pdf support in read tool (#5222)

Co-authored-by: ammi1378 <ammi1378@users.noreply.github.com>

packages/opencode/src/provider/transform.ts

@@ -2,6 +2,17 @@ import type { APICallError, ModelMessage } from "ai"
 import { unique } from "remeda"
 import type { JSONSchema } from "zod/v4/core"
 import type { Provider } from "./provider"
+import type { ModelsDev } from "./models"
+
+type Modality = NonNullable<ModelsDev.Model["modalities"]>["input"][number]
+
+function mimeToModality(mime: string): Modality | undefined {
+  if (mime.startsWith("image/")) return "image"
+  if (mime.startsWith("audio/")) return "audio"
+  if (mime.startsWith("video/")) return "video"
+  if (mime === "application/pdf") return "pdf"
+  return undefined
+}
 
 export namespace ProviderTransform {
   function normalizeMessages(msgs: ModelMessage[], model: Provider.Model): ModelMessage[] {
@@ -148,7 +159,32 @@ export namespace ProviderTransform {
     return msgs
   }
 
+  function unsupportedParts(msgs: ModelMessage[], model: Provider.Model): ModelMessage[] {
+    return msgs.map((msg) => {
+      if (msg.role !== "user" || !Array.isArray(msg.content)) return msg
+
+      const filtered = msg.content.map((part) => {
+        if (part.type !== "file" && part.type !== "image") return part
+
+        const mime = part.type === "image" ? part.image.toString().split(";")[0].replace("data:", "") : part.mediaType
+        const filename = part.type === "file" ? part.filename : undefined
+        const modality = mimeToModality(mime)
+        if (!modality) return part
+        if (model.capabilities.input[modality]) return part
+
+        const name = filename ? `"${filename}"` : modality
+        return {
+          type: "text" as const,
+          text: `ERROR: Cannot read ${name} (this model does not support ${modality} input). Inform the user.`,
+        }
+      })
+
+      return { ...msg, content: filtered }
+    })
+  }
+
   export function message(msgs: ModelMessage[], model: Provider.Model) {
+    msgs = unsupportedParts(msgs, model)
     msgs = normalizeMessages(msgs, model)
     if (model.providerID === "anthropic" || model.api.id.includes("anthropic") || model.api.id.includes("claude")) {
       msgs = applyCaching(msgs, model.providerID)