package master

import (
	"context"
	"fmt"

	mcpv1 "git.wntrmute.dev/mc/mcp/gen/mcp/v1"
	"git.wntrmute.dev/mc/mcp/internal/masterdb"
)

// Status returns the status of services across the fleet.
func (m *Master) Status(ctx context.Context, req *mcpv1.MasterStatusRequest) (*mcpv1.MasterStatusResponse, error) {
	m.Logger.Debug("Status", "service", req.GetServiceName())

	resp := &mcpv1.MasterStatusResponse{}

	// If a specific service is requested, look up its placement.
	if name := req.GetServiceName(); name != "" {
		placement, err := masterdb.GetPlacement(m.DB, name)
		if err != nil {
			return nil, fmt.Errorf("lookup placement: %w", err)
		}
		if placement == nil {
			return resp, nil // empty — service not found
		}

		ss := m.getServiceStatus(ctx, placement)
		resp.Services = append(resp.Services, ss)
		return resp, nil
	}

	// All services.
	placements, err := masterdb.ListPlacements(m.DB)
	if err != nil {
		return nil, fmt.Errorf("list placements: %w", err)
	}

	for _, p := range placements {
		ss := m.getServiceStatus(ctx, p)
		resp.Services = append(resp.Services, ss)
	}

	return resp, nil
}

func (m *Master) getServiceStatus(ctx context.Context, p *masterdb.Placement) *mcpv1.ServiceStatus {
	ss := &mcpv1.ServiceStatus{
		Name:   p.ServiceName,
		Node:   p.Node,
		Tier:   p.Tier,
		Status: "unknown",
	}

	// Query the agent for live status.
	client, err := m.Pool.Get(p.Node)
	if err != nil {
		ss.Status = "unreachable"
		return ss
	}

	statusCtx, cancel := context.WithTimeout(ctx, m.Config.Timeouts.HealthCheck.Duration)
	defer cancel()

	agentResp, err := client.GetServiceStatus(statusCtx, &mcpv1.GetServiceStatusRequest{
		Name: p.ServiceName,
	})
	if err != nil {
		ss.Status = "unreachable"
		return ss
	}

	// Map agent status to master status.
	for _, info := range agentResp.GetServices() {
		if info.GetName() == p.ServiceName {
			if info.GetActive() {
				ss.Status = "running"
			} else {
				ss.Status = "stopped"
			}
			break
		}
	}

	// Attach edge route info.
	edgeRoutes, err := masterdb.ListEdgeRoutesForService(m.DB, p.ServiceName)
	if err == nil {
		for _, er := range edgeRoutes {
			ss.EdgeRoutes = append(ss.EdgeRoutes, &mcpv1.EdgeRouteStatus{
				Hostname: er.Hostname,
				EdgeNode: er.EdgeNode,
			})
		}
	}

	return ss
}

// ListNodes returns all nodes in the registry with placement counts.
func (m *Master) ListNodes(_ context.Context, _ *mcpv1.ListNodesRequest) (*mcpv1.ListNodesResponse, error) {
	m.Logger.Debug("ListNodes")

	nodes, err := masterdb.ListNodes(m.DB)
	if err != nil {
		return nil, fmt.Errorf("list nodes: %w", err)
	}

	counts, err := masterdb.CountPlacementsPerNode(m.DB)
	if err != nil {
		return nil, fmt.Errorf("count placements: %w", err)
	}

	resp := &mcpv1.ListNodesResponse{}
	for _, n := range nodes {
		ni := &mcpv1.NodeInfo{
			Name:       n.Name,
			Role:       n.Role,
			Address:    n.Address,
			Arch:       n.Arch,
			Status:     n.Status,
			Containers: int32(n.Containers), //nolint:gosec // small number
			Services:   int32(counts[n.Name]), //nolint:gosec // small number
		}
		if n.LastHeartbeat != nil {
			ni.LastHeartbeat = n.LastHeartbeat.Format("2006-01-02T15:04:05Z")
		}
		resp.Nodes = append(resp.Nodes, ni)
	}

	return resp, nil
}