commit 40c22b2bae1fe465bf2374a55aada72a828a44bc · bretton.dev/coves

+14

internal/core/unfurl/errors.go

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       package unfurl

     

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       import "errors"

     

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       var (

     

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       	// ErrNotFound is returned when an unfurl cache entry is not found or has expired

     

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       	ErrNotFound = errors.New("unfurl cache entry not found or expired")

     

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       	// ErrInvalidURL is returned when the provided URL is invalid

     

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       	ErrInvalidURL = errors.New("invalid URL")

     

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       	// ErrInvalidTTL is returned when the provided TTL is invalid (e.g., negative or zero)

     

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       	ErrInvalidTTL = errors.New("invalid TTL: must be positive")

     

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       )

+19

internal/core/unfurl/interfaces.go

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       package unfurl

     

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       import (

     

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       	"context"

     

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       	"time"

     

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       )

     

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       // Repository defines the interface for unfurl cache persistence

     

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       type Repository interface {

     

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       	// Get retrieves a cached unfurl result for the given URL.

     

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       	// Returns nil, nil if not found or expired (not an error condition).

     

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       	// Returns error only on database failures.

     

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       	Get(ctx context.Context, url string) (*UnfurlResult, error)

     

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       	// Set stores an unfurl result in the cache with the specified TTL.

     

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       	// If an entry already exists for the URL, it will be updated.

     

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       	// The expires_at is calculated as NOW() + ttl.

     

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       	Set(ctx context.Context, url string, result *UnfurlResult, ttl time.Duration) error

     

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       }

+117

internal/core/unfurl/repository.go

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       package unfurl

     

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       import (

     

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       	"context"

     

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       	"database/sql"

     

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       	"encoding/json"

     

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       	"fmt"

     

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       	"time"

     

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       )

     

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       type postgresUnfurlRepo struct {

     

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       	db *sql.DB

     

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       }

     

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       // NewRepository creates a new PostgreSQL unfurl cache repository

     

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       func NewRepository(db *sql.DB) Repository {

     

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       	return &postgresUnfurlRepo{db: db}

     

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       }

     

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       // Get retrieves a cached unfurl result for the given URL.

     

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       // Returns nil, nil if not found or expired (not an error condition).

     

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       // Returns error only on database failures.

     

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       func (r *postgresUnfurlRepo) Get(ctx context.Context, url string) (*UnfurlResult, error) {

     

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       	query := `

     

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       		SELECT metadata, thumbnail_url, provider

     

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       		FROM unfurl_cache

     

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       		WHERE url = $1 AND expires_at > NOW()

     

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       	`

     

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       	var metadataJSON []byte

     

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       	var thumbnailURL sql.NullString

     

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       	var provider string

     

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       	err := r.db.QueryRowContext(ctx, query, url).Scan(&metadataJSON, &thumbnailURL, &provider)

     

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       	if err == sql.ErrNoRows {

     

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       		// Not found or expired is not an error

     

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       		return nil, nil

     

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       	}

     

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       	if err != nil {

     

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       		return nil, fmt.Errorf("failed to get unfurl cache entry: %w", err)

     

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       	}

     

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       	// Unmarshal metadata JSONB to UnfurlResult

     

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       	var result UnfurlResult

     

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       	if err := json.Unmarshal(metadataJSON, &result); err != nil {

     

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       		return nil, fmt.Errorf("failed to unmarshal metadata: %w", err)

     

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       	}

     

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       	// Ensure provider and thumbnailURL are set (may not be in metadata JSON)

     

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       	result.Provider = provider

     

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       	if thumbnailURL.Valid {

     

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       		result.ThumbnailURL = thumbnailURL.String

     

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       	}

     

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       	return &result, nil

     

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       }

     

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       // Set stores an unfurl result in the cache with the specified TTL.

     

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       // If an entry already exists for the URL, it will be updated.

     

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       // The expires_at is calculated as NOW() + ttl.

     

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       func (r *postgresUnfurlRepo) Set(ctx context.Context, url string, result *UnfurlResult, ttl time.Duration) error {

     

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       	// Marshal UnfurlResult to JSON for metadata column

     

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       	metadataJSON, err := json.Marshal(result)

     

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       	if err != nil {

     

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       		return fmt.Errorf("failed to marshal metadata: %w", err)

     

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       	}

     

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       	// Store thumbnail_url separately for potential queries

     

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       	var thumbnailURL sql.NullString

     

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       	if result.ThumbnailURL != "" {

     

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       		thumbnailURL.String = result.ThumbnailURL

     

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       		thumbnailURL.Valid = true

     

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       	}

     

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       	// Convert Go duration to PostgreSQL interval string

     

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       	// e.g., "1 hour", "24 hours", "7 days"

     

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       	intervalStr := formatInterval(ttl)

     

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       	query := `

     

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       		INSERT INTO unfurl_cache (url, provider, metadata, thumbnail_url, expires_at)

     

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       		VALUES ($1, $2, $3, $4, NOW() + $5::interval)

     

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       		ON CONFLICT (url) DO UPDATE

     

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       		SET provider = EXCLUDED.provider,

     

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       		    metadata = EXCLUDED.metadata,

     

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       		    thumbnail_url = EXCLUDED.thumbnail_url,

     

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       		    expires_at = EXCLUDED.expires_at,

     

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       		    fetched_at = NOW()

     

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       	`

     

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       	_, err = r.db.ExecContext(ctx, query, url, result.Provider, metadataJSON, thumbnailURL, intervalStr)

     

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       	if err != nil {

     

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       		return fmt.Errorf("failed to insert/update unfurl cache entry: %w", err)

     

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       	}

     

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       	return nil

     

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       }

     

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       // formatInterval converts a Go duration to a PostgreSQL interval string

     

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       // PostgreSQL accepts intervals like "1 hour", "24 hours", "7 days"

     

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       func formatInterval(d time.Duration) string {

     

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       	seconds := int64(d.Seconds())

     

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       	// Convert to appropriate unit for readability

     

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       	switch {

     

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       	case seconds >= 86400: // >= 1 day

     

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       		days := seconds / 86400

     

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       		return fmt.Sprintf("%d days", days)

     

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       	case seconds >= 3600: // >= 1 hour

     

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       		hours := seconds / 3600

     

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       		return fmt.Sprintf("%d hours", hours)

     

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       	case seconds >= 60: // >= 1 minute

     

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       		minutes := seconds / 60

     

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       		return fmt.Sprintf("%d minutes", minutes)

     

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       	default:

     

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       		return fmt.Sprintf("%d seconds", seconds)

     

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       	}

     

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       }

+23

internal/db/migrations/017_create_unfurl_cache.sql

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       -- +goose Up

     

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       CREATE TABLE unfurl_cache (

     

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           url TEXT PRIMARY KEY,

     

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           provider TEXT NOT NULL,

     

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           metadata JSONB NOT NULL,

     

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           thumbnail_url TEXT,

     

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           fetched_at TIMESTAMP NOT NULL DEFAULT NOW(),

     

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           expires_at TIMESTAMP NOT NULL,

     

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           created_at TIMESTAMP NOT NULL DEFAULT NOW()

     

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       );

     

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       CREATE INDEX idx_unfurl_cache_expires ON unfurl_cache(expires_at);

     

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       COMMENT ON TABLE unfurl_cache IS 'Cache for oEmbed/URL unfurl results to reduce external API calls';

     

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       COMMENT ON COLUMN unfurl_cache.url IS 'The URL that was unfurled (primary key)';

     

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       COMMENT ON COLUMN unfurl_cache.provider IS 'Provider name (streamable, youtube, reddit, etc.)';

     

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       COMMENT ON COLUMN unfurl_cache.metadata IS 'Full unfurl result as JSON (title, description, type, etc.)';

     

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       COMMENT ON COLUMN unfurl_cache.thumbnail_url IS 'URL of the thumbnail image';

     

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       COMMENT ON COLUMN unfurl_cache.expires_at IS 'When this cache entry should be refetched (TTL-based)';

     

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       -- +goose Down

     

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       DROP INDEX IF EXISTS idx_unfurl_cache_expires;

     

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       DROP TABLE IF EXISTS unfurl_cache;