feat: file_save_disk, file_delete, file_serve, upload_parse, upload_handler, thumbnail_generate (issue 0014 fase 3)

2026-04-18 17:15:39 +02:00
parent 1675d2bb84
commit 4b420fb24b
18 changed files with 1114 additions and 0 deletions
@@ -0,0 +1,46 @@
+---
+name: thumbnail_generate
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func ThumbnailGenerate(srcPath string, dstPath string, maxWidth int, maxHeight int) error"
+description: "Lee una imagen JPEG o PNG, la redimensiona manteniendo aspect ratio para que quepa en (maxWidth, maxHeight) y la guarda en dstPath. Solo soporta entrada/salida JPEG y PNG."
+tags: [image, thumbnail, resize, file, upload, infra]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [fmt, image, image/jpeg, image/png, os, path/filepath, strings]
+params:
+  - name: srcPath
+    desc: "ruta de la imagen original (JPEG o PNG)"
+  - name: dstPath
+    desc: "ruta destino del thumbnail (extension determina formato de salida: .jpg/.jpeg/.png)"
+  - name: maxWidth
+    desc: "ancho maximo del thumbnail en pixeles (>0)"
+  - name: maxHeight
+    desc: "alto maximo del thumbnail en pixeles (>0)"
+output: "nil si el thumbnail se genero correctamente, error si falla la lectura, decode, encode o si la extension no es soportada"
+tested: true
+tests: ["genera thumbnail JPEG mas pequeno que el original", "preserva aspect ratio", "rechaza extension de salida no soportada", "no agranda imagenes ya pequenas"]
+test_file_path: "functions/infra/thumbnail_generate_test.go"
+file_path: "functions/infra/thumbnail_generate.go"
+---
+
+## Ejemplo
+
+```go
+err := ThumbnailGenerate("./uploads/photo.jpg", "./uploads/thumbs/photo.jpg", 200, 200)
+if err != nil {
+    log.Fatal(err)
+}
+```
+
+## Notas
+
+Implementacion solo con stdlib (`image`, `image/jpeg`, `image/png`). Resize nearest-neighbor: rapido y sin dependencias, pero baja calidad. Para apps que necesiten thumbnails de alta calidad usar `golang.org/x/image/draw` con `BiLinear` o `CatmullRom`.
+
+NO soporta WebP, AVIF, HEIC ni GIF. Si la imagen original ya es mas pequena que (maxWidth, maxHeight), se guarda sin redimensionar (no se agranda).