package network

import (
	"context"
	"errors"
	"fmt"
	"strings"

	"github.com/flowy-live/llink/internal/utils"
	"github.com/jackc/pgx/v5/pgxpool"
)

var ErrNotFound = errors.New("network not found")
var ErrInvalidName = errors.New("name cannot be empty")
var ErrCapacityExceeded = errors.New("active stream capacity exceeded")
var ErrInvalidRetentionHours = errors.New("message retention hours must be between 24 and 336")

type Service interface {
	// Create creates a network and adds adminHumanId as the first member. Returns ErrInvalidName if name is empty.
	Create(ctx context.Context, name, adminHumanId string) (*Network, error)
	// GetByID returns ErrNotFound if network doesn't exist.
	GetByID(ctx context.Context, id string) (*Network, error)
	// SetName returns ErrNotFound or ErrInvalidName.
	SetName(ctx context.Context, id, name string) error
	AddMembers(ctx context.Context, networkID string, humanIds []string) error
	RemoveMember(ctx context.Context, networkID, humanId string) error
	ListForHuman(ctx context.Context, humanId string) ([]*Network, error)
	IsMember(ctx context.Context, networkID, humanId string) (bool, error)
	// ListAll returns all networks with their members
	ListAll(ctx context.Context) ([]*Network, error)

	// Invitations (email-based, for users who haven't registered yet)
	InviteByEmail(ctx context.Context, networkID string, emails []string) error
	ListInvitationsForEmail(ctx context.Context, email string) ([]*Invitation, error)
	ListInvitationsForNetwork(ctx context.Context, networkID string) ([]*Invitation, error)
	AcceptInvitation(ctx context.Context, networkID, email, humanId string) error
	RevokeInvitation(ctx context.Context, networkID, email string) error
}

type serviceImpl struct {
	repo repository
}

func NewService(pool *pgxpool.Pool) Service {
	return &serviceImpl{repo: newRepository(pool)}
}

func (s *serviceImpl) Create(ctx context.Context, name, adminHumanId string) (*Network, error) {
	name = strings.TrimSpace(name)
	if name == "" {
		return nil, ErrInvalidName
	}

	network, err := s.repo.create(ctx, name, adminHumanId)
	if err != nil {
		return nil, err
	}

	err = s.AddMembers(ctx, network.ID, []string{adminHumanId})
	if err != nil {
		return nil, err
	}

	return network, nil
}

func (s *serviceImpl) GetByID(ctx context.Context, id string) (*Network, error) {
	n, err := s.repo.getByID(ctx, id)
	if errors.Is(err, errNotFound) {
		return nil, ErrNotFound
	}
	return n, err
}

func (s *serviceImpl) SetName(ctx context.Context, id, name string) error {
	name = strings.TrimSpace(name)
	if name == "" {
		return ErrInvalidName
	}

	err := s.repo.updateName(ctx, id, name)
	if errors.Is(err, errNotFound) {
		return ErrNotFound
	}
	return err
}

func (s *serviceImpl) AddMembers(ctx context.Context, networkID string, humanIds []string) error {
	for _, humanId := range humanIds {
		if humanId == "" {
			return fmt.Errorf("invalid humanId")
		}
		if err := s.repo.addMember(ctx, networkID, humanId); err != nil {
			return err
		}
	}
	return nil
}

func (s *serviceImpl) RemoveMember(ctx context.Context, networkID, humanId string) error {
	if humanId == "" {
		return fmt.Errorf("invalid humanId")
	}
	return s.repo.removeMember(ctx, networkID, humanId)
}

func (s *serviceImpl) ListForHuman(ctx context.Context, humanId string) ([]*Network, error) {
	if humanId == "" {
		return nil, fmt.Errorf("invalid humanId")
	}
	return s.repo.getNetworksForHuman(ctx, humanId)
}

func (s *serviceImpl) IsMember(ctx context.Context, networkID, humanId string) (bool, error) {
	if humanId == "" {
		return false, fmt.Errorf("invalid humanId")
	}
	return s.repo.isMember(ctx, networkID, humanId)
}

func (s *serviceImpl) ListAll(ctx context.Context) ([]*Network, error) {
	return s.repo.listAll(ctx)
}

// Invitation methods

func (s *serviceImpl) InviteByEmail(ctx context.Context, networkID string, emails []string) error {
	for _, email := range emails {
		normalized, err := utils.NormalizeEmail(email)
		if err != nil {
			return fmt.Errorf("invalid email %q: %w", email, err)
		}
		if err := s.repo.createInvitation(ctx, networkID, normalized); err != nil {
			return err
		}
	}
	return nil
}

func (s *serviceImpl) ListInvitationsForEmail(ctx context.Context, email string) ([]*Invitation, error) {
	normalized, err := utils.NormalizeEmail(email)
	if err != nil {
		return nil, fmt.Errorf("invalid email: %w", err)
	}
	return s.repo.getInvitationsByEmail(ctx, normalized)
}

func (s *serviceImpl) ListInvitationsForNetwork(ctx context.Context, networkID string) ([]*Invitation, error) {
	return s.repo.getInvitationsByNetwork(ctx, networkID)
}

func (s *serviceImpl) AcceptInvitation(ctx context.Context, networkID, email, humanId string) error {
	normalized, err := utils.NormalizeEmail(email)
	if err != nil {
		return fmt.Errorf("invalid email: %w", err)
	}
	if humanId == "" {
		return fmt.Errorf("invalid humanId")
	}

	if err := s.repo.deleteInvitation(ctx, networkID, normalized); err != nil {
		return err
	}
	return s.repo.addMember(ctx, networkID, humanId)
}

func (s *serviceImpl) RevokeInvitation(ctx context.Context, networkID, email string) error {
	normalized, err := utils.NormalizeEmail(email)
	if err != nil {
		return fmt.Errorf("invalid email: %w", err)
	}
	return s.repo.deleteInvitation(ctx, networkID, normalized)
}