import sys
import os

# ==================================================
# File locations
# ==================================================
studFile = "./students"      # These are PARALLEL files
emailFile = "./emails"       # These are PARALLEL files
projDir = "."

# total arguments
n = len(sys.argv)

if (n != 2):
    print(f"\n   Usage: python {sys.argv[0]} projName \n")
    print("\nThis program sends out grades to all receivers in emailFile\n")
    exit(0)

proj = sys.argv[1]
subject = "Your grade for assignment " + proj

if (not os.path.isfile(emailFile)):
    print(f"\n   Error: email file '{emailFile}' does NOT exists\n")
    exit(0)

if (not os.path.isfile(studFile)):
    print(f"\n   Error: studentfile '{studFile}' does NOT exists\n")
    exit(0)


# ============================================
# Read students
# ============================================
with open(studFile, "r") as inp:
    lines = inp.readlines()
# print(x)

studs = list(x.strip() for x in lines)
print(studs)

# ============================================
# Read emails
# ============================================
with open(emailFile, "r") as inp:
    lines = inp.readlines()
# print(x)

emails = list(x.strip() for x in lines)
print(emails)

studEmails = list(zip(studs, emails))
print(studEmails)

for e in studEmails:
    inpFile = projDir + "/" + proj + "/" + e[0]

    print(f"Sending '{inpFile}' to '{e[1]}'")

    cmd = "python sendmail.py "    
    cmd = cmd + str(e[1]) + " " + str(inpFile) + " '" + str(subject) + "'"

    print(f"{cmd}")         # DEBUG: show command
#   os.system(cmd)