package discord

import (
	"context"
	"fmt"
	"time"

	"gitea.dwysokinski.me/twhelp/dcbot/internal/domain"
	"github.com/bwmarrin/discordgo"
	"github.com/robfig/cron/v3"
	"go.uber.org/zap"
)

type GroupService interface {
	Create(ctx context.Context, params domain.CreateGroupParams) (domain.Group, error)
	SetChannelGains(ctx context.Context, id, serverID, channel string) (domain.Group, error)
	SetChannelLosses(ctx context.Context, id, serverID, channel string) (domain.Group, error)
	SetInternals(ctx context.Context, id, serverID string, internals bool) (domain.Group, error)
	SetBarbarians(ctx context.Context, id, serverID string, barbarians bool) (domain.Group, error)
	CleanUp(ctx context.Context) error
	List(ctx context.Context, params domain.ListGroupsParams) ([]domain.Group, error)
	Delete(ctx context.Context, id, serverID string) error
}

type MonitorService interface {
	Create(ctx context.Context, groupID, serverID, tribeTag string) (domain.Monitor, error)
	List(ctx context.Context, groupID, serverID string) ([]domain.MonitorWithTribe, error)
	Execute(ctx context.Context) ([]domain.EnnoblementNotification, error)
	Delete(ctx context.Context, id, serverID string) error
}

type ChoiceService interface {
	Versions(ctx context.Context) ([]domain.Choice, error)
}

type Bot struct {
	s          *discordgo.Session
	c          *cron.Cron
	groupSvc   GroupService
	monitorSvc MonitorService
	choiceSvc  ChoiceService
	logger     *zap.Logger
}

func NewBot(
	token string,
	groupSvc GroupService,
	monitorSvc MonitorService,
	client ChoiceService,
	logger *zap.Logger,
) (*Bot, error) {
	s, err := discordgo.New("Bot " + token)
	if err != nil {
		return nil, fmt.Errorf("discordgo.New: %w", err)
	}

	s.Identify.Intents = discordgo.IntentsNone

	b := &Bot{
		s: s,
		c: cron.New(
			cron.WithLocation(time.UTC),
			cron.WithChain(
				cron.SkipIfStillRunning(cron.DiscardLogger),
			),
		),
		groupSvc:   groupSvc,
		monitorSvc: monitorSvc,
		choiceSvc:  client,
		logger:     logger,
	}

	b.s.AddHandler(b.handleSessionReady)
	b.s.AddHandler(b.logCommands)

	return b, nil
}

func (b *Bot) Run() error {
	if err := b.initCron(); err != nil {
		return fmt.Errorf("initCron: %w", err)
	}

	if err := b.s.Open(); err != nil {
		return fmt.Errorf("s.Open: %w", err)
	}

	if err := b.registerCommands(); err != nil {
		_ = b.s.Close()
		return fmt.Errorf("couldn't register commands: %w", err)
	}

	b.c.Run()

	return nil
}

type command interface {
	name() string
	register(s *discordgo.Session) error
}

func (b *Bot) registerCommands() error {
	commands := []command{
		&groupCommand{groupSvc: b.groupSvc, choiceSvc: b.choiceSvc},
		&monitorCommand{svc: b.monitorSvc},
	}

	for _, c := range commands {
		if err := b.registerCommand(c); err != nil {
			return err
		}
	}

	return nil
}

func (b *Bot) registerCommand(cmd command) error {
	if err := cmd.register(b.s); err != nil {
		return fmt.Errorf("couldn't register command '%s': %w", cmd.name(), err)
	}
	return nil
}

func (b *Bot) initCron() error {
	jobs := []struct {
		spec string
		job  cron.Job
	}{
		{
			spec: "@every 1m",
			job:  &executeMonitorsJob{svc: b.monitorSvc, s: b.s, logger: b.logger},
		},
		{
			spec: "0 */8 * * *",
			job:  &cleanUpGroupsJob{svc: b.groupSvc, logger: b.logger},
		},
	}

	for _, j := range jobs {
		_, err := b.c.AddJob(j.spec, j.job)
		if err != nil {
			return err
		}
	}

	return nil
}

func (b *Bot) handleSessionReady(s *discordgo.Session, _ *discordgo.Ready) {
	_ = s.UpdateGameStatus(0, "Tribal Wars")
}

func (b *Bot) logCommands(_ *discordgo.Session, i *discordgo.InteractionCreate) {
	if i.Type != discordgo.InteractionApplicationCommand {
		return
	}

	cmdData := i.ApplicationCommandData()
	cmd := cmdData.Name
	options := cmdData.Options
	for len(options) > 0 && options[0].Type == discordgo.ApplicationCommandOptionSubCommand {
		cmd += " " + options[0].Name
		options = options[0].Options
	}

	userID := ""
	if i.User != nil {
		userID = i.User.ID
	} else if i.Member != nil {
		userID = i.Member.User.ID
	}

	b.logger.Info(
		"executing command",
		zap.String("command", cmd),
		zap.String("user", userID),
		zap.String("serverID", i.GuildID),
		zap.String("channelID", i.ChannelID),
	)
}

func (b *Bot) Close() error {
	<-b.c.Stop().Done()
	return b.s.Close()
}