# -*- coding: utf-8 -*-

"""
Post_DeleteDB.py
***************************************************************************
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU General Public License as published by  *
*   the Free Software Foundation; either version 2 of the License, or     *
*   (at your option) any later version.                                   *
*                                                                         *
***************************************************************************
"""
__author__ = 'Leandro França'
__date__ = '2021-03-10'
__copyright__ = '(C) 2020, Leandro França'

from qgis.core import (QgsProcessingException,
                       QgsProcessingAlgorithm,
                       QgsProcessingParameterString,
                       QgsProcessingParameterEnum,
                       QgsApplication,
                       QgsSettings
                       )

from lftools.geocapt.imgs import Imgs
from lftools.translations.translate import translate
import os
from pathlib import Path
from qgis.PyQt.QtGui import QIcon

class DeleteDB(QgsProcessingAlgorithm):

    LOC = QgsApplication.locale()[:2]

    def tr(self, *string):
        return translate(string, self.LOC)

    def createInstance(self):
        return DeleteDB()

    def name(self):
        return 'deletedb'

    def displayName(self):
        return self.tr('Delete database', 'Deletar BD')

    def group(self):
        return self.tr('PostGIS')

    def groupId(self):
        return 'postgis'

    def tags(self):
        return 'GeoOne,postgis,postgresql,database,BD,DB,delete,drop,manager,clean'.split(',')

    def icon(self):
        return QIcon(os.path.join(os.path.dirname(os.path.dirname(__file__)), 'images/postgis.png'))

    txt_en = '''This tool allows you to delete / drop any PostgreSQL database.
Notes:
- To run this operation, the database must be disconnected. This means, that it must not be opened in any software (PgAdmin, QGIS, etc.).
- To delete more than one database, the names must be filled and separated by "comma".
<p style="color:red;">Attention: This operation is irreversible, so be sure before running it!</p>'''
    txt_pt = """Esta ferramenta permite apagar (delete/drop) qualquer banco do PostgreSQL.
Obs.:
- Para realizar esta operação, é necessário que o banco esteja desconectado, ou seja, não esteja aberto em nenhum software (PgAdmin, QGIS, etc).
- Para deletar mais de um BD, os nomes devem ser preenchidos separados por vírgula.
<p style="color:red;">Atenção: Esta operação é irreversível, portanto esteja seguro quando for executá-la!</p>"""
    figure = 'images/tutorial/post_deletedb.jpg'

    def shortHelpString(self):
        social_BW = Imgs().social_BW
        footer = '''<div align="center">
                      <img src="'''+ os.path.join(os.path.dirname(os.path.dirname(__file__)), self.figure) +'''">
                      </div>
                      <div align="left">
                      <p>
                      <b><a href="'''+ self.tr('https://portal.geoone.com.br/m/lessons/postgis?classId=3436') + '''" target="_blank">'''+ self.tr('Click here to watch a full class on this tool',
                                    'Clique aqui para assistir uma aula completa sobre esta ferramenta') +'''</a></b>
                      </p>
                      <p>
                      <b><a href="'''+ self.tr('https://geoone.com.br/pvpostgis/') + '''" target="_blank">'''+ self.tr("Sign up for GeoOne's PostGIS course",
                                    'Inscreva-se no curso de PostGIS da GeoOne') +'</a><br><br>'+ self.tr('Author: Leandro Franca', 'Autor: Leandro França')+'''</b>
                      </p>'''+ social_BW + '''
                    </div>'''
        return self.tr(self.txt_en, self.txt_pt) + footer

    DELETED = 'DELETED'
    HOST = 'HOST'
    USER = 'USER'
    PORT = 'PORT'
    VERSION = 'VERSION'
    versions = ['9.5', '9.6', '10', '11', '12', '13', '14', '15', '16', '17','18']

    def initAlgorithm(self, config=None):
        # INPUT
        self.addParameter(
            QgsProcessingParameterString(
                self.DELETED,
                self.tr('DB Name(s) to be deleted', 'Nome(s) do(s) BD a serem deletado(s)')
            )
        )

        self.addParameter(
            QgsProcessingParameterString(
                self.HOST,
                self.tr('Host', 'Host'),
                defaultValue = 'localhost'
            )
        )

        self.addParameter(
            QgsProcessingParameterString(
                self.PORT,
                self.tr('Port', 'Porta'),
                defaultValue = '5432'
            )
        )

        self.addParameter(
            QgsProcessingParameterString(
                self.USER,
                self.tr('User', 'Usuário'),
                defaultValue = 'postgres'
            )
        )

        my_settings = QgsSettings()
        postgresql_version = my_settings.value("LFTools/postgresql_version", 10)

        self.addParameter(
            QgsProcessingParameterEnum(
                self.VERSION,
                self.tr('PostgreSQL version', 'Versão do PostgreSQL'),
				options = self.versions,
                defaultValue = postgresql_version
            )
        )

    def processAlgorithm(self, parameters, context, feedback):

        deleted = self.parameterAsString(
            parameters,
            self.DELETED,
            context
        )
        if not deleted or deleted == '' or ' ' in deleted:
            raise QgsProcessingException(self.invalidSourceError(parameters, self.DELETED))

        host = self.parameterAsString(
            parameters,
            self.HOST,
            context
        )

        port = self.parameterAsString(
            parameters,
            self.PORT,
            context
        )

        version = self.parameterAsEnum(
            parameters,
            self.VERSION,
            context
        )

        my_settings = QgsSettings()
        my_settings.setValue("LFTools/postgresql_version", version)
        
        version = self.versions[version]

        user = self.parameterAsString(
            parameters,
            self.USER,
            context
        )

        # Procurando arquivo psql
        win64 = 'C:/Program Files (x86)/PostgreSQL/'+version+'/bin'
        win64d = 'D:/Program Files (x86)/PostgreSQL/'+version+'/bin'
        win32 = 'C:/Program Files/PostgreSQL/'+version+'/bin'
        win32d = 'D:/Program Files/PostgreSQL/'+version+'/bin'
        mac = '/Library/PostgreSQL/'+version+'/bin/'
        linux = '/usr/lib/postgresql/'+version+'/bin/'
        if os.path.isdir(win64):
            os.chdir(win64)
        elif os.path.isdir(win64d):
            os.chdir(win64d)
        elif os.path.isdir(win32):
            os.chdir(win32)
        elif os.path.isdir(win32d):
            os.chdir(win32d)
        elif os.path.isdir(mac):
            os.chdir(mac)
        elif os.path.isdir(linux):
            os.chdir(linux)
        else:
            raise QgsProcessingException(self.tr('Make sure your PostgreSQL version is correct!', 'Verifique se a versão do seu PostgreSQL está correta!'))

        # Renomeando BD
        file_path = str(Path(Path.home(), "deleted.sql"))
        arquivo = open(file_path,'w')
        for item in deleted.split(','):
            arquivo.write('DROP DATABASE ' + item +';\n')
        arquivo.close()
        comando = 'psql -d postgres -U '+user+' -h '+host+' -p '+port+' -f ' + file_path
        feedback.pushInfo('\n' + self.tr('Command: ','Comando: ') + comando)
        feedback.pushInfo('\n' + self.tr('Starting delete/drop database(s)...', 'Iniciando processo de delete/drop BD...'))
        result = os.system(comando)
        os.remove(file_path)

        if result==0:
            feedback.pushInfo(self.tr('Operation completed successfully!', 'Operação finalizada com sucesso!'))
            feedback.pushInfo(self.tr('Leandro Franca - Cartographic Engineer', 'Leandro França - Eng Cart'))
        else:
            feedback.pushInfo(self.tr('There was a problem while executing the command. Please check the input parameters.',
                                      'Houve algum problema durante a execução do comando. Por favor, verifique os parâmetros de entrada.'))

        return {}
