package pushnotify

import (
	"context"

	"github.com/jackc/pgx/v5/pgxpool"
)

// Service is the full surface for per-device push token storage. HTTP handlers
// use Register/Unregister; the worker's notifier uses ListForHumans and
// DeleteByToken. Both consumers share the same underlying repository.
type Service interface {
	// Register upserts a token for the given human. Returns ErrInvalidToken /
	// ErrInvalidPlatform on bad input.
	Register(ctx context.Context, humanID string, in RegisterInput) error
	// Unregister removes a token, scoped to the calling human so a user can't
	// delete another user's token. Returns ErrNotFound if the token doesn't
	// belong to humanID (or doesn't exist).
	Unregister(ctx context.Context, humanID, token string) error
	// ListForHumans returns every push token belonging to any of the given
	// human IDs. Returns an empty slice when nothing matches.
	ListForHumans(ctx context.Context, humanIDs []string) ([]*PushToken, error)
	// DeleteByToken removes a token regardless of owning human. Used by the
	// notifier to clean up after Expo returns DeviceNotRegistered.
	DeleteByToken(ctx context.Context, token string) error
}

type RegisterInput struct {
	Token      string
	Platform   Platform
	AppVersion string
}

type serviceImpl struct {
	repo repository
}

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

func (s *serviceImpl) Register(ctx context.Context, humanID string, in RegisterInput) error {
	if !in.Platform.Valid() {
		return ErrInvalidPlatform
	}
	if !IsValidExpoToken(in.Token) {
		return ErrInvalidToken
	}
	return s.repo.upsert(ctx, &PushToken{
		Token:      in.Token,
		HumanID:    humanID,
		Platform:   in.Platform,
		AppVersion: in.AppVersion,
	})
}

func (s *serviceImpl) Unregister(ctx context.Context, humanID, token string) error {
	if token == "" {
		return ErrInvalidToken
	}
	return s.repo.deleteForHuman(ctx, humanID, token)
}

func (s *serviceImpl) ListForHumans(ctx context.Context, humanIDs []string) ([]*PushToken, error) {
	return s.repo.listForHumans(ctx, humanIDs)
}

func (s *serviceImpl) DeleteByToken(ctx context.Context, token string) error {
	return s.repo.deleteByToken(ctx, token)
}