package main

import (
	"errors"
	"fmt"

	"github.com/mattermost/focalboard/server/services/config"
	"github.com/mattermost/focalboard/server/services/notify/notifymentions"
	"github.com/mattermost/focalboard/server/services/notify/notifysubscriptions"
	"github.com/mattermost/focalboard/server/services/notify/plugindelivery"
	"github.com/mattermost/focalboard/server/services/permissions"
	"github.com/mattermost/focalboard/server/services/store"
	"github.com/mattermost/focalboard/server/ws"

	pluginapi "github.com/mattermost/mattermost-plugin-api"
	apierrors "github.com/mattermost/mattermost-plugin-api/errors"

	"github.com/mattermost/mattermost-server/v6/model"

	"github.com/mattermost/mattermost-server/v6/shared/mlog"
)

const (
	botUsername    = "boards"
	botDisplayname = "Boards"
	botDescription = "Created by Boards plugin."
)

type notifyBackendParams struct {
	cfg         *config.Configuration
	client      *pluginapi.Client
	permissions permissions.PermissionsService
	store       store.Store
	wsAdapter   ws.Adapter
	serverRoot  string
	logger      *mlog.Logger
}

func createMentionsNotifyBackend(params notifyBackendParams) (*notifymentions.Backend, error) {
	delivery, err := createDelivery(params.client, params.serverRoot)
	if err != nil {
		return nil, err
	}

	backendParams := notifymentions.BackendParams{
		Store:       params.store,
		Permissions: params.permissions,
		Delivery:    delivery,
		WSAdapter:   params.wsAdapter,
		Logger:      params.logger,
	}

	backend := notifymentions.New(backendParams)

	return backend, nil
}

func createSubscriptionsNotifyBackend(params notifyBackendParams) (*notifysubscriptions.Backend, error) {
	delivery, err := createDelivery(params.client, params.serverRoot)
	if err != nil {
		return nil, err
	}

	backendParams := notifysubscriptions.BackendParams{
		ServerRoot:             params.serverRoot,
		Store:                  params.store,
		Permissions:            params.permissions,
		Delivery:               delivery,
		WSAdapter:              params.wsAdapter,
		Logger:                 params.logger,
		NotifyFreqCardSeconds:  params.cfg.NotifyFreqCardSeconds,
		NotifyFreqBoardSeconds: params.cfg.NotifyFreqBoardSeconds,
	}
	backend := notifysubscriptions.New(backendParams)

	return backend, nil
}

func createDelivery(client *pluginapi.Client, serverRoot string) (*plugindelivery.PluginDelivery, error) {
	bot := &model.Bot{
		Username:    botUsername,
		DisplayName: botDisplayname,
		Description: botDescription,
	}
	botID, err := client.Bot.EnsureBot(bot)
	if err != nil {
		return nil, fmt.Errorf("failed to ensure %s bot: %w", botDisplayname, err)
	}

	pluginAPI := &pluginAPIAdapter{client: client}

	return plugindelivery.New(botID, serverRoot, pluginAPI), nil
}

type pluginAPIAdapter struct {
	client *pluginapi.Client
}

func (da *pluginAPIAdapter) GetDirectChannel(userID1, userID2 string) (*model.Channel, error) {
	return da.client.Channel.GetDirect(userID1, userID2)
}

func (da *pluginAPIAdapter) CreatePost(post *model.Post) error {
	return da.client.Post.CreatePost(post)
}

func (da *pluginAPIAdapter) GetUserByID(userID string) (*model.User, error) {
	return da.client.User.Get(userID)
}

func (da *pluginAPIAdapter) GetUserByUsername(name string) (*model.User, error) {
	return da.client.User.GetByUsername(name)
}

func (da *pluginAPIAdapter) GetTeamMember(teamID string, userID string) (*model.TeamMember, error) {
	return da.client.Team.GetMember(teamID, userID)
}

func (da *pluginAPIAdapter) GetChannelByID(channelID string) (*model.Channel, error) {
	return da.client.Channel.Get(channelID)
}

func (da *pluginAPIAdapter) GetChannelMember(channelID string, userID string) (*model.ChannelMember, error) {
	return da.client.Channel.GetMember(channelID, userID)
}

func (da *pluginAPIAdapter) IsErrNotFound(err error) bool {
	return errors.Is(err, apierrors.ErrNotFound)
}