package main

import (
	"errors"
	"github.com/emersion/go-imap/v2"
	"github.com/emersion/go-imap/v2/imapserver"
	"github.com/google/uuid"
	"sort"
	"strings"
)

const mailboxDelim rune = '/'

type User struct {
	server *Server // may be nil if sub is not set
	sub    uuid.UUID
}

func (u *User) Login(_, token string) error {
	sub, err := Authenticate(token, u.server.config)
	if err != nil {
		return err
	}

	u.sub = sub

	_, err = u.mailbox("INBOX")
	if err != nil {
		if errors.Is(err, ErrNoSuchMailbox) {
			err := u.Create("INBOX", nil)
			if err != nil {
				return err
			}
		} else {
			return err
		}
	}

	return nil
}

func (u *User) mailbox(name string) (*Mailbox, error) {
	return loadMbox(name, u)
}

func (u *User) Status(name string, options *imap.StatusOptions) (*imap.StatusData, error) {
	mbox, err := u.mailbox(name)
	if err != nil {
		return nil, err
	}
	return mbox.StatusData(options), nil
}

func (u *User) List(w *imapserver.ListWriter, ref string, patterns []string, options *imap.ListOptions) error {
	// TODO: fail if ref doesn't exist

	if len(patterns) == 0 {
		return w.WriteList(&imap.ListData{
			Attrs: []imap.MailboxAttr{imap.MailboxAttrNoSelect},
			Delim: mailboxDelim,
		})
	}

	mailboxQuery, err := Database.DB.Query("SELECT id, mailbox, subscribed FROM mailboxes WHERE owner = $1", u.sub[:])
	if err != nil {
		return err
	}

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

	var l []imap.ListData
	for mailboxQuery.Next() {
		var id []byte
		var name string
		var subscribed bool
		err := mailboxQuery.Scan(&id, &name, &subscribed)
		if err != nil {
			return err
		}

		mbox, err := loadMboxRaw(subscribed, id, name, u)
		if err != nil {
			return err
		}

		match := false
		for _, pattern := range patterns {
			match = imapserver.MatchList(name, mailboxDelim, ref, pattern)
			if match {
				break
			}
		}
		if !match {
			continue
		}

		data, err := mbox.list(options)
		if err != nil {
			return err
		}
		if data != nil {
			l = append(l, *data)
		}
	}

	sort.Slice(l, func(i, j int) bool {
		return l[i].Mailbox < l[j].Mailbox
	})

	for _, data := range l {
		err := w.WriteList(&data)
		if err != nil {
			return err
		}
	}

	return nil
}

func (u *User) Create(name string, _ *imap.CreateOptions) error {
	name = strings.TrimRight(name, string(mailboxDelim))

	err := u.NameNotExists(name)
	if err != nil {
		return err
	}

	newUUID := uuid.New()

	err = CreateMailbox(newUUID, name, u)
	if err != nil {
		return err
	}

	return nil
}

func (u *User) Delete(name string) error {
	mbox, err := u.mailbox(name)
	if err != nil {
		return err
	}

	err = mbox.Delete()
	if err != nil {
		return err
	}

	return nil
}

func (u *User) NameNotExists(name string) error {
	rows, err := Database.DB.Query("SELECT 1 FROM mailboxes WHERE mailbox = $1", name)
	if err != nil {
		return err
	}

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

	if !rows.Next() {
		return nil
	} else {
		return &imap.Error{
			Type: imap.StatusResponseTypeNo,
			Code: imap.ResponseCodeAlreadyExists,
			Text: "Mailbox already exists",
		}
	}
}

func (u *User) Rename(oldName, newName string) error {
	newName = strings.TrimRight(newName, string(mailboxDelim))

	mbox, err := u.mailbox(oldName)
	if err != nil {
		return err
	}

	err = u.NameNotExists(newName)
	if err != nil {
		return err
	}

	err = mbox.rename(newName)
	if err != nil {
		return err
	}

	return nil
}

func (u *User) Subscribe(name string) error {
	mbox, err := u.mailbox(name)
	if err != nil {
		return err
	}
	err = mbox.SetSubscribed(true)
	if err != nil {
		return err
	}
	return nil
}

func (u *User) Unsubscribe(name string) error {
	mbox, err := u.mailbox(name)
	if err != nil {
		return err
	}
	err = mbox.SetSubscribed(false)
	if err != nil {
		return err
	}
	return nil
}

func (u *User) Namespace() (*imap.NamespaceData, error) {
	return &imap.NamespaceData{
		Personal: []imap.NamespaceDescriptor{{Delim: mailboxDelim}},
	}, nil
}