feat: better image handling (auto resize & max size constraints) (#26401)

packages/opencode/src/image/image.ts

@@ -0,0 +1,180 @@
+import { Config } from "@/config/config"
+import type { MessageV2 } from "@/session/message-v2"
+import * as Log from "@opencode-ai/core/util/log"
+import { Context, Effect, Layer, Schema } from "effect"
+
+const MAX_BASE64_BYTES = 4.5 * 1024 * 1024
+const MAX_WIDTH = 2000
+const MAX_HEIGHT = 2000
+const AUTO_RESIZE = true
+const JPEG_QUALITIES = [80, 85, 70, 55, 40]
+const log = Log.create({ service: "image" })
+
+export class PhotonUnavailableError extends Schema.TaggedErrorClass<PhotonUnavailableError>()(
+  "ImagePhotonUnavailableError",
+  {},
+) {
+  override get message() {
+    return "Photon image processor is unavailable"
+  }
+}
+
+export class InvalidDataUrlError extends Schema.TaggedErrorClass<InvalidDataUrlError>()("ImageInvalidDataUrlError", {
+  url: Schema.String,
+}) {
+  override get message() {
+    return "Image URL must be a base64 data URL"
+  }
+}
+
+export class DecodeError extends Schema.TaggedErrorClass<DecodeError>()("ImageDecodeError", {}) {
+  override get message() {
+    return "Image could not be decoded"
+  }
+}
+
+export class SizeError extends Schema.TaggedErrorClass<SizeError>()("ImageSizeError", {
+  bytes: Schema.Number,
+  max: Schema.Number,
+  width: Schema.Number,
+  height: Schema.Number,
+  max_width: Schema.Number,
+  max_height: Schema.Number,
+}) {
+  override get message() {
+    return `Image ${this.width}x${this.height} with base64 size ${this.bytes} exceeds configured limits and could not be resized below ${this.max_width}x${this.max_height}/${this.max} bytes`
+  }
+}
+
+export type Error = PhotonUnavailableError | InvalidDataUrlError | DecodeError | SizeError
+
+export interface Interface {
+  readonly normalize: (input: MessageV2.FilePart) => Effect.Effect<MessageV2.FilePart, Error>
+}
+
+export class Service extends Context.Service<Service, Interface>()("@opencode/Image") {}
+
+export const layer = Layer.effect(
+  Service,
+  Effect.gen(function* () {
+    const config = yield* Config.Service
+    const loadPhoton = yield* Effect.cached(
+      Effect.promise(async () => {
+        try {
+          const photonWasm = (await import("@silvia-odwyer/photon-node/photon_rs_bg.wasm", { with: { type: "file" } }))
+            .default
+          // Patched photon-node reads this during module init so Bun compiled binaries use the embedded wasm path.
+          ;(globalThis as typeof globalThis & { __OPENCODE_PHOTON_WASM_PATH?: string }).__OPENCODE_PHOTON_WASM_PATH =
+            photonWasm
+          return await import("@silvia-odwyer/photon-node")
+        } catch {
+          return null
+        }
+      }),
+    )
+
+    const normalize = Effect.fn("Image.normalize")(function* (input: MessageV2.FilePart) {
+      const image = (yield* config.get()).attachment?.image
+      const info = {
+        autoResize: image?.auto_resize ?? AUTO_RESIZE,
+        maxWidth: image?.max_width ?? MAX_WIDTH,
+        maxHeight: image?.max_height ?? MAX_HEIGHT,
+        maxBase64Bytes: image?.max_base64_bytes ?? MAX_BASE64_BYTES,
+      }
+      if (!input.url.startsWith("data:") || !input.url.includes(";base64,"))
+        return yield* new InvalidDataUrlError({ url: input.url })
+
+      const base64 = input.url.slice(input.url.indexOf(";base64,") + ";base64,".length)
+      const photon = yield* loadPhoton
+      if (!photon) return yield* new PhotonUnavailableError()
+
+      const decoded = yield* Effect.sync(() => {
+        try {
+          return photon.PhotonImage.new_from_byteslice(Buffer.from(base64, "base64"))
+        } catch {
+          return undefined
+        }
+      })
+      if (!decoded) return yield* new DecodeError()
+
+      try {
+        const originalWidth = decoded.get_width()
+        const originalHeight = decoded.get_height()
+        if (
+          originalWidth <= info.maxWidth &&
+          originalHeight <= info.maxHeight &&
+          Buffer.byteLength(base64, "utf8") <= info.maxBase64Bytes
+        )
+          return input
+        if (!info.autoResize)
+          return yield* new SizeError({
+            bytes: Buffer.byteLength(base64, "utf8"),
+            max: info.maxBase64Bytes,
+            width: originalWidth,
+            height: originalHeight,
+            max_width: info.maxWidth,
+            max_height: info.maxHeight,
+          })
+
+        const scale = Math.min(1, info.maxWidth / originalWidth, info.maxHeight / originalHeight)
+        for (const size of Array.from({ length: 32 }).reduce<Array<{ width: number; height: number }>>((acc) => {
+          const previous = acc.at(-1) ?? {
+            width: Math.max(1, Math.round(originalWidth * scale)),
+            height: Math.max(1, Math.round(originalHeight * scale)),
+          }
+          const next =
+            acc.length === 0
+              ? previous
+              : {
+                  width: previous.width === 1 ? 1 : Math.max(1, Math.floor(previous.width * 0.75)),
+                  height: previous.height === 1 ? 1 : Math.max(1, Math.floor(previous.height * 0.75)),
+                }
+          return acc.some((item) => item.width === next.width && item.height === next.height) ? acc : [...acc, next]
+        }, [])) {
+          const resized = photon.resize(decoded, size.width, size.height, photon.SamplingFilter.Lanczos3)
+          const candidate = [
+            { data: Buffer.from(resized.get_bytes()).toString("base64"), mime: "image/png" },
+            ...JPEG_QUALITIES.map((quality) => ({
+              data: Buffer.from(resized.get_bytes_jpeg(quality)).toString("base64"),
+              mime: "image/jpeg",
+            })),
+          ]
+            .map((item) => ({ ...item, bytes: Buffer.byteLength(item.data, "utf8") }))
+            .find((item) => item.bytes <= info.maxBase64Bytes)
+          resized.free()
+
+          if (candidate) {
+            log.info("using resized image", {
+              from_mime: input.mime,
+              to_mime: candidate.mime,
+              from: `${originalWidth}x${originalHeight}`,
+              to: `${size.width}x${size.height}`,
+            })
+            return {
+              ...input,
+              mime: candidate.mime,
+              url: `data:${candidate.mime};base64,${candidate.data}`,
+            }
+          }
+        }
+
+        return yield* new SizeError({
+          bytes: Buffer.byteLength(base64, "utf8"),
+          max: info.maxBase64Bytes,
+          width: originalWidth,
+          height: originalHeight,
+          max_width: info.maxWidth,
+          max_height: info.maxHeight,
+        })
+      } finally {
+        decoded.free()
+      }
+    })
+
+    return Service.of({ normalize })
+  }),
+)
+
+export const defaultLayer = layer.pipe(Layer.provide(Config.defaultLayer))
+
+export * as Image from "./image"