#!/usr/bin/env python3
import os
import sys
import re
import subprocess
import tempfile

suffixes = {"sub": ".txt",
            "note": ".md"}

def getItem(num):
    with open(os.getenv("TODO_FILE"), "r") as todoFile:
        return todoFile.readlines()[num-1]

def getSub(item):
    if "/:" not in item:
        return None
    try:
        sub = re.findall("[^ ]+/:[.A-Za-z0-9_]+", item)[0]
    except IndexError:
        return None
    return sub.split("/:")

def addSub(num, sub, edit=True):
    with open(os.getenv("TODO_FILE"), "r") as todoFile:
        lines = todoFile.readlines()
    print(getSub(lines[num-1]))
    if getSub(lines[num-1]) is not None and getSub(lines[num-1])[0] == sub:
        sys.exit("The item already has a sub \"" + sub + "\":" + "\n" + lines[num-1][:-1])
    if not os.path.exists(os.path.join(os.getenv("TODO_DIR"), sub)):
        os.mkdir(os.path.join(os.getenv("TODO_DIR"), sub))
    f, name = tempfile.mkstemp(suffixes[sub], "", os.path.join(os.getenv("TODO_DIR"), sub))
    lines[num-1] = lines[num-1][:-1] + " " + sub + "/:" + os.path.basename(name) + "\n"
    with open(os.getenv("TODO_FILE"), "w") as todoFile:
        todoFile.writelines(lines)
    if edit:
        editSub(num)

def editSub(num):
    sub = getSub(getItem(num))
    if sub is None:
        sys.exit("This item does not have a sub")
    editor = os.getenv("EDITOR")
    if editor is not None and editor != "":
        editor = editor.split()
    else:
        sys.exit("$EDITOR is unset, cannot edit")
    subprocess.call(editor + [os.path.join(os.getenv("TODO_DIR"), sub[0], sub[1])])

def showSub(item, indent=0, color=True):
    sub = getSub(item)
    if sub is None:
        sys.exit("This item does not have a sub")
    command = ["todo.sh", "listfile", os.path.join(sub[0], sub[1])]
    if not color:
        command.insert(1, "-p")
    p = subprocess.Popen(command, stdout=subprocess.PIPE)
    output = p.communicate()[0].decode("utf-8")
    output = '\n'.join(" "*indent + i for i in output.splitlines()[:-2]) + "\n"
    return output

def showAll(out=sys.stdout, color=True):
    command = ["todo.sh", "list"]
    if not color:
        command.insert(1, "-p")
    p = subprocess.Popen(command, stdout=subprocess.PIPE)
    lines = p.communicate()[0].decode("utf-8").splitlines()
    for line in lines:
        out.write(line + "\n")
        if getSub(line) is not None:
            out.write(showSub(line, indent=2, color=color))

def main(argv):
    if(argv[1] == "usage"):
        print("    sub")
        print("      list subs")
        print("    sub add [itemNum] [sub]")
        print("      add a sub [sub] to [itemNum]")
        print("    sub edit [itemNum]")
        print("      edit the sub in [itemNum]")
    elif len(argv) < 3:
        showAll()
    elif argv[2] == "add":
        if len(argv) != 5:
            sys.exit("Usage: " + argv[1] + " add [itemNum] [sub]")
        itemNum = int(argv[3])
        addSub(itemNum, argv[4])
    elif argv[2] == "edit":
        if len(argv) != 4:
            sys.exit("Usage: " + argv[1] + " edit [itemNum]")
        itemNum = int(argv[3])
        editSub(itemNum)
    else:
        sys.exit("Command not recognized")

if __name__ == '__main__':
    main(sys.argv)