package repositories

import (
	"context"
	"database/sql"
	"errors"
	"thamanyah/discovery/internal/models"

	"github.com/lib/pq"
)

type VideoRepository struct {
	SQLDB *sql.DB
}

var VideoRepo VideoRepository

// SaveVideo records an announced video, replacing what the catalogue already
// held for that id.
//
// The upsert is what makes the consumer safe to retry: the catalogue topic
// delivers at-least-once, so the same announcement can arrive twice, and a
// plain INSERT would fail the second time on the primary key. Re-announcing a
// video is also how it is corrected — a later announcement wins, which is why
// every column is overwritten rather than merged.
func (svc VideoRepository) SaveVideo(ctx context.Context, v models.Video) error {
	_, err := svc.SQLDB.ExecContext(ctx, `
		INSERT INTO videos (id, title, playback_url, categories)
		VALUES ($1, $2, $3, $4)
		ON CONFLICT (id) DO UPDATE
		SET title = EXCLUDED.title,
		    playback_url = EXCLUDED.playback_url,
		    categories = EXCLUDED.categories,
		    updated_at = now()
	`, v.ID, v.Title, v.PlaybackURL, pq.Array(v.Categories))
	return err
}

// GetVideoByID reads the catalogue's copy of one video. It returns
// ErrVideoNotFound when the catalogue has not heard about it — which, for a
// video cms has only just made ready, is a matter of timing rather than a
// mistake.
func (svc VideoRepository) GetVideoByID(ctx context.Context, id string) (models.Video, error) {
	var v models.Video

	err := svc.SQLDB.QueryRowContext(ctx, `
		SELECT id, title, playback_url, categories, created_at, updated_at
		FROM videos
		WHERE id = $1
	`, id).Scan(&v.ID, &v.Title, &v.PlaybackURL, pq.Array(&v.Categories), &v.CreatedAt, &v.UpdatedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return models.Video{}, ErrVideoNotFound
	}
	if err != nil {
		return models.Video{}, err
	}

	return v, nil
}