#!/usr/bin/env python3
import argparse
import sys
import os
import atexit

def parseYN(s, default = False):
    if default == False:
        return s.lower() in ['true', '1', 't', 'y', 'yes', 'yeah', 'yup', 'certainly', 'uh-huh', 'go for it']
    else: return not s.lower() in ['false', '0', 'f', 'n', 'no', 'nah', 'nope', 'certainly not', 'nuh-huh', 'bugger that']

def getYN(b):
    return "yes" if b else "no"

def parseConfig(args=None,config_path=None):
    # default settings
    if args:
        config = { "no_count": args.no_count, "mailbox_symbol": "📬", "mutt": args.mutt, "ssl": True, "server": "", "port": 0, "user": "", "password": "" }
    if not config_path:
        config_path = args.config
    filename = os.path.expanduser(config_path)
    # if we have a config file, parse it
    if os.path.exists(filename):
        with open(filename) as f:
            for line in f:
                line = line.strip()
                if len(line) == 0: continue
                if line[0] == "#": continue # skip commented lines
                kv = line.strip().split("=",1);
                kv[0] = kv[0].replace("-","_");
                if len(kv)==1:
                    continue
                try:
                    # load types appropriately
                    if type(config[kv[0]]) == type(True):
                        config[kv[0]] = (kv[1] == 'True') # cast to boolean
                    elif type(config[kv[0]]) == type(1):
                        config[kv[0]] = int(kv[1])
                    else:
                        config[kv[0]] = kv[1]
                except:
                    print("uvgotmail: unknown option: "+kv[0])
            # sort booleans
    # otherwise, prompt the user to create one
    elif(args.daemon and not args.mutt):
        if parseYN(input("uvgotmail: no config file exists. create now? [Y/n] "),default=True):
            createConfig(config_path, config,args)
            return
        else:
            print("uvgotmail: failed to start.")
            exit(1)

    # if no port is specified, use default
    if config["port"] == 0:
        config["port"] = 993 if config["ssl"] else 143

    # read muttrc if we should do that
    if config["mutt"] == True:
        try: # try both locations of dotfile
            with open(os.path.expanduser("~/.muttrc")) as f:
                muttrc = f.readlines();
        except Exception as e:
            try:
                with open(os.path.expanduser("~/.mutt/muttrc")) as f:
                    muttrc = f.readlines();
            except Exception as f:
                print(e)
                print(f)
                print("uvgotmail: could not read your muttrc. does it exist?")
                exit(1)
        for line in muttrc:
            line = line.strip()
            if len(line) == 0:
                continue
            if line[0] == "#": continue # skip commented lines
            if "set imap_user" in line:
                config["user"]=line.split("=",1)[1].strip().replace('"','')
            if "set imap_pass" in line:
                # voodoo to remove "s only from the start and end of password, if present
                config["password"]="".join(line.split("=",1)[1].strip().replace('"','',1).rsplit('"',1))
            if "set folder" in line:
                folder = line.split("=",1)[1].strip().replace('"','')
                if folder.startswith("imaps"):
                    config["ssl"] = True
                server_port = folder.split("//")[1].split(":")
                config["server"] = server_port[0]
                config["port"] = server_port[1]

    # make sure at least a server and a username are set
    if config["server"] == "" or config["user"] == "":
        print("uvgotmail: failed to start. no imap server or username specified.")
    return config

def createConfig(config_path, config,args):
    # helper function to deal with setting each item
    def getInput(prompt, existing):
        boolean = type(existing) == type(True)
        existing_str = getYN(existing) if boolean else str(existing)
        inp = input(prompt + " [" + existing_str + "]: ")
        if inp=="":
            return existing
        if boolean:
            inp = parseYN(inp)
        return inp

    import datetime
    config_path = getInput("where do you want to put your config file? (directory tree will be created if necessary)",config_path)
    config["mailbox_symbol"] = getInput("what symbol do you want to display when there are unread messages?",config["mailbox_symbol"])
    config["no_count"] = not getInput("do you want to display the number of unread messages?",not config["no_count"])
    config["mutt"] = getInput("do you want to use your muttrc for the server settings?",config["mutt"])
    if not config["mutt"]:
        config["server"] = getInput("what's your IMAP server?",config["server"])
        config["ssl"] = getInput("are you using ssl? it's " + str(datetime.date.today().year) +" so you really should be",config["ssl"])
        if(config["port"] == ""):
            config["port"] = 993 if config["ssl"] else 143
        config["port"] = getInput("what's the IMAP port?",config["port"])
        config["user"]= getInput("what's your IMAP username?",config["user"])
        config["password"] = getInput("what's your IMAP password?",config["password"])
    # confirm all this is correct; if not go round again
    if(not parseYN(input("is this correct? [y/N] "))):
        createConfig(config_path,config)
        return
    else:
        from pathlib import Path
        while True:
            path =  Path(os.path.expanduser(config_path))
            try:
                path.parent.mkdir(parents=True, exist_ok=True,mode=0o700)
                path.touch(mode=0o600,exist_ok=False)
                with path.open(mode="w") as f:
                    for i,key in enumerate(config):
                        f.write(key+"="+str(config[key])+("\n" if i < len(config)-1 else ""))
                print("config file created; starting daemon")
                parseConfig(config_path = config_path,args=args)
                break
            except Exception as e:
                if not parseYN(input("failed to create config file: " + str(e) +"... retry? [Y/n] ")):
                    exit(1)
                config_path = getInput("where do you want to put your config file? (directory tree will be created if necessary)",config_path)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("--daemon", help="run in daemon mode (put this at end of .bashrc)", action="store_true")
    parser.add_argument("--config", help="specify config file (default: ~/.uvgotmail/config)", default="~/.uvgotmail/config")
    parser.add_argument("--mutt", help="use existing mutt configuration (experimental)", action="store_true")
    parser.add_argument("--check", help="run in check mode (put this in PS1)", action="store_true")
    parser.add_argument("--no-count", help="don't display how many unread messages there are", action="store_true")
    parser.add_argument("--mailbox-symbol", help="specify a string instead of the mailbox emoji",default="")
    parser.add_argument("--debug", help="print errors",action="store_true")
    args = parser.parse_args()


    global config
    config = parseConfig(args);

    config["debug"] = args.debug

    if(args.daemon == args.check):
        parser.print_help()
        sys.exit(0)
    if(args.daemon):
        daemon()
    else:
        check()

def check():
    filename = os.path.expanduser('~/.uvgotmail/unread')
    if os.path.exists(filename):
        with open(filename) as f:
            unread = f.read();
            if unread != '':
                unread = int(unread)
            else:
                unread = 0
        if unread == 0:
            sys.exit(0)
        pre = ""
        if(unread > 1 and config["no_count"] == False):
            pre = "("+str(unread)+") "
        print(pre+config["mailbox_symbol"],end=' ')
    # if there's no unread count file, just exit quietly

def writeUnreadFile(unseen):
    try:
        with open(os.path.expanduser('~/.uvgotmail/unread'),'w') as f:
            if len(unseen) == 0:
                f.write('')
            elif(len(unseen) > 1 and config["no_count"] == False):
                f.write("("+str(len(unseen))+") "+config["mailbox_symbol"]+' ')
            else:
                f.write(config["mailbox_symbol"]+' ')
    except Exception as e:
        if config["debug"]: print(e)
        print("uvgotmail: could not write to unread file")

# we're implementing this in a disgusting way. i'm sorry.
import time
import socket
import re

def daemon():


    # first check if daemon is already running
    pidfile = os.path.expanduser('~/.uvgotmail/.run.pid')
    if os.path.exists(pidfile):
        with open(pidfile) as f:
            pid = f.read()
            if pid != '':
                pid = int(pid)
            else:
                pid = 0
            running_cmd = os.popen("ps -p" + str(pid) +" -o command").read()
            current_cmd = os.popen("ps -p" + str(os.getpid()) +" -o command").read()
            if running_cmd == current_cmd or os.path.basename(sys.argv[0]) in running_cmd:
                # the process is running; we don't need to start up at all
                exit(0)
    try:
        with open(pidfile,'w') as f:
            f.write(str(os.getpid()))
        def delPid(pidfile):
            os.remove(pidfile)
        atexit.register(delPid,pidfile)
    except:
        print("uvgotmail: failed to write to PID file")
        exit(1)

    # main loop
    import time
    import imaplib
    IMAP4_func = imaplib.IMAP4_SSL if config["ssl"] else imaplib.IMAP4
    while True:
        try:
            with IMAP4_func(config["server"],config["port"]) as conn:
                conn.login(user=config["user"],password=config["password"])
                conn.select(mailbox='INBOX',readonly=True)
                typ,msgnums = conn.search(None, "UNSEEN");
                unseen = [n.decode() for n in msgnums if n != b'']
                if len(unseen)>0:
                    unseen=unseen[0].split(' ')
                else:
                    unseen=[]
                if config["debug"]: print(unseen)
                writeUnreadFile(unseen)
                conn.logout()
            time.sleep(30)

        except Exception as e:
            if config["debug"]:
                print(e)
            print("uvgotmail: failed to log in to server. dumping config.")
            print(config);
            exit(1)

# handle ctrl+c gracefully
if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        print('Interrupted')
        exit(130)