import os
import re
import sys
from pathlib import Path

from django.conf import settings
from django.db import transaction

from troggle.settings import SURVEX_DATA, EXPOWEB
from troggle.core.models.troggle import DataIssue
from troggle.core.models.caves import Area, Cave, Entrance, CaveSlug, EntranceSlug, CaveAndEntrance
'''Reads all the cave description data by parsing the xml files (stored as e.g. :EXPOWEB:/cave-data/1623-161.html )
and creating the various Cave, Entrance and necessary Area objects.

BUT in Django 2.0 and later we cannot do any queries on data we have just entered 
because this is all happening inside one transaction. Bummer.

django.db.transaction.TransactionManagementError: 
An error occurred in the current transaction. You can't execute queries until the end of the 'atomic' block.
'''

entrances_xslug = {}
caves_xslug = {}
areas_xslug = {}

def do_pending_cave(k, url, area_1623):
    '''
    default for a PENDING cave, should be overwritten in the db later if a real cave of the same name exists 
    in expoweb/cave_data/1623-"k".html 
    '''
    default_note = f"_Survex file found in loser repo but no description in expoweb <br><br><br>\n" 
    default_note += f"INSTRUCTIONS: First open 'This survex file' (link above the CaveView panel) to find the date and info. Then " 
    default_note += f"<br>\n - search in the Expo for that year e.g. <a href='/expedition/{k[0:4]}'>{k[0:4]}</a> to find a "  
    default_note += f"relevant logbook entry, then <br>\n - " 
    default_note += f"click on 'Edit this cave' and copy the information you find in the survex file and the logbook" 
    default_note += f"<br>\n - " 
    default_note += f"When you Submit it will create a file file in expoweb/cave_data/ " 
    default_note += f"<br>\n - Now you can edit the entrance info: click on Edit below for the dummy entrance. " 
    default_note += f"and then Submit to save it. NB your entrance info will not be visible after a reboot of the server until a programmer has edited  parser/caves.py (python code) to remove the cave form the [pending] list. But it won't be lost."

    slug = "1623-" + k
    
    cave = Cave(
            unofficial_number = k, 
            underground_description = "Pending cave write-up - creating as empty object. No XML file available yet.",
            survex_file = "caves-1623/" + k + "/" + k +".svx",
            url = url,
            notes = default_note)
    if cave:
        cave.save() # must save to have id before foreign keys work. This is also a ManyToMany key.
        cave.area.add(area_1623[0])
        cave.save()
        message = f" ! {k:12} {cave.underground_description}"
        DataIssue.objects.create(parser='caves', message=message, url=url)
        print(message)
        
        try: # Now create a cave slug ID
            cs = CaveSlug.objects.update_or_create(cave = cave,
                      slug = slug, primary = False)
        except:
            message = f" ! {k:11s}  PENDING cave SLUG create failure"
            DataIssue.objects.create(parser='caves', message=message)
            print(message)
    else:
        message = f' ! {k:11s}  PENDING cave create failure'
        DataIssue.objects.create(parser='caves', message=message)
        print(message)
        
    ent = Entrance(
            name = k, 
            entrance_description = "Dummy entrance: auto-created when registering a new cave." +
                    "This file WILL NOT BE LOADED while the cave is in the pending[] list in parsers/caves.py",
            marking = '?')
    if ent:
        ent.save() # must save to have id before foreign keys work.
        try: # Now create a entrance slug ID
            es = EntranceSlug.objects.update_or_create(entrance = ent,
                      slug = slug, primary = False)
        except:
            message = f" ! {k:11s}  PENDING entrance create failure"
            DataIssue.objects.create(parser='caves', message=message)
            print(message)

        # Now we will actually write this default entrance slugfile. Yes it's naughty, but an extra
        # entrance file is less hassle than a missing one! And people always forget to save the entrance file
        # when they are saving the edited cave file.
        
        #This WILL then casue an error when the parser then tries to import this file and we get an import failure because 
        # the entrance exists in the db.
        ent.cached_primary_slug = slug
        ent.filename = slug + ".html"
        ent.save()
        if not ent.get_file_path().is_file():
            # don't overwrite if by some chnace it exists
            # but the pre-existing file won't be parsed later until the cave is removed from the pending list
            ent.writeDataFile()
    else:
        message = f" ! {k:11s}  PENDING cave SLUG '{slug}' create failure"
        DataIssue.objects.create(parser='caves', message=message)
        print(message)

    try:
        ceinsts = CaveAndEntrance.objects.update_or_create(cave = cave, entrance_letter = "", entrance = ent)
        for ceinst in ceinsts:
            if str(ceinst) == str(cave):  # magic runes... why is the next value a Bool?
                ceinst.cave = cave
                ceinst.save()
                break
    except:
        message = f" ! {k:11s}  PENDING entrance + cave UNION create failure  '{cave}' [{ent}]"
        DataIssue.objects.create(parser='caves', message=message)
        print(message)


def readcaves():
    '''Reads the xml-format HTML files in the EXPOWEB repo, not from the loser repo.
    '''
    # For those caves which do not have cave_data/1623-xxx.html XML files even though they exist and have surveys
    pending = ["2007-06", "2009-02", 
            "2010-06", "2010-07", "2012-ns-01", "2012-ns-02", "2010-04", "2012-ns-05", "2012-ns-06", 
            "2012-ns-07", "2012-ns-08", "2012-ns-12", "2012-ns-14", "2012-ns-15", "2014-bl888", 
            "2018-pf-01", "2018-pf-02"]

    with transaction.atomic():
        print(" - Deleting Caves and Entrances")
        Cave.objects.all().delete()
        Entrance.objects.all().delete()
        # Clear the cave data issues and the caves as we are reloading
        DataIssue.objects.filter(parser='caves').delete()
        DataIssue.objects.filter(parser='entrances').delete()
        
        area_1623 = Area.objects.update_or_create(short_name = "1623", parent = None)
        # This seems to return a tuple, not a single object! i.e. (<Area: 1623>, True)
        #print(f' ! - READ CAVES: {area_1623}')

        area_1626 = Area.objects.update_or_create(short_name = "1626", parent = None)

        print (" - Setting pending caves")
        # Do this first, so that these empty entries are overwritten as they get properly created.
        

        for k in pending:
            url = "1623/" + k # Note we are not appending the .htm as we are modern folks now.
            try:    
                do_pending_cave(k, url, area_1623)
            except:
                message = " ! Error. Cannot create pending cave and entrance, pending-id:{}".format(k)
                DataIssue.objects.create(parser='caves', message=message)
                print(message)
                raise

    with transaction.atomic():
        print(" - settings.CAVEDESCRIPTIONS: ", settings.CAVEDESCRIPTIONS)
        print(" - Reading Entrances from entrance descriptions xml files")
        for filename in next(os.walk(settings.ENTRANCEDESCRIPTIONS))[2]: #Should be a better way of getting a list of files
            if filename.endswith('.html'):
                if Path(filename).stem[5:] in pending:
                        print(f'Skipping pending entrance dummy file <{filename}>')
                else:
                    readentrance(filename)

        print(" - Reading Caves from cave descriptions xml files")
        for filename in next(os.walk(settings.CAVEDESCRIPTIONS))[2]: #Should be a better way of getting a list of files
            if filename.endswith('.html'):
                readcave(filename)

def readentrance(filename):
    global entrances_xslug
    global caves_xslug
    global areas_xslug

    # Note: these are HTML files in the EXPOWEB repo, not from the loser repo.
    with open(os.path.join(settings.ENTRANCEDESCRIPTIONS, filename)) as f:
        contents = f.read()
    context = filename
    #print("Reading file ENTRANCE {} / {}".format(settings.ENTRANCEDESCRIPTIONS, filename))
    entrancecontentslist = getXML(contents, "entrance", maxItems = 1, context = context)
    if len(entrancecontentslist) != 1:
        message = f'! BAD ENTRANCE at "{filename}"'
        DataIssue.objects.create(parser='caves', message=message)
        print(message)
    else:
        entrancecontents = entrancecontentslist[0]
        non_public = getXML(entrancecontents, "non_public", maxItems = 1, context = context)
        name = getXML(entrancecontents, "name", maxItems = 1, context = context)
        slugs = getXML(entrancecontents, "slug", context = context)
        entrance_description = getXML(entrancecontents, "entrance_description", maxItems = 1, context = context)
        explorers = getXML(entrancecontents, "explorers", maxItems = 1, context = context)
        map_description = getXML(entrancecontents, "map_description", maxItems = 1, context = context)
        location_description = getXML(entrancecontents, "location_description", maxItems = 1, context = context)
        approach = getXML(entrancecontents, "approach", maxItems = 1, context = context)
        underground_description = getXML(entrancecontents, "underground_description", maxItems = 1, context = context)
        photo = getXML(entrancecontents, "photo", maxItems = 1, context = context)
        marking = getXML(entrancecontents, "marking", maxItems = 1, context = context)
        marking_comment = getXML(entrancecontents, "marking_comment", maxItems = 1, context = context)
        findability = getXML(entrancecontents, "findability", maxItems = 1, context = context)
        findability_description = getXML(entrancecontents, "findability_description", maxItems = 1, context = context)
        alt = getXML(entrancecontents, "alt", maxItems = 1, context = context)
        northing = getXML(entrancecontents, "northing", maxItems = 1, context = context)
        easting = getXML(entrancecontents, "easting", maxItems = 1, context = context)
        tag_station = getXML(entrancecontents, "tag_station", maxItems = 1, context = context)
        exact_station = getXML(entrancecontents, "exact_station", maxItems = 1, context = context)
        other_station = getXML(entrancecontents, "other_station", maxItems = 1, context = context)
        other_description = getXML(entrancecontents, "other_description", maxItems = 1, context = context)
        bearings = getXML(entrancecontents, "bearings", maxItems = 1, context = context)
        url = getXML(entrancecontents, "url", maxItems = 1, context = context)
        if len(non_public) == 1 and len(slugs) >= 1 and len(name) >= 1 and  len(entrance_description) == 1 and  len(explorers) == 1 and  len(map_description) == 1 and  len(location_description) == 1 and  len(approach) == 1 and  len(underground_description) == 1 and  len(marking) == 1 and  len(marking_comment) == 1 and  len(findability) == 1 and  len(findability_description) == 1 and  len(alt) == 1 and  len(northing) == 1 and  len(easting) == 1 and  len(tag_station) == 1 and  len(exact_station) == 1 and  len(other_station) == 1 and  len(other_description) == 1 and  len(bearings) == 1 and  len(url) == 1:
            e, state = Entrance.objects.update_or_create(name = name[0],
                         non_public = {"True": True, "False": False, "true": True, "false": False,}[non_public[0]],
                         entrance_description = entrance_description[0],
                         explorers = explorers[0],
                         map_description = map_description[0],
                         location_description = location_description[0],
                         approach = approach[0],
                         underground_description = underground_description[0],
                         photo = photo[0],
                         marking = marking[0],
                         marking_comment = marking_comment[0],
                         findability = findability[0],
                         findability_description = findability_description[0],
                         alt = alt[0],
                         northing = northing[0],
                         easting = easting[0],
                         tag_station = tag_station[0],
                         exact_station = exact_station[0],
                         other_station = other_station[0],
                         other_description = other_description[0],
                         bearings = bearings[0],
                         url = url[0],
                         filename = filename,
                         cached_primary_slug = slugs[0])
            primary = True
            for slug in slugs:
                #print("entrance slug:{} filename:{}".format(slug, filename))
                try:
                    cs = EntranceSlug.objects.update_or_create(entrance = e,
                                             slug = slug,
                                             primary = primary)
                except:
                    # need to cope with duplicates
                    message = f" ! FAILED to get precisely one ENTRANCE when updating using: cave_entrance/{filename}"
                    DataIssue.objects.create(parser='caves', message=message, url=f'/cave/{slug}/edit/')
                    kents = EntranceSlug.objects.all().filter(entrance = e,
                                                 slug = slug,
                                                 primary = primary)
                    for k in kents:
                        message = " ! - DUPLICATE in db. entrance:"+ str(k.entrance) + ", slug:" + str(k.slug()) 
                        DataIssue.objects.create(parser='caves', message=message, url=f'/cave/{slug}/edit/')
                        print(message)
                    for k in kents:
                        if k.slug() != None:
                            print(" ! - OVERWRITING this one: slug:"+ str(k.slug()))
                            k.notes = "DUPLICATE entrance found on import. Please fix\n" + k.notes
                            c = k
                primary = False
        else: # more than one item in long list
            message = f' ! {slug:12} ABORT loading this entrance. in "{filename}"'
            DataIssue.objects.create(parser='caves', message=message, url=f'/cave/{slug}/edit/')
            print(message)

def readcave(filename):
    '''Assumes any area it hasn't seen before is a subarea of 1623
    '''
    global entrances_xslug
    global caves_xslug
    global areas_xslug
    
    # Note: these are HTML files in the EXPOWEB repo, not from the loser repo.
    with open(os.path.join(settings.CAVEDESCRIPTIONS, filename)) as f:
        contents = f.read()
    context = filename
    cavecontentslist = getXML(contents, "cave", maxItems = 1, context = context)
    if len(cavecontentslist) != 1:
        message = f'! BAD CAVE at "{filename}"'
        DataIssue.objects.create(parser='caves', message=message)
        print(message)
    else:
        cavecontents = cavecontentslist[0]
        non_public = getXML(cavecontents, "non_public", maxItems = 1, context = context)
        slugs = getXML(cavecontents, "caveslug", maxItems = 1, context = context)
        official_name = getXML(cavecontents, "official_name", maxItems = 1, context = context)
        areas = getXML(cavecontents, "area", context = context)
        kataster_code = getXML(cavecontents, "kataster_code", maxItems = 1, context = context)
        kataster_number = getXML(cavecontents, "kataster_number", maxItems = 1, context = context)
        unofficial_number = getXML(cavecontents, "unofficial_number", maxItems = 1, context = context)
        explorers = getXML(cavecontents, "explorers", maxItems = 1, context = context)
        underground_description = getXML(cavecontents, "underground_description", maxItems = 1, context = context)
        equipment = getXML(cavecontents, "equipment", maxItems = 1, context = context)
        references = getXML(cavecontents, "references", maxItems = 1, context = context)
        survey = getXML(cavecontents, "survey", maxItems = 1, context = context)
        kataster_status = getXML(cavecontents, "kataster_status", maxItems = 1, context = context)
        underground_centre_line = getXML(cavecontents, "underground_centre_line", maxItems = 1, context = context)
        notes = getXML(cavecontents, "notes", maxItems = 1, context = context)
        length = getXML(cavecontents, "length", maxItems = 1, context = context)
        depth = getXML(cavecontents, "depth", maxItems = 1, context = context)
        extent = getXML(cavecontents, "extent", maxItems = 1, context = context)
        survex_file = getXML(cavecontents, "survex_file", maxItems = 1, context = context)
        description_file = getXML(cavecontents, "description_file", maxItems = 1, context = context)
        url = getXML(cavecontents, "url", maxItems = 1, context = context)
        entrances = getXML(cavecontents, "entrance", context = context)
        
        if len(non_public) == 1 and len(slugs) >= 1 and len(official_name) == 1 and len(areas) >= 1 and len(kataster_code) == 1 and len(kataster_number) == 1 and len(unofficial_number) == 1 and len(explorers) == 1 and len(underground_description) == 1 and len(equipment) == 1 and len(references) == 1 and len(survey) == 1 and len(kataster_status) == 1 and len(underground_centre_line) == 1 and len(notes) == 1 and len(length) == 1 and len(depth) == 1 and len(extent) == 1 and len(survex_file) == 1 and len(description_file ) == 1 and len(url) == 1 and len(entrances) >= 1:
            try:
                c, state = Cave.objects.update_or_create(non_public = {"True": True, "False": False, "true": True, "false": False,}[non_public[0]],
                         official_name = official_name[0],
                         kataster_code = kataster_code[0],
                         kataster_number = kataster_number[0],
                         unofficial_number = unofficial_number[0],
                         explorers = explorers[0],
                         underground_description = underground_description[0],
                         equipment = equipment[0],
                         references = references[0],
                         survey = survey[0],
                         kataster_status = kataster_status[0],
                         underground_centre_line = underground_centre_line[0],
                         notes = notes[0],
                         length = length[0],
                         depth = depth[0],
                         extent = extent[0],
                         survex_file = survex_file[0],
                         description_file = description_file[0],
                         url = url[0],
                         filename = filename)
            except:
                print(" ! FAILED to get only one CAVE when updating using: "+filename)
                kaves = Cave.objects.all().filter(kataster_number=kataster_number[0])
                for k in kaves:
                    message = " ! - DUPLICATES in db. kataster:"+ str(k.kataster_number) + ", slug:" + str(k.slug()) 
                    DataIssue.objects.create(parser='caves', message=message)
                    print(message)
                for k in kaves:
                    if k.slug() != None:
                        print(" ! - OVERWRITING this one: slug:"+ str(k.slug()))
                        k.notes = "DUPLICATE kataster number found on import. Please fix\n" + k.notes
                        c = k
                
            for area_slug in areas:
                if area_slug in areas_xslug:
                    newArea = areas_xslug[area_slug]
                else:
                    area = Area.objects.filter(short_name = area_slug)
                    if area:
                        newArea = area[0]
                    else:
                        newArea = Area(short_name = area_slug, parent = Area.objects.get(short_name = "1623"))
                        newArea.save()
                    areas_xslug[area_slug] = newArea
                c.area.add(newArea)
            primary = True
            for slug in slugs:
                if slug in caves_xslug:
                    cs = caves_xslug[slug]
                else:
                    try: # we want to overwrite a PENDING cave if we are now importing the 1623-xxx.html file for it
                        cs = CaveSlug.objects.update_or_create(cave = c,
                                  slug = slug,
                                  primary = primary)
                        caves_xslug[slug] = cs
                    except Exception as ex:
                        message = " ! Cave update/create failure : %s, skipping file cave_data/%s with exception\nException: %s" % (slug, context, ex.__class__)
                        DataIssue.objects.create(parser='caves', message=message)
                        print(message)
                    
                primary = False

            for entrance in entrances:
                eslug = getXML(entrance, "entranceslug", maxItems = 1, context = context)[0]
                letter = getXML(entrance, "letter", maxItems = 1, context = context)[0]
                try:
                    if eslug in entrances_xslug:
                        entrance = entrances_xslug[eslug]
                    else:
                        entrance = Entrance.objects.get(entranceslug__slug = eslug)
                        entrances_xslug[eslug] = entrance
                    ce = CaveAndEntrance.objects.update_or_create(cave = c, entrance_letter = letter, entrance = entrance)
                except:
                    message = f' ! Entrance setting failure, slug:"{slug}" letter:"{letter}" cave:"{c}" filename:"{filename}"'
                    DataIssue.objects.create(parser='caves', message=message)
                    print(message)
                    
            if survex_file[0]:
                if not (Path(SURVEX_DATA) / survex_file[0]).is_file():
                    message = f' ! {slug:12} survex filename does not exist :LOSER:"{survex_file[0]}" in "{filename}"'
                    DataIssue.objects.create(parser='caves', message=message, url=f'/cave/{slug}/edit/')
                    print(message)
                    
            if description_file[0]:
                if not (Path(EXPOWEB) / description_file[0]).is_file():
                    message = f' ! {slug:12} description filename does not exist :{EXPOWEB}:"{description_file[0]}" in "{filename}"'
                    DataIssue.objects.create(parser='caves', message=message, url=f'/cave/{slug}/edit/')
                    print(message)
                    #c.description_file="" # done only once, to clear out cruft.
                    #c.save()
        else: # more than one item in long list
            message = f' ! ABORT loading this cave. in "{filename}"'
            DataIssue.objects.create(parser='caves', message=message, url=f'/cave/{slugs}/edit/')
            print(message)

def getXML(text, itemname, minItems = 1, maxItems = None, printwarnings = True, context = ""):
    items = re.findall("<%(itemname)s>(.*?)</%(itemname)s>" % {"itemname": itemname}, text, re.S)
    if len(items) < minItems and printwarnings:
        message = " ! %(count)i x %(itemname)s found, at least %(min)i expected. Load ABORT. " % {"count": len(items),
                                                                           "itemname": itemname,
                                                                           "min": minItems} + " in file " + context
        DataIssue.objects.create(parser='caves', message=message, url=""+context)
        print(message)
        
    if maxItems is not None and len(items) > maxItems and printwarnings:
        message = " ! %(count)i x %(itemname)s found, no more than %(max)i expected in this XML unit. Load ABORT. " % {"count": len(items),
                                                                               "itemname": itemname,
                                                                               "max": maxItems} + " in file " + context
        DataIssue.objects.create(parser='caves', message=message)
        print(message)
    return items