import sys
import re

if len(sys.argv) < 4:
    print("Expected: ./extract_db.py [sql file name] [database name] [new file name]")
    sys.exit(-1)

with open(sys.argv[1], 'rb') as f_in:
    create_db = re.compile(bytes("CREATE DATABASE .*?`{}`".format(sys.argv[2]), encoding='utf-8'))
    create_stmt = re.compile(bytes("CREATE DATABASE", encoding='utf-8'))
    in_section = False
    line_count = 0
    with open(sys.argv[3], 'wb') as f_out:
        for line in f_in:
            if not in_section:
                if create_db.match(line):
                    print("Found the section where the db def starts")
                    in_section = True
                    f_out.write(line)
                    line_count += 1
            else:
                if not create_stmt.match(line):
                    f_out.write(line)
                    line_count += 1
                else:
                    print("Cut out {} lines that define the {} database.".format(line_count, sys.argv[2]))
                    f_out.close()
                    f_in.close()
                    sys.exit(0)
    print("Wasn't able to find a definition for a database of that name")