package main

import (
	"context"
	"fmt"
	"path/filepath"
	"strings"

	"github.com/spf13/cobra"

	mcpv1 "git.wntrmute.dev/mc/mcp/gen/mcp/v1"
	"git.wntrmute.dev/mc/mcp/internal/config"
	"git.wntrmute.dev/mc/mcp/internal/runtime"
	"git.wntrmute.dev/mc/mcp/internal/servicedef"
)

func deployCmd() *cobra.Command {
	var direct bool

	cmd := &cobra.Command{
		Use:   "deploy <service>[/<component>]",
		Short: "Deploy service from service definition",
		Args:  cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			cfg, err := config.LoadCLIConfig(cfgPath)
			if err != nil {
				return fmt.Errorf("load config: %w", err)
			}

			serviceName, component := parseServiceArg(args[0])

			def, err := loadServiceDef(cmd, cfg, serviceName)
			if err != nil {
				return err
			}

			// Auto-build missing images if the service has build config.
			rt := &runtime.Podman{}
			if err := ensureImages(cmd.Context(), cfg, def, rt, component); err != nil {
				return err
			}

			spec := servicedef.ToProto(def)

			// Route through master if configured and not in direct mode.
			if cfg.Master != nil && cfg.Master.Address != "" && !direct {
				return deployViaMaster(cfg, spec)
			}

			// Direct mode: deploy to agent.
			address, err := findNodeAddress(cfg, def.Node)
			if err != nil {
				return err
			}

			client, conn, err := dialAgent(address, cfg)
			if err != nil {
				return fmt.Errorf("dial agent: %w", err)
			}
			defer func() { _ = conn.Close() }()

			resp, err := client.Deploy(context.Background(), &mcpv1.DeployRequest{
				Service:   spec,
				Component: component,
			})
			if err != nil {
				return fmt.Errorf("deploy: %w", err)
			}

			printComponentResults(resp.GetResults())
			return nil
		},
	}
	cmd.Flags().StringP("file", "f", "", "service definition file")
	cmd.Flags().BoolVar(&direct, "direct", false, "bypass master, deploy directly to agent (v1 mode)")
	return cmd
}

func deployViaMaster(cfg *config.CLIConfig, spec *mcpv1.ServiceSpec) error {
	client, conn, err := dialMaster(cfg.Master.Address, cfg)
	if err != nil {
		return fmt.Errorf("dial master: %w", err)
	}
	defer func() { _ = conn.Close() }()

	resp, err := client.Deploy(context.Background(), &mcpv1.MasterDeployRequest{
		Service: spec,
	})
	if err != nil {
		return fmt.Errorf("master deploy: %w", err)
	}

	fmt.Printf("  %s: placed on %s\n", spec.GetName(), resp.GetNode())
	if r := resp.GetDeployResult(); r != nil {
		printStepResult("deploy", r)
	}
	if r := resp.GetDnsResult(); r != nil {
		printStepResult("dns", r)
	}
	if r := resp.GetEdgeRouteResult(); r != nil {
		printStepResult("edge", r)
	}
	if !resp.GetSuccess() {
		return fmt.Errorf("deploy failed: %s", resp.GetError())
	}
	return nil
}

func printStepResult(name string, r *mcpv1.StepResult) {
	if r.GetSuccess() {
		fmt.Printf("  %s: ok\n", name)
	} else {
		fmt.Printf("  %s: FAILED — %s\n", name, r.GetError())
	}
}

// parseServiceArg splits a "service/component" argument into its parts.
func parseServiceArg(arg string) (service, component string) {
	parts := strings.SplitN(arg, "/", 2)
	service = parts[0]
	if len(parts) == 2 {
		component = parts[1]
	}
	return service, component
}

// loadServiceDef attempts to load a service definition from the -f flag,
// the configured services directory, or by falling back to the agent registry.
func loadServiceDef(cmd *cobra.Command, cfg *config.CLIConfig, serviceName string) (*servicedef.ServiceDef, error) {
	// Check -f flag first.
	filePath, _ := cmd.Flags().GetString("file")
	if filePath != "" {
		def, err := servicedef.Load(filePath)
		if err != nil {
			return nil, fmt.Errorf("load service def from %q: %w", filePath, err)
		}
		return def, nil
	}

	// Try services directory.
	dirPath := filepath.Join(cfg.Services.Dir, serviceName+".toml")
	def, err := servicedef.Load(dirPath)
	if err == nil {
		return def, nil
	}

	// Fall back to agent registry: query each node for the service.
	for _, node := range cfg.Nodes {
		client, conn, dialErr := dialAgent(node.Address, cfg)
		if dialErr != nil {
			continue
		}

		resp, listErr := client.ListServices(context.Background(), &mcpv1.ListServicesRequest{})
		_ = conn.Close()
		if listErr != nil {
			continue
		}

		for _, svc := range resp.GetServices() {
			if svc.GetName() == serviceName {
				return servicedef.FromProto(serviceSpecFromInfo(svc), node.Name), nil
			}
		}
	}

	return nil, fmt.Errorf("service definition %q not found in %q or agent registry", serviceName, cfg.Services.Dir)
}

// serviceSpecFromInfo converts a ServiceInfo to a ServiceSpec for use with
// servicedef.FromProto. This is needed because the agent registry returns
// ServiceInfo, not ServiceSpec.
func serviceSpecFromInfo(info *mcpv1.ServiceInfo) *mcpv1.ServiceSpec {
	spec := &mcpv1.ServiceSpec{
		Name:    info.GetName(),
		Active:  info.GetActive(),
		Comment: info.GetComment(),
	}
	for _, c := range info.GetComponents() {
		spec.Components = append(spec.Components, &mcpv1.ComponentSpec{
			Name:  c.GetName(),
			Image: c.GetImage(),
		})
	}
	return spec
}