#!/usr/bin/python3
from pathlib import Path
from json import load as load_json, decoder
import shutil
from sys import exit
class ControlParser():
    def __init__(self):
        try:
            fp = Path('debian/control').open('r', encoding='utf-8')
        except IOError:
            raise Exception('cannot find debian/control file')
        self.lines = fp.readlines()
        self.packages = []
        self.source_name = None

    def load_info(self):
        for line in self.lines:
            if line.lower().startswith('package:'):
                self.packages.append(line[8:].strip())
            elif line.lower().startswith('source:'):
                self.source_name = line[7:].strip()


class DHelper():
    def __init__(self, controlparser):
        self.n4d_base_path = Path('/var/lib/n4d')
        self.n4d_inbox_path = self.n4d_base_path.joinpath('variables-inbox')
        self.n4d_trash_path = self.n4d_base_path.joinpath('variables-trash')
        self.n4d_vars_path = self.n4d_base_path.joinpath('variables')
        self.packages_to_remove={}
        self.controlparser = controlparser
        if Path('debian/n4dvars').exists():
            shutil.copyfile('debian/n4dvars', 'debian/{f}.n4dvars'.format(f=controlparser.packages[0]))
         
    def write_lintian(self, package):
        with Path( 'debian/{package}.lintian-overrides'.format( package = package )).open('a', encoding = 'utf-8' ) as fd:
            fd.write( '{package}: possibly-insecure-handling-of-tmp-files-in-maintainer-script\n'.format( package = package ) )
            
    def process_vars(self, package):
        error_list = []
        file_path = Path('debian/{package}.n4dvars'.format( package = package ))
        if not file_path.exists():
            return error_list
        with file_path.open('r', encoding='utf-8' ) as fd:
            for line in fd.readlines():
                variable_path = Path(line.strip())
                if not variable_path.exists():
                    error_list.append('[{package}]: {file} var file not exists. You can delete this reference in {parentfile} or create {file}'
                                        .format(package=package, file=str(variable_path), parentfile=str(file_path)))
                    continue
                if variable_path.is_file():
                    error_list.extend( self.install_files( package, variable_path ) )
                if variable_path.is_dir():
                    for iter_variable_path in variable_path.iterdir():
                        if iter_variable_path.is_file():
                            error_list.extend( self.install_files( package, iter_variable_path ) )
        self.write_postinst(package)
        self.write_prerm(package)
        return error_list


    def install_files( self, package, variable_file_path ):
        error_list = []
        try:
            j = load_json( variable_file_path.open('r',encoding='utf-8') )
        except decoder.JSONDecodeError:
            error_list.append('[{package}]: {file} has syntax error'.format(package=package, file=str(variable_file_path)))
        vars_template = {'package': package, 'inboxpath': str(self.n4d_inbox_path), 'varspath':str(self.n4d_vars_path), 'name': variable_file_path.name}
        Path('debian/{package}/{inboxpath}'.format(**vars_template)).mkdir(parents=True,exist_ok=True)
        shutil.copyfile(str(variable_file_path), 'debian/{package}/{inboxpath}/{package}.n4dvars.{name}'.format(**vars_template))
        self.packages_to_remove[package].append('{varspath}/{package}.n4dvars.{name}'.format(**vars_template))
        
        return error_list

    def run(self):
        error_list = []
        for package in self.controlparser.packages:
            self.packages_to_remove[package]=[]
            error_list.extend(self.process_vars(package))
            self.write_lintian(package)
        if len(error_list) > 0:
            print("Error on n4d debhelper")
            print("======================")
            for x in error_list:
                print(x+"\n")
            exit(1)
 

    def write_postinst(self, package):
        with Path('debian/{package}.postinst.debhelper'.format(package=package)).open('a',encoding='utf-8') as fd:
            fd.write('''
############################################
# Automatically generated by dn4dh_install #
############################################
case "$1" in 
    configure)
        if [ -e '/run/n4d/token' ]; then
                        AUX_PID=$(cat /run/n4d/token)
                        STATUS=$(ps -p $AUX_PID -o args= | grep n4d-server || true)
                        if [ "$STATUS" != "" ]; then
                    n4d-vars readinbox || true
                        fi
                fi
    ;;
    *)
    ;;
esac
################################################
# END Automatically generated by dn4dh_install #
################################################
            ''')

    def write_prerm(self, package):
        packages_to_remove = " ".join("'{0}'".format(w) for w in self.packages_to_remove[package] )
        with Path('debian/{package}.prerm.debhelper'.format(package=package)).open('a',encoding='utf-8') as fd:
            fd.write('''
############################################
# Automatically generated by dn4dh_install #
############################################
case "$1" in 
    remove|purge)
        if [ -d "{path_installed_vars}" ]; then
            for x in {vars_to_delete}; do
                if [ -e "$x" ]; then
                    cp $x {path_trash_vars}
                fi
            done
        if [ -e '/run/n4d/token' ]; then
            AUX_PID=$(cat /run/n4d/token)
            STATUS=$(ps -p $AUX_PID -o args= | grep n4d-server || true)
                        if [ "$STATUS" != "" ]; then
                    n4d-vars emptytrash || true
            fi
        fi
    fi
    ;;
    *)
    ;;
esac
################################################
# END Automatically generated by dn4dh_install #
################################################
        '''.format(path_installed_vars=self.n4d_vars_path, path_trash_vars=self.n4d_trash_path, vars_to_delete=packages_to_remove))

def main():
    control = ControlParser()
    control.load_info()
    dhelper = DHelper(control)
    dhelper.run()

if __name__ == '__main__':
    main()