feat: image capability detection and user-friendly errors; warn and filter images for unsupported models

lib/model-capabilities.ts

@@ -0,0 +1,76 @@
+export function supportsImages(provider?: string, modelId?: string): boolean {
+    const p = (provider || "").toLowerCase()
+    const m = (modelId || "").toLowerCase()
+    if (!p && !m) return false
+    if (p === "openai" && m.includes("gpt-4o")) return true
+    if (p === "google" || m.includes("gemini")) return true
+    if (p === "siliconflow") {
+        if (m.includes("vl")) return true
+        if (m.includes("glm-4v")) return true
+        if (m.includes("yi-vl")) return true
+        return false
+    }
+    if (p === "openrouter") {
+        if (m.includes("gpt-4o")) return true
+        if (m.includes("gemini")) return true
+        if (m.includes("vl")) return true
+        if (m.includes("glm-4v")) return true
+        if (m.includes("yi-vl")) return true
+        return false
+    }
+    return false
+}
+
+const LS_KEY = "next-ai-draw-io-image-capabilities"
+
+function readCache(): Record<string, boolean> {
+    if (typeof window === "undefined") return {}
+    try {
+        const raw = localStorage.getItem(LS_KEY)
+        return raw ? (JSON.parse(raw) as Record<string, boolean>) : {}
+    } catch {
+        return {}
+    }
+}
+
+function writeCache(cache: Record<string, boolean>) {
+    if (typeof window === "undefined") return
+    try {
+        localStorage.setItem(LS_KEY, JSON.stringify(cache))
+    } catch {
+        // ignore
+    }
+}
+
+function capabilityKey(provider?: string, modelId?: string): string {
+    return `${(provider || "").toLowerCase()}::${(modelId || "").toLowerCase()}`
+}
+
+export function getCachedImageCapability(
+    provider?: string,
+    modelId?: string,
+): boolean | undefined {
+    const cache = readCache()
+    const key = capabilityKey(provider, modelId)
+    return key in cache ? cache[key] : undefined
+}
+
+export function setCachedImageCapability(
+    provider?: string,
+    modelId?: string,
+    supported?: boolean,
+) {
+    if (supported === undefined) return
+    const cache = readCache()
+    cache[capabilityKey(provider, modelId)] = supported
+    writeCache(cache)
+}
+
+export function resolveImageSupport(
+    provider?: string,
+    modelId?: string,
+): boolean {
+    const cached = getCachedImageCapability(provider, modelId)
+    if (cached !== undefined) return cached
+    return supportsImages(provider, modelId)
+}