aggregator

type AggregatedCapabilities struct {
	// Tools are the aggregated tools (ready to expose to clients).
	Tools []vmcp.Tool

	// Resources are the aggregated resources.
	Resources []vmcp.Resource

	// Prompts are the aggregated prompts.
	Prompts []vmcp.Prompt

	// SupportsLogging indicates if logging is supported.
	SupportsLogging bool

	// SupportsSampling indicates if sampling is supported.
	SupportsSampling bool

	// RoutingTable maps capabilities to their backend targets.
	RoutingTable *vmcp.RoutingTable

	// Metadata contains aggregation statistics and info.
	Metadata *AggregationMetadata
}

type AggregationMetadata struct {
	// BackendCount is the number of backends aggregated.
	BackendCount int

	// ToolCount is the total number of tools.
	ToolCount int

	// ResourceCount is the total number of resources.
	ResourceCount int

	// PromptCount is the total number of prompts.
	PromptCount int

	// ConflictsResolved is the number of conflicts that were resolved.
	ConflictsResolved int

	// ConflictStrategy is the strategy used for conflict resolution.
	ConflictStrategy vmcp.ConflictResolutionStrategy
}

type Aggregator interface {
	// QueryCapabilities queries a backend for its MCP capabilities.
	// Returns the raw capabilities (tools, resources, prompts) from the backend.
	QueryCapabilities(ctx context.Context, backend vmcp.Backend) (*BackendCapabilities, error)

	// QueryAllCapabilities queries all backends for their capabilities in parallel.
	// Handles backend failures gracefully (logs and continues with remaining backends).
	QueryAllCapabilities(ctx context.Context, backends []vmcp.Backend) (map[string]*BackendCapabilities, error)

	// ResolveConflicts applies conflict resolution strategy to handle
	// duplicate capability names across backends.
	ResolveConflicts(ctx context.Context, capabilities map[string]*BackendCapabilities) (*ResolvedCapabilities, error)

	// MergeCapabilities creates the final unified capability view and routing table.
	// Uses the backend registry to populate full BackendTarget information for routing.
	MergeCapabilities(
		ctx context.Context,
		resolved *ResolvedCapabilities,
		registry vmcp.BackendRegistry,
	) (*AggregatedCapabilities, error)

	// AggregateCapabilities is a convenience method that performs the full aggregation pipeline:
	// 1. Query all backends
	// 2. Resolve conflicts
	// 3. Merge into final view
	AggregateCapabilities(ctx context.Context, backends []vmcp.Backend) (*AggregatedCapabilities, error)
}

type BackendCapabilities struct {
	// BackendID identifies the source backend.
	BackendID string

	// Tools are the tools exposed by this backend.
	Tools []vmcp.Tool

	// Resources are the resources exposed by this backend.
	Resources []vmcp.Resource

	// Prompts are the prompts exposed by this backend.
	Prompts []vmcp.Prompt

	// SupportsLogging indicates if the backend supports MCP logging.
	SupportsLogging bool

	// SupportsSampling indicates if the backend supports MCP sampling.
	SupportsSampling bool
}

type BackendDiscoverer interface {
	// Discover finds all backend workloads in the specified group.
	// Returns only healthy/running backends.
	// The groupRef format is platform-specific (group name for CLI, MCPGroup name for K8s).
	Discover(ctx context.Context, groupRef string) ([]vmcp.Backend, error)
}

type ConflictResolver interface {
	// ResolveToolConflicts resolves tool name conflicts using the configured strategy.
	ResolveToolConflicts(ctx context.Context, tools map[string][]vmcp.Tool) (map[string]*ResolvedTool, error)
}

type ResolvedCapabilities struct {
	// Tools are the conflict-resolved tools.
	// Map key is the resolved tool name, value contains original name and backend.
	Tools map[string]*ResolvedTool

	// Resources are passed through (conflicts rare, namespaced by URI).
	Resources []vmcp.Resource

	// Prompts are passed through (conflicts rare, namespaced by name).
	Prompts []vmcp.Prompt

	// SupportsLogging is true if any backend supports logging.
	SupportsLogging bool

	// SupportsSampling is true if any backend supports sampling.
	SupportsSampling bool
}

type ResolvedTool struct {
	// ResolvedName is the final name exposed to clients (after conflict resolution).
	ResolvedName string

	// OriginalName is the tool's name in the backend.
	OriginalName string

	// Description is the tool description (may be overridden).
	Description string

	// InputSchema is the JSON Schema for parameters.
	InputSchema map[string]any

	// BackendID identifies the backend providing this tool.
	BackendID string

	// ConflictResolutionApplied indicates which strategy was used.
	ConflictResolutionApplied vmcp.ConflictResolutionStrategy
}

type ToolFilter interface {
	// FilterTools returns only the tools that should be included.
	FilterTools(ctx context.Context, tools []vmcp.Tool) ([]vmcp.Tool, error)
}

type ToolOverride interface {
	// ApplyOverrides modifies tool names and descriptions.
	ApplyOverrides(ctx context.Context, tools []vmcp.Tool) ([]vmcp.Tool, error)
}