import datetime
import difflib
import os
import re
import socket
from pathlib import Path
from collections import namedtuple

from django import forms
from django.db import models
from django.db.models import Q

from django.core.exceptions import MultipleObjectsReturned, ObjectDoesNotExist
from django.http import HttpResponse
from django.shortcuts import render
from django.views.decorators.csrf import ensure_csrf_cookie

import troggle.settings as settings
from troggle.core.models.logbooks import LogbookEntry
from troggle.core.models.caves import Cave
from troggle.core.models.survex import SurvexFile, SurvexBlock
from troggle.core.models.wallets import Wallet
from troggle.core.utils import only_commit

"""Everything that views survexfiles 
but also displays data on a cave or caves when there is ambiguity
"""

todo = """- survexcavesingle is not properly producing any result for Homecoming, 1626-359, 2018-dm-07
even though there are dozens of surveys.

- Never actual uses the object for the survexfile, works entirely from the filepath! Make it check and validate

- Save the edited survexfile as a survexfile object and re-parse it, and update
all its dependencies
"""

survexdatasetpath = Path(settings.SURVEX_DATA)

survextemplatefile = """; *** THIS IS A TEMPLATE FILE NOT WHAT YOU MIGHT BE EXPECTING ***

*** DO NOT SAVE THIS FILE WITHOUT RENAMING IT !! ***
;[Stuff in square brackets is example text to be replaced with real data, 
; removing the square brackets]

*begin [surveyname]

; stations linked into other surveys (or likely to)
*export [1 8 12 34]

; Cave:
; Area in cave/QM: 
*title ""
*date [2040.07.04]            ;  <-- CHANGE THIS DATE
*team Insts [Fred Fossa]
*team Notes [Brenda Badger]
*team Pics [Luke Lynx]
*team Tape [Albert Aadvark]
*instrument [SAP #+Laser Tape/DistoX/Compass # ; Clino #]
; Calibration: [Where, readings]
*ref [2040#00]                ;  <-- CHANGE THIS TOO
; the #number is on the clear pocket containing the original notes

; if using a tape:
*calibrate tape +0.0	; +ve if tape was too short, -ve if too long

; Centreline data
*data normal from to length bearing gradient ignoreall
[ 1   2    5.57	    034.5     -12.8 ]

;-----------
;recorded station details (leave commented out)
;(NP=Nail Polish, LHW/RHW=Left/Right Hand Wall)
;Station Left Right Up Down Description
;[Red] nail varnish markings
[;1   0.8   0     5.3   1.6  ; NP on boulder. pt 23 on foo survey ]
[;2   0.3   1.2   6     1.2  ; NP '2' LHW ]
[;3   1.3   0     3.4   0.2  ; Rock on floor - not refindable ]


;LRUDs arranged into passage tubes
;new *data command for each 'passage',
;repeat stations and adjust numbers as needed
*data passage station left right up down 
;[ 1   0.8   0     5.3   1.6 ]
;[ 2   0.3   1.2   6     1.2 ]
*data passage station left right up down
;[ 1   1.3   1.5   5.3   1.6 ]
;[ 3   2.4   0     3.4   0.2 ]


;-----------
;Question Mark List  ;(leave commented-out)
; The nearest-station is the name of the survey and station which are nearest to
; the QM. The resolution-station is either '-' to indicate that the QM hasn't
; been checked; or the name of the survey and station which push that QM. If a
; QM doesn't go anywhere, set the resolution-station to be the same as the
; nearest-station. Include any relevant details of how to find or push the QM in
; the textual description.
;Serial number   grade(A/B/C/X)  nearest-station  resolution-station  description
;[ QM1    A    surveyname.3    -    description of QM ]
;[ QM2    B    surveyname.5    -    description of QM ]

;------------
;Cave description  ;(leave commented-out)
;freeform text describing this section of the cave

*end [surveyname]
"""


class SvxForm(forms.Form):
    """Two-pane form, upper half is the raw survex file, lower half (with green background)
    is the output of running 'cavern' on the survex file.
    """

    dirname = forms.CharField(widget=forms.TextInput(attrs={"readonly": True}))
    filename = forms.CharField(widget=forms.TextInput(attrs={"readonly": True}))
    datetime = forms.DateTimeField(widget=forms.TextInput(attrs={"readonly": True}))
    outputtype = forms.CharField(widget=forms.TextInput(attrs={"readonly": True}))
    code = forms.CharField(widget=forms.Textarea(attrs={"cols": 140, "rows": 36}))
    survexfile = models.ForeignKey(SurvexFile, blank=True, null=True, on_delete=models.SET_NULL) # 1:1 ?

    template = False

    def GetDiscCode(self):
        fname = survexdatasetpath / (self.data["filename"] + ".svx")
        if not fname.is_file():
            print(">>> >>> WARNING - svx file not found, showing TEMPLATE SVX", fname, flush=True)
            self.template = True
            return survextemplatefile
        refs = SurvexFile.objects.filter(path=self.data["filename"])
        if len(refs)==1:
            self.survexfile = SurvexFile.objects.get(path=self.data["filename"])
        else:
            self.survexfile = refs[0]
            # OK this is due to a bug in the import file parsing, whoops.
            print("BUG - to be fixed in the survex parser - not critical..")
            print(f"Number of SurvexFile objects found: {len(refs)}")
            for s in refs:
                print (s.path, s.survexdirectory, s.cave)     
        try:
            fin = open(fname, "r", encoding="utf8", newline="")
            svxtext = fin.read()
            fin.close()
        except:
            # hack. Replace this with something better.
            fin = open(fname, "r", encoding="iso-8859-1", newline="")
            svxtext = fin.read()
            fin.close()
        return svxtext

    def DiffCode(self, rcode):
        code = self.GetDiscCode()
        difftext = difflib.unified_diff(code.splitlines(), rcode.splitlines())
        difflist = [diffline.strip() for diffline in difftext if not re.match(r"\s*$", diffline)]
        return difflist

    def SaveCode(self, rcode):
        fname = survexdatasetpath / (self.data["filename"] + ".svx")
        if not os.path.isfile(fname):
            if re.search(r"\[|\]", rcode):
                return "Error: remove all []s from the text. They are only template guidance."
            mbeginend = re.search(r"(?s)\*begin\s+(\w+).*?\*end\s+(\w+)", rcode)
            if not mbeginend:
                return "Error: no begin/end block here"
            if mbeginend.group(1) != mbeginend.group(2):
                return "Error: mismatching begin/end labels"

        # Make this create new survex folders if needed
        try:
            fout = open(fname, "w", encoding="utf8", newline="\n")
        except FileNotFoundError:
            pth = os.path.dirname(self.data["filename"])
            newpath = survexdatasetpath / pth
            if not os.path.exists(newpath):
                os.makedirs(newpath)
            fout = open(fname, "w", encoding="utf8", newline="\n")
        except PermissionError:
            return (
                "CANNOT  save this file.\nPERMISSIONS incorrectly set on server for this file. Ask a nerd to fix this."
            )

        # javascript seems to insert CRLF on WSL1 whatever you say. So fix that:
        fout.write(rcode.replace("\r", ""))
        fout.write("\n")
        fout.close()

        if socket.gethostname() == "expo":
            comment = f"Online survex edit: {self.data['filename']}.svx"
        else:
            comment = f"Online survex edit: {self.data['filename']}.svx on dev machine '{socket.gethostname()}' "
        only_commit(fname, comment)

        return "SAVED and committed to git"

    def Process(self):
        print(">>>>....\n....Processing\n")
        froox = os.fspath(survexdatasetpath / (self.data["filename"] + ".svx"))
        froog = os.fspath(survexdatasetpath / (self.data["filename"] + ".log"))
        cwd = os.getcwd()
        os.chdir(os.path.split(froox)[0])
        os.system(settings.CAVERN + " --log " + froox)
        os.chdir(cwd)

        # Update this to use the new syntax..
        # sp = subprocess.run([settings.CAVERN, "--log", f'--output={outputdir}', f'{fullpath}.svx'],
        # capture_output=True, check=False, text=True)
        # if sp.returncode != 0:
        # message = f' ! Error running {settings.CAVERN}: {fullpath}'
        # DataIssue.objects.create(parser='entrances', message=message)
        # print(message)
        # print(f'stderr:\n\n' + str(sp.stderr) + '\n\n' + str(sp.stdout)  + '\n\nreturn code: ' + str(sp.returncode))

        filepatherr = Path(survexdatasetpath / str(self.data["filename"] + ".err"))
        if filepatherr.is_file():
            if filepatherr.stat().st_size == 0:
                filepatherr.unlink()  # delete empty closure error file

        fin = open(froog, "r", encoding="utf8")
        log = fin.read()
        fin.close()
        # log = re.sub("(?s).*?(Survey contains)", "\\1", log) # this omits any ERROR MESSAGES ! Don't do it.
        for s in [
            "Removing trailing traverses...\n\n",
            "Concatenating traverses...\n\n" "Simplifying network...\n\n",
            "Calculating network...\n\n",
            "Calculating traverses...\n\n",
            "Calculating trailing traverses...\n\n",
            "Calculating statistics...\n\n",
        ]:
            log = log.replace(s, "")
        return log


@ensure_csrf_cookie
def svx(request, survex_file):
    """Displays a single survex file in an textarea window (using a javascript online editor to enable
    editing) with buttons which allow SAVE, check for DIFFerences from saved, and RUN (which runs the
    cavern executable and displays the output below the main textarea).
    Requires CSRF to be set up correctly, and requires permission to write to  the filesystem.
    """
    warning = False

    # get the basic data from the file given in the URL
    dirname = os.path.split(survex_file)[0] # replace with proper pathlib function..
    dirname += "/"
    nowtime = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    outputtype = "normal"
    form = SvxForm({"filename": survex_file, "dirname": dirname, "datetime": nowtime, "outputtype": outputtype})

    # if the form has been returned
    difflist = []
    logmessage = ""
    message = ""

    if request.method == "POST":  # If the form has been submitted...
        rform = SvxForm(request.POST)  #
        if rform.is_valid():  # All validation rules pass (how do we check it against the filename and users?)
            rcode = rform.cleaned_data["code"]
            outputtype = rform.cleaned_data["outputtype"] # used by CodeMirror ajax I think
            difflist = form.DiffCode(rcode)
            # print(">>>> ", rform.data)

            if "revert" in rform.data:
                pass
            if "process" in rform.data:
                if not difflist:
                    logmessage = form.Process()
                    if logmessage:
                        message = f"OUTPUT FROM PROCESSING\n{logmessage}"
                else:
                    message = "SAVE FILE FIRST"
                    form.data["code"] = rcode
            if "save" in rform.data:
                if request.user.is_authenticated:
                    message = form.SaveCode(rcode)
                else:
                    message = "You do not have authority to save this file. Please log in."
                if message != "SAVED":
                    form.data["code"] = rcode
            if "diff" in rform.data:
                print("Differences: ")
                form.data["code"] = rcode

    # process(survex_file)
    if "code" not in form.data:
        form.data["code"] = form.GetDiscCode()
        if form.template:
            warning = True
    if not difflist:
        difflist.append("No differences - file was saved")
    if message:
        difflist.insert(0, message)

    # print [ form.data['code'] ]
    svxincludes = re.findall(r"(?i)\*include\s+(\S+)", form.data["code"] or "")

    svxfile = form.survexfile # only valid once form.GetDiscCode() called
    try:
        svxblocksall = svxfile.survexblock_set.all()
    except AttributeError: # some survexfiles just *include files and have no blocks themselves
        svxblocksall = []
    
    # collect all the survex blocks which actually have a valid date
    svxblocks = svxfile.survexblock_set.filter(date__isnull=False).order_by('date')


    events = events_on_dates(svxblocks)

    vmap = {
        "settings": settings,
        "warning": warning,
        "has_3d": (Path(survexdatasetpath) / Path(survex_file + ".3d")).is_file(),
        "title": survex_file,
        "svxblocks": svxblocks,
        "svxincludes": svxincludes,
        "difflist": difflist,
        "logmessage": logmessage,
        "form": form,
        "events": events,
    }
    # vmap.update(csrf(request)) # this now refreshes to the wrong value, now that we user render(request,

    if outputtype == "ajax": # used by CodeMirror ajax I think
        return render(request, "svxfiledifflistonly.html", vmap)

    return render(request, "svxfile.html", vmap)

SameDateEvents = namedtuple('SameDateEvents', ['trips', 'svxfiles', 'wallets', 'blocks'])

def events_on_dates(svxblocks):
    """Returns a dictionary of indexed by date. For each date there is a named tuple of 3 lists:
    logbookentries, survexfiles (NB files, not blocks), and wallets.
    """
    # deduplicate but maintain date order
    dates = [] 
    for b in svxblocks:
        if b.date not in dates:
            dates.append(b.date)
            # print(f"- {b.date}")
            
    events = {}
    for date in dates:
        trips = LogbookEntry.objects.filter(date=date)
        
        svxfiles = SurvexFile.objects.filter(survexblock__date=date).distinct()
        
        # https://stackoverflow.com/questions/739776/how-do-i-do-an-or-filter-in-a-django-query
        wallets = Wallet.objects.filter(Q(survexblock__date=date) | Q(walletdate=date)).distinct()
        
        blocks = []
        for b in svxblocks:
            if b.date == date:
                blocks.append(b.name)
        
        events[date] = SameDateEvents(trips=trips, svxfiles=svxfiles, wallets=wallets, blocks=blocks)
    # print(events)
    return events

# The cavern running function. This is NOT where it is run inside the form! see SvxForm.Process() for that
def process(survex_file):
    """This runs cavern only where a .3d, .log or .err file is requested."""
    filepathsvx = survexdatasetpath / str(survex_file + ".svx")
    cwd = os.getcwd()
    os.chdir(os.path.split(os.fspath(survexdatasetpath / survex_file))[0])
    os.system(settings.CAVERN + " --log " + str(filepathsvx))
    os.chdir(cwd)

    # Update this to use the new syntax..
    # sp = subprocess.run([settings.CAVERN, "--log", f'--output={outputdir}', f'{fullpath}.svx'],
    # capture_output=True, check=False, text=True)
    # if sp.returncode != 0:
    # message = f' ! Error running {settings.CAVERN}: {fullpath}'
    # DataIssue.objects.create(parser='entrances', message=message)
    # print(message)
    # print(f'stderr:\n\n' + str(sp.stderr) + '\n\n' + str(sp.stdout)  + '\n\nreturn code: ' + str(sp.returncode))

    filepatherr = Path(survexdatasetpath / str(survex_file + ".err"))
    if filepatherr.is_file():
        if filepatherr.stat().st_size == 0:
            filepatherr.unlink()  # delete empty closure error file


def threed(request, survex_file):
    filepath3d = survexdatasetpath / str(survex_file + ".3d")
    survexdatasetpath / str(survex_file + ".log")
    if filepath3d.is_file():
        threed = open(filepath3d, "rb")
        return HttpResponse(threed, content_type="application/x-aven")
    else:
        process(survex_file)  # should not need to do this if it already exists, as it should.
        log = open(survexdatasetpath / str(survex_file + ".log"), "r", encoding="utf-8")
        return HttpResponse(log, content_type="text")


def svxlog(request, survex_file):
    """Used for rendering .log files from survex outputtype"""
    filepathlog = survexdatasetpath / str(survex_file + ".log")
    if not filepathlog.is_file():
        process(survex_file)
    log = open(filepathlog, "r")
    return HttpResponse(log, content_type="text/plain; charset=utf-8")  # default: "text/html; charset=utf-8"


def err(request, survex_file):
    filepatherr = survexdatasetpath / str(survex_file + ".err")
    if not filepatherr.is_file():  # probably not there because it was empty, but re-run anyway
        process(survex_file)
    process(survex_file)
    if filepatherr.is_file():
        err = open(filepatherr, "r")
        return HttpResponse(err, content_type="text/plain; charset=utf-8")
    else:
        return HttpResponse(
            f"No closure errors. \nEmpty {filepatherr} file produced. \nSee the .log file.",
            content_type="text/plain; charset=utf-8",
        )


def identifycavedircontents(gcavedir):
    # find the primary survex file in each cave directory
    # this should be in a configuration, not buried in the code...
    name = os.path.split(gcavedir)[1]
    subdirs = []
    subsvx = []
    primesvx = None
    for f in os.listdir(gcavedir):  # These may get outdated as data gets tidied up. This should not be in the code!
        if name == "204" and (f in ["skel.svx", "template.svx", "204withents.svx"]):
            pass
        elif name == "136" and (f in ["136-noents.svx"]):
            pass
        elif name == "115" and (f in ["115cufix.svx", "115fix.svx"]):
            pass

        elif os.path.isdir(os.path.join(gcavedir, f)):
            if f[0] != ".":
                subdirs.append(f)
        elif f[-4:] == ".svx":
            nf = f[:-4]

            if (
                nf.lower() == name.lower()
                or nf[:3] == "all"
                or (name, nf) in [("resurvey2005", "145-2005"), ("cucc", "cu115")]
            ):
                if primesvx:
                    if nf[:3] == "all":
                        # assert primesvx[:3] != "all", (name, nf, primesvx, gcavedir, subsvx)
                        primesvx = nf
                    else:
                        # assert primesvx[:3] == "all", (name, nf, primesvx, gcavedir, subsvx)
                        pass
                else:
                    primesvx = nf
            else:
                subsvx.append(nf)
        else:
            pass
            # assert re.match(".*?(?:.3d|.log|.err|.txt|.tmp|.diff|.e?spec|~)$", f), (gcavedir, f)
    subsvx.sort()
    # assert primesvx, (gcavedir, subsvx)
    if primesvx:
        subsvx.insert(0, primesvx)
    return subdirs, subsvx


def get_survexareapath(area):
    return survexdatasetpath / str("caves-" + area)


# direct local non-database browsing through the svx file repositories
# every time the page is viewed! Should cache this.
def survexcaveslist(request):
    """This reads the entire list of caves in the Loser repo directory and produces a complete report.
    It can find caves which have not yet been properly registered in the system by Databasereset.py because
    someone may have uploaded the survex files without doing the rest of the integration process.
    """
    # TO DO - filter out the non-public caves  from display UNLESS LOGGED IN
    # This is very impenetrable code, original from Aaron Curtis I think.
    onefilecaves = []
    multifilecaves = []
    subdircaves = []
    fnumlist = []

    for area in ["1623", "1626", "1624", "1627"]:
        cavesdir = get_survexareapath(area)
        arealist = sorted([(area, -int(re.match(r"\d*", f).group(0) or "0"), f) for f in os.listdir(cavesdir)])
        fnumlist += arealist

    # print(fnumlist)

    # go through the list and identify the contents of each cave directory
    for area, num, cavedir in fnumlist:

        # these have sub dirs /cucc/ /arge/ /old/ but that is no reason to hide them in this webpage
        # so these are now treated the same as 142 and 113 which also have a /cucc/ sub dir
        # if cavedir in ["144", "40"]:
        #    continue

        # This all assumes that the first .svx file has the same name as the cave name,
        # which usually but not always true. e.g. caves-1623/78/allkaese.svx not caves-1623/78/78.svx
        # which is why we now also pass through the cavedir

        # Still fails for loutitohoehle etc even though this is set correctly when the pending cave is created
        cavesdir = get_survexareapath(area)
        gcavedir = os.path.join(cavesdir, cavedir)
        if os.path.isdir(gcavedir) and cavedir[0] != ".":
            subdirs, subsvx = identifycavedircontents(gcavedir)

            check_cave_registered(
                area, cavedir
            )  # should do this only once per database load or it will be slow
            survdirobj = []
            for lsubsvx in subsvx:
                survdirobj.append(("caves-" + area + "/" + cavedir + "/" + lsubsvx, lsubsvx))

            # caves with subdirectories
            if subdirs:
                subsurvdirs = []
                for subdir in subdirs:
                    dsubdirs, dsubsvx = identifycavedircontents(os.path.join(gcavedir, subdir))
                    # assert not dsubdirs # handle case of empty sub directory
                    lsurvdirobj = []
                    for lsubsvx in dsubsvx:
                        lsurvdirobj.append(("caves-" + area + "/" + cavedir + "/" + subdir + "/" + lsubsvx, lsubsvx))
                    if len(dsubsvx) >= 1:
                        subsurvdirs.append(
                            (subdir, lsurvdirobj[0], lsurvdirobj[0:])
                        )  # list now includes the first item too
                subdircaves.append((cavedir, (survdirobj[0], survdirobj[1:]), subsurvdirs))

            # multifile caves
            elif len(survdirobj) > 1:
                multifilecaves.append((survdirobj[0], cavedir, survdirobj[1:]))
            # single file caves
            elif len(survdirobj) == 1:
                onefilecaves.append(survdirobj[0])

    return render(
        request,
        "svxfilecavelist.html",
        {
            "settings": settings,
            "onefilecaves": onefilecaves,
            "multifilecaves": multifilecaves,
            "subdircaves": subdircaves,
        },
    )


def survexcavesingle(request, survex_cave):
    """parsing all the survex files of a single cave and showing that it's consistent and can find all
    the files and people.   Should explicitly fix the kataster number thing.
    kataster numbers are not unique across areas. This used to be a db constraint but we need to manage
    this ourselves as we don't want the parser aborting with an error message.

    Should use getCave() from models_caves
    """
    sc = survex_cave
    try:
        cave = Cave.objects.get(kataster_number=sc)  # This may not be unique.
        return render(request, "svxcavesingle.html", {"settings": settings, "cave": cave})

    except ObjectDoesNotExist:
        # can get here if the survex file is in a directory labelled with unofficial number not kataster number.
        # maybe - and _ mixed up, or CUCC-2017- instead of 2017-CUCC-, or CUCC2015DL01 . Let's not get carried away..

        # or it might be an exact search for a specific survefile but just missing the '.svx.
        if (Path(survexdatasetpath) / Path(survex_cave + ".svx")).is_file():
            return svx(request, survex_cave)

        for unoff in [sc, sc.replace("-", "_"), sc.replace("_", "-"), sc.replace("-", ""), sc.replace("_", "")]:
            try:
                cave = Cave.objects.get(unofficial_number=unoff)  # return on first one we find
                return render(request, "svxcavesingle.html", {"settings": settings, "cave": cave})
            except ObjectDoesNotExist:
                continue  # next attempt in for loop
        return render(request, "errors/svxcavesingle404.html", {"settings": settings, "cave": sc})

    except MultipleObjectsReturned:
        caves = Cave.objects.filter(kataster_number=survex_cave)
        return render(request, "svxcaveseveral.html", {"settings": settings, "caves": caves})

    except:
        return render(request, "errors/svxcavesingle404.html", {"settings": settings, "cave": sc})


def check_cave_registered(area, survex_cave):
    """Checks whether a cave has been properly registered when it is found in the Loser repo
    This should really be called by databaseReset not here in a view
    Currently Caves are only registered if they are listed in :expoweb: settings.CAVEDESCRIPTIONS
    so we need to add in any more here.

    This function runs but does not seem to be used?!
    A serious bodge anyway.
    """
    try:
        cave = Cave.objects.get(kataster_number=survex_cave)
        return str(cave)

    except MultipleObjectsReturned:
        caves = Cave.objects.filter(kataster_number=survex_cave)
        for c in caves:
            if str(c) == area + "-" + survex_cave:
                return str(c)  # just get the first that matches
        return None  # many returned but none in correct area

    except ObjectDoesNotExist:
        pass

    try:
        cave = Cave.objects.get(unofficial_number=survex_cave)  # should be unique!
        if cave.kataster_number:
            return str(cave)
        else:
            return None
    except ObjectDoesNotExist:
        pass

    return None