##########################################################################
#
# pgAdmin 4 - PostgreSQL Tools
#
# Copyright (C) 2013 - 2016, The pgAdmin Development Team
# This software is released under the PostgreSQL Licence
#
##########################################################################

"""Implements the Check Constraint Module."""

import simplejson as json
from functools import wraps

import pgadmin.browser.server_groups.servers.databases as database
from flask import render_template, make_response, request, jsonify
from flask_babel import gettext as _
from pgadmin.browser.collection import CollectionNodeModule
from pgadmin.browser.server_groups.servers.databases.schemas.tables.constraints.type \
    import ConstraintRegistry
from pgadmin.browser.utils import PGChildNodeView
from pgadmin.utils.ajax import make_json_response, \
    make_response as ajax_response, internal_server_error
from pgadmin.utils.ajax import precondition_required
from pgadmin.utils.driver import get_driver

from config import PG_DEFAULT_DRIVER


class CheckConstraintModule(CollectionNodeModule):
    """
    class CheckConstraintModule(CollectionNodeModule):

        This class represents The Check Constraint Module.

    Methods:
    -------
    * __init__(*args, **kwargs)
      - Initialize the Check Constraint Module.

    * get_nodes(gid, sid, did, scid)
      - Generate the Check Constraint collection node.

    * node_inode(gid, sid, did, scid)
      - Returns Check Constraint node as leaf node.

    * script_load()
      - Load the module script for the Check Constraint, when any of the
        Check node is initialized.
    """
    NODE_TYPE = 'check_constraints'
    COLLECTION_LABEL = _("Check Constraints")

    def __init__(self, *args, **kwargs):
        super(CheckConstraintModule, self).__init__(*args, **kwargs)
        self.min_ver = None
        self.max_ver = None

    def get_nodes(self, gid, sid, did, scid, doid):
        """
        Generate the Check Constraint collection node.
        """
        yield self.generate_browser_collection_node(doid)

    @property
    def node_inode(self):
        """
        Returns Check Constraint node as leaf node.
        """
        return False

    @property
    def script_load(self):
        """
        Load the module script for the Check Constraint, when any of the
        Check node is initialized.
        """
        return database.DatabaseModule.NODE_TYPE

    @property
    def csssnippets(self):
        """
        Returns a snippet of css to include in the page
        """
        return [
            render_template(
                "check_constraint/css/check_constraint.css",
                node_type=self.node_type
            )
        ]


blueprint = CheckConstraintModule(__name__)


class CheckConstraintView(PGChildNodeView):
    """
    class CheckConstraintView(PGChildNodeView):

    This class inherits PGChildNodeView to get the different routes for
    the module.

    The class is responsible to Create, Read, Update and Delete operations for
    the Check Constraint.

    Methods:
    -------

    * module_js():
      - Load JS file (check-constraints.js) for this module.

    * check_precondition(f):
      - Works as a decorator.
      -  Checks database connection status.
      -  Attach connection object and template path.

    * list(gid, sid, did, scid, doid):
      - List the Check Constraints.

    * nodes(gid, sid, did, scid):
      - Returns all the Check Constraints to generate Nodes in the browser.

    * properties(gid, sid, did, scid, doid):
      - Returns the Check Constraint properties.

    * create(gid, sid, did, scid):
      - Creates a new Check Constraint object.

    * update(gid, sid, did, scid, doid):
      - Updates the Check Constraint object.

    * delete(gid, sid, did, scid, doid):
      - Drops the Check Constraint object.

    * sql(gid, sid, did, scid, doid=None):
      - Returns the SQL for the Check Constraint object.

    * msql(gid, sid, did, scid, doid=None):
      - Returns the modified SQL.

    * get_sql(gid, sid, data, scid, tid=None):
      - Generates the SQL statements to create/update the Check Constraint.
        object.

    * dependents(gid, sid, did, scid, tid, cid):
      - Returns the dependents for the Check Constraint object.

    * dependencies(gid, sid, did, scid, tid, cid):
      - Returns the dependencies for the Check Constraint object.

    * validate_check_constraint(gid, sid, did, scid, tid, cid):
      - Validate check constraint.
    """
    node_type = blueprint.node_type

    parent_ids = [
        {'type': 'int', 'id': 'gid'},
        {'type': 'int', 'id': 'sid'},
        {'type': 'int', 'id': 'did'},
        {'type': 'int', 'id': 'scid'},
        {'type': 'int', 'id': 'tid'}
    ]
    ids = [
        {'type': 'int', 'id': 'cid'}
    ]

    operations = dict({
        'obj': [
            {'get': 'properties', 'delete': 'delete', 'put': 'update'},
            {'get': 'list', 'post': 'create'}
        ],
        'delete': [{'delete': 'delete'}],
        'children': [{'get': 'children'}],
        'nodes': [{'get': 'node'}, {'get': 'nodes'}],
        'sql': [{'get': 'sql'}],
        'msql': [{'get': 'msql'}, {'get': 'msql'}],
        'stats': [{'get': 'statistics'}],
        'dependency': [{'get': 'dependencies'}],
        'dependent': [{'get': 'dependents'}],
        'module.js': [{}, {}, {'get': 'module_js'}],
        'validate': [{'get': 'validate_check_constraint'}],
    })

    def module_js(self):
        """
        Load JS file (check_constraint.js) for this module.
        """
        return make_response(
            render_template(
                "check_constraint/js/check_constraint.js",
                _=_
            ),
            200, {'Content-Type': 'application/x-javascript'}
        )

    def check_precondition(f):
        """
        Works as a decorator.
        Checks database connection status.
        Attach connection object and template path.
        """

        @wraps(f)
        def wrap(*args, **kwargs):
            self = args[0]
            driver = get_driver(PG_DEFAULT_DRIVER)
            self.manager = driver.connection_manager(kwargs['sid'])
            self.conn = self.manager.connection(did=kwargs['did'])
            self.qtIdent = driver.qtIdent

            # If DB not connected then return error to browser
            if not self.conn.connected():
                return precondition_required(
                    _("Connection to the server has been lost!")
                )

            ver = self.manager.version

            # we will set template path for sql scripts
            if ver >= 90200:
                self.template_path = 'check_constraint/sql/9.2_plus'
            elif ver >= 90100:
                self.template_path = 'check_constraint/sql/9.1_plus'

            SQL = render_template("/".join([self.template_path,
                                            'get_parent.sql']),
                                  tid=kwargs['tid'])
            status, rset = self.conn.execute_2darray(SQL)
            if not status:
                return internal_server_error(errormsg=rset)

            self.schema = rset['rows'][0]['schema']
            self.table = rset['rows'][0]['table']

            return f(*args, **kwargs)

        return wrap

    def end_transaction(self):
        """
            End database transaction.
        Returns:

        """
        SQL = "END;"
        self.conn.execute_scalar(SQL)

    @check_precondition
    def list(self, gid, sid, did, scid, tid, cid=None):
        """
        List the Check Constraints.

        Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Table Id
            cid: Check Id
        """
        try:
            res = self.get_node_list(gid, sid, did, scid, tid, cid)
            return ajax_response(
                response=res,
                status=200
            )
        except Exception as e:
            return internal_server_error(errormsg=str(e))

    @check_precondition
    def get_node_list(self, gid, sid, did, scid, tid, cid=None):
        """
        This function returns all check constraints
        nodes within that collection as a list.

        Args:
          gid: Server Group ID
          sid: Server ID
          did: Database ID
          scid: Schema ID
          tid: Table ID
          cid: Cehck constraint ID

        Returns:

        """
        SQL = render_template("/".join([self.template_path, 'properties.sql']),
                              tid=tid)
        status, res = self.conn.execute_dict(SQL)

        return res['rows']

    @check_precondition
    def nodes(self, gid, sid, did, scid, tid, cid=None):
        """
        Returns all the Check Constraints.

        Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Table Id
            cid: Check constraint Id.
        """
        try:
            res = self.get_nodes(gid, sid, did, scid, tid, cid)
            return make_json_response(
                data=res,
                status=200
            )
        except Exception as e:
            return internal_server_error(errormsg=str(e))

    @check_precondition
    def get_nodes(self, gid, sid, did, scid, tid, cid=None):
        """
        This function returns all event check constraint as a list.

        Args:
          gid: Server Group ID
          sid: Server ID
          did: Database ID
          scid: Schema ID
          tid: Table ID
          cid: Check constraint ID

        Returns:

        """
        res = []
        SQL = render_template("/".join([self.template_path,
                                        'nodes.sql']),
                              tid=tid)
        status, rset = self.conn.execute_2darray(SQL)

        for row in rset['rows']:
            if "convalidated" in row and row["convalidated"]:
                icon = "icon-check_constraints_bad"
                valid = False
            else:
                icon = "icon-check_constraints"
                valid = True
            res.append(
                self.blueprint.generate_browser_node(
                    row['oid'],
                    tid,
                    row['name'],
                    icon=icon,
                    valid=valid
                ))
        return res

    @check_precondition
    def properties(self, gid, sid, did, scid, tid, cid):
        """
        Returns the Check Constraints property.

        Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Check Id
            cid: Check Constraint Id
        """

        SQL = render_template("/".join([self.template_path,
                                        'properties.sql']),
                              tid=tid, cid=cid)
        status, res = self.conn.execute_dict(SQL)
        if not status:
            return internal_server_error(errormsg=res)

        data = res['rows'][0]
        return ajax_response(
            response=data,
            status=200
        )

    @check_precondition
    def create(self, gid, sid, did, scid, tid, cid=None):
        """
        This function will create a primary key.

        Args:
          gid: Server Group ID
          sid: Server ID
          did: Database ID
          scid: Schema ID
          tid: Table ID
          cid: Check constraint ID

        Returns:

        """
        required_args = ['consrc']

        data = request.form if request.form else json.loads(
            request.data, encoding='utf-8'
        )

        for k, v in data.items():
            try:
                data[k] = json.loads(v, encoding='utf-8')
            except (ValueError, TypeError, KeyError):
                data[k] = v

        for arg in required_args:
            if arg not in data or data[arg] == '':
                return make_json_response(
                    status=400,
                    success=0,
                    errormsg=_(
                        "Couldn't find the required parameter (%s)." % arg
                    )
                )

        data['schema'] = self.schema
        data['table'] = self.table
        try:
            if 'name' not in data or data['name'] == "":
                SQL = "BEGIN;"
                # Start transaction.
                status, res = self.conn.execute_scalar(SQL)
                if not status:
                    self.end_transaction()
                    return internal_server_error(errormsg=res)

            # The below SQL will execute CREATE DDL only
            SQL = render_template(
                "/".join([self.template_path, 'create.sql']),
                data=data
            )

            status, msg = self.conn.execute_scalar(SQL)
            if not status:
                self.end_transaction()
                return internal_server_error(errormsg=msg)

            if 'name' not in data or data['name'] == "":
                sql = render_template(
                    "/".join([self.template_path,
                              'get_oid_with_transaction.sql'],
                             ),
                    tid=tid)

                status, res = self.conn.execute_dict(sql)
                if not status:
                    self.end_transaction()
                    return internal_server_error(errormsg=res)

                self.end_transaction()

                data['name'] = res['rows'][0]['name']

            else:
                sql = render_template("/".join([self.template_path, 'get_oid.sql']),
                                      tid=tid,
                                      name=data['name'])
                status, res = self.conn.execute_dict(sql)
                if not status:
                    self.end_transaction()
                    return internal_server_error(errormsg=res)

            if "convalidated" in res['rows'][0] and res['rows'][0]["convalidated"]:
                icon = "icon-check_constraints_bad"
                valid = False
            else:
                icon = "icon-check_constraints"
                valid = True

            return jsonify(
                node=self.blueprint.generate_browser_node(
                    res['rows'][0]['oid'],
                    tid,
                    data['name'],
                    icon=icon,
                    valid=valid
                )
            )

        except Exception as e:
            self.end_transaction()
            return make_json_response(
                status=400,
                success=0,
                errormsg=e
            )

    @check_precondition
    def delete(self, gid, sid, did, scid, tid, cid):
        """
        Drops the Check Constraint object.

        Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Check Id
            cid: Check Constraint Id
        """
        try:
            SQL = render_template("/".join([self.template_path,
                                            'properties.sql']),
                                  tid=tid, cid=cid)
            status, res = self.conn.execute_dict(SQL)

            if not status:
                return internal_server_error(errormsg=res)

            if not res['rows']:
                return make_json_response(
                    success=0,
                    errormsg=_(
                        'Error: Object not found.'
                    ),
                    info=_(
                        'The specified check constraint could not be found.\n'
                    )
                )

            data = res['rows'][0]

            SQL = render_template("/".join([self.template_path,
                                            'delete.sql']),
                                  data=data)
            status, res = self.conn.execute_scalar(SQL)
            if not status:
                return internal_server_error(errormsg=res)

            return make_json_response(
                success=1,
                info=_("Check Constraint dropped"),
                data={
                    'id': tid,
                    'scid': scid,
                    'sid': sid,
                    'gid': gid,
                    'did': did
                }
            )

        except Exception as e:
            return internal_server_error(errormsg=str(e))

    @check_precondition
    def update(self, gid, sid, did, scid, tid, cid):
        """
        Updates the Check Constraint object.

        Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Table Id
            cid: Check Constraint Id
        """
        data = request.form if request.form else json.loads(
            request.data, encoding='utf-8'
        )

        try:
            data['schema'] = self.schema
            data['table'] = self.table

            SQL = self.get_sql(gid, sid, data, scid, tid, cid)
            SQL = SQL.strip('\n').strip(' ')
            if SQL != "":
                status, res = self.conn.execute_scalar(SQL)
                if not status:
                    return internal_server_error(errormsg=res)

                sql = render_template("/".join([self.template_path, 'get_name.sql']),
                                      cid=cid)
                status, res = self.conn.execute_dict(sql)
                if not status:
                    return internal_server_error(errormsg=res)

                if "convalidated" in res['rows'][0] and res['rows'][0]["convalidated"]:
                    icon = 'icon-check_constraints_)bad'
                    valid = False
                else:
                    icon = 'icon-check_constraints'
                    valid = True

                return make_json_response(
                    success=1,
                    info="Check Constraint updated",
                    data={
                        'id': cid,
                        'tid': tid,
                        'scid': scid,
                        'sid': sid,
                        'gid': gid,
                        'did': did,
                        'icon': icon,
                        'val    id': valid
                    }
                )
            else:
                return make_json_response(
                    success=1,
                    info="Nothing to update",
                    data={
                        'id': cid,
                        'tid': tid,
                        'scid': scid,
                        'sid': sid,
                        'gid': gid,
                        'did': did
                    }
                )

        except Exception as e:
            return internal_server_error(errormsg=str(e))

    @check_precondition
    def sql(self, gid, sid, did, scid, tid, cid=None):
        """
        Returns the SQL for the Check Constraint object.

        Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Table Id
            cid: Check Constraint Id
        """

        SQL = render_template("/".join([self.template_path,
                                        'properties.sql']),
                              tid=tid, cid=cid)
        status, res = self.conn.execute_dict(SQL)
        if not status:
            return internal_server_error(errormsg=res)

        data = res['rows'][0]
        data['schema'] = self.schema
        data['table'] = self.table

        SQL = render_template("/".join([self.template_path,
                                        'create.sql']),
                              data=data)

        sql_header = "-- Constraint: {0}\n\n-- ".format(data['name'])
        if hasattr(str, 'decode'):
            sql_header = sql_header.decode('utf-8')

        sql_header += render_template(
            "/".join([self.template_path, 'delete.sql']),
            data=data)
        sql_header += "\n"

        SQL = sql_header + SQL

        return ajax_response(response=SQL)

    @check_precondition
    def msql(self, gid, sid, did, scid, tid, cid=None):
        """
        Returns the modified SQL.

        Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Table Id
            cid: Check Constraint Id

        Returns:
            Check Constraint object in json format.
        """
        data = {}
        for k, v in request.args.items():
            try:
                data[k] = json.loads(v, encoding='utf-8')
            except ValueError:
                data[k] = v

        data['schema'] = self.schema
        data['table'] = self.table
        try:
            sql = self.get_sql(gid, sid, data, scid, tid, cid)
            sql = sql.strip('\n').strip(' ')

            return make_json_response(
                data=sql,
                status=200
            )

        except Exception as e:
            return internal_server_error(errormsg=str(e))

    def get_sql(self, gid, sid, data, scid, tid, cid=None):
        """
        Generates the SQL statements to create/update the Check Constraint.

         Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Table Id
            cid: Check Constraint Id
        """
        try:
            if cid is not None:
                SQL = render_template("/".join([self.template_path,
                                                'properties.sql']),
                                      tid=tid, cid=cid)
                status, res = self.conn.execute_dict(SQL)

                if not status:
                    return False, internal_server_error(errormsg=res)

                old_data = res['rows'][0]
                required_args = ['name']
                for arg in required_args:
                    if arg not in data:
                        data[arg] = old_data[arg]

                SQL = render_template(
                    "/".join([self.template_path, 'update.sql']),
                    data=data, o_data=old_data, conn=self.conn
                )
            else:
                required_args = ['consrc']

                for arg in required_args:
                    if arg not in data:
                        return _('-- definition incomplete')
                    elif isinstance(data[arg], list) and len(data[arg]) < 1:
                        return _('-- definition incomplete')

                SQL = render_template("/".join([self.template_path,
                                                'create.sql']),
                                      data=data)

            return SQL
        except Exception as e:
            return False, internal_server_error(errormsg=str(e))

    @check_precondition
    def dependents(self, gid, sid, did, scid, tid, cid):
        """
        This function get the dependents and return ajax response
        for the Check Constraint node.

        Args:
            gid:  Server Group Id
            sid:  Server Id
            did:  Database Id
            scid: Schema Id
            tid: Table Id
            cid: Check Constraint Id
        """
        dependents_result = self.get_dependents(self.conn, cid)
        return ajax_response(
            response=dependents_result,
            status=200
        )

    @check_precondition
    def dependencies(self, gid, sid, did, scid, tid, cid):
        """
        This function get the dependencies and return ajax response
        for the Check Constraint node.

        Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Table Id
            cid: Check Constraint Id
        """
        dependencies_result = self.get_dependencies(self.conn, cid)
        return ajax_response(
            response=dependencies_result,
            status=200
        )

    @check_precondition
    def validate_check_constraint(self, gid, sid, did, scid, tid, cid):
        """
        Validate check constraint.
        Args:
            gid: Server Group Id
            sid: Server Id
            did: Database Id
            scid: Schema Id
            tid: Table Id
            cid: Check Constraint Id

        Returns:

        """
        data = {}
        try:
            data['schema'] = self.schema
            data['table'] = self.table
            sql = render_template("/".join([self.template_path, 'get_name.sql']), cid=cid)
            status, res = self.conn.execute_scalar(sql)
            if not status:
                return internal_server_error(errormsg=res)

            data['name'] = res
            sql = render_template("/".join([self.template_path, 'validate.sql']), data=data)
            status, res = self.conn.execute_dict(sql)
            if not status:
                return internal_server_error(errormsg=res)

            return make_json_response(
                success=1,
                info=_("Check constraint updated."),
                data={
                    'id': cid,
                    'tid': tid,
                    'scid': scid,
                    'did': did
                }
            )

        except Exception as e:
            return internal_server_error(errormsg=str(e))


constraint = ConstraintRegistry(
    'check_constraint', CheckConstraintModule, CheckConstraintView
)
CheckConstraintView.register_node_view(blueprint)
