chore: import upstream snapshot with attribution

ai/capabilities.go

@@ -0,0 +1,159 @@
+package ai
+
+import "sort"
+
+// CapabilityRow is one deterministic row in a provider capability matrix.
+type CapabilityRow struct {
+	// Provider is the registered provider name.
+	Provider string `json:"provider"`
+	Capabilities
+}
+
+// Capabilities describes the AI interfaces a provider has registered.
+// It is intentionally based on package registration rather than external
+// provider marketing claims, so it reflects what this build can actually use.
+type Capabilities struct {
+	// Model reports whether ai.New can construct a chat/text model provider.
+	Model bool `json:"model"`
+	// Image reports whether ai.NewImage can construct an image model provider.
+	Image bool `json:"image"`
+	// Video reports whether ai.NewVideo can construct a video model provider.
+	Video bool `json:"video"`
+	// Stream reports whether the provider has registered end-to-end token streaming.
+	// Providers that only satisfy the Model interface with ErrStreamingUnsupported
+	// leave this false until their Stream implementation is usable.
+	Stream bool `json:"stream"`
+	// ToolStream reports whether the provider supports agent Stream requests that
+	// include tool schemas. Providers may support plain token streaming while
+	// leaving this false when their streaming API cannot accept tools.
+	ToolStream bool `json:"tool_stream"`
+}
+
+// ProviderCapabilities reports the capabilities registered for provider.
+func ProviderCapabilities(provider string) Capabilities {
+	_, hasModel := providers[provider]
+	_, hasImage := imageProviders[provider]
+	_, hasVideo := videoProviders[provider]
+	_, hasStream := streamProviders[provider]
+	_, hasToolStream := toolStreamProviders[provider]
+
+	return Capabilities{
+		Model:      hasModel,
+		Image:      hasImage,
+		Video:      hasVideo,
+		Stream:     hasStream,
+		ToolStream: hasToolStream,
+	}
+}
+
+// CapabilityMatrix returns a snapshot of all registered AI providers and the
+// interfaces they support. The returned map is a copy and can be modified by
+// callers without mutating the registry. Use CapabilityRows when rendering a
+// deterministic table or report.
+func CapabilityMatrix() map[string]Capabilities {
+	names := map[string]struct{}{}
+	for name := range providers {
+		names[name] = struct{}{}
+	}
+	for name := range imageProviders {
+		names[name] = struct{}{}
+	}
+	for name := range videoProviders {
+		names[name] = struct{}{}
+	}
+	for name := range streamProviders {
+		names[name] = struct{}{}
+	}
+	for name := range toolStreamProviders {
+		names[name] = struct{}{}
+	}
+
+	matrix := make(map[string]Capabilities, len(names))
+	for name := range names {
+		matrix[name] = ProviderCapabilities(name)
+	}
+	return matrix
+}
+
+// CapabilityRows returns a deterministic capability support matrix for every
+// registered AI provider. It is the ordered form of CapabilityMatrix, intended
+// for CLIs, docs generators, and conformance reports that need stable output.
+func CapabilityRows() []CapabilityRow {
+	names := RegisteredProviders("")
+	rows := make([]CapabilityRow, 0, len(names))
+	for _, name := range names {
+		rows = append(rows, CapabilityRow{
+			Provider:     name,
+			Capabilities: ProviderCapabilities(name),
+		})
+	}
+	return rows
+}
+
+// RegisterStream records that provider has a usable Stream implementation.
+// Providers should call this from init alongside Register once Stream returns
+// chunks instead of ErrStreamingUnsupported.
+func RegisterStream(provider string) {
+	streamProviders[provider] = struct{}{}
+}
+
+// RegisterToolStream records that provider can accept tool schemas in Stream
+// requests. This is intentionally separate from RegisterStream because some
+// providers can stream tokens but cannot expose tools while streaming.
+func RegisterToolStream(provider string) {
+	toolStreamProviders[provider] = struct{}{}
+}
+
+var streamProviders = make(map[string]struct{})
+var toolStreamProviders = make(map[string]struct{})
+
+// RegisteredProviders returns the registered provider names in sorted order.
+// kind may be "model", "image", "video", "stream", "tool_stream", or empty for the union of all
+// provider registries.
+func RegisteredProviders(kind string) []string {
+	names := map[string]struct{}{}
+	add := func(registry any) {
+		switch r := registry.(type) {
+		case map[string]NewFunc:
+			for name := range r {
+				names[name] = struct{}{}
+			}
+		case map[string]NewImageFunc:
+			for name := range r {
+				names[name] = struct{}{}
+			}
+		case map[string]NewVideoFunc:
+			for name := range r {
+				names[name] = struct{}{}
+			}
+		case map[string]struct{}:
+			for name := range r {
+				names[name] = struct{}{}
+			}
+		}
+	}
+
+	switch kind {
+	case "model":
+		add(providers)
+	case "stream":
+		add(streamProviders)
+	case "tool_stream":
+		add(toolStreamProviders)
+	case "image":
+		add(imageProviders)
+	case "video":
+		add(videoProviders)
+	default:
+		add(providers)
+		add(imageProviders)
+		add(videoProviders)
+	}
+
+	out := make([]string, 0, len(names))
+	for name := range names {
+		out = append(out, name)
+	}
+	sort.Strings(out)
+	return out
+}