import json
import os
import sys
import lxml.etree as etree

from nitpo import Nitpo
import filing

import uuid
import subprocess

class Sheets(Nitpo):

    def __init__(self, do_verbose=False):
        super().__init__()
        # # complied stylesheets, done once
        self.sheets = {}
        if not self.has_conf('folders', 'style'):
            print("sheets need a folder to continue.")
            sys.exit()
        self.do_verbose = do_verbose
        return None

    def load_sheet(self, shena):
        sheet_fufi = self.get_sheet_fufi(shena)
        sheet_doc = etree.parse(sheet_fufi)
        sheet = etree.XSLT(sheet_doc)
        sheet.set_global_max_depth(1000000)
        self.sheets[shena] = sheet
        return sheet

    def return_sheet(self, shena):
        sheet_fufi = self.get_sheet_fufi(shena)
        if self.do_verbose:
            print(f"sheets chooses fufi {sheet_fufi}")
        sheet_doc = etree.parse(sheet_fufi)
        sheet = etree.XSLT(sheet_doc)
        #sheet.set_global_max_depth(1000000)
        return sheet

    def get_result(self, shena, in_doc, params=None):
        """uses a sheet name"""
        if shena not in self.sheets:
            # print(f"sheets loads {shena}", file=sys.stderr)
            self.load_sheet(shena)
        this_sheet = self.sheets[shena]
        if params is None:
            result = this_sheet(in_doc)
        else:
            # # don't know what the ** means here
            result = this_sheet(in_doc, **params)
        return result

    def get_sheet_fufi(self, shena):
        """get a sheet, in many ways"""
        if os.path.isfile(shena):
            return shena
        if self.has_conf('sheets', shena):
            sheet_fufi = self.conf['sheets'][shena]
            return sheet_fufi
        bana = shena + self.const['xslt_ext']
        if self.has_conf('folders', 'empros'):
            empro_dir = self.conf['folders']['empros']
            test_fufi = empro_dir + '/' + bana
            if os.path.isfile(test_fufi):
                return test_fufi
        if self.has_conf('folders', 'xslt'):
            sheet_fufi = self.conf['folders']['xslt'] + '/' + bana
            # print(sheet_fufi)
            if os.path.isfile(sheet_fufi):
                return sheet_fufi
        sheet_fufi = self.conf['folders']['style'] + '/' + bana
        if os.path.isfile(sheet_fufi):
            return sheet_fufi
        raise Exception(f"I don't see a sheet file for {shena}")

    def fufi_to_fufi(self, shena, in_fufi, out_fufi, params=None):
        sheet_fufi = self.get_sheet_fufi(shena)
        if not filing.donere(out_fufi, [sheet_fufi, in_fufi]):
            return False
        in_doc = etree.parse(in_fufi)
        out_doc = self.get_result(shena, in_doc)
        out_bytes = bytes(out_doc)
        out_string = out_bytes.decode('utf-8')
        filing.prepare(out_fufi)
        filing.srite(out_fufi, out_string)
        return out_string

    def fufi_to_docu(self, shena, in_fufi, out_fufi, params=None):
        sheet_fufi = self.get_sheet_fufi(shena)
        if not filing.donere(out_fufi, [sheet_fufi, in_fufi]):
            return False
        in_doc = etree.parse(in_fufi)
        out_doc = self.get_result(shena, in_doc)
        out_bytes = bytes(out_doc)
        out_string = out_bytes.decode('utf-8')
        filing.prepare(out_fufi)
        filing.srite(out_fufi, out_string)
        return out_string

    def fufi_to_string(self, shena, in_fufi, params=None):
        sheet_fufi = self.get_sheet_fufi(shena)
        in_doc = etree.parse(in_fufi)
        out_doc = self.get_result(shena, in_doc)
        out_bytes = bytes(out_doc)
        out_string = out_bytes.decode('utf-8')
        return out_string

    def via_system(self, shena, in_doc):
        """for papers screen transformation because so maxvars in lxml"""
        sheet_fufi = self.get_sheet_fufi(shena)
        randna = '/tmp/' + str(uuid.uuid4())[:8]
        out_fufi = randna + '_out.xml'
        in_fufi = randna + '_in.xml'
        in_doc.write(in_fufi, pretty_print=True)
        err_fufi = randna + '.err'
        args = '--maxvars 1000000 --maxdepth 1000000'
        s = f"/usr/bin/xsltproc {args} {sheet_fufi} {in_fufi}"
        s += f" > {out_fufi} 2> {err_fufi}"
        try:
            subprocess.run(s, check=True, shell=True)
        except subprocess.CalledProcessError:
            err_file = open(err_fufi, 'r')
            err = err_file.read()
            print(err, file=sys.stderr)
            return None
        ## try read as XML, if that fails, it's text
        try:
            doc = etree.parse(out_fufi)
        except etree.XMLSyntaxError:
            out_file = open(out_fufi, 'r')
            doc = out_file.read()
        for fufi in [in_fufi, out_fufi, err_fufi]:
            if os.path.isfile(fufi):
                os.remove(fufi)
        return doc