mcp refactor wip

lib/mcp/backend_memory.v

@@ -0,0 +1,153 @@
+module mcp
+
+import x.json2
+
+pub struct MemoryBackend {
+pub mut:
+	// Resource related fields
+	resources          map[string]Resource
+	subscriptions      []string // list of subscribed resource uri's
+	resource_contents  map[string][]ResourceContent
+	resource_templates map[string]ResourceTemplate
+
+	// Prompt related fields
+	prompts         map[string]Prompt
+	prompt_messages map[string][]PromptMessage
+	prompt_handlers map[string]PromptHandler
+
+	// Tool related fields
+	tools         map[string]Tool
+	tool_handlers map[string]ToolHandler
+}
+
+pub type ToolHandler = fn (arguments map[string]json2.Any) !ToolCallResult
+
+pub type PromptHandler = fn (arguments []string) ![]PromptMessage
+
+fn (b &MemoryBackend) resource_exists(uri string) !bool {
+	return uri in b.resources
+}
+
+fn (b &MemoryBackend) resource_get(uri string) !Resource {
+	return b.resources[uri] or { return error('resource not found') }
+}
+
+fn (b &MemoryBackend) resource_list() ![]Resource {
+	return b.resources.values()
+}
+
+fn (mut b MemoryBackend) resource_subscribe(uri string) ! {
+	if uri !in b.subscriptions {
+		b.subscriptions << uri
+	}
+}
+
+fn (b &MemoryBackend) resource_subscribed(uri string) !bool {
+	return uri in b.subscriptions
+}
+
+fn (mut b MemoryBackend) resource_unsubscribe(uri string) ! {
+	b.subscriptions = b.subscriptions.filter(it != uri)
+}
+
+fn (b &MemoryBackend) resource_contents_get(uri string) ![]ResourceContent {
+	return b.resource_contents[uri] or { return error('resource contents not found') }
+}
+
+fn (b &MemoryBackend) resource_templates_list() ![]ResourceTemplate {
+	return b.resource_templates.values()
+}
+
+// Prompt related methods
+
+fn (b &MemoryBackend) prompt_exists(name string) !bool {
+	return name in b.prompts
+}
+
+fn (b &MemoryBackend) prompt_get(name string) !Prompt {
+	return b.prompts[name] or { return error('prompt not found') }
+}
+
+fn (b &MemoryBackend) prompt_list() ![]Prompt {
+	return b.prompts.values()
+}
+
+fn (b &MemoryBackend) prompt_messages_get(name string, arguments map[string]string) ![]PromptMessage {
+	// Get the base messages for this prompt
+	base_messages := b.prompt_messages[name] or { return error('prompt messages not found') }
+
+	// Apply arguments to the messages
+	mut messages := []PromptMessage{}
+
+	for msg in base_messages {
+		mut content := msg.content
+
+		// If the content is text, replace argument placeholders
+		if content.typ == 'text' {
+			mut text := content.text
+
+			// Replace each argument in the text
+			for arg_name, arg_value in arguments {
+				text = text.replace('{{${arg_name}}}', arg_value)
+			}
+
+			content = PromptContent{
+				typ:      content.typ
+				text:     text
+				data:     content.data
+				mimetype: content.mimetype
+				resource: content.resource
+			}
+		}
+
+		messages << PromptMessage{
+			role:    msg.role
+			content: content
+		}
+	}
+
+	return messages
+}
+
+
+fn (b &MemoryBackend) prompt_call(name string, arguments []string) ![]PromptMessage {
+	// Get the tool handler
+	handler := b.prompt_handlers[name] or { return error('tool handler not found') }
+
+	// Call the handler with the provided arguments
+	return handler(arguments) or {panic(err)}
+}
+
+
+// Tool related methods
+
+fn (b &MemoryBackend) tool_exists(name string) !bool {
+	return name in b.tools
+}
+
+fn (b &MemoryBackend) tool_get(name string) !Tool {
+	return b.tools[name] or { return error('tool not found') }
+}
+
+fn (b &MemoryBackend) tool_list() ![]Tool {
+	return b.tools.values()
+}
+
+fn (b &MemoryBackend) tool_call(name string, arguments map[string]json2.Any) !ToolCallResult {
+	// Get the tool handler
+	handler := b.tool_handlers[name] or { return error('tool handler not found') }
+
+	// Call the handler with the provided arguments
+	return handler(arguments) or {
+		// If the handler throws an error, return it as a tool error
+		return ToolCallResult{
+			is_error: true
+			content:  [
+				ToolContent{
+					typ:  'text'
+					text: 'Error: ${err.msg()}'
+				},
+			]
+		}
+	}
+}