from collections import namedtuple
from csv import QUOTE_ALL
from unittest import TestCase

import pytest

from bonobo import CsvReader, CsvWriter
from bonobo.constants import EMPTY
from bonobo.util.testing import FilesystemTester, BufferingNodeExecutionContext, WriterTest, ConfigurableNodeTest, \
    ReaderTest

csv_tester = FilesystemTester('csv')
csv_tester.input_data = 'a,b,c\na foo,b foo,c foo\na bar,b bar,c bar'

defaults = {'lineterminator': '\n'}

incontext = ConfigurableNodeTest.incontext


def test_read_csv_from_file_kwargs(tmpdir):
    fs, filename, services = csv_tester.get_services_for_reader(tmpdir)

    with BufferingNodeExecutionContext(CsvReader(filename, **defaults), services=services) as context:
        context.write_sync(EMPTY)

    assert context.get_buffer_args_as_dicts() == [{
        'a': 'a foo',
        'b': 'b foo',
        'c': 'c foo',
    }, {
        'a': 'a bar',
        'b': 'b bar',
        'c': 'c bar',
    }]


###
# CSV Readers / Writers
###


class Csv:
    extension = 'csv'
    ReaderNodeType = CsvReader
    WriterNodeType = CsvWriter


L1, L2, L3, L4 = ('a', 'hey'), ('b', 'bee'), ('c', 'see'), ('d', 'dee')
LL = ('i', 'have', 'more', 'values')


class CsvReaderTest(Csv, ReaderTest, TestCase):
    input_data = '\n'.join((
        'id,name',
        '1,John Doe',
        '2,Jane Doe',
        ',DPR',
        '42,Elon Musk',
    ))

    def check_output(self, context, *, prepend=None):
        out = context.get_buffer()
        assert out == (prepend or list()) + [
            ('1', 'John Doe'),
            ('2', 'Jane Doe'),
            ('', 'DPR'),
            ('42', 'Elon Musk'),
        ]

    @incontext()
    def test_nofields(self, context):
        context.write_sync(EMPTY)
        context.stop()
        self.check_output(context)
        assert context.get_output_fields() == ('id', 'name')

    @incontext(output_type=tuple)
    def test_output_type(self, context):
        context.write_sync(EMPTY)
        context.stop()
        self.check_output(context, prepend=[('id', 'name')])

    @incontext(
        output_fields=(
            'x',
            'y',
        ), skip=1
    )
    def test_output_fields(self, context):
        context.write_sync(EMPTY)
        context.stop()
        self.check_output(context)
        assert context.get_output_fields() == ('x', 'y')

    @incontext(quoting=QUOTE_ALL)
    def test_quoting(self, context):
        context.write_sync(EMPTY)
        context.stop()
        self.check_output(context)
        assert context.get_output_fields() == ('id', 'name')


class CsvWriterTest(Csv, WriterTest, TestCase):
    @incontext()
    def test_fields(self, context):
        context.set_input_fields(['foo', 'bar'])
        context.write_sync(('a', 'b'), ('c', 'd'))
        context.stop()

        assert self.readlines() == (
            'foo,bar',
            'a,b',
            'c,d',
        )

    @incontext()
    def test_fields_from_type(self, context):
        context.set_input_type(namedtuple('Point', 'x y'))
        context.write_sync((1, 2), (3, 4))
        context.stop()

        assert self.readlines() == ('x,y', '1,2', '3,4')

    @incontext()
    def test_nofields_multiple_args(self, context):
        # multiple args are iterated onto and flattened in output
        context.write_sync((L1, L2), (L3, L4))
        context.stop()

        assert self.readlines() == (
            'a,hey',
            'b,bee',
            'c,see',
            'd,dee',
        )

    @incontext()
    def test_nofields_multiple_args_length_mismatch(self, context):
        # if length of input vary, then we get a TypeError (unrecoverable)
        with pytest.raises(TypeError):
            context.write_sync((L1, L2), (L3, ))

    @incontext()
    def test_nofields_single_arg(self, context):
        # single args are just dumped, shapes can vary.
        context.write_sync((L1, ), (LL, ), (L3, ))
        context.stop()

        assert self.readlines() == (
            'a,hey',
            'i,have,more,values',
            'c,see',
        )

    @incontext()
    def test_nofields_empty_args(self, context):
        # empty calls are ignored
        context.write_sync(EMPTY, EMPTY, EMPTY)
        context.stop()

        assert self.readlines() == ()