// The snapd module's tools (novox/hq research 027/02, 026/05): the snaps on this machine, their
// revisions and the space they take, the store's pending updates, snapd's changes, and installing,
// removing and refreshing a snap. A Go bundle the node's runtime launches over stdio (ADR 0188,
// ADR 0193); it runs as the operator account, and an act goes through `sudo -n`.
//
// The module installs nothing: snapd is not in the distribution's official repositories (README).
package main

import (
	"fmt"
	"os"

	stdio "git.novox.be/novox/mesh-sdk/go"
)

var providedBy = map[string]string{
	"snap":      "snapd is not installed; it is not in the official repositories, and this module does not install it (see its README)",
	"systemctl": "the systemd package",
}

func main() {
	if err := stdio.Serve("", tools()); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}

var nameArg = map[string]any{"type": "string", "description": "the snap's name"}

func tools() []stdio.Tool {
	return []stdio.Tool{
		{
			Name: "snapd_status",
			Description: "Whether snapd is here and working: its version, its units (socket, service, AppArmor loader), " +
				"whether the kernel runs AppArmor (without it strict snaps are not confined), and whether /snap exists " +
				"for classic snaps. (r)",
			Input: map[string]any{},
			Run:   func(map[string]any) (any, error) { return Status() },
		},
		{
			Name: "snapd_list",
			Description: "Every installed snap and revision: version, revision, channel tracked, publisher, notes, and " +
				"whether the revision is disabled (kept for rollback, taking space). (r)",
			Input: map[string]any{},
			Run:   func(map[string]any) (any, error) { return List() },
		},
		{
			Name:        "snapd_info",
			Description: "One snap as the store and snapd describe it: summary, publisher, licence, commands, tracking, and the channels with their versions. (r)",
			Input:       map[string]any{"name": nameArg},
			Run: func(args map[string]any) (any, error) {
				name, err := snapName(args)
				if err != nil {
					return nil, err
				}
				return Info(name)
			},
		},
		{
			Name:        "snapd_updates",
			Description: "What a refresh would change: each snap with an update, its new version, revision and size. (r)",
			Input:       map[string]any{},
			Run:         func(map[string]any) (any, error) { return Updates() },
		},
		{
			Name: "snapd_disk_usage",
			Description: "The space each snap's revisions take in /var/lib/snapd/snaps, which of it is disabled revisions " +
				"kept for rollback, and the total. (r)",
			Input: map[string]any{},
			Run:   func(map[string]any) (any, error) { return DiskUsage() },
		},
		{
			Name:        "snapd_services",
			Description: "The services installed snaps provide, with whether each starts at boot and runs now. (r)",
			Input:       map[string]any{},
			Run:         func(map[string]any) (any, error) { return Services() },
		},
		{
			Name: "snapd_changes",
			Description: "snapd's recent changes (installs, refreshes, removals): id, status, when, summary; or, with id, " +
				"one change's tasks. An act answers the change id to follow here. (r)",
			Input: map[string]any{"id": map[string]any{"type": "string", "description": "one change's id, for its tasks"}},
			Run: func(args map[string]any) (any, error) {
				id, err := optText(args, "id", "")
				if err != nil {
					return nil, err
				}
				return Changes(id)
			},
		},
		{
			Name: "snapd_install",
			Description: "Install a snap from the store, optionally from a channel and in classic confinement. snapd " +
				"carries it out in the background; the answer is the change id to follow with snapd_changes. (a)",
			Input: map[string]any{
				"name":    nameArg,
				"channel": map[string]any{"type": "string", "description": "a channel such as latest/stable or 3.x/edge"},
				"classic": map[string]any{"type": "boolean", "description": "classic confinement, for a snap that asks for it"},
			},
			Run: func(args map[string]any) (any, error) {
				name, err := snapName(args)
				if err != nil {
					return nil, err
				}
				channel, err := optText(args, "channel", "")
				if err != nil {
					return nil, err
				}
				classic, err := optFlag(args, "classic", false)
				if err != nil {
					return nil, err
				}
				return Install(name, channel, classic)
			},
		},
		{
			Name:        "snapd_remove",
			Description: "Remove a snap, keeping a snapshot of its data unless purge is set. Answers the change id. (a)",
			Input: map[string]any{
				"name":  nameArg,
				"purge": map[string]any{"type": "boolean", "description": "remove its data too, without a snapshot"},
			},
			Run: func(args map[string]any) (any, error) {
				name, err := snapName(args)
				if err != nil {
					return nil, err
				}
				purge, err := optFlag(args, "purge", false)
				if err != nil {
					return nil, err
				}
				return Remove(name, purge)
			},
		},
		{
			Name:        "snapd_refresh",
			Description: "Refresh one snap, or every snap when no name is given. Answers the change id, or that nothing needed it. (a)",
			Input:       map[string]any{"name": map[string]any{"type": "string", "description": "the snap to refresh (default all)"}},
			Run: func(args map[string]any) (any, error) {
				name, err := optText(args, "name", "")
				if err != nil {
					return nil, err
				}
				if name != "" {
					if err := checkSnapName(name); err != nil {
						return nil, err
					}
				}
				return Refresh(name)
			},
		},
	}
}