/*
Package econetmcpgen exposes an MCP server, mounted as an HTTP handler at
/api/mcp, whose tools are generated from the EconetService proto by
protoc-gen-go-mcp and forwarded to the in-process gRPC server.

It is the generated-code counterpart to econetmcp (which hand-writes a single
list_water_heaters tool). Both expose an identical package API, so switching
between them is a one-line import change in pkg/econet/econet.go.
*/
package econetmcpgen

import (
	"context"
	"net/http"

	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/http/opts"
	"github.com/modelcontextprotocol/go-sdk/mcp"
	"github.com/redpanda-data/protoc-gen-go-mcp/pkg/runtime/gosdk"
	"github.com/rs/zerolog"

	v1alpha1mcp "gitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1/v1alpha1mcp"
	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/config"
	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetgrpc"
)

var EconetMCPImpl = &mcp.Implementation{
	Name:  "Econet MCP Server",
	Title: "Econet Exporter MCP",
}

type EconetMCPServer struct {
	ctx        context.Context
	cfg        *config.ServiceConfig
	log        *zerolog.Logger
	server     *mcp.Server
	econetGRPC *econetgrpc.EconetGRPCServer
}

func NewEconetMCPServer(ctx context.Context, cfg *config.ServiceConfig,
	grpc *econetgrpc.EconetGRPCServer,
) *EconetMCPServer {
	return &EconetMCPServer{
		ctx:        ctx,
		cfg:        cfg,
		log:        zerolog.Ctx(ctx),
		econetGRPC: grpc,
		server: mcp.NewServer(EconetMCPImpl, &mcp.ServerOptions{
			Instructions: "Use these tools to inspect Rheem EcoNet water heaters: " +
				"current mode, setpoint, hot water availability, connectivity, and alerts.",
			HasTools: true,
		}),
	}
}

func (m *EconetMCPServer) GetHandlers() []opts.HTTPHandler {
	// Register the generated tools against the in-process gRPC server via the
	// go-sdk adapter, so the generated code shares our configured *mcp.Server.
	v1alpha1mcp.RegisterEconetServiceHandler(gosdk.Wrap(m.server), m.econetGRPC)

	handler := mcp.NewStreamableHTTPHandler(func(*http.Request) *mcp.Server {
		return m.server
	}, &mcp.StreamableHTTPOptions{})

	m.log.Debug().Msg("Econet MCP tools ready (generated)")

	return []opts.HTTPHandler{
		{
			Prefix:  "/api/mcp",
			Handler: handler,
		},
	}
}