package main

import (
	"cmp"
	"errors"
	"fmt"
	"isle/bootstrap"
	"isle/daemon"
	"isle/daemon/daecommon"
	"isle/daemon/network"
	"isle/jsonutil"
	"isle/nebula"
	"isle/toolkit"
	"path/filepath"
	"slices"
	"strconv"
	"strings"
)

var subCmdNetworkCreate = subCmd{
	name:  "create",
	descr: "Create's a new network, with this host being the first host in that network.",
	do: func(ctx subCmdCtx) error {
		var (
			ipNet         ipNetFlag
			hostName      hostNameFlag
			vpnPublicAddr addrFlag
		)

		name := ctx.flags.StringP(
			"name", "N", "",
			"Human-readable name to identify the network as.",
		)

		domain := ctx.flags.StringP(
			"domain", "d", "",
			"Domain name that should be used as the root domain in the network.",
		)

		ipNetF := ctx.flags.VarPF(
			&ipNet, "ip-net", "i",
			`An IP subnet, in CIDR form, which will be the overall range of`+
				` possible IPs in the network. The first IP in this network`+
				` range will become this first host's IP.`,
		)

		hostNameF := ctx.flags.VarPF(
			&hostName,
			"hostname", "n",
			"Name of this host, which will be the first host in the network",
		)

		vpnPublicAddrF := ctx.flags.VarPF(
			&vpnPublicAddr,
			"vpn-public-address",
			"",
			"Public address (host:port) that this host is publicly available on",
		)

		storageAllocStrs := ctx.flags.StringArray(
			"storage-allocation",
			nil,
			"Storage allocation on this host, in the form '<capacity-in-gb>@<path>`",
		)

		ctx, err := ctx.withParsedFlags(&withParsedFlagsOpts{
			noNetwork: true,
		})
		if err != nil {
			return fmt.Errorf("parsing flags: %w", err)
		}

		if *name == "" ||
			*domain == "" ||
			!ipNetF.Changed ||
			!hostNameF.Changed {
			return errors.New("--name, --domain, --ip-net, and --hostname are required")
		}

		type storageAlloc struct {
			capacity uint64
			path     string
		}

		storageAllocs := make([]storageAlloc, len(*storageAllocStrs))
		for i, str := range *storageAllocStrs {
			capStr, path, ok := strings.Cut(str, "@")
			if !ok {
				return fmt.Errorf(
					"malformed --storage-allocation %q, no '@' found", str,
				)
			}

			capacity, err := strconv.ParseUint(capStr, 10, 64)
			if err != nil {
				return fmt.Errorf(
					"invalid --storage-allocation capacity %q", capStr,
				)
			}

			storageAllocs[i] = storageAlloc{capacity, path}
		}

		daemonRPC, err := ctx.newDaemonRPC()
		if err != nil {
			return fmt.Errorf("creating daemon RPC client: %w", err)
		}
		defer daemonRPC.Close()

		var networkConfig *daecommon.NetworkConfig
		if vpnPublicAddrF.Changed || len(storageAllocs) > 0 {
			networkConfig = toolkit.Ptr(
				daecommon.NewNetworkConfig(func(c *daecommon.NetworkConfig) {
					c.VPN.PublicAddr = string(vpnPublicAddr.V)
					for _, a := range storageAllocs {
						c.Storage.Allocations = append(
							c.Storage.Allocations,
							daecommon.ConfigStorageAllocation{
								DataPath: filepath.Join(a.path, "data"),
								MetaPath: filepath.Join(a.path, "meta"),
								Capacity: int(a.capacity),
							},
						)
					}
				}),
			)
		}

		err = daemonRPC.CreateNetwork(
			ctx,
			ctx.opts.bootstrapNewCreationParams(*name, *domain),
			ipNet.V,
			hostName.V,
			&daemon.CreateNetworkOpts{Config: networkConfig},
		)
		if err != nil {
			return fmt.Errorf("creating network: %w", err)
		}

		return nil
	},
}

var subCmdNetworkJoin = subCmd{
	name:  "join",
	descr: "Joins this host to an existing network",
	do: func(ctx subCmdCtx) error {
		bootstrapPath := ctx.flags.StringP(
			"bootstrap-path", "b", "", "Path to a bootstrap.json file.",
		)

		ctx, err := ctx.withParsedFlags(&withParsedFlagsOpts{
			noNetwork: true,
		})
		if err != nil {
			return fmt.Errorf("parsing flags: %w", err)
		}

		if *bootstrapPath == "" {
			return errors.New("--bootstrap-path is required")
		}

		var newBootstrap network.JoiningBootstrap
		if err := jsonutil.LoadFile(&newBootstrap, *bootstrapPath); err != nil {
			return fmt.Errorf(
				"loading bootstrap from %q: %w", *bootstrapPath, err,
			)
		}

		daemonRPC, err := ctx.newDaemonRPC()
		if err != nil {
			return fmt.Errorf("creating daemon RPC client: %w", err)
		}
		defer daemonRPC.Close()

		return daemonRPC.JoinNetwork(ctx, newBootstrap)
	},
}

var subCmdNetworkList = subCmd{
	name:  "list",
	descr: "Lists all networks which have been joined",
	do: doWithOutput(func(ctx subCmdCtx) (any, error) {
		ctx, err := ctx.withParsedFlags(&withParsedFlagsOpts{
			noNetwork: true,
		})
		if err != nil {
			return nil, fmt.Errorf("parsing flags: %w", err)
		}

		daemonRPC, err := ctx.newDaemonRPC()
		if err != nil {
			return nil, fmt.Errorf("creating daemon RPC client: %w", err)
		}
		defer daemonRPC.Close()

		networkCreationParams, err := daemonRPC.GetNetworks(ctx)
		if err != nil {
			return nil, fmt.Errorf("calling GetNetworks: %w", err)
		}

		type lighthouseView struct {
			PublicAddr string `yaml:"public_addr,omitempty"`
			IP         string `yaml:"ip"`
		}

		type networkView struct {
			bootstrap.CreationParams `yaml:",inline"`
			CACert                   nebula.Certificate `yaml:"ca_cert"`
			SubnetCIDR               string             `yaml:"subnet_cidr"`
			Lighthouses              []lighthouseView   `yaml:"lighthouses"`
		}

		networkViews := make([]networkView, len(networkCreationParams))

		for i, creationParams := range networkCreationParams {
			ctx := daemon.WithNetwork(ctx, creationParams.ID)

			networkBootstrap, err := daemonRPC.GetBootstrap(ctx)
			if err != nil {
				return nil, fmt.Errorf(
					"calling GetBootstrap with network:%+v: %w",
					networkCreationParams,
					err,
				)
			}

			var (
				caCert        = networkBootstrap.CAPublicCredentials.Cert
				caCertDetails = caCert.Unwrap().Details
				subnet        = caCertDetails.Subnets[0]

				lighthouseViews []lighthouseView
			)

			for _, h := range networkBootstrap.HostsOrdered() {
				if h.Nebula.PublicAddr == "" {
					continue
				}

				lighthouseViews = append(lighthouseViews, lighthouseView{
					PublicAddr: h.Nebula.PublicAddr,
					IP:         h.IP().String(),
				})
			}

			networkViews[i] = networkView{
				CreationParams: creationParams,
				CACert:         caCert,
				SubnetCIDR:     subnet.String(),
				Lighthouses:    lighthouseViews,
			}
		}

		slices.SortFunc(networkViews, func(a, b networkView) int {
			return cmp.Or(
				cmp.Compare(a.Name, b.Name),
				cmp.Compare(a.ID, b.ID),
			)
		})

		return networkViews, nil
	}),
}

var subCmdNetworkGetConfig = subCmd{
	name:  "get-config",
	descr: "Displays the currently active configuration for a joined network",
	do: doWithOutput(func(ctx subCmdCtx) (any, error) {
		ctx, err := ctx.withParsedFlags(nil)
		if err != nil {
			return nil, fmt.Errorf("parsing flags: %w", err)
		}

		daemonRPC, err := ctx.newDaemonRPC()
		if err != nil {
			return nil, fmt.Errorf("creating daemon RPC client: %w", err)
		}
		defer daemonRPC.Close()

		return daemonRPC.GetConfig(ctx)
	}),
}

var subCmdNetwork = subCmd{
	name:   "network",
	descr:  "Sub-commands related to network membership",
	plural: "s",
	do: func(ctx subCmdCtx) error {
		return ctx.doSubCmd(
			subCmdNetworkCreate,
			subCmdNetworkJoin,
			subCmdNetworkList,
			subCmdNetworkGetConfig,
		)
	},
}