import csv
import sys

# Ensure correct usage
if len(sys.argv) != 3:
    sys.exit("Usage: python dna.py database.csv sequence.txt")

# setting array with search STRs
str_search_big = ["AGATC", "TTTTTTCT", "AATG", "TCTAG", "GATA", "TATC", "GAAA", "TCTG"]
str_search_small = ["AGATC", "AATG", "TATC"]

if sys.argv[1].count("small") > 0:
    str_search = str_search_small
else:
    str_search = str_search_big

search_len = len(str_search)


# searches for longest repeated STR sequence
def str_repeat(seq, dna_str, dbcount):
    match_count = 0
    pattern = dna_str
    while dna_str in seq:
        match_count += 1
        dna_str += pattern
    # if longest sequence doesn't match with DB, remove this person from match list
    if match_count != int(dbcount):
        try:
            match.remove(key["name"])
        except:
            return


# initialiaze variables
filename = sys.argv[1]
database = []
match = []

#   Read database into memory from file
with open(filename) as file:
    reader = csv.DictReader(file)
    for row in reader:
        database.append(row)
        # populate match list with all possible names
        match.append(row["name"])
# get sequence string from txt
sequence = open(sys.argv[2], "r")
sequence = sequence.read()
# loop through all searchable STRs
for i in range(search_len):
    # loop through all database entries
    for key in database:
        str_repeat(sequence, str_search[i], key[str_search[i]])

# if only one person is left at the end, print his name
if len(match) == 1:
    print(match[0])
else:
    print("No match")