package service

import (
	"context"
	"errors"
	"fmt"

	"gitea.dwysokinski.me/twhelp/dcbot/internal/domain"
	"gitea.dwysokinski.me/twhelp/dcbot/internal/twhelp"
)

const (
	maxGroupsPerServer = 10
)

//counterfeiter:generate -o internal/mock/group_repository.gen.go . GroupRepository
type GroupRepository interface {
	Create(ctx context.Context, params domain.CreateGroupParams) (domain.Group, error)
	UpdateByID(ctx context.Context, id string, params domain.UpdateGroupParams) (domain.Group, error)
	List(ctx context.Context, params domain.ListGroupsParams) ([]domain.Group, error)
}

type Group struct {
	repo   GroupRepository
	client TWHelpClient
}

func NewGroup(repo GroupRepository, client TWHelpClient) *Group {
	return &Group{repo: repo, client: client}
}

func (g *Group) Create(ctx context.Context, params domain.CreateGroupParams) (domain.Group, error) {
	groups, err := g.repo.List(ctx, domain.ListGroupsParams{
		ServerIDs: []string{params.ServerID()},
	})
	if err != nil {
		return domain.Group{}, fmt.Errorf("GroupRepository.List: %w", err)
	}

	if len(groups) >= maxGroupsPerServer {
		return domain.Group{}, domain.GroupLimitReachedError{
			Current: len(groups),
			Limit:   maxGroupsPerServer,
		}
	}

	server, err := g.client.GetServer(ctx, params.VersionCode(), params.ServerKey())
	if err != nil {
		var apiErr twhelp.APIError
		if !errors.As(err, &apiErr) {
			return domain.Group{}, fmt.Errorf("TWHelpClient.GetServer: %w", err)
		}
		return domain.Group{}, domain.ServerDoesNotExistError{
			VersionCode: params.VersionCode(),
			Key:         params.ServerKey(),
		}
	}

	if !server.Open {
		return domain.Group{}, domain.ServerIsClosedError{
			VersionCode: params.VersionCode(),
			Key:         params.ServerKey(),
		}
	}

	group, err := g.repo.Create(ctx, params)
	if err != nil {
		return domain.Group{}, fmt.Errorf("GroupRepository.Create: %w", err)
	}

	return group, nil
}

func (g *Group) SetTWServer(ctx context.Context, id, versionCode, serverKey string) (domain.Group, error) {
	if err := g.checkTWServer(ctx, versionCode, serverKey); err != nil {
		return domain.Group{}, err
	}

	group, err := g.repo.UpdateByID(ctx, id, domain.UpdateGroupParams{
		VersionCode: domain.NullString{
			String: versionCode,
			Valid:  true,
		},
		ServerKey: domain.NullString{
			String: serverKey,
			Valid:  true,
		},
	})
	if err != nil {
		return domain.Group{}, fmt.Errorf("GroupRepository.UpdateByID: %w", err)
	}

	return group, nil
}

func (g *Group) SetChannelGains(ctx context.Context, id, channel string) (domain.Group, error) {
	group, err := g.repo.UpdateByID(ctx, id, domain.UpdateGroupParams{
		ChannelGains: domain.NullString{
			String: channel,
			Valid:  true,
		},
	})
	if err != nil {
		return domain.Group{}, fmt.Errorf("GroupRepository.UpdateByID: %w", err)
	}
	return group, nil
}

func (g *Group) SetChannelLosses(ctx context.Context, id, channel string) (domain.Group, error) {
	group, err := g.repo.UpdateByID(ctx, id, domain.UpdateGroupParams{
		ChannelLosses: domain.NullString{
			String: channel,
			Valid:  true,
		},
	})
	if err != nil {
		return domain.Group{}, fmt.Errorf("GroupRepository.UpdateByID: %w", err)
	}
	return group, nil
}

func (g *Group) List(ctx context.Context, params domain.ListGroupsParams) ([]domain.Group, error) {
	groups, err := g.repo.List(ctx, params)
	if err != nil {
		return nil, fmt.Errorf("GroupRepository.List: %w", err)
	}
	return groups, nil
}

func (g *Group) checkTWServer(ctx context.Context, versionCode, serverKey string) error {
	server, err := g.client.GetServer(ctx, versionCode, serverKey)
	if err != nil {
		var apiErr twhelp.APIError
		if !errors.As(err, &apiErr) {
			return fmt.Errorf("TWHelpClient.GetServer: %w", err)
		}
		return domain.ServerDoesNotExistError{
			VersionCode: versionCode,
			Key:         serverKey,
		}
	}

	if !server.Open {
		return domain.ServerIsClosedError{
			VersionCode: versionCode,
			Key:         serverKey,
		}
	}

	return nil
}