yarnom
f0b50d13ea
Add Go/Postgres admin APIs, Angular admin UI, manual build flow, asset uploads, markdown import/export, configurable slug generation, and the Yar reading theme. Exclude local docs and generated development artifacts from version control.
80 lines
2.1 KiB
Go
80 lines
2.1 KiB
Go
package admin
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import (
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"context"
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"crypto/sha256"
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"encoding/hex"
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"fmt"
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"io"
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"mime/multipart"
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"net/http"
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"os"
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"path/filepath"
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"regexp"
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"strings"
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)
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const maxAssetSizeBytes = 12 * 1024 * 1024
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var safeAssetNamePattern = regexp.MustCompile(`[^a-zA-Z0-9._-]+`)
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type AssetUploader struct {
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store *Store
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assetsDir string
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}
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func NewAssetUploader(store *Store, assetsDir string) *AssetUploader {
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return &AssetUploader{store: store, assetsDir: assetsDir}
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}
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func (u *AssetUploader) Upload(ctx context.Context, file multipart.File, header *multipart.FileHeader) (Asset, error) {
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if header.Size > maxAssetSizeBytes {
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return Asset{}, fmt.Errorf("asset is too large: max %d bytes", maxAssetSizeBytes)
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}
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data, err := io.ReadAll(io.LimitReader(file, maxAssetSizeBytes+1))
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if err != nil {
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return Asset{}, fmt.Errorf("read asset: %w", err)
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}
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if int64(len(data)) > maxAssetSizeBytes {
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return Asset{}, fmt.Errorf("asset is too large: max %d bytes", maxAssetSizeBytes)
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}
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mimeType := http.DetectContentType(data)
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if !strings.HasPrefix(mimeType, "image/") {
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return Asset{}, fmt.Errorf("unsupported asset type: %s", mimeType)
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}
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sum := sha256.Sum256(data)
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sha := hex.EncodeToString(sum[:])
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name := assetFilename(header.Filename, sha)
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if err := os.MkdirAll(u.assetsDir, 0o755); err != nil {
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return Asset{}, fmt.Errorf("create assets dir: %w", err)
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}
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if err := os.WriteFile(filepath.Join(u.assetsDir, name), data, 0o644); err != nil {
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return Asset{}, fmt.Errorf("write asset: %w", err)
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}
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asset := Asset{
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Path: "/assets/" + name,
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OriginalName: header.Filename,
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MimeType: mimeType,
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SizeBytes: int64(len(data)),
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SHA256: sha,
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}
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return u.store.CreateAsset(ctx, asset)
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}
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func assetFilename(original string, sha string) string {
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ext := strings.ToLower(filepath.Ext(original))
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base := strings.TrimSuffix(filepath.Base(original), filepath.Ext(original))
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base = strings.Trim(safeAssetNamePattern.ReplaceAllString(base, "-"), "-._")
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if base == "" {
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base = "image"
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}
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if ext == "" {
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ext = ".bin"
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}
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return fmt.Sprintf("%s-%s%s", base, sha[:12], ext)
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}
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