#!/usr/bin/env python3

# From: https://gist.github.com/varunagrawal/2b93c5dc721520ff6876e940c420ab05
# This hooks script logs any finished tasks currently in the todo.txt file
# pointed to by its settings.
# The on-exit event is triggered once, after all processing is complete.

import re
import os
import sys
from subprocess import Popen, PIPE, check_output
import options as opts
import json
from datetime import datetime

TODAY = datetime.today().strftime("%Y-%m-%d")


def get_todo_block_date(line, todo_block_title):
    result = re.search(
        rf"^\[(\d{{4}}-\d{{2}}-\d{{2}}).*\] ({re.escape(todo_block_title)}$)?",
        line,
    )
    # we are entering todotxt data block
    if result and result[2]:
        return result[1]
    # we enter block but not one for todotxt
    elif result and not result[2]:
        return False
    # nothing changed, we didn't cross a date line
    return "same"


def process_file(options):
    fname = options.jrnl_fname
    lines_to_delete = []
    today_exists = False
    with open(fname) as file:
        line_number = 0
        for line in file:
            line_number += 1

            todo_block = get_todo_block_date(line, options.todo_block_title)
            if todo_block == False:
                curdate = ""
                continue
            if todo_block != "same":
                curdate = todo_block
                continue
            if not curdate:
                continue

            if handle_completed_tasks(line, curdate, options):
                lines_to_delete.append(line_number)

            if handle_open_tasks(line, curdate, options):
                lines_to_delete.append(line_number)

            if is_today(curdate):
                today_exists = True

        if lines_to_delete:
            delete_lines_from_file(fname, lines_to_delete, options.dryrun)

        if not today_exists:
            add_today(fname, options)


def handle_completed_tasks(line, date, options):
    completed_task = re.search(
        rf"^{options.regex_task_completed} ((?:\([A-D]\))? ?.*)$",
        line,
    )
    if completed_task and options.taskwarrior_log_completed:
        log_completed_to_taskwarrior(completed_task[1], date, options)
        return True
    return False


def log_completed_to_taskwarrior(task_string, date, options):
    overrides = options.taskwarrior_overrides
    cmd = [
        "task",
        *overrides,
        "log",
        task_string,
        f"entry:{date}",
        f"end:{date}",
        get_prio_string(task_string),
    ]
    if options.dryrun:
        print(cmd)
        return
    Popen(cmd)


def handle_open_tasks(line, date, options):
    completed_task = re.search(
        rf"^{options.regex_task_incomplete} ((?:\([A-D]\))? ?.*)$",
        line,
    )
    if completed_task and options.taskwarrior_add_incomplete:
        add_incomplete_to_taskwarrior(completed_task[1], date, options)
        return True
    return False


def add_incomplete_to_taskwarrior(task_string, date, options):
    overrides = options.taskwarrior_overrides
    cmd = [
        "task",
        *overrides,
        "add",
        task_string,
        f"entry:{date}",
        f"scheduled:{date}",
        get_prio_string(task_string),
    ]
    if options.dryrun:
        print(cmd)
        return
    Popen(cmd)


def get_prio_string(task_string):
    prio = re.search(r"^\(([ABC])\) (.*)$", task_string)
    prio_string = ""
    if prio:
        task_string = prio[2]
        if prio[1] == "A":
            prio_string = "prio:H"
        elif prio[1] == "B":
            prio_string = "prio:M"
        elif prio[1] == "C":
            prio_string = "prio:L"
    return prio_string


def delete_lines_from_file(fname, lines, dryrun):
    if dryrun:
        print(f"deleting lines: {lines}")
        return

    cur_line = 0
    repl_file = fname + ".bak"
    with open(fname) as read_file, open(repl_file, "w") as write_file:
        for line in read_file:
            cur_line += 1
            if lines and cur_line == lines[0]:
                lines.pop(0)
                continue
            write_file.write(line)
    os.rename(repl_file, fname)


def is_today(cur_date):
    if cur_date == TODAY:
        return True
    return False


def add_today(fname, options):
    cmd = ["task", "+TODAY or +OVERDUE", "export"]
    tasks = f"[{TODAY} 21:00] {options.todo_block_title}\n"
    for task in json.loads(check_output(cmd)):
        tasks += f"{task['description']}\n"

    if options.dryrun:
        print(f"\nWRITING TODAY:\n{tasks}")
        return

    repl_file = fname + ".bak"
    with open(fname) as read_file, open(repl_file, "w") as write_file:
        write_file.write(tasks + "\n")
        for line in read_file:
            write_file.write(line)
    os.rename(repl_file, fname)


if __name__ == "__main__":
    process_file(opts.init())
    sys.exit(0)