package node

import (
	"os"
	"strings"

	"github.com/docker/cli/cli/command/completion"
	"github.com/moby/moby/api/types/swarm"
	"github.com/moby/moby/client"
	"github.com/spf13/cobra"
)

var (
	// nodePsFilters are the filters that can be used with "docker node ps --filter".
	nodePsFilters = []string{"desired-state", "id", "label", "name"}

	// taskDesiredStates are the valid values for the "desired-state" task filter.
	taskDesiredStates = []string{
		string(swarm.TaskStateRunning),
		string(swarm.TaskStateShutdown),
		string(swarm.TaskStateAccepted),
	}
)

// completeNodeNames offers completion for swarm node (host)names and optional IDs.
// By default, only names are returned.
// Set DOCKER_COMPLETION_SHOW_NODE_IDS=yes to also complete IDs.
//
// TODO(thaJeztah): add support for filters.
func completeNodeNames(dockerCLI completion.APIClientProvider) cobra.CompletionFunc {
	// https://github.com/docker/cli/blob/f9ced58158d5e0b358052432244b483774a1983d/contrib/completion/bash/docker#L41-L43
	showIDs := os.Getenv("DOCKER_COMPLETION_SHOW_NODE_IDS") == "yes"
	return func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
		res, err := dockerCLI.Client().NodeList(cmd.Context(), client.NodeListOptions{})
		if err != nil {
			return nil, cobra.ShellCompDirectiveError
		}

		names := make([]string, 0, len(res.Items)+1)
		for _, node := range res.Items {
			if showIDs {
				names = append(names, node.Description.Hostname, node.ID)
			} else {
				names = append(names, node.Description.Hostname)
			}
		}
		// Nodes allow "self" as magic word for the current node.
		names = append(names, "self")
		return names, cobra.ShellCompDirectiveNoFileComp
	}
}

// completeNodePsFilters provides completion for the filters that can be used
// with "docker node ps --filter".
func completeNodePsFilters(_ completion.APIClientProvider) cobra.CompletionFunc {
	return func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
		key, _, ok := strings.Cut(toComplete, "=")
		if !ok {
			return completion.WithSuffix("=", nodePsFilters), cobra.ShellCompDirectiveNoSpace
		}
		switch key {
		case "desired-state":
			return completion.WithPrefix("desired-state=", taskDesiredStates), cobra.ShellCompDirectiveNoFileComp
		case "id", "name", "label":
			// Task IDs, names, and labels are not easily discoverable; only offer the key.
			return nil, cobra.ShellCompDirectiveNoFileComp
		default:
			return completion.WithSuffix("=", nodePsFilters), cobra.ShellCompDirectiveNoSpace | cobra.ShellCompDirectiveNoFileComp
		}
	}
}