import getpass, imaplib, email, re
import numbers
import decimal





def connect():

    username = input("Username: ")
    password = input("Password: ")

    print("Logging into mail server...")
    M = imaplib.IMAP4_SSL('imap.gmail.com', 993)
    M.login(username, password)
    M.select('inbox')

    return M

def get_new_reports(M):

    print("Looking at mailbox for unseen reports...")
    (retcode, messages) = M.search(None, '(UNSEEN)', 'SUBJECT "Expense Report"')
    num_messages =  len(messages[0].split())
    print("New Reports: ", num_messages)

    if retcode == 'OK' and num_messages > 0:
        return messages
    else:
        return None


def parse_reports(messages, M):
    n = 1
    for num in messages[0].split():
        print("Fetching report: ", n)
        typ, data = M.fetch(num, '(RFC822)')
        raw_email = data[0][1];
        n = n + 1
        print("Decoding...")
        raw_email_string = raw_email.decode('utf-8')
        # converts byte literal to string removing b''
        email_message = email.message_from_string(raw_email_string)


        if (email_message.is_multipart()):
            print("multipart")
        else:
            print("not multipart")

        for part in email_message.walk():
                        if part.get_content_type() == "text/plain": # ignore attachments/html
                                body = str(part).replace("Content-Type: text/plain; charset=UTF-8", "");
                                print("Parsing...")
                                process(body);
    i = input("")
    M.close()
    M.logout()

def process(body):

    expense_report = Report();
        # Use a hashmap to hold entries to map account_num --> list [start_date, end_date, amount, vender, requester] all under the same project number
    entries = dict();
    sections = body.split("------------------------------")
    # ----variables global to each report ---
    project_num = '';
    report_name = '';
    employee_name = '';
    last_code = None;
    # ---------------------------------------
    for sub in sections:
       # If Expense report section, grab project # ------------
        if ("Expense Report" in sub):
            expense_report.project_num = re.findall( r'\d+\.*\d*', sub )[0]
        #   print("Project #", expense_report.project_num)
           # get Report name by finding index
            i = sub.find("Report Name :") + 14
            j = i
            while(sub[j] != '\n'):
                j = j + 1
            expense_report.report_name = sub[i:j]
        # If Exployee Name section, grab Employee name ----------
        if ("Employee Name :" in sub):
            i = sub.find("Employee Name :")+16
            #get index of 'Employee Name' substring
            j = i
            while(sub[j] != '\n'):
                #concatenate employee name
                j = j + 1
            expense_report.employee_name = sub[i:j]
            #split by transaction

        #divide up by expense
        for expense in sub.split("Expense Type"):
            #get account code unique to expense set
            account_code = ''
            result = (re.findall(r"\D(\d{5})\D", expense))

            if result:
                #get account code -------------------------------
                account_code = int(result[0])
                #filter out strange results
                if (account_code < 6000 or account_code > 69999):
                    continue
            #   print("Account Code Group:", account_code)

                #get [Expense Type] -----------------------------
                if ("Amount" in expense):
                    i = expense.find("Amount") + 20
                    j = i
                while (expense[j] != "\n"):
                    j = j + 1
                expense_type = expense[i:j]
            #   print("Expense_type: ", expense_type)

                #get allocations -------------------------------
                for transaction in expense.split("Allocations"):
                    amount = '';
                    i = -1
                    j = -1
                    i = transaction.find("(")
                    j = transaction.find(")");
                    if (i < 0 or j < 0):
                        # if amount not found, continue to next iteration
                        continue
                    #set amount of allocation
                    amount = float(transaction[i+2:j])
                    #get date
                    result = re.search("([0-9]{2}\/[0-9]{2}\/[0-9]{4})", transaction)
                    date = ''
                    if result is not None:
                        date = result.group(1)
                #   print("Transaction Date: ", date)
                #   print("Transaction Amount: ", amount)

                    #make entry in dictionary
                    expense_report.allocate(account_code, expense_type, date, amount)

    print("---------New report entry ready--------")
    print("Project Number: ", expense_report.project_num)
    print("Start Date: ", expense_report.getFirstDate())
    print("Report name: ", expense_report.report_name)
    print("Requester: ", expense_report.employee_name)
    print("Approver: VP Administration")
    for key in expense_report.entries:
        print("Account Code: ", key, ", Date: ", expense_report.entries[key][0], ", Amount: ", expense_report.entries[key][1],  ", Expense Type: ", expense_report.entries[key][2])
    print("---------------------------------------")

class Report():
    print("New Report")
    def __init__(self):
        self.project_num = None    # instance variable unique to each instance
        self.report_name = None
        self.first_date = None
        self.employee_name = None
        self.entries = dict()
    def getFirstDate(self):
        if ("-" in self.report_name): # if date duration
            i = self.report_name.find("-");
            return self.report_name[0:i];
        i = self.report_name.find(" ");
        return self.report_name[0:i];
    def allocate(self, account_code, expense_type, date, amount):
    # check if we've already made an entry under this account code:
        if (account_code in self.entries):
            # we have, so just append the allocation
        #   print("Allocation already made for account code: ", account_code, "Appending new allocation: ", amount)
            self.entries[account_code][1] += amount;
        else:
            # we have not made an entry for this account code
        #   print("No entry present under account code: ", account_code, "adding new entry!")

            self.entries[account_code] = list()
            self.entries[account_code].append(date)
            self.entries[account_code].append(amount)
            self.entries[account_code].append(expense_type)

mailbox = connect();
reports = get_new_reports(mailbox);
# if reports is not None, parse
if(reports):
    parse_reports(reports, mailbox);