from csv import reader
from difflib import ndiff
from json import loads as jloads
from logging import getLogger
from os import path

from scriptshifter.trans import transliterate
from tests import TEST_DATA_DIR

logger = getLogger(__name__)


def test_sample(dset):
    """
    Test an individual sample set and produce a human-readable report.

    Used outside of automated tests.

    @param dset (str): sample set name (without the .csv extension) found in
    the `data/script_samples` directory.
    """
    deltas = []
    dset_fpath = path.join(TEST_DATA_DIR, "script_samples", dset + ".csv")
    log_fpath = path.join(TEST_DATA_DIR, f"test_{dset}.log")

    with open(dset_fpath, newline="") as fh:
        csv = reader(fh)
        i = 1
        for row in csv:
            logger.info(f"CSV row #{i}")
            i += 1
            lang, script, rom = row[:3]
            if not lang:
                continue
            opts = jloads(row[3]) if len(row) > 3 and row[3] else {}
            trans, warnings = transliterate(
                    script, lang, t_dir="s2r",
                    capitalize=opts.get("capitalize"), options=opts)
            if (trans == rom):
                print(".", end="")
            else:
                print("F", end="")
                deltas.append((lang, script, ndiff([trans], [rom])))

    with open(log_fpath, "w") as fh:
        # If no deltas, just truncate the file.
        for lang, script, delta in deltas:
            fh.write(f"Language: {lang}\n")
            fh.write(f"Original: {script}\nDiff (result vs. expected):\n")
            for dline in delta:
                fh.write(dline.strip() + "\n")
            fh.write("\n\n")

    ct = len(deltas)
    if ct > 0:
        print(f"{ct} failed tests. See report at {log_fpath}")
    else:
        print("All tests passed.")