package logic

import (
	"context"
	"errors"
	"time"

	"spark-server/internal/module/square/entity"
	"spark-server/internal/pkg/errs"
)

func (s *Service) Like(ctx context.Context, userID, postID int64, channel entity.Channel) (*View, error) {
	post, err := s.visiblePost(ctx, userID, postID, channel)
	if err != nil {
		return nil, err
	}
	if !s.allowInteract(ctx, userID) {
		return nil, errs.ErrRateLimited
	}
	created, err := s.repo.AddLike(ctx, &entity.Like{PostID: postID, UserID: userID, CreatedAtMS: time.Now().UnixMilli()})
	if err != nil {
		return nil, err
	}
	if created {
		_ = s.notify(ctx, []*entity.Notice{s.newNotice(post.UserID, userID, entity.NoticeLike, post.Channel, postID, 0)})
	}
	return s.Get(ctx, userID, postID, channel)
}

func (s *Service) Unlike(ctx context.Context, userID, postID int64, channel entity.Channel) (*View, error) {
	if _, err := s.visiblePost(ctx, userID, postID, channel); err != nil {
		return nil, err
	}
	if err := s.repo.RemoveLike(ctx, postID, userID); err != nil && !errors.Is(err, errs.ErrNotFound) {
		return nil, err
	}
	return s.Get(ctx, userID, postID, channel)
}

func (s *Service) visiblePost(ctx context.Context, viewerID, postID int64, channel entity.Channel) (*entity.Post, error) {
	if !s.ready() || viewerID <= 0 {
		return nil, errs.ErrUnauthorized
	}
	if postID <= 0 {
		return nil, errs.ErrInvalidArgument
	}
	channel = normalizeChannel(channel)
	post, err := s.repo.GetPost(ctx, postID)
	if err != nil {
		return nil, err
	}
	if normalizeChannel(post.Channel) != channel {
		return nil, errs.ErrNotFound
	}
	vis, err := s.visFor(ctx, viewerID, []*entity.Post{post})
	if err != nil {
		return nil, err
	}
	if !vis.canSee(post) {
		return nil, errs.ErrNotFound
	}
	return post, nil
}