124 lines
3.9 KiB
TypeScript
124 lines
3.9 KiB
TypeScript
import z from "zod";
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/**
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* Supported image formats as string literals.
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*/
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const IMAGE_FORMATS = ["png", "jpeg", "gif", "webp", "bmp"] as const;
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/**
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* Map of supported image format keys to their MIME types.
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*/
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const MIME_MAP = {
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png: "image/png",
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jpeg: "image/jpeg",
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gif: "image/gif",
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webp: "image/webp",
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bmp: "image/bmp",
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} as const;
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/*
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|--------------------------------------------------------------------------------
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| Raw Image
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| Defines the raw structure of an image as stored in the database.
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| This schema captures all the immutable attributes of an image (id, folder
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| reference, URL, file metadata, etc.) but does not include any derived values
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| such as the MIME type.
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*/
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const RawImageSchema = z.strictObject({
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_id: z.uuid().describe("Primary identifier of the image"),
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folderId: z.uuid().optional().describe("Primary identifier of the folder the image belongs to"),
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name: z.string().min(1).describe("Original file name (e.g., cat.png)"),
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format: z.enum(IMAGE_FORMATS).describe("Image format"),
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size: z.number().positive().max(500).describe("File size in bytes"),
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hash: z.string().min(1).describe("Image hash to ensure we don't store the same image multiple times"),
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width: z.number().positive().describe("Image width in pixels"),
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height: z.number().positive().describe("Image height in pixels"),
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url: z.url().describe("Public URL to access the image"),
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description: z.string().max(500).optional().describe("Optional description or caption (max 500 chars)"),
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tags: z.array(z.string().min(1)).default([]).describe("Array of tags for search / categorization"),
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createdAt: z.coerce.date().describe("Timestamp when the image was stored"),
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});
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/*
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| Image
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| A strict representation of an image that includes a derived `mime` field. The
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| `ImageSchema` takes `RawImageSchema` and attaches the MIME type based on the
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| format. No extra keys are permitted.
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*/
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export const ImageSchema = RawImageSchema.transform((data) => ({
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...data,
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mime: mimeForFormat(data.format),
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}));
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export type Image = z.output<typeof ImageSchema>;
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/*
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|--------------------------------------------------------------------------------
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| Database
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|--------------------------------------------------------------------------------
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| Schemas used for interacting with the persistence layer.
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| `ImageInsertSchema` is used when inserting a new image – it omits
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| automatically generated fields such as `_id` and `createdAt`. It also
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| normalises the `tags` array to contain unique values.
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*/
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/**
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* Schema used when inserting a new image.
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* It omits _id, and createdAt – those are generated by the DB.
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*/
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export const ImageInsertSchema = z
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.strictObject({
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...RawImageSchema.omit({ _id: true, createdAt: true }).shape,
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})
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.transform((data) => ({
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...data,
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tags: Array.from(new Set(data.tags)),
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}));
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export type ImageInsert = z.input<typeof ImageInsertSchema>;
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/*
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| Utilities
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*/
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/**
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* Returns the MIME type corresponding to the given image format.
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* If the format is unknown, defaults to "application/octet-stream".
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*
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* @param format - The image format key (e.g., "png").
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*
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* @returns The MIME type string.
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*/
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function mimeForFormat<TKey extends keyof MIMEMap>(format: TKey): MIMEMap[TKey] | "application/octet-stream" {
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return MIME_MAP[format] ?? "application/octet-stream";
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}
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/*
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|--------------------------------------------------------------------------------
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| Types
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*/
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type MIMEMap = typeof MIME_MAP;
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