import imaplib
from functools import wraps
from flask import Blueprint, render_template, request, flash, abort, make_response, redirect, url_for
from flask_login import login_required, current_user
from flask_wtf import FlaskForm
from wtforms import DateField, SelectField, SubmitField
from wtforms.validators import DataRequired
from time import strftime, strptime, mktime, localtime
from typing import List

from mailbox.email import Mail, HTML, PLAIN
from .page import get_page, get_max_page
from .logger import Logger


mailbox = Blueprint("mailbox", __name__)


class ToMailboxForm(FlaskForm):
    date = DateField("发信时间", description="信件发送时间", validators=[DataRequired("必须选择时间")])
    select = SelectField("文件夹", description="INBOX或其他文件夹", validators=[DataRequired("必须选择文件夹")])
    submit = SubmitField("查询")

    def __init__(self, select: list):
        super(ToMailboxForm, self).__init__()

        try:
            del select[select.index("INBOX")]
            select = ["INBOX"] + select
        except ValueError:
            pass


        self.select.choices = select
        self.select.coerce = str
        self.select.default = "INBOX"


def except_imap_error(func):
    @wraps(func)
    def new_func(*args, **kwargs):
        try:
            res = func(*args, **kwargs)
        except imaplib.IMAP4.error:
            flash("IMAP连接异常, 请重新尝试")
            return redirect(url_for("mailbox.mail_list_page"))
        else:
            return res
    return new_func


def __load_mailbox_page(mail_list, page, to_mail=None, date=None, select=None, next_date=None, last_date=None):
    if not to_mail:
        to_mail = ToMailboxForm(current_user.get_inbox_list())

    max_page = get_max_page(len(mail_list), 10)
    page_list = get_page("mailbox.mail_list_page", page, max_page, date=date, select=select)
    page_mail_list: List[Mail] = mail_list[(page - 1) * 10: page * 10]

    Logger.print_load_page_log(f"mail-list date:{date} select:{select}")
    return render_template("mailbox/mailbox.html",
                           to_mail=to_mail,
                           date=date,
                           select=select,
                           page_list=page_list,
                           page=page,
                           mail_list=page_mail_list,
                           max_page=max_page,
                           empty=(len(page_mail_list) == 0),
                           next_date=next_date,
                           last_date=last_date)


@mailbox.route("/")
@login_required
@except_imap_error
def mail_list_page():
    date = request.args.get("date", None, type=str)
    select = request.args.get("select", "INBOX", type=str)
    page = request.args.get("page", 1, type=int)

    if date:
        date_obj = strptime(date, "%Y-%m-%d")
        mail_list, download = current_user.get_mail_list(select, strftime('%d-%b-%Y', date_obj))
        if mail_list is None and not download:
            flash("旧任务未完成，正在下载邮件，请稍后")
            mail_list = []
        elif download:
            flash("启动新任务下载邮件，请稍后")

        next_date = strftime("%Y-%m-%d", localtime(mktime(date_obj) + 24 * 60 * 60))
        last_date = strftime("%Y-%m-%d", localtime(mktime(date_obj) - 24 * 60 * 60))
    else:
        mail_list = []
        next_date = None
        last_date = None

    return __load_mailbox_page(mail_list,
                               page,
                               date=date,
                               select=select,
                               next_date=next_date,
                               last_date=last_date)


def __get_mail() -> (Mail, str, str, int):
    mail_id = request.args.get("mail", None, type=int)
    date = request.args.get("date", None, type=str)
    select = request.args.get("select", None, type=str)
    if not mail_id or not date or not select:
        abort(404)

    date_obj = strftime('%d-%b-%Y', strptime(date, "%Y-%m-%d"))
    mail: Mail = current_user.get_mail(date_obj, select, mail_id)
    if not mail:
        abort(404)
    return mail, date, select, mail_id


@mailbox.route("/html")
@login_required
@except_imap_error
def html_page():
    html_id = request.args.get("id", 1, type=int)
    mail, *_ = __get_mail()

    count = 0
    for i in mail.body_list:
        count += 1
        if type(i) is HTML:
            if count == html_id:
                return i.body
    return abort(404)


@mailbox.route("/file")
@login_required
@except_imap_error
def file_page():
    filename = request.args.get("filename", None, type=str)
    if not filename:
        abort(404)
    mail, *_ = __get_mail()
    byte, content_type, content_disposition = mail.get_file(filename)
    if not byte:
        abort(404)

    response = make_response(byte)
    response.headers['Content-Type'] = content_type
    response.headers['Content-Disposition'] = content_disposition
    return response


@mailbox.route("/mail")
@login_required
@except_imap_error
def mail_page():
    mail, date, select, mail_id = __get_mail()

    count = 0
    html_id = []
    plain = []
    for i in mail.body_list:
        count += 1
        if type(i) is HTML:
            html_id.append(count)
        elif type(i) is PLAIN:
            plain.append(i)
    file_list = mail.file_list
    Logger.print_load_page_log(f"mail-{mail_id}")
    return render_template("mailbox/mail.html",
                           date=date,
                           select=select,
                           mail_id=mail_id,
                           mail=mail,
                           html_id=html_id,
                           plain=plain,
                           file_list=file_list)