"""Testing dft"""

import os
import sqlite3
from io import BytesIO
from os.path import dirname
from os.path import join as pjoin

from ..testing import suppress_warnings

with suppress_warnings():
    from .. import dft

import unittest

import pytest

from .. import nifti1

# Shield optional package imports
from ..optpkg import optional_package

have_dicom = optional_package('pydicom')[1]
PImage, have_pil, _ = optional_package('PIL.Image')

data_dir = pjoin(dirname(__file__), 'data')


def setup_module():
    if os.name == 'nt':
        raise unittest.SkipTest('FUSE not available for windows, skipping dft tests')
    if not have_dicom:
        raise unittest.SkipTest('Need pydicom for dft tests, skipping')


class Test_DBclass:
    """Some tests on the database manager class that don't get exercised through the API"""

    def setup_method(self):
        self._db = dft._DB(fname=':memory:', verbose=False)

    def test_repr(self):
        assert repr(self._db) == "<DFT ':memory:'>"

    def test_cursor_conflict(self):
        rwc = self._db.readwrite_cursor
        statement = ('INSERT INTO directory (path, mtime) VALUES (?, ?)', ('/tmp', 0))
        with pytest.raises(sqlite3.IntegrityError):
            # Whichever exits first will commit and make the second violate uniqueness
            with rwc() as c1, rwc() as c2:
                c1.execute(*statement)
                c2.execute(*statement)


@pytest.fixture
def db(monkeypatch):
    """Build a dft database in memory to avoid cross-process races
    and not modify the host filesystem."""
    database = dft._DB(fname=':memory:')
    monkeypatch.setattr(dft, 'DB', database)
    return database


def test_init(db):
    dft.clear_cache()
    dft.update_cache(data_dir)
    # Verify a second update doesn't crash
    dft.update_cache(data_dir)


def test_study(db):
    # First pass updates the cache, second pass reads it out
    for base_dir in (data_dir, None):
        studies = dft.get_studies(base_dir)
        assert len(studies) == 1
        assert studies[0].uid == '1.3.12.2.1107.5.2.32.35119.30000010011408520750000000022'
        assert studies[0].date == '20100114'
        assert studies[0].time == '121314.000000'
        assert studies[0].comments == 'dft study comments'
        assert studies[0].patient_name == 'dft patient name'
        assert studies[0].patient_id == '1234'
        assert studies[0].patient_birth_date == '19800102'
        assert studies[0].patient_sex == 'F'


def test_series(db):
    studies = dft.get_studies(data_dir)
    assert len(studies[0].series) == 1
    ser = studies[0].series[0]
    assert ser.uid == '1.3.12.2.1107.5.2.32.35119.2010011420292594820699190.0.0.0'
    assert ser.number == '12'
    assert ser.description == 'CBU_DTI_64D_1A'
    assert ser.rows == 256
    assert ser.columns == 256
    assert ser.bits_allocated == 16
    assert ser.bits_stored == 12


def test_storage_instances(db):
    studies = dft.get_studies(data_dir)
    sis = studies[0].series[0].storage_instances
    assert len(sis) == 2
    assert sis[0].instance_number == 1
    assert sis[1].instance_number == 2
    assert sis[0].uid == '1.3.12.2.1107.5.2.32.35119.2010011420300180088599504.0'
    assert sis[1].uid == '1.3.12.2.1107.5.2.32.35119.2010011420300180088599504.1'


@unittest.skipUnless(have_pil, 'could not import PIL.Image')
def test_png(db):
    studies = dft.get_studies(data_dir)
    data = studies[0].series[0].as_png()
    im = PImage.open(BytesIO(data))
    assert im.size == (256, 256)


def test_nifti(db):
    studies = dft.get_studies(data_dir)
    data = studies[0].series[0].as_nifti()
    assert len(data) == 352 + 2 * 256 * 256 * 2
    h = nifti1.Nifti1Header(data[:348])
    assert h.get_data_shape() == (256, 256, 2)