package matrixbotlib

import (
	"os"
	"strings"

	"gopkg.in/yaml.v2"
	"maunium.net/go/mautrix"
	"maunium.net/go/mautrix/event"
	"maunium.net/go/mautrix/id"
)

// NewMatrixClient returns a new logged in Mautrix Client struct
func NewMatrixClient(config *MatrixClientConfig, store mautrix.Storer) (*mautrix.Client, error) {
	var client *mautrix.Client
	var err error
	// make sure username is lower case otherwise token login breaks
	uname := strings.ToLower(config.Username)
	if config.Token == "" {
		client, err = mautrix.NewClient(config.Homeserver, "", "")
		if err != nil {
			return client, err
		}
	} else {
		client, err = mautrix.NewClient(config.Homeserver, id.NewUserID(uname, config.Domain), config.Token)
		if err != nil {
			return client, err
		}
	}
	client.Store = store
	if config.Token == "" {
		loginRes, err := client.Login(&mautrix.ReqLogin{
			Type:             "m.login.password",
			Identifier:       mautrix.UserIdentifier{Type: mautrix.IdentifierTypeUser, User: uname},
			Password:         config.Password,
			StoreCredentials: true,
		})
		if err != nil {
			return client, err
		}
		config.Token = loginRes.AccessToken
		err = SyncToken(config)
		if err != nil {
			return nil, err
		}
	}
	return client, err
}

func SyncToken(config *MatrixClientConfig) error {
	t := make(map[string]interface{})
	data, err := os.ReadFile(config.filename)
	if err != nil {
		return err
	}
	err = yaml.Unmarshal([]byte(data), &t)
	if err != nil {
		return err
	}
	t["token"] = config.Token
	file, err := os.OpenFile(config.filename, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o600)
	if err != nil {
		return err
	}
	defer file.Close()

	enc := yaml.NewEncoder(file)

	err = enc.Encode(t)
	if err != nil {
		return err
	}
	return nil
}

// SetupAccountDataStore sets the client to use a AccountData store and filter appropriately
func SetupAccountDataStore(client *mautrix.Client, token string) error {
	dataFilter := &mautrix.Filter{
		AccountData: mautrix.FilterPart{
			Limit: 20,
			NotTypes: []event.Type{
				event.NewEventType(token),
			},
		},
	}

	store := mautrix.NewAccountDataStore(token, client)
	fID, err := client.CreateFilter(dataFilter)
	if err != nil {
		// don't want to continue if we can't keep state
		return err
	}
	uid := client.UserID
	store.SaveFilterID(uid, fID.FilterID)
	client.Store = store
	return nil
}