"""Views used by the SqlAlchemy connector"""
from flask import flash, Markup, redirect
from flask_appbuilder import CompactCRUDMixin, expose
from flask_appbuilder.actions import action
from flask_appbuilder.models.sqla.interface import SQLAInterface
from flask_babel import gettext as __
from flask_babel import lazy_gettext as _
from past.builtins import basestring

from superset import appbuilder, db, security, sm, utils
from superset.connectors.base.views import DatasourceModelView
from superset.utils import has_access
from superset.views.base import (
    DatasourceFilter, DeleteMixin, get_datasource_exist_error_mgs,
    ListWidgetWithCheckboxes, SupersetModelView,
)
from . import models


class TableColumnInlineView(CompactCRUDMixin, SupersetModelView):  # noqa
    datamodel = SQLAInterface(models.TableColumn)

    list_title = _('List Columns')
    show_title = _('Show Column')
    add_title = _('Add Column')
    edit_title = _('Edit Column')

    can_delete = False
    list_widget = ListWidgetWithCheckboxes
    edit_columns = [
        'column_name', 'verbose_name', 'description',
        'type', 'groupby', 'filterable',
        'table', 'count_distinct', 'sum', 'min', 'max', 'expression',
        'is_dttm', 'python_date_format', 'database_expression']
    add_columns = edit_columns
    list_columns = [
        'column_name', 'verbose_name', 'type', 'groupby', 'filterable', 'count_distinct',
        'sum', 'min', 'max', 'is_dttm']
    page_size = 500
    description_columns = {
        'is_dttm': _(
            'Whether to make this column available as a '
            '[Time Granularity] option, column has to be DATETIME or '
            'DATETIME-like'),
        'filterable': _(
            'Whether this column is exposed in the `Filters` section '
            'of the explore view.'),
        'type': _(
            'The data type that was inferred by the database. '
            'It may be necessary to input a type manually for '
            'expression-defined columns in some cases. In most case '
            'users should not need to alter this.'),
        'expression': utils.markdown(
            'a valid SQL expression as supported by the underlying backend. '
            'Example: `substr(name, 1, 1)`', True),
        'python_date_format': utils.markdown(Markup(
            'The pattern of timestamp format, use '
            '<a href="https://docs.python.org/2/library/'
            'datetime.html#strftime-strptime-behavior">'
            'python datetime string pattern</a> '
            'expression. If time is stored in epoch '
            'format, put `epoch_s` or `epoch_ms`. Leave `Database Expression` '
            'below empty if timestamp is stored in '
            'String or Integer(epoch) type'), True),
        'database_expression': utils.markdown(
            'The database expression to cast internal datetime '
            'constants to database date/timestamp type according to the DBAPI. '
            'The expression should follow the pattern of '
            '%Y-%m-%d %H:%M:%S, based on different DBAPI. '
            'The string should be a python string formatter \n'
            "`Ex: TO_DATE('{}', 'YYYY-MM-DD HH24:MI:SS')` for Oracle "
            'Superset uses default expression based on DB URI if this '
            'field is blank.', True),
    }
    label_columns = {
        'column_name': _('Column'),
        'verbose_name': _('Verbose Name'),
        'description': _('Description'),
        'groupby': _('Groupable'),
        'filterable': _('Filterable'),
        'table': _('Table'),
        'count_distinct': _('Count Distinct'),
        'sum': _('Sum'),
        'min': _('Min'),
        'max': _('Max'),
        'expression': _('Expression'),
        'is_dttm': _('Is temporal'),
        'python_date_format': _('Datetime Format'),
        'database_expression': _('Database Expression'),
        'type': _('Type'),
    }


appbuilder.add_view_no_menu(TableColumnInlineView)


class SqlMetricInlineView(CompactCRUDMixin, SupersetModelView):  # noqa
    datamodel = SQLAInterface(models.SqlMetric)

    list_title = _('List Metrics')
    show_title = _('Show Metric')
    add_title = _('Add Metric')
    edit_title = _('Edit Metric')

    list_columns = ['metric_name', 'verbose_name', 'metric_type']
    edit_columns = [
        'metric_name', 'description', 'verbose_name', 'metric_type',
        'expression', 'table', 'd3format', 'is_restricted', 'warning_text']
    description_columns = {
        'expression': utils.markdown(
            'a valid SQL expression as supported by the underlying backend. '
            'Example: `count(DISTINCT userid)`', True),
        'is_restricted': _('Whether the access to this metric is restricted '
                           'to certain roles. Only roles with the permission '
                           "'metric access on XXX (the name of this metric)' "
                           'are allowed to access this metric'),
        'd3format': utils.markdown(
            'd3 formatting string as defined [here]'
            '(https://github.com/d3/d3-format/blob/master/README.md#format). '
            'For instance, this default formatting applies in the Table '
            'visualization and allow for different metric to use different '
            'formats', True,
        ),
    }
    add_columns = edit_columns
    page_size = 500
    label_columns = {
        'metric_name': _('Metric'),
        'description': _('Description'),
        'verbose_name': _('Verbose Name'),
        'metric_type': _('Type'),
        'expression': _('SQL Expression'),
        'table': _('Table'),
        'd3format': _('D3 Format'),
        'is_restricted': _('Is Restricted'),
        'warning_text': _('Warning Message'),
    }

    def post_add(self, metric):
        if metric.is_restricted:
            security.merge_perm(sm, 'metric_access', metric.get_perm())

    def post_update(self, metric):
        if metric.is_restricted:
            security.merge_perm(sm, 'metric_access', metric.get_perm())


appbuilder.add_view_no_menu(SqlMetricInlineView)


class TableModelView(DatasourceModelView, DeleteMixin):  # noqa
    datamodel = SQLAInterface(models.SqlaTable)

    list_title = _('List Tables')
    show_title = _('Show Table')
    add_title = _('Add Table')
    edit_title = _('Edit Table')

    list_columns = [
        'link', 'database',
        'changed_by_', 'modified']
    order_columns = ['modified']
    add_columns = ['database', 'schema', 'table_name']
    edit_columns = [
        'table_name', 'sql', 'filter_select_enabled', 'slices',
        'fetch_values_predicate', 'database', 'schema',
        'description', 'owner',
        'main_dttm_col', 'default_endpoint', 'offset', 'cache_timeout']
    show_columns = edit_columns + ['perm']
    related_views = [TableColumnInlineView, SqlMetricInlineView]
    base_order = ('changed_on', 'desc')
    search_columns = (
        'database', 'schema', 'table_name', 'owner',
    )
    description_columns = {
        'slices': _(
            'The list of slices associated with this table. By '
            'altering this datasource, you may change how these associated '
            'slices behave. '
            'Also note that slices need to point to a datasource, so '
            'this form will fail at saving if removing slices from a '
            'datasource. If you want to change the datasource for a slice, '
            "overwrite the slice from the 'explore view'"),
        'offset': _('Timezone offset (in hours) for this datasource'),
        'table_name': _(
            'Name of the table that exists in the source database'),
        'schema': _(
            'Schema, as used only in some databases like Postgres, Redshift '
            'and DB2'),
        'description': Markup(
            'Supports <a href="https://daringfireball.net/projects/markdown/">'
            'markdown</a>'),
        'sql': _(
            'This fields acts a Superset view, meaning that Superset will '
            'run a query against this string as a subquery.',
        ),
        'fetch_values_predicate': _(
            'Predicate applied when fetching distinct value to '
            'populate the filter control component. Supports '
            'jinja template syntax. Applies only when '
            '`Enable Filter Select` is on.',
        ),
        'default_endpoint': _(
            'Redirects to this endpoint when clicking on the table '
            'from the table list'),
        'filter_select_enabled': _(
            "Whether to populate the filter's dropdown in the explore "
            "view's filter section with a list of distinct values fetched "
            'from the backend on the fly'),
    }
    base_filters = [['id', DatasourceFilter, lambda: []]]
    label_columns = {
        'slices': _('Associated Slices'),
        'link': _('Table'),
        'changed_by_': _('Changed By'),
        'database': _('Database'),
        'changed_on_': _('Last Changed'),
        'filter_select_enabled': _('Enable Filter Select'),
        'schema': _('Schema'),
        'default_endpoint': _('Default Endpoint'),
        'offset': _('Offset'),
        'cache_timeout': _('Cache Timeout'),
        'table_name': _('Table Name'),
        'fetch_values_predicate': _('Fetch Values Predicate'),
        'owner': _('Owner'),
        'main_dttm_col': _('Main Datetime Column'),
        'description': _('Description'),
    }

    def pre_add(self, table):
        with db.session.no_autoflush:
            table_query = db.session.query(models.SqlaTable).filter(
                models.SqlaTable.table_name == table.table_name,
                models.SqlaTable.schema == table.schema,
                models.SqlaTable.database_id == table.database.id)
            if db.session.query(table_query.exists()).scalar():
                raise Exception(
                    get_datasource_exist_error_mgs(table.full_name))

        # Fail before adding if the table can't be found
        if not table.database.has_table(table):
            raise Exception(_(
                'Table [{}] could not be found, '
                'please double check your '
                'database connection, schema, and '
                'table name').format(table.name))

    def post_add(self, table, flash_message=True):
        table.fetch_metadata()
        security.merge_perm(sm, 'datasource_access', table.get_perm())
        if table.schema:
            security.merge_perm(sm, 'schema_access', table.schema_perm)

        if flash_message:
            flash(_(
                'The table was created. '
                'As part of this two phase configuration '
                'process, you should now click the edit button by '
                'the new table to configure it.'), 'info')

    def post_update(self, table):
        self.post_add(table, flash_message=False)

    def _delete(self, pk):
        DeleteMixin._delete(self, pk)

    @expose('/edit/<pk>', methods=['GET', 'POST'])
    @has_access
    def edit(self, pk):
        """Simple hack to redirect to explore view after saving"""
        resp = super(TableModelView, self).edit(pk)
        if isinstance(resp, basestring):
            return resp
        return redirect('/superset/explore/table/{}/'.format(pk))

    @action(
        'refresh',
        __('Refresh Metadata'),
        __('Refresh column metadata'),
        'fa-refresh')
    def refresh(self, tables):
        for t in tables:
            t.fetch_metadata()
        msg = _(
            'Metadata refreshed for the following table(s): %(tables)s',
            tables=', '.join([t.table_name for t in tables]))
        flash(msg, 'info')
        return redirect('/tablemodelview/list/')


appbuilder.add_view(
    TableModelView,
    'Tables',
    label=__('Tables'),
    category='Sources',
    category_label=__('Sources'),
    icon='fa-table',)

appbuilder.add_separator('Sources')