import logging

from unittest import TestCase, TestSuite, TextTestRunner
from csv import reader
from glob import glob
from json import loads as jloads
from os import environ, path

from tests import TEST_DATA_DIR, reload_tables
from scriptshifter.trans import transliterate
import scriptshifter.tables


logger = logging.getLogger(__name__)


class TestTrans(TestCase):
    """
    Test S2R transliteration.

    Modified test case class to run independent tests for each CSV row.

    TODO use a comprehensive sample table and report errors for unsupported
    languages.
    """

    maxDiff = None

    def sample_s2r(self):
        """
        Test S2R transliteration for one CSV sample.

        This function name won't start with `test_` otherwise will be
        automatically run without parameters.
        """
        config = scriptshifter.tables.load_table(self.tbl)
        if "script_to_roman" in config:
            txl = transliterate(
                    self.script, self.tbl,
                    capitalize=self.options.get("capitalize", False),
                    options=self.options)[0]
            self.assertEqual(
                    txl, self.roman,
                    f"S2R transliteration error for {self.tbl}!\n"
                    f"Original: {self.script}")

    def sample_r2s(self):
        """
        Test R2S transliteration for one CSV sample.

        This function name won't start with `test_` otherwise will be
        automatically run without parameters.
        """
        config = scriptshifter.tables.load_table(self.tbl)
        if "roman_to_script" in config:
            txl = transliterate(
                    self.roman, self.tbl,
                    t_dir="r2s",
                    capitalize=self.options.get("capitalize", False),
                    options=self.options)[0]
            self.assertEqual(
                    txl, self.script,
                    f"R2S transliteration error for {self.tbl}!\n"
                    f"Original: {self.roman}")


def make_suite():
    """
    Build parametrized test cases.
    """
    if "TXL_CONFIG_TABLE_DIR" in environ:
        del environ["TXL_CONFIG_TABLE_DIR"]
    reload_tables()

    suite = TestSuite()

    for fpath in glob(path.join(TEST_DATA_DIR, "script_samples", "*.csv")):
        with open(fpath, newline="") as fh:
            csv = reader(fh)
            for row in csv:
                if len(row[0]):
                    # Inject transliteration info in the test case.
                    for tname in ("sample_s2r", "sample_r2s"):
                        tcase = TestTrans(tname)
                        tcase.tbl = row[0]
                        tcase.script = row[1].strip()
                        tcase.roman = row[2].strip()
                        tcase.options = jloads(row[3]) if len(row[3]) else {}
                        suite.addTest(tcase)

    return suite


TextTestRunner().run(make_suite())