package main

import (
	"errors"
	"github.com/emersion/go-imap"
	"github.com/emersion/go-imap/backend"
	"github.com/google/uuid"
)

type User struct {
	username     string
	sub          uuid.UUID
	openMessages map[*Message]struct{}
}

func (u *User) Username() string {
	return u.username
}

func (u *User) ListMailboxes(subscribed bool) (mailboxes []backend.Mailbox, err error) {
	mailboxQuery, err := Database.DB.Query("SELECT mailbox, subscribed FROM mailboxes")
	if err != nil {
		return nil, err
	}

	defer func() {
		err := mailboxQuery.Close()
		if err != nil {
			log("Failed to close rows: "+err.Error()+", resource leaks may occur", 1)
		}
	}()

	for mailboxQuery.Next() {
		var name string
		var subscribed bool
		err := mailboxQuery.Scan(&name, &subscribed)
		if err != nil {
			return nil, err
		}

		mbox := &Mailbox{
			name: name,
			user: u,
		}
		mbox.Subscribed = subscribed

		err = Database.DB.QueryRow("SELECT id FROM mailboxes WHERE mailbox = $1", name).Scan(&mbox.id)
		if err != nil {
			return nil, err
		}

		mailboxes = append(mailboxes, mbox)
	}

	return mailboxes, nil
}

func (u *User) GetRawMailbox(name string) (mailbox *Mailbox, err error) {
	mailbox = &Mailbox{
		name: name,
		user: u,
	}

	err = Database.DB.QueryRow("SELECT id, subscribed FROM mailboxes WHERE mailbox = $1", name).Scan(&mailbox.id, &mailbox.Subscribed)
	if err != nil {
		return nil, err
	}

	return mailbox, nil
}

func (u *User) GetMailbox(name string) (mailbox backend.Mailbox, err error) {
	return u.GetRawMailbox(name)
}

func (u *User) CreateMailbox(name string) error {
	newUUID := uuid.New()
	_, err := Database.DB.Exec("INSERT INTO mailboxes (mailbox, id, owner) VALUES ($1, $2, $3)", name, newUUID[:], u.sub[:])
	if err != nil {
		return err
	}

	return nil
}

func (u *User) DeleteMailbox(name string) error {
	if name == "INBOX" {
		return errors.New("cannot delete INBOX")
	}

	_, err := Database.DB.Exec("DELETE FROM mailboxes WHERE mailbox = $1", name)
	if err != nil {
		return err
	}

	return nil
}

func (u *User) RenameMailbox(existingName, newName string) error {
	if existingName != "INBOX" {
		_, err := Database.DB.Exec("UPDATE mailboxes SET mailbox = $1 WHERE mailbox = $2", newName, existingName)
		if err != nil {
			return err
		}
	} else {
		// INBOX is a special case, we need to create a new mailbox and copy the contents
		err := u.CreateMailbox(newName)
		if err != nil {
			return err
		}

		inbox, err := u.GetRawMailbox(newName)
		if err != nil {
			return err
		}

		set := new(imap.SeqSet)
		set.AddRange(1, 4294967295) // uint32 maximum value, essentially means all messages

		err = inbox.CopyMessages(true, set, newName)
		if err != nil {
			return err
		}

		err = inbox.Expunge()
		if err != nil {
			return err
		}
	}

	return nil
}

func (u *User) Logout() error {
	for msg := range u.openMessages {
		err := msg.Close()
		if err != nil {
			return err
		}
	}

	return nil
}