"../flightgear"),path_join(basedir,"../simgear")])#everywhere using full names
        subprocess.call(["grep","-r","-E","--exclude-dir=Aircraft","--exclude-dir=Textures.high","--exclude-dir=Models","--exclude-dir=Materials","--exclude-dir=Effects","--exclude-dir=.git","-e","("+")|(".join(all_f)+")",basedir,path_join(basedir,"../flightgear"),path_join(basedir,"../simgear")])#restricted (to avoid false positives from Terrain.winter vs Terrain) using filenames
        subprocess.call(["grep","-r","-E","--exclude-dir=Aircraft","--exclude-dir=Textures.high","--exclude-dir=Models","--exclude-dir=Materials","--exclude-dir=Effects","--exclude-dir=.git","-e",'[."\']dds',basedir,path_join(basedir,"../flightgear"),path_join(basedir,"../simgear")])#check for programmatic .png -> .dds swap; none found
        print("\n\nUse of sourceless textures:")
        subprocess.call(["grep","-r","-E","--exclude-dir=Aircraft","--exclude-dir=.git","-e","("+")|(".join(sourceless)+")",basedir,path_join(basedir,"../flightgear"),path_join(basedir,"../simgear")])
    if output_rsync_rules:
        print("\n\nFull flightgear-data:\n")
        rsync_rules(basedir,unused)
        rsync_rules(basedir,low_unneeded,high=False)
        print("\n\nMinimal flightgear-data:\n")
        rsync_rules(basedir,low_textures-used_noreg_low,high=False)
        rsync_rules(basedir,high_textures-used_noreg_onlyhigh,high=True)
    if output_removal_commands:
        r_script=open('delete_unused_textures.sh','w')
        r_script.write("cd "+basedir+"\n")
        r_script.write("#Unused duplicates\n")
        r_script.write(removal_command(basedir,unused_duplicate))
        r_script.write("#Unused .dds versions\n")
        r_script.write(removal_command(basedir,unused_dds-unused_dds_matchhigh,high=False))
        r_script.write(removal_command(basedir,unused_dds-unused_dds_matchlow,high=True))
        r_script.write("#Unused reduced-resolution versions\n")
        r_script.write(removal_command(basedir,low_unneeded_duplicate|(unused_other&high_textures&low_textures)-set(lowres_maybe_source),high=False))
        r_script.write("#Unused unique .png (move to Unused)\n")
        r_script.write("\n".join(["mkdir -p Textures/Unused/"+d for d in ['Terrain','Terrain.winter','Trees','Terrain.high','Terrain.winter.high','Trees.high','Runway','Water']])+"\n")
        r_script.write(move_command(basedir,[f for f in unused_other&high_textures if (f[-4:]!=".dds" and f[:5]!="Signs" and f[:6]!="Runway")],high=True))
        r_script.write(move_command(basedir,[f for f in (unused_other-high_textures)|low_unneeded_nondup if (f[-4:]!=".dds" and f[:5]!="Signs" and f[:6]!="Runway")],high=False))
        r_script.write("#Unused unique .dds\n")
        r_script.write("#It is my opinion that these should go, but if you'd prefer to move them to Unused I won't argue further\n")
        r_script.write(removal_command(basedir,[f for f in (unused_other&high_textures)|unused_dds_matchlow if (f[-4:]==".dds" and f[:5]!="Signs" and f[:6]!="Runway")],high=True))
        r_script.write(removal_command(basedir,[f for f in (unused_other-high_textures)|low_unneeded_nondup|unused_dds_matchhigh if f[-4:]==".dds"],high=False))
        r_script.write(move_command(basedir,[f for f in (unused_other&high_textures)|unused_dds_matchlow if (f[-4:]==".dds" and f[:5]!="Signs" and f[:6]!="Runway")],high=True,comment=True))
        r_script.write(move_command(basedir,[f for f in (unused_other-high_textures)|low_unneeded_nondup|unused_dds_matchhigh if (f[-4:]==".dds" and f[:5]!="Signs" and f[:6]!="Runway")],high=False,comment=True))
        r_script.close()
    if return_used_noregions:
        return used_noregions|set([path_join('Sky',f) for f in rfilelist(path_join(basedir,'Textures/Sky'))])
def find_locally_unused_models(basedir):
    """Find models not used in the base scenery (these do need to be in Terrasync as they may well be used in other locations, but don't need to be in the base flightgear-data package)
    Known bug: doesn't search everywhere: check /Nasal,.eff <image>,<inherits-from>,/(AI/)Aircraft not referenced in AI scenarios, unusual tags in Aircraft/Generic/Human/Models/walker.xml,HLA/av-aircraft.xml,/Environment,MP/aircraft_types.xml,preferences.xml"""
    models_allfiles={path_join('Models',f):s for f,s in rfilelist(path_join(basedir,'Models')).items()}
    t_size=lambda flist: sum(models_allfiles[f] for f in flist if f in models_allfiles)
    used_models=set(files_used(path=path_join(basedir,'Scenery'),filetypes=".stg",pattern=r'OBJECT_SHARED (\S+?) '))|set(files_used(path=path_join(basedir,'AI'),exclude_dirs=["Aircraft","Traffic"],pattern=r'<model>[\\/]?(\S+?)</model>'))|set(f for f in files_used(path=path_join(basedir,'Materials'),filetypes=".xml",pattern=r'<path>[\\/]?(\S+?)</path>') if f[-4:]==".xml")
    n=0
    while n!=len(used_models):
        n=len(used_models)
        used_models=used_models|set(f for f in files_used(path=basedir,filelist=used_models,filetypes=".xml",pattern=r'<path>[\\/]?(\S+?)</path>') if f[-4:]==".xml")
    used_textures=set(files_used(path=basedir,filelist=used_models,filetypes=".ac",pattern=r'texture "(\S+?)"',relative_path=True))|set(files_used(path=basedir,filelist=used_models,filetypes=".xml",pattern=r'<texture>[\\/]?(\S+?)</texture>',relative_path=True))
    extra_used_models=set()
    for f1 in used_models:
        if f1[-4:]!=".xml":
            continue
        for f2 in files_used(path=basedir,filelist=[f1],pattern=r'<path>[\\/]?(\S+?)</path>',relative_path=True):
            if f2[-3:]!=".ac":
                continue
            extra_used_models=extra_used_models|set([f2])
            p2=[f for f in files_used(path=basedir,filelist=[f1],pattern=r'<texture-path>[\\/]?(\S+?)</texture-path>',relative_path=True)]
            if len(p2)==0:
                p2=[os.path.dirname(f1)]
            if len(p2)!=1:
                print("non-unique/not found:",f1,f2,p2)
                continue
            try:
                used_textures=used_textures|set(os.path.normpath(path_join(p2[0],f)) for f in files_used(path=basedir,filelist=[f2],filetypes=".ac",pattern=r'texture "(\S+?)"'))
            except (IOError,OSError):
                print("not found",f1,f2,p2)
    used_models=used_models|extra_used_models
    unused=set(models_allfiles.keys())-(used_models|used_textures)
    missing=set(f for f in (used_models|used_textures) if ((f.startswith('Models') and f not in models_allfiles.keys()) or not os.path.isfile(path_join(basedir,f))))
    print("used\n",sorted(used_models),"\nsize=",t_size(used_models),"\n\n",sorted(used_textures),"\nsize=",t_size(used_textures),"\n\nunused\n",sorted(unused),"\nsize=",t_size(unused),"\n\nmissing\n",sorted(missing),"\nsize=",t_size(missing))

class FilesetSizes:
    def __init__(self):
        self.count=0
        self.ncsize=0
        self.csize=0
    @property
    def size(self):
        if self.csize>0:
            return self.csize
        else:
            return self.ncsize
    def __str__(self):
        if self.csize>0:
            return "{0:10,} {1:15,} {2:15,}".format(self.count,self.ncsize,self.csize)
        else:
            return "{0:10,} {1:15,}".format(self.count,self.ncsize)
    def __add__(self,other):
        result=FilesetSizes()
        result.count=self.count+other.count
        result.ncsize=self.ncsize+other.ncsize
        result.csize=self.csize+other.csize
        return result
def size_by_category(path,exclude_dirs,keyfn,compressed_size=False):
    """Total size of files, in each category returned from keyfn"""
    files=rfilelist(path,exclude_dirs)
    result=defaultdict(FilesetSizes)
    gzdir=tempfile.TemporaryDirectory()
    gzpath=gzdir.name
    gzcount=0
    for file,size in files.items():
        cat=keyfn(file,size)
        if cat is None:
            continue
        result[cat].count=result[cat].count+1
        result[cat].ncsize=result[cat].ncsize+size
        if compressed_size:
            try:
                result[cat].targz.add(path_join(path,file))
            except AttributeError:
                result[cat].targzname=path_join(gzpath,str(gzcount)+".tar.gz")
                result[cat].targz=tarfile.open(result[cat].targzname,mode="w:gz")
                gzcount=gzcount+1
                result[cat].targz.add(path_join(path,file))
    if compressed_size:
        for cat in result:
            result[cat].targz.close()
            result[cat].csize=os.path.getsize(result[cat].targzname)
    return result
def fgdata_size(path,by_size=False,exclude_dirs=None,compressed_size=False,min_size=1e6,include_aircraft=['UIUC','777','777-200','b1900d','CitationX','ZLT-NT','dhc2','Cub','sopwithCamel','f-14b','ASK13','bo105','Dragonfly','SenecaII','A6M2'],sections={"Aircraft/c172p":"Aircraft-base","Aircraft/Generic":"Aircraft-base","Aircraft/Instruments":"Aircraft-base","Aircraft/Instruments-3d":"Aircraft-base","Aircraft/ufo":"Aircraft-base","Aircraft/777":"Aircraft-777","Aircraft/777-200":"Aircraft-777","Aircraft":"Aircraft-other","Textures":"Textures","Textures.high":"Textures","AI/Aircraft":"AI-aircraft","AI":"AI-other","Scenery":"scenery","Models":"models"}):
    if any('\\' in s for s in sections):
        raise ValueError("sections always uses forward slashes")
    if "" not in sections:
        sections[""]="Other"
    if exclude_dirs is None:
        if os.path.exists(path_join(path,".git")):
            exclude_dirs=[".git","Textures/Unused"]+[path_join("Aircraft",d) for d in os.listdir(path_join(path,"Aircraft")) if d not in ["c172p","ufo","Generic","Instruments","Instruments-3d"]+include_aircraft]
        else:
            exclude_dirs=[]
    if by_size:
        keyfn=lambda file,size: ("texture",math.frexp(size)[1]) if os.path.splitext(file)[1] in [".png",".dds",".rgb",".jpg"] else ("nontexture",math.frexp(size)[1])
    else:
        def keyfn(file,size):
            file_ext=os.path.splitext(file)[1]
            if file_ext==".gz":
                file_ext=os.path.splitext(os.path.splitext(file)[0])[1]+file_ext
            file0=file.replace('\\','/')
            section=sections[max((s for s in sections if file0.startswith(s)),key=len)]
            return (section,file_ext)
    result=size_by_category(path,exclude_dirs,keyfn,compressed_size)
    #print(result)
    totals1=defaultdict(FilesetSizes)
    totals2=defaultdict(FilesetSizes)
    other=defaultdict(FilesetSizes)
    for cat in result:
        totals1[cat[0]]=totals1[cat[0]]+result[cat]
        totals2[cat[1]]=totals2[cat[1]]+result[cat]
        if (not by_size) and (result[cat].size<min_size):
            other[cat[0]]=other[cat[0]]+result[cat]
    print("{0:>10} {1:>15} {2:>15}".format("Count","Size","Compr.size"))
    for cat0,r0 in sorted(totals1.items(),key=lambda p:-p[1].size):
        print(cat0)
        for cat,r in sorted([(c[1],r) for (c,r) in result.items() if (c[0]==cat0 and (by_size or r.size>min_size))],key=(lambda p:p[0]) if by_size else (lambda p:-p[1].size)):
            print(r,cat)
        if not by_size:
            print(other[cat0],"other")
        print(totals1[cat0],"all")
    print("All")
    for cat,r in sorted([(c,r) for (c,r) in totals2.items() if (by_size or r.size>min_size)],key=(lambda p:p[0]) if by_size else (lambda p:-p[1].size)):
        print(r,cat)
    if not by_size:
        print(sum((r for r in totals2.values() if r.size<min_size),FilesetSizes()),"other")
    print(sum(totals1.values(),FilesetSizes()),"all")
def create_reduced_file(input_path,output_path,temp_path,cdir,file,downsample_this,compress_this,compress_names_find, compressed_format,texture_filetypes,binary_types,fclass):
    """Process a single file in create_reduced_fgdata.  (Separate function to allow parallel processing)"""
    retcode=0
    if downsample_this or compress_this:
        image_type=texture_filetypes[os.path.splitext(file)[1]]
        output_image_type=compressed_format if compress_this else os.path.splitext(file)[1]
        output_file=os.path.splitext(file)[0]+output_image_type
        output_image_type=texture_filetypes[output_image_type]
        if "{0}" in output_path and fclass=="base-textures":#downsampled in base-textures, full resolution in extra-textures
            shutil.copy(path_join(input_path,cdir,file),path_join(output_path.format("extra-textures"),cdir,file))
        if output_image_type=="DDS":# in Ubuntu, neither imagemagick nor graphicsmagick can write .dds
            #doesn't work (for dds -> smaller dds): subprocess.call(["nvzoom","-s","0.5","-f","box",path_join(input_path,cdir,file),path_join(output_path.format(fclass),cdir,file)])
            if subprocess.call(["convert",image_type+":"+path_join(input_path,cdir,file)]+(["-flip"] if ((image_type=="DDS")!=(output_image_type=="DDS")) else [])+(["-sample","50%"] if downsample_this else [])+[path_join(temp_path,cdir,os.path.splitext(file)[0]+".png")]):#fails on some DDS formats, so just copy them
                shutil.copy(path_join(input_path,cdir,file),path_join(output_path.format(fclass),cdir,file))
                print(path_join(cdir,file),"unsupported type, probably normal map")
                if compress_this:
                    raise TypeError#copy will have the wrong name
            else:
                try:
                    image_properties=subprocess.check_output(["identify","-verbose",path_join(temp_path,cdir,os.path.splitext(file)[0]+".png")])
                except subprocess.CalledProcessError as err:
                    print("identify error on",path_join(cdir,file),"after ",["convert",image_type+":"+path_join(input_path,cdir,file)]+(["-flip"] if ((image_type=="DDS")!=(output_image_type=="DDS")) else [])+(["-sample","50%"] if downsample_this else [])+[path_join(temp_path,cdir,os.path.splitext(file)[0]+".png")],["identify","-verbose",path_join(temp_path,cdir,os.path.splitext(file)[0]+".png")],err)
                    raise
                has_alpha=b"Alpha" in image_properties
                needs_alpha=has_alpha
                if has_alpha and re.search(rb"Alpha:\s*min: 255 \(1\)",image_properties):
                    print(path_join(cdir,file),"has always-255 alpha")
                    needs_alpha=False
                retcode=subprocess.call(["nvcompress","-bc3" if needs_alpha else "-bc1",path_join(temp_path,cdir,os.path.splitext(file)[0]+".png"),path_join(output_path.format(fclass),cdir,output_file)],stdout=devnull)
        else:
            retcode=subprocess.call(["convert",image_type+":"+path_join(input_path,cdir,file)]+(["-sample","50%"] if downsample_this else [])+[output_image_type+":"+path_join(output_path.format(fclass),cdir,output_file)])#we use sample rather than an averaging filter to not break mask/rotation/... maps
    else:#not to be downsampled/compressed
        if os.path.splitext(file)[1] in binary_types:#just copy
            shutil.copy(path_join(input_path,cdir,file),path_join(output_path.format(fclass),cdir,file))
        else:#texture name replacement
            file_in=open(path_join(input_path,cdir,file),'rb')
            file_out=open(path_join(output_path.format(fclass),cdir,file),'wb')
            file_str=file_in.read(None)
            file_in.close()
            (file_strout,num_matches)=compress_names_find.subn(lambda mf: os.path.splitext(mf.group(0))[0]+(compressed_format.encode('utf-8')),file_str)
            file_out.write(file_strout)
            file_out.close()
            #if ((os.path.splitext(file)[1] not in textureuser_types) and num_matches>0):
                #print("Warning: ",num_matches," unexpected use(s) in ",path_join(cdir,file))
            #if compress_names_find0.search(file_strout):
                #print("Warning: unreplaced match(es) in ",path_join(cdir,file),compress_names_find0.search(file_strout).group(0))
            """Warning: unreplaced match(es) in... correct rejections of match within a filename:
                Aircraft/Instruments-3d/AN-APS-13.ac b'panel.png'
                Aircraft/Instruments-3d/magneto-switch/mag_switch.ac b'black.png'
                Nasal/canvas/map/Images/chart_symbols.svg b'wash.png'
                Models/Airport/blast-deflector49m.ac b'generic.png'
                Models/Airport/blast-deflector63m.ac b'generic.png'
                Models/Industrial/oilrig09.ac b'yellow.png'
                Models/Industrial/oilrig10.ac b'yellow.png'
                Models/Industrial/oilrig09.ac.before-color-change b'yellow.png'
                Models/Industrial/oilrig10.ac.before-color-change b'yellow.png'
                Models/Maritime/Civilian/Tanker.ac b'black.png'
                Models/Transport/flatcar.xml b'evergreen.png'
                Models/Commercial/tower-grey-black.ac b'black.png'
                Materials/base/materials-base.xml b'yellow.png'
                
                Warning: unexpected use(s) in...
                Docs/README.local_weather.html (the only one that looke like an actual problem; hence, Docs is now skipped)
                Nasal/canvas/map/Images/chart_symbols.svg (probably inkscape:export-filename, which are creator-specific absolute paths anyway, but now skipped)
                oilrig09.ac.before-color-change,oilrig10.ac.before-color-change,stbd_coaming_panel.ac.bak (presumably backup files)
                """
    if retcode:
        print("Error ",retcode," in ",path_join(cdir,file))

def create_reduced_fgdata(input_path,output_path,reject_positional_args=None,split_textures=False,exclude_parts=[],include_aircraft=['UIUC','777','777-200','b1900d','CitationX','ZLT-NT','dhc2','Cub','sopwithCamel','f-14b','ASK13','bo105','Dragonfly','SenecaII','A6M2'],dirs_to_downsample=(),dirs_to_compress=(),compressed_format=".dds",downsample_min_filesize=1e5,compress_min_filesize=3e4,use_ready_compressed=True):
    """Create a smaller, reduced-quality flightgear-data package
Can downsample textures 50%, change texture format, and/or omit sections (region-specific textures, aircraft, AI traffic)
Downsampling and format change require imagemagick or graphicsmagick (for convert) and libnvtt-bin (for nvcompress)

Optional parts, use exclude_parts to omit:
ai: no background traffic, but tankers etc do still work
extra-textures (requires split_textures=True): no region-specific textures

The c172p and ufo are always included; other aircraft are added by include_aircraft

Texture downsampling: textures in dirs_to_downsample and larger than downsample_min_filesize downsampled 50%
Texture format conversion: textures in dirs_to_compress and larger than compress_min_filesize converted to compressed_format
use_ready_compressed determines what happens if a same-basename file in compressed_format already exists: True uses the already-compressed one, False uses the uncompressed one, None keeps both
Suggested dirs_to_downsample:
3.2: ('Textures.high/Terrain','Textures.high/Trees','Textures.high/Terrain.winter','AI/Aircraft','Models')
3.3: ('Textures/Terrain','Textures/Trees','Textures/Terrain.winter','AI/Aircraft','Models')
To do "everything" (a few are always skipped due to potential breakage), use dirs_to_compress=('',)

To put each section in its own directory (e.g. for building a Debian-style flightgear-data-* set of packages) use {0} in output_path, e.g.
python3 -c "import fgdata_checkers; fgdata_checkers.create_reduced_fgdata(input_path='/home/rnpalmer/fs_dev/git/fgdata',output_path='/home/rnpalmer/fs_dev/flightgear/data_split/debian/flightgear-data-{0}/usr/share/games/flightgear',include_aircraft=['UIUC','b1900d','CitationX','ZLT-NT','dhc2','Cub','sopwithCamel','f-14b','ASK13','bo105','Dragonfly','SenecaII','A6M2'])"
This creates separate preferences-regions.xml and preferences-noregions.xml files for with and without regional textures; you need to handle symlinking preferences.xml to the correct one
"""
    start_time=time.time()
    if reject_positional_args is not None:
        raise TypeError("Keyword arguments only please: this is not a stable API")
    if use_ready_compressed not in (True,False,None):
        raise TypeError("invalid use_ready_compressed setting")
    texture_filetypes={".png":"PNG",".dds":"DDS",".jpg":"JPEG"}#,".rgb":"SGI" loses cloud transparency
    if compressed_format not in texture_filetypes:
        raise ValueError("Invalid compressed_format (include the .)")
    textureuser_types={".eff",".xml",".ac",".nas"}
    binary_types={".png",".dds",".rgb",".RGB",".jpg",".wav",".WAV",".btg.gz",".zip",".tar.gz"}#don't search these for texture name replacement
    """Textures named directly in flightgear/simgear code:
gui/images/shadow.png,gui/cursor-spin-cw.png (probably safest to treat this as gui/*, they're all small)
Textures/Globe/world.topo.bathy.200407.3x4096x2048.png
Textures/buildings.png,Textures/buildings-lightmap.png
Textures/Sky/*
Textures/Splash*.png
unknown.rgb (probably Textures/ or Textures/Terrain/, neither exists)
Aircraft/Instruments/Textures/nd-symbols.png (doesn't actually exist),Aircraft/Instruments/Textures/compass-ribbon.rgb,Aircraft/Instruments/Textures/od_wxradar.rgb,Aircraft/Instruments/Textures/od_wxradar.rgb,Aircraft/Instruments/Textures/wxecho.rgb,Aircraft/Instruments/Textures/od_groundradar.rgb (doesn't actually exist)
also, Aircraft/{Instruments,Instruments-3d,Generic} may be used by downloaded aircraft, and Docs images are used in .html
Nasal (Canvas map) probably wouldn't break anything, but guessing it's a bad idea visually"""
    no_compress_pattern=re.compile(r'mask|light|relief|nmap|nm\.|normal|dudv|^Splash[0-9].png$|^buildings.png$|^buildings-lightmap.png$|^world.topo.bathy.200407.3x4096x2048.png$|^ocean_depth_1.png$')#edge blurring from lossy compression may break masks (converting ocean_depth_1.png is known to give black water near shore at effects>=4), and this script doesn't know how to create DDS normal maps
    no_compress_dirs=("gui","Docs","webgui","Nasal","Textures/Sky","Aircraft/Instruments","Aircraft/Instruments-3d","Aircraft/Generic")
    exclude_dirs=[".git","Textures/Unused"]
    exclude_unnamed_subdirs=["Aircraft"]#these are a separate mechanism from subtree_class/exclude_parts mostly to save time (subtree_class still fully scans excluded directories because the class may change again further down the tree, e.g. AI/Aircraft ai -> performancedb.xml base; these don't)
    subtree_class={"Aircraft/c172p":"base","Aircraft/Generic":"base","Aircraft/Instruments":"base","Aircraft/Instruments-3d":"base","Aircraft/ufo":"base","Textures":"textures","Textures.high":"textures","AI/Aircraft":"ai","AI/Traffic":"ai","AI/Aircraft/performancedb.xml":"base","Scenery":"scenery","Models":"models"}
    for aircraft in include_aircraft:
        if "Aircraft/"+aircraft not in subtree_class:
            subtree_class["Aircraft/"+aircraft]="aircraft"
    include_files=[]
    if split_textures:
        base_texture_files=[]
        for t in find_unused_textures(input_path,return_used_noregions=True):
            base_texture_files.extend([path_join("Textures",t),path_join("Textures.high",t)])
    #no longer a significant problem with exclude_dirs: if os.path.exists(path_join(input_path,".git")):
        #print(input_path,"appears to be a git clone; this will work, but the result will be larger than starting from a standard flightgear-data package.\nTo create this use (adjusting paths as necessary) rsync -av --filter=\"merge /home/rnpalmer/fs_dev/git/fgmeta/base-package.rules\" ~/fs_dev/git/fgdata ~/fs_dev/flightgear/data_full")
    if os.path.exists(output_path.format("base")) and os.listdir(output_path.format("base")):
        print("output path",output_path,"non-empty, aborting to avoid data loss\nIf you did want to lose its previous contents, run:\nrm -r",output_path,"\nthen re-run this script")
        return
    if compressed_format==".jpg":
        print("Warning: selected compression format does not support transparency")
    compress_names=set()
    if dirs_to_compress:#need this preliminary pass to get names to change in .xml,etc
        no_compress_names=set()
        dirs={"":"base"}
        while dirs:
            cdir,cclass=dirs.popitem()
            cdirfiles=os.listdir(path_join(input_path,cdir))
            for file in cdirfiles:
                fclass=subtree_class.get(path_join(cdir,file),cclass)
                if os.path.isdir(path_join(input_path,cdir,file)):
                    if (path_join(cdir,file) not in exclude_dirs) and (cdir not in exclude_unnamed_subdirs or path_join(cdir,file) in subtree_class):
                        dirs[path_join(cdir,file)]=fclass
                else:#file
                    compress_this=cdir.startswith(dirs_to_compress) and (os.path.splitext(file)[1] in texture_filetypes) and (os.path.splitext(file)[1]!=compressed_format) and (os.path.getsize(path_join(input_path,cdir,file))>compress_min_filesize) and not no_compress_pattern.search(file) and not cdir.startswith(no_compress_dirs) and (file not in no_compress_names) and ((use_ready_compressed is not None) or not os.path.exists(path_join(input_path,cdir,os.path.splitext(file)[0]+compressed_format)))
                    if compress_this:
                        compress_names.add(file)
                    else:
                        no_compress_names.add(file)
                        compress_names.discard(file)#if there are two with the same name in different directories, compress both or neither, to simplify name replacement
    compress_names_find=re.compile(('(?<=["\'>/\\\\ \\n])('+'|'.join(re.escape(f) for f in compress_names)+')($|(?=["\'< \\n]))').encode('utf-8'))
    compress_names_find0=re.compile(('|'.join(re.escape(f) for f in compress_names)).encode('utf-8'))
    #print(compress_names,"\n\n",no_compress_names,"\n\n",'(?<=["\'>/\\\\ \\n])('+'|'.join(re.escape(f) for f in compress_names)+')($|(?=["\'< \\n]))',"\n\n",'|'.join(re.escape(f) for f in compress_names),"\n\n")
    print("Starting conversion...",len(compress_names),"files to change format, runtime so far=",int(time.time()-start_time),"sec")
    dirs={"":"base"}
    subprocess_pool=multiprocessing.Pool(processes=8)
    subprocess_list=[]
    temp_dir=tempfile.TemporaryDirectory()
    temp_path=temp_dir.name
    while dirs:
        cdir,cclass=dirs.popitem()
        cdirfiles=os.listdir(path_join(input_path,cdir))
        for file in cdirfiles:
            fclass=subtree_class.get(path_join(cdir,file),cclass)
            if os.path.isdir(path_join(input_path,cdir,file)):
                if (path_join(cdir,file) not in exclude_dirs) and (cdir not in exclude_unnamed_subdirs or path_join(cdir,file) in subtree_class):
                    dirs[path_join(cdir,file)]=fclass
            else:#file
                if split_textures and fclass=="textures":
                    if path_join(cdir,file) in base_texture_files:
                        fclass="base-textures"
                    else:
                        fclass="extra-textures"
                if fclass in exclude_parts:
                    continue
                if not os.path.exists(path_join(output_path.format(fclass),cdir)):
                    os.makedirs(path_join(output_path.format(fclass),cdir))#errors out if the directory does exist, so calling it in the per-file subprocess would be a race condition
                if "{0}" in output_path and fclass=="base-textures" and not os.path.exists(path_join(output_path.format("extra-textures"),cdir)):#downsampled in base-textures, full resolution in extra-textures
                    os.makedirs(path_join(output_path.format("extra-textures"),cdir))
                if not os.path.exists(path_join(temp_path,cdir)):
                    os.makedirs(path_join(temp_path,cdir))
                downsample_this=(cdir.startswith(dirs_to_downsample)) and (os.path.splitext(file)[1] in texture_filetypes) and (os.path.getsize(path_join(input_path,cdir,file))>downsample_min_filesize)
                compress_this=(file in compress_names)
                if compress_this and use_ready_compressed==True and os.path.exists(path_join(input_path,cdir,os.path.splitext(file)[0]+compressed_format)):
                    continue
                if (not compress_this) and use_ready_compressed==False and os.path.splitext(file)[1]==compressed_format and any((os.path.exists(path_join(input_path,cdir,os.path.splitext(file)[0]+f)) and os.path.splitext(file)[0]+f in compress_names) for f in texture_filetypes if f!=os.path.splitext(file)[1]):
                    continue
                subprocess_list.append(subprocess_pool.apply_async(create_reduced_file,args=(input_path,output_path,temp_path,cdir,file,downsample_this,compress_this,compress_names_find, compressed_format,texture_filetypes,binary_types,fclass)))
    print(len(subprocess_list),"file tasks started...runtime so far=",int(time.time()-start_time),"sec\n(Not a linear progress indicator: they are different lengths.)")
    last_report=time.time()-100#print first report immediately
    for s0 in subprocess_list:
        if time.time()>last_report+60:
            print("Waiting for",len([s for s in subprocess_list if not s.ready()]),"file tasks...runtime so far=",int(time.time()-start_time),"sec")
            last_report=time.time()
        s0.get()
    subprocess_pool.close()
    subprocess_pool.join()
    if "{0}" in output_path:
        os.rename(path_join(output_path.format("base"),"preferences.xml"),path_join(output_path.format("base"),"preferences-regions.xml"))
    if "extra-textures" in exclude_parts or "{0}" in output_path:
        prefs_in=open(path_join(input_path,"preferences.xml"),'r')
        prefs_out=open(path_join(output_path.format("base"),"preferences-noregions.xml" if "{0}" in output_path else "preferences.xml"),'w')
        prefs_str=prefs_in.read(None)
        prefs_in.close()
        prefs_str=prefs_str.replace("Materials/regions/materials.xml","Materials/default/materials.xml")#turn off regional textures
        prefs_out.write(prefs_str)
        prefs_out.close()
    print("Total runtime=",int(time.time()-start_time),"sec")
def check_text_encoding(path,filelist=None,binary_types=(".png",".dds",".rgb",".RGB",".jpg",".wav",".WAV",".btg.gz",".xcf.gz",".xcf",".XCF","Thumbs.db",".blend",".bmp",".gif", ".3ds",".3DS",".pdf",".ttf",".txf",".htsvoice",".odt",".ods",".xls",".mp3",".zip",".tar.gz"),exclude_dirs=[".git","Timezone"]):
    """filelist is intended for quick testing: see fgdata_nonascii_filelist.py"""
    def err_context(err):
        start=max(err.object.rfind(b'\n',0,err.start)+1,err.start-30,0)
        end=min(err.object.find(b'\n',err.start),err.start+30,len(err.object))
        if end<0:#not found
            end=err.start+30
        return err.object[start:end]
    def dict_print(d):
        return "".join(i[0]+"\n\t"+str(i[1])+"\n\t"+(str(i[1],encoding="utf-8",errors="replace")+"\n\t"+str(i[1],encoding="latin-1") if type(i[1])==bytes else "")+"\n" for i in sorted(d.items()))
    if filelist is None:
        filelist=[f for f in rfilelist(path,exclude_dirs) if not f.endswith(tuple(binary_types))]
    utf8_files={}
    withnulls_files=[]
    othertext_files={}
    mislabeled_xml={}
    mislabeled_xml_nocomments={}
    xml_encoding_pattern=re.compile(r'<\?xml.*?encoding="(\S+?)".*?\?>')
    xml_noencoding_pattern=re.compile(r'<\?xml.*?\?>')
    utf8_files_nocomments={}
    othertext_files_nocomments={}
    for fname in filelist:
        if os.path.splitext(fname)[1]==".gz":
            fobj=gzip.open(path_join(path,fname),mode='rb')
        else:
            fobj=open(path_join(path,fname),mode='rb')
        fdata=fobj.read()
        if b"\0" in fdata:
            withnulls_files.append(fname)#two look like corrupted files: Aircraft/p51d/Resources/WIP/P-51D-25NA.ac (hangs gedit,large block of nulls in middle) Docs/Serial/nmeafaq.txt (block of nulls at end), rest are probably-binary types
            continue
        if os.path.splitext(fname)[1] in (".xml",".svg",".xhtml"):
            encoding_mark=xml_encoding_pattern.search(str(fdata.split(b'\n',maxsplit=1)[0],encoding="utf-8"))
            if encoding_mark:
                encoding_mark=encoding_mark.group(1)
                if encoding_mark not in ("utf-8","UTF-8","ISO-8859-1"):
                    mislabeled_xml_nocomments[fname]="unrecognised encoding "+encoding_mark
                    encoding_mark=None
            else:
                if xml_noencoding_pattern.search(str(fdata.split(b'\n',maxsplit=1)[0],encoding="utf-8")):
                    encoding_mark="utf-8"#XML standard allows either UTF-8 or UTF-16 (with BOM) in unlabeled files, but we only use -8
                else:
                    encoding_mark=None
                    #mislabeled_xml_nocomments[fname]="no xml header"
        else:
            encoding_mark=None
        try:
            fdata.decode(encoding="ascii")
            continue
        except UnicodeError as err:
            errline=err_context(err)
        try:
            fdata.decode(encoding="utf-8")
            utf8_files[fname]=errline
            if encoding_mark not in ("utf-8","UTF-8",None):
                mislabeled_xml[fname]=bytes(encoding_mark,encoding="ascii")+errline
        except UnicodeError as err:
            errline=err_context(err)
            othertext_files[fname]=errline
            if encoding_mark not in ("ISO-8859-1",None):
                mislabeled_xml[fname]=bytes(encoding_mark,encoding="ascii")+errline
        if os.path.basename(fname) in ("Read-Me.txt","README.txt","Readme.txt","readme.txt","LIS-MOI_GNU-GPL"):
            continue
        fdata_nocomments=strip_comments(fdata,filename=fname)
        if fdata_nocomments.startswith(bytes([0xef,0xbb,0xbf])) and fname not in mislabeled_xml:#UTF-8 BOM
            fdata_nocomments=fdata_nocomments[3:]
        try:
            fdata_nocomments.decode(encoding="ascii")
            continue
        except UnicodeError as err:
            errline=err_context(err)
        try:
            fdata_nocomments.decode(encoding="utf-8")
            if encoding_mark is None:
                utf8_files_nocomments[fname]=errline
            if encoding_mark not in ("utf-8","UTF-8",None):
                mislabeled_xml_nocomments[fname]=bytes(encoding_mark,encoding="ascii")+errline
        except UnicodeError as err:
            errline=err_context(err)
            if encoding_mark is None:
                othertext_files_nocomments[fname]=errline
            if encoding_mark not in ("ISO-8859-1",None):
                mislabeled_xml_nocomments[fname]=bytes(encoding_mark,encoding="ascii")+errline
    print("non-ASCII valid UTF-8:",dict_print(utf8_files),"\n\nother:",dict_print(othertext_files),"\n\nmislabeled/unrecognised",dict_print(mislabeled_xml),"\n\nwith nulls (binary or UTF-16/32):",sorted(withnulls_files),"\n\nnon-ASCII valid UTF-8 (outside BOM/comments):",dict_print(utf8_files_nocomments),"\n\nother (outside comments):",dict_print(othertext_files_nocomments),"\n\nmislabeled/unrecognised (outside comments)",dict_print(mislabeled_xml_nocomments))