from dataclasses import dataclass

from arrow import Arrow
from flask import render_template, request, redirect, url_for, flash
from flask_login import login_required, current_user
from sqlalchemy import or_, func, case
from sqlalchemy.exc import IntegrityError
from sqlalchemy.orm import joinedload

from app import email_utils
from app.config import PAGE_LIMIT
from app.dashboard.base import dashboard_bp
from app.extensions import db
from app.log import LOG
from app.models import (
    Alias,
    ClientUser,
    Contact,
    EmailLog,
    DeletedAlias,
    AliasGeneratorEnum,
    Mailbox,
)


@dataclass
class AliasInfo:
    alias: Alias
    mailbox: Mailbox

    nb_forward: int
    nb_blocked: int
    nb_reply: int

    latest_email_log: EmailLog = None
    latest_contact: Contact = None


@dashboard_bp.route("/", methods=["GET", "POST"])
@login_required
def index():
    query = request.args.get("query") or ""
    page = 0
    if request.args.get("page"):
        page = int(request.args.get("page"))

    highlight_alias_id = None
    if request.args.get("highlight_alias_id"):
        highlight_alias_id = int(request.args.get("highlight_alias_id"))

    # User generates a new email
    if request.method == "POST":
        if request.form.get("form-name") == "trigger-email":
            alias_id = request.form.get("alias-id")
            alias = Alias.get(alias_id)

            LOG.d("trigger an email to %s", alias)
            email_utils.send_test_email_alias(alias.email, alias.user.name)

            flash(
                f"An email sent to {alias.email} is on its way, please check your inbox/spam folder",
                "success",
            )

        elif request.form.get("form-name") == "create-custom-email":
            if current_user.can_create_new_alias():
                return redirect(url_for("dashboard.custom_alias"))
            else:
                flash(f"You need to upgrade your plan to create new alias.", "warning")

        elif request.form.get("form-name") == "create-random-email":
            if current_user.can_create_new_alias():
                scheme = int(
                    request.form.get("generator_scheme") or current_user.alias_generator
                )
                if not scheme or not AliasGeneratorEnum.has_value(scheme):
                    scheme = current_user.alias_generator
                alias = Alias.create_new_random(user=current_user, scheme=scheme)

                alias.mailbox_id = current_user.default_mailbox_id

                db.session.commit()

                LOG.d("generate new email %s for user %s", alias, current_user)
                flash(f"Alias {alias.email} has been created", "success")

                return redirect(
                    url_for(
                        "dashboard.index", highlight_alias_id=alias.id, query=query,
                    )
                )
            else:
                flash(f"You need to upgrade your plan to create new alias.", "warning")

        elif request.form.get("form-name") == "switch-email-forwarding":
            alias_id = request.form.get("alias-id")
            alias: Alias = Alias.get(alias_id)

            LOG.d("switch email forwarding for %s", alias)

            alias.enabled = not alias.enabled
            if alias.enabled:
                flash(f"Alias {alias.email} is enabled", "success")
            else:
                flash(f"Alias {alias.email} is disabled", "warning")

            db.session.commit()
            return redirect(
                url_for("dashboard.index", highlight_alias_id=alias.id, query=query)
            )

        elif request.form.get("form-name") == "delete-email":
            alias_id = request.form.get("alias-id")
            alias: Alias = Alias.get(alias_id)

            LOG.d("delete gen email %s", alias)
            email = alias.email
            Alias.delete(alias.id)
            db.session.commit()
            flash(f"Alias {email} has been deleted", "success")

            # try to save deleted alias
            try:
                DeletedAlias.create(user_id=current_user.id, email=email)
                db.session.commit()
            # this can happen when a previously deleted alias is re-created via catch-all or directory feature
            except IntegrityError:
                LOG.error("alias %s has been added before to DeletedAlias", email)
                db.session.rollback()

        elif request.form.get("form-name") == "set-note":
            alias_id = request.form.get("alias-id")
            alias: Alias = Alias.get(alias_id)
            note = request.form.get("note")

            alias.note = note
            db.session.commit()

            flash(f"Update note for alias {alias.email}", "success")
            return redirect(
                url_for("dashboard.index", highlight_alias_id=alias.id, query=query)
            )

        elif request.form.get("form-name") == "set-mailbox":
            alias_id = request.form.get("alias-id")
            alias: Alias = Alias.get(alias_id)
            mailbox_email = request.form.get("mailbox")

            mailbox = Mailbox.get_by(email=mailbox_email)
            if not mailbox or mailbox.user_id != current_user.id:
                flash("Something went wrong, please retry", "warning")
            else:
                alias.mailbox_id = mailbox.id
                db.session.commit()
                LOG.d("Set alias %s mailbox to %s", alias, mailbox)

                flash(
                    f"Update mailbox for {alias.email} to {mailbox_email}", "success",
                )
                return redirect(
                    url_for(
                        "dashboard.index", highlight_alias_id=alias.id, query=query,
                    )
                )

        return redirect(url_for("dashboard.index", query=query))

    client_users = (
        ClientUser.filter_by(user_id=current_user.id)
        .options(joinedload(ClientUser.client))
        .options(joinedload(ClientUser.alias))
        .all()
    )

    sorted(client_users, key=lambda cu: cu.client.name)

    mailboxes = current_user.mailboxes()

    show_intro = False
    if not current_user.intro_shown:
        LOG.d("Show intro to %s", current_user)
        show_intro = True

        # to make sure not showing intro to user again
        current_user.intro_shown = True
        db.session.commit()

    return render_template(
        "dashboard/index.html",
        client_users=client_users,
        alias_infos=get_alias_infos_with_pagination(current_user, page, query),
        highlight_alias_id=highlight_alias_id,
        query=query,
        AliasGeneratorEnum=AliasGeneratorEnum,
        mailboxes=mailboxes,
        show_intro=show_intro,
        page=page,
    )


def get_alias_infos_with_pagination(user, page: int, query=None) -> [AliasInfo]:
    ret: [AliasInfo] = []
    latest_activity = func.max(
        case(
            [
                (Alias.created_at > EmailLog.created_at, Alias.created_at),
                (Alias.created_at < EmailLog.created_at, EmailLog.created_at),
            ],
            else_=Alias.created_at,
        )
    ).label("latest")

    q = (
        db.session.query(Alias, latest_activity)
        .options(joinedload(Alias.mailbox))
        .join(Contact, Alias.id == Contact.alias_id, isouter=True)
        .join(EmailLog, Contact.id == EmailLog.contact_id, isouter=True)
        .filter(Alias.user_id == user.id)
        .group_by(Alias.id)
        .order_by(latest_activity.desc())
    )

    if query:
        q = q.filter(
            or_(Alias.email.ilike(f"%{query}%"), Alias.note.ilike(f"%{query}%"))
        )

    q = q.limit(PAGE_LIMIT).offset(page * PAGE_LIMIT)

    for alias, latest_activity in q:
        ret.append(get_alias_info(alias))

    return ret


def get_alias_info(alias: Alias) -> AliasInfo:
    q = (
        db.session.query(Contact, EmailLog)
        .filter(Contact.alias_id == alias.id)
        .filter(EmailLog.contact_id == Contact.id)
    )

    latest_activity: Arrow = alias.created_at
    latest_email_log = None
    latest_contact = None

    alias_info = AliasInfo(
        alias=alias, nb_blocked=0, nb_forward=0, nb_reply=0, mailbox=alias.mailbox
    )

    for contact, email_log in q:
        if email_log.is_reply:
            alias_info.nb_reply += 1
        elif email_log.blocked:
            alias_info.nb_blocked += 1
        else:
            alias_info.nb_forward += 1

        if email_log.created_at > latest_activity:
            latest_activity = email_log.created_at
            latest_email_log = email_log
            latest_contact = contact

    alias_info.latest_contact = latest_contact
    alias_info.latest_email_log = latest_email_log

    return alias_info