troggle/core/views/wallets_edit.py

import datetime
import json
import os
import re
import socket
import subprocess
import urllib
from pathlib import Path

from django import forms
from django.core.exceptions import MultipleObjectsReturned, ObjectDoesNotExist
from django.core.files.storage import FileSystemStorage
from django.http import HttpResponseRedirect
from django.shortcuts import render

import settings
from troggle.core.models.caves import Cave
from troggle.core.models.logbooks import LogbookEntry  # , PersonLogEntry
from troggle.core.models.survex import SurvexBlock, SurvexFile, SurvexPersonRole
from troggle.core.models.troggle import DataIssue, Expedition
from troggle.core.models.wallets import Wallet, YEAR_RANGE

from troggle.core.views.caves import getCave
from troggle.core.views.scans import caveifywallet, oldwallet
from troggle.core.views.uploads import FilesForm

from troggle.parsers.scans import contentsjson


"""Main wallet editing form, which includes scan file upload into the wallet 
"""

todo = """
- Nasty bug in navingating to 'previous wallet' when we have a 2-year gap in expos
  The xxxx#00 wallet is not getting edited correctly. Something is off by one somewhere..

- Register uploaded filenames in the Django db without needing to wait for a reset & bulk file import

- Refactor walletedit() as it contains all the wallets 'complaints' code from the pre-2022 
  script 'wallets.py'

- Need to validate uploaded file as being a valid image file, not a dubious script or hack
"""
WALLET_BLANK_JSON = {
    "cave": "",
    "date": "",
    "free text": "",
    # "description url": "1623/NNN",
    "description written": False,
    "electronic survey": False,
    "elev drawn": False,
    "elev not required": False,
    "name": "",
    "people": ["Unknown"],
    "plan drawn": False,
    "plan not required": False,
    "notes not required": False,
    "qms written": False,
    "survex file": [],
    "survex not required": False,
    "website updated": False,
}

class WalletGotoForm(forms.Form):  # not a model-form, just a form-form
    walletgoto = forms.CharField(strip=True, required=False)


class WalletForm(forms.Form):  # not a model-form, just a form-form
    descriptionw = forms.CharField(strip=True, required=False)
    people = forms.CharField(strip=True, required=False)
    survexnr = forms.CharField(strip=True, required=False)
    qmsw = forms.CharField(strip=True, required=False)
    date = forms.CharField(strip=True, required=True)  # the only required field
    websiteupt = forms.CharField(strip=True, required=False)
    elevnr = forms.CharField(strip=True, required=False)
    cave = forms.CharField(strip=True, required=False)
    psg = forms.CharField(strip=True, required=False)
    freetext = forms.CharField(strip=True, required=False)
    plannr = forms.CharField(strip=True, required=False)
    notesnr = forms.CharField(strip=True, required=False)
    electronic = forms.CharField(strip=True, required=False)
    pland = forms.CharField(strip=True, required=False)
    elevd = forms.CharField(strip=True, required=False)
    # url = forms.CharField(strip=True, required=False)
    survex = forms.CharField(strip=True, required=False)


xlate = {
    # "url": "description url",
    "descriptionw": "description written",
    "people": "people",
    "date": "date",
    "cave": "cave",
    "plannr": "plan not required",
    "notesnr": "notes not required",
    "survexnr": "survex not required",
    "qmsw": "qms written",
    "elevnr": "elev not required",
    "websiteupt": "website updated",
    "electronic": "electronic survey",
    "pland": "plan drawn",
    "elevd": "elev drawn",
    "psg": "name",  # a name for this wallet
    "freetext": "free text",
    "survex": "survex file",
}


def get_complaints(complaints, waldata, svxfiles, files, wallet, wurl):
    """Taken from old script wallets.py and edited to make more comprehensible
    Loads the survex files names and processes all complaints

    """
    # If skipping through the wallets on the upload form, the wallet may not yet exist
    try:
        w = Wallet.objects.get(walletname=wallet)
    except ObjectDoesNotExist:
        return None, None

    # Date
    if not waldata["date"]:
        complaints.append(
            "A date is mandatory. No data can be updated or edited unless you specify a date. Look in the survex file if there is one."
        )

    # People
    if (
        not waldata["people"]
        or waldata["people"] == ["NOBODY"]
        or waldata["people"] == ["Unknown"]
        or waldata["people"] == [""]
    ):
        complaints.append(
            "Somebody must have done this. Look in the survex file, or in the logbook entries for this date, for the people who created this data."
        )

    # survex, but get_ticks has already done much of this ??
    survex_complaint = ""

    if waldata["survex file"]:
        if not type(waldata["survex file"]) == list:  # a string also is a sequence type, so do it this way
            waldata["survex file"] = [waldata["survex file"]]
        for sx in waldata["survex file"]:
            # this logic appears in several places, inc get_ticks(). Refactor.
            if sx != "":
                if Path(sx).suffix.lower() != ".svx":
                    sx = sx + ".svx"
                svxfiles.append(sx)
                if not (Path(settings.SURVEX_DATA) / sx).is_file():
                    file_complaint = f"{wallet} Incorrect survex file name. File {sx} was not found in LOSER repo"
                    complaints.append(file_complaint)
                    message = f"! {file_complaint}"
                    print(message)
                    DataIssue.objects.update_or_create(
                        parser="scans", message=message, url=wurl
                    )  # set URL to this wallet folder
                else:
                    try:
                        sxpath = str(Path(sx).with_suffix(""))
                        SurvexFile.objects.get(path=sxpath)
                    except MultipleObjectsReturned:
                        # can happen if connecting a wallet to a survex file.. i think..
                        QSsvxfiles = SurvexFile.objects.filter(path=sxpath)
                        for s in QSsvxfiles:
                            print(s.path, s.cave, s.survexdirectory)
                        # QSsvxfiles[0]  # dont' know how this happened, fix later..
                    except:
                        file_complaint = (
                            f"{wallet} Survex file {sx} exists, but is not registered in the database {sxpath}. How?.."
                        )
                        complaints.append(file_complaint)
                        message = f"! {file_complaint}"
                        print(message)
                        DataIssue.objects.update_or_create(
                            parser="scans", message=message, url=wurl
                        )  # set URL to this wallet folder

    if waldata["survex not required"] and waldata["survex file"] != [""]:
        survex_complaint = (
            f'Survex is stated as not required and yet there is a survex file! ({waldata["survex file"]})'
        )
    if not waldata["survex not required"] and waldata["survex file"] == [""]:
        survex_complaint = "A survex file is required, but has not been specified!"
    if survex_complaint:
        complaints.append(survex_complaint)

    ticks = w.get_ticks()

    # Notes required
    if ticks["N"] != "green":
        complaints.append(
            "The notes needs scanning (or renaming) or tick 'Notes not required' checkbox. No noteNN.jpg or XXnote.jpg file was found; this is not an electronic survey."
        )

    # Plan drawing required
    if ticks["P"] != "green":
        complaints.append(
            "The plan needs drawing (or renaming, or tick 'Plan drawn' checkbox or 'Plan not required' checkbox): no planNN.jpg or XXplan.jpg file found."
        )

    # Elev drawing required
    if ticks["E"] != "green":
        complaints.append(
            "The elevation needs drawing (or renaming, or tick 'Elev drawn' checkbox or 'Elev not required' checkbox): no elevNN.jpg or XXelev.jpg file found."
        )

    # Therion
    if ticks["T"] != "green":
        complaints.append(
            "Tunnel or Therion drawing files need drawing. Or if this an electronic survey, please tick the 'Electronic survey' checkbox."
        )

    # Description
    if not waldata["description written"]:
        complaints.append(
            "The guidebook description needs writing into the survex file. Tick the 'Cave description written' checkbox when this is done."
        )
    # QMs
    if not waldata["qms written"] and w.year() and int(w.year()) >= 2015:
        complaints.append(
            "The QMs needs writing into the survex file. Tick the 'QMs written' checkbox when this is done."
        )

    # Website
    if not waldata["website updated"]:
        complaints.append(
            "The cave description website is marked as needing updating using the guidebook description from the survex file. Tick the 'Website updated' checkbox when this is done."
        )

    # Find the cave, if it exists
    if waldata["cave"]:
        try:
            caveid = waldata["cave"]
            if type(caveid) is list:
                for i in caveid:
                    i = i.replace("/", "-")
                    caveobject = getCave(i)  # only the last one gets recorded.. ouch.
            else:
                caveid = caveid
                caveobject = getCave(caveid)
            print(f'getCave for id "{waldata["cave"]}" {caveobject}')
            # if not caveobject.url == waldata["description url"]:
            # complaints.append(f'The URL of cave description \"{waldata["description url"]}\" does not match the one on record for this cave which is: "{caveobject.url}". If the wallet is not for a cave, put a useful URL here.')
        except Cave.MultipleObjectsReturned:
            complaints.append(f'The cave ID \'{waldata["cave"]}\' is AMBIGUOUS. Please fix it.')
            caveobject = None
        except ObjectDoesNotExist:
            complaints.append(f'The cave ID \'{waldata["cave"]}\' is not recognised. Please fix it.')
            caveobject = None
    else:
        complaints.append(
            'No cave ID is given. If there is no survex file, please give something, even if it is just "1623-000", "surface survey" or "scraps found in hut"'
        )
        caveobject = None

    return complaints, caveobject


# @login_required_if_public
def walletedit(request, path=None):
    """Create a new wallet or upload scanned image files into a wallet on /expofiles
    Also display AND EDIT the contents.json data in the wallet.

    This is the main wallet display and edit page.

    The Wallet object and the contents.json file are created when the user
    creates the wallet AND THEN SAVES IT WITH A DATE.

    This does NOT use a Django model linked to a Django form. Just a simple Django form.
    You will find the Django documentation on forms very confusing,
    as it covers many very differnet things we do not need. This is simpler.

    This subsumes much of the code which was in the pre-2022 non-troggle wallets.py script 
    and so this function is very long indeed and needs refactoring.

    REWRITE bits using the ticklist, dateify, caveify, populate etc utility functions in core.view.scans.py
    """
    git = settings.GIT
    filesaved = False
    actual_saved = []
    
    def get_next_empty():
        """Gets the next most number for a new wallet just after the most recent one in the 
        db. But if it has no date set, then ignore it as it was only just created"""
        latest = Wallet.objects.filter(walletname__startswith="20",walletdate__isnull=False).latest('walletname')
        next = int(latest.walletname[5:]) + 1
        return f"{latest.walletname[:4]}:{next:02d}"
    
    def preprocess_path(path):
        if path:
            wpath = urllib.parse.unquote(path)
        else:
            return (None, get_next_empty() )

        try:
            year = wpath[:4] # if path too short, exception catches it
            sepr = wpath[4]
            y = int(year) # exception catches non-integer [:4]
            wnumber = int(wpath[5:]) # exception catches nonumeric wallet number
            if sepr != "#" and sepr != ":":
                return (oldwallet(request, path), None)
        except:
            # if nonumeric wpath name for example
            return (oldwallet(request, path), None)

        if not re.match("(19|20)\d\d[:#]\d\d\d?", wpath):
            return (None, get_next_empty() )
            
        ymin, ymax = YEAR_RANGE
        if int(year) < ymin:
            year = str(ymin+2)
        if int(year) > ymax:
            return (None, get_next_empty() )
            
        wallet = f"{year}:{wnumber:02d}"
        return (None, wallet)
        
    def identify_most_recent_wallet(wallet, currentyear):
        """ Need to find the last wallet of the previous year
        Has to cope with years when there are no wallets
        Has to cope with weirdly named imported wallets from 1999 & earlier
        Has to cope if the 'current' wallet is one that happens to 'not exist' too.
        
        Frankly this has just become too bizarre and we should devise a quite different
        navigation system.
        """
        current_name = wallet.replace(":","#")
           
        try:
            allwallets = Wallet.objects.all().order_by('walletname')
            recent_wallet = allwallets.first()
            for w in allwallets:
                if len(w.walletname) < 5:
                    continue
                if w.walletname[4] != "#":
                    continue
   
                if w.walletname == current_name:
                    break
                if int(w.walletyear.year) >= int(currentyear):
                    break
                recent_wallet = w
            recent_name = recent_wallet.walletname
        except:
            raise
      
        recent_year = recent_name[:4]
        recent_number = recent_name[5:]       
              
        # print(f"---identify_most_recent_wallet: {recent_year=} {recent_number=}")
        return recent_year, recent_number
                
    def create_nav_links(wallet):
        """Find the previous wallet and next wallet and create navigation shortcuts"""
        y = wallet[:4]
        n = wallet[5:]

        if int(n) == 0: 
            recent_year, recent_number = identify_most_recent_wallet(wallet, y)
            prevy = recent_year # same as most recent wallet
            recent_number = f"{int(recent_number):02d}"
        else:
            prevy = f"{int(y)-1}" # the previous year
            recent_year = y # current year
            recent_number = f"{int(n)-1:02d}" # previous number
               
        nexty = f"{int(y)+1}"       
        next = f"{int(n)+1:02d}"
        return  prevy, recent_year, recent_number, y, next, nexty

    def read_json(contents_path):
        """Read JSON from the wallet metadata file in the repo
        or fills with blank data if that files can't be read

        Should sanitise to ensure no spurious backslashes e.g. in windows style paths"""
        waldata = {}
        if contents_path.is_file():
            with open(contents_path) as json_file:
                try:
                    waldata = json.load(json_file)
                except:
                    message = f"! {wallet} Failed to load {contents_path} JSON file"
                    print(message)
                    DataIssue.objects.create(parser="scans", message=message, url=wurl)  # set URL to this wallet folder
                    raise
        else:  # no JSON file exists
            print("--- No JSON exists, so using default copy")
            waldata = WALLET_BLANK_JSON.copy()
        if not waldata["survex file"]:
            try:
                w = Wallet.objects.get(walletname=wallet)
                b = SurvexBlock.objects.filter(scanswallet=w)
                waldata["survex file"] = []
                for bsf in b:
                    waldata["survex file"].append(bsf.survexfile.path)
            except:
                print(f"--- No wallet {wallet} exists in database")
        return waldata

    def save_json(jsondict):
        # print(f'--- Wallet directory in :drawings: repo {newfolder=} {jsondict}')
        if not os.path.exists(contents_path.parent):
            print("--- No wallet directory in :drawings: repo, so creating it")
            os.makedirs(contents_path.parent)

        with open(contents_path, "w") as jfile:
            json.dump(jsondict, jfile, indent=1)
        # print(f'--- FINISHED saving to JSON at {contents_path}')

    def make_wallet(walletname):
        """We need a wallet Object so that the django template stuff can find the files"""
        try:
            w, created = Wallet.objects.get_or_create(walletname=walletname)
            # print(f"--- Wallet string {walletname}, wallet object {w} created new?: {created}")
            if created:
                w.fpath = Path(settings.SCANS_ROOT, walletname[0:4], walletname)
                _ = w.year() # sets the walletyear property as a side-effect
                w.save()
        except:
            print(f"!-- Wallet string {walletname}, FAIL TO GET or create WALLET OBJECT")
            raise
        return w

    def commit_json(waldata):
        destfolder = contents_path.parent
        dr_add = subprocess.run([git, "add", contentsjson], cwd=destfolder, capture_output=True, text=True)
        if dr_add.returncode != 0:
            msgdata = (
                "Ask a nerd to fix this.\n--"
                + dr_add.stderr
                + "\n--"
                + dr_add.stdout
                + "\n--return code: "
                + str(dr_add.returncode)
            )
            message = (
                f"CANNOT git on server for this file {contentsjson}. Edits saved but not added to git.\n\n" + msgdata
            )
            print(message)
            return render(request, "errors/generic.html", {"message": message})
        else:
            if socket.gethostname() != "expo":
                comment = f"on dev machine '{socket.gethostname()}' "
            else:
                comment = ""
            if "cave" in waldata:
                label = waldata["cave"]
            else:
                if "name" in waldata:
                    label = waldata["name"]
                else:
                    label = ""

            dr_commit = subprocess.run(
                [git, "commit", "-m", f"JSON update wallet {wallet} {label} {comment}"],
                cwd=destfolder,
                capture_output=True,
                text=True,
            )
            # This produces return code = 1 if it commits OK
            if dr_commit.returncode != 0:
                msgdata = (
                    "Ask a nerd to fix this.\n\n"
                    + dr_commit.stderr
                    + "\n\n"
                    + dr_commit.stdout
                    + "\n\nreturn code: "
                    + str(dr_commit.returncode)
                )
                message = (
                    f"Error code with git on server for this {contentsjson}. File is added to git, but NOT committed.\n"
                    + msgdata
                )
                print(message)
                return render(request, "errors/generic.html", {"message": message})

    def get_logbook_trips():
        return None
    
    def no_people(team):
            return (team == ["Unknown"]
                    or team == [""]
                    or team == "")
  
    def empty_string(thing):
            return (thing == [""]
                    or thing == []
                    or thing == ""
                    or thing == "[]"
                    or thing is None)

    def make_valid_date(date):
        datestr = date.replace(".", "-")
        try:
            samedate = datetime.date.fromisoformat(datestr)
        except ValueError:
            # probably a single digit day number. HACKUS MAXIMUS.
            # clearly we need to fix this when we first import date strings..
            datestr = datestr[:-1] + "0" + datestr[-1]
            # datestr = f"{datestr:02d}"
            print(f"! - ValueError, trying.. {datestr=} ")
            try:
                samedate = datetime.date.fromisoformat(datestr)
            except:
                try:
                    samedate = datetime.date.fromisoformat(datestr[:10])
                except:
                    print(f"! - ValueError, FAILED {datestr=} ")
                    samedate = None
        return samedate
        
    def scan_survexblocks(svxfile):
        """Scans for *team people attached to all the survex blocks in this svxfile
        This could be rather a lot for some compedious survex files! So would need
        culling manually and only those relevant put in the JSON file"""
        wallet_refs = []
        dates = []
        blocknames = []
        team = []
        try:
            blocks = SurvexBlock.objects.filter(survexfile=svxfile)
            for b in blocks:
                # print(f" - - - - {b=} {b.scanswallet.walletname} {b.date=}  ")
                if b.scanswallet:
                    wallet_refs.append(b.scanswallet) # other wallets
                    #if b.scanswallet.walletname == wallet: # only if we assume *ref all correct!
                    if b.date:
                        dates.append(b.date)
                    if b.name != b.title:
                        blocknames.append(str(b.name) + "|" + str(b.title))
                    else:
                        blocknames.append(str(b.name))
                    QSpeople = SurvexPersonRole.objects.filter(survexblock=b)
                    # print(f" - - {QSpeople=}")
                    for p in QSpeople:
                        # print(f" - - {p.personname} ")
                        team.append(p.personname)
        except: 
            message = " -   No associated survex blocks found for this wallet"
            print(message)
        # print(f" - - - ", wallet_refs, dates, blocknames, team)
        return wallet_refs, dates, blocknames, team
        
    def scan_survexfiles(survex_paths):
        """Read data from the list of survex file names attached to the wallet JSON file
        
        NEED TO ALSO CHECK survex files which have a *ref to this wallet !
        """
        cave_refs = []
        wallet_refs = []
        caves = []
        dates = []
        names = []
        team = []
        
        if not type(survex_paths) == list:  # a string also is a sequence type, so do it this way
                survex_paths = [survex_paths]

        for svxf in survex_paths:
            if not svxf: # not a blank string
                continue
                
            # print(f" - - {svxf=} ")
            svx = Path(svxf)
            if svx.suffix.lower() != ".svx":
                svx = svx.with_suffix(".svx")
            f = Path(settings.SURVEX_DATA) / svx
            if not f.is_file():
                continue
                
            fpath = svx.parent / svx.stem
            # print(f' - {fpath=}')
            try:
                svxfile = SurvexFile.objects.get(path=fpath)

                if svxfile.cave:
                    caves.append(svxfile.cave)
                    cave_refs.append(svxfile.cave.reference()) # this is a string?!
                    
                
                w, d, n, t = scan_survexblocks(svxfile)
                wallet_refs.extend(w)
                dates.extend(d)
                names.extend(n)
                team.extend(t)
            except:
                message = "Specified survex file not found - database may be empty."
                print(message)
                # This failure will also get picked up by the "S" colour code red or orange
           
        caves = list(set(caves))
        if len(caves) == 1:
            caves = caves[0]
            
        elif len(caves) > 1:
            print(
                f" - More than one Cave {caves} in this wallet {wallet}. Not managed in this troggle release."
            )
            
        if len(names) == 1:
            names = names[0]
        elif len(names) > 1:
            names = f"several, please edit: {names}"
            print(
                f" - More than one block name is relevant {names} in this wallet {wallet}. Not managed in this troggle release."
            )

        cave_refs = list(set(cave_refs))
        firstdate = None
        if dates:
           firstdate = min(dates).isoformat()
        return firstdate, list(set(team)), caves, cave_refs, wallet_refs, names
    
    checkboxes = [
        "description written",
        "survex not required",
        "qms written",
        "website updated",
        "plan not required",
        "plan drawn",
        "elev not required",
        "elev drawn",
        "notes not required",
        "electronic survey",
    ]
    
    redirect, wallet = preprocess_path(path)
    if redirect:
        return redirect
    prevy, recent_year, recent_number, year, next, nexty = create_nav_links(wallet)    

    wurl = f"/walletedit/{wallet}".replace("#", ":")
    wallet = wallet.replace(":", "#")
    dirpath = Path(settings.SCANS_ROOT, year, wallet)
    contents_path = Path(settings.DRAWINGS_DATA, "walletjson") / year / wallet / contentsjson
    
    fresh_wallet = False

    form = FilesForm()

    if request.method == "POST":
        # print(f'--- POST processing starts {wallet=} {path=}')
        if "psg" in request.POST:  # handle metadata form
            formj = WalletForm(request.POST)
            # Beware. All fields returned as strings. So must re-type them as 
            # lists etc. before using or re-saving
            
            # Unset checkboxes do not return any value, checked ones return "True". 
            # So all need initialising to False
            if formj.is_valid():
                posted = request.POST.copy()
                posted.pop("csrfmiddlewaretoken")  # discard this
                wd = WALLET_BLANK_JSON.copy()
                for f in checkboxes:
                    wd[f] = False
                    # print(f'--- wd ${f}$  - {wd[f]}')
                for f in posted:
                    wd[xlate[f]] = posted[f].replace("'", '"')
                    print(f"'{f}' -{xlate[f]}- {posted[f]}")
                    if posted[f] == "True":
                        wd[xlate[f]] = True
                
                newdate = make_valid_date(posted["date"])
                wd["people"] = wd["people"][1:-1].replace('"', "").split(",")
                for i, elem in enumerate(wd["people"]):
                    wd["people"][i] = elem.strip()
                if wd["cave"]:
                    if wd["cave"][0] == "[":
                        wd["cave"] = wd["cave"][1:-1].replace('"', "").split(",")
                        for i, elem in enumerate(wd["cave"]):
                            wd["cave"][i] = elem.strip()

                if wd["survex file"]:  # allow for no survex file at all
                    if wd["survex file"][0] == "[":
                        wd["survex file"] = wd["survex file"][1:-1]
                    wd["survex file"] = wd["survex file"].replace('"', "").split(",")
                    for i, elem in enumerate(wd["survex file"]):
                        wd["survex file"][i] = elem.strip()
                

                save_json(wd)
                # walletobject will already exist as creation does not happen here anymore
                walletobject = make_wallet(wallet) 
                walletobject.walletdate = newdate # must be valid date
                print(f"---Setting VALID new date to db {walletobject} {walletobject.walletdate}")
                walletobject.save() 
                print(f"---Setting VALID new date to db {walletobject} {walletobject.walletdate}")
                commit_json(wd)

            else:
                print("--- INVALID JSON Update form submitted")
                print(formj.errors)
                return render(request, "errors/generic.html", {"message": formj.errors})

        elif (
            "walletgoto" in request.POST
        ):  # not editing wallet data or uploading a file.. going direct to a named wallet
            formg = WalletGotoForm(request.POST, request.FILES)
            if formg.is_valid():
                walletgoto = request.POST["walletgoto"]

                return HttpResponseRedirect(f'/walletedit/{walletgoto.replace("#",":")}')

        else:  # Creating a wallet . 
            # NOT editing wallet data, or uploading a file. Should not overwrite metadata at all.
            if "submitbutton" in request.POST:
                print(f"--- Submit button value {request.POST['submitbutton']}")
                if request.POST['submitbutton']=="Create":
                    w = WALLET_BLANK_JSON.copy()
                    save_json(w)
                    walletobject = make_wallet(wallet) # no date set yet
                    commit_json(w)
         
            form = FilesForm(request.POST, request.FILES)
            if form.is_valid():
                # print(f'--- FORM walletedit multiple BUT EMPTY METADATA supposedly {WALLET_BLANK_JSON["date"]=}')
                multiple = request.FILES.getlist("uploadfiles")
                fs = FileSystemStorage(os.path.join(dirpath))  # creates wallet folder if necessary

                waldata = read_json(contents_path)
                actual_saved = []
                if multiple:
                    for f in multiple:
                        try:  # crashes in Django os.chmod call if on WSL, but does save file!
                            saved_filename = fs.save(f.name, content=f)
                        except:
                            print(f"\n !! Permissions failure ?! on attempting to save scanfile {f.name}")
                            if "saved_filename" in locals():
                                if saved_filename.is_file():
                                    actual_saved.append(saved_filename)
                                    # print(f'! - FORM walletedit multiple {actual_saved}')
                                    filesaved = True
                    # print(f'--- FORM walletedit multiple BUT EMPTY METADATA supposedly {WALLET_BLANK_JSON["date"]=}')
                    save_json(waldata)
                    walletobject = make_wallet(wallet)
                    commit_json(waldata)
            else:
                print("--- Upload files form invalid, which is correct if just created.")
    #
    # Not a POST, so a GET starts here. And also control gets here after a POST is processed.
    #
    files = []
    dirs = []
    # print(f'! - FORM walletedit - start {wallet} {dirpath}')
    if dirpath.is_dir():
        create = False  # wallet exists because folder exists, even if nothing in it
        try:
            for f in dirpath.iterdir():
                if f.is_dir():
                    for d in f.iterdir():
                        dirs.append(f"{f.name}/{d.name}")
                if f.is_file():
                    files.append(f.name)
        except FileNotFoundError:
            files.append(
                "(No wallet yet. It would be created if you upload a scan and then save the form with a date.)"
            )
    else:
        # either on GET or on dropping-through after the POST creating a new wallet object:
        if Wallet.objects.filter(walletname=wallet).exists():
            create = False
        else:
            create = True

    if len(files) > 0:
        files = sorted(files)

    if dirs:
        dirs = sorted(dirs)
    try:
        waldata = read_json(contents_path) 
    except:
        message = f"Nasty failure in parsing wallets metadata in {contents_path}. Probably backslash not forward slash in filename path"
        return render(request, "errors/generic.html", {"message": message})

    jsonfile = Path(settings.DRAWINGS_DATA, "walletjson") / wallet[0:4] / wallet / "contents.json"
    # print(f'! - FORM walletedit - jsonfile {jsonfile}')
    if not Path(jsonfile).is_file():
        metadataurl = ""
        metadata =""
    else:
        metadataurl = Path("/dwgdataraw", "walletjson") / wallet[0:4] / wallet.replace("#", ":") / "contents.json"
        with open(jsonfile, 'r') as f:
            metadata = f.read()
    psg = ""
    freetext = ""
    chkplannr = ""
    chknotesnr = ""
    chkpland = ""
    svxfiles = []
    trips = []
    checked = {}
    context = {}
    if not waldata:  # should always be true as populated by blank data if json file doesn't exist
        message = f" !! No Wallet data initialised or read ! Should not happen."
        print(message)
        return render(request, "errors/generic.html", {"message": message})

    refs = []
    
    if "survex file" in waldata:
        date, team, caves, caverefs, wallet_refs, names  = scan_survexfiles(waldata["survex file"])
    # Override the discovered values with those in the JSON file:
    if not waldata["date"]: # either absent or empty string
        waldata["date"] = date 

    if no_people(waldata["people"]):
        people = team
        waldata["people"] = team
    else:
        people = waldata["people"]  # text string

    if empty_string(waldata["cave"]):
        cave = caverefs # a list, potentially
        waldata["cave"] = cave
    else:
        cave = waldata["cave"]  # text string
        
    if empty_string(waldata["name"]):
        psg = names
        waldata["name"] = names
    else:
        psg = waldata["name"]
        
    if "free text" in waldata:
        freetext = waldata["free text"]
        
    if 'notes not required' not in waldata: # cope with schema change
        waldata['notes not required'] = False

    # for a in waldata:
        # print(f"'{waldata[a]}' {a}")
    # find trips and survex files of the same date
    walletobject = make_wallet(wallet)
    if waldata["date"]:
        samedate = make_valid_date(waldata["date"])
        walletobject.walletdate = samedate
        walletobject.save()

        try:
            thisexpo = Expedition.objects.get(year=int(year))
        except: # creating a wallet for an expo that does not exist perhaps
            message = f"Trying to access an Expo for '{year}' which does not exist (yet)." 
            message += " See /handbook/computing/newyear.html"
            print(message)
            return render(request, "errors/generic.html", {"message": message})
        if samedate:
            svxothers = SurvexBlock.objects.filter(date=samedate)
            trips = LogbookEntry.objects.filter(date=samedate)
        else:
            svxothers = None
            trips = None

    else:
        svxothers = None
        trips = None

    # Survex and survex complaints, comes from json file on disc, not as pre-populated as above
    complaints, caveobject = get_complaints([], waldata, svxfiles, files, wallet, wurl)
    # print(f' - {caveobject=}')

    for f in checkboxes:
        if waldata[f]:
            checked[f] = "checked"

    survexsize = str(min(len(str(waldata["survex file"])), 46))

    try:
        thiswallet = walletobject # Wallet.objects.get(walletname=wallet)
        caveifywallet(thiswallet)
        thiswallet.ticks = thiswallet.get_ticks()  # the complaints in colour form
        # fixsurvextick(thiswallet, thiswallet.ticks)
        # print(f"--- {wallet}  {thiswallet} walletdate={thiswallet.walletdate} immediately before form render")
    except:
        thiswallet = None
    context = {
        "year": year,
        "recent_year": recent_year,
        "recent_number": recent_number,
        "next": next,
        "prevy": prevy,
        "nexty": nexty,
        "files": files,
        "dirs": dirs,
        "waldata": waldata,
        "svxfiles": svxfiles,
        "survex": waldata["survex file"],
        "survexsize": survexsize,
        "checked": checked,
        "trips": trips,
        "manywallets": [thiswallet],
        "svxothers": svxothers,
        "create": create,
        "metadataurl": metadataurl,
        "metadata": metadata,
        "complaints": complaints,
        "caveobject": caveobject,
        "people": people,
        "peoplesize": str(len(str(people))),
        "filesaved": filesaved,
        "actual_saved": actual_saved,
    }

    return render(
        request,
        "walletform.html",
        {
            "form": form,
            "wallet": wallet,
            **context,
            "date": waldata["date"],
            #'url':  waldata["description url"], 'urlsize': str(len(str(waldata["description url"]))),
            "cave": cave,
            "psg": psg,
            "freetext": freetext,
            "psgsize": str(max(12, len(str(psg)))),
            "freetextsize": str(max(60, len(str(freetext)))),
        },
    )