package daemon

import (
	"cmp"
	"context"
	"fmt"
	"isle/bootstrap"
	"isle/nebula"
	"slices"

	"golang.org/x/exp/maps"
)

// GetHostsResult wraps the results from the GetHosts RPC method.
type GetHostsResult struct {
	Hosts []bootstrap.Host
}

// RemoveHostRequest contains the arguments to the RemoveHost RPC method.
//
// All fields are required.
type RemoveHostRequest struct {
	HostName nebula.HostName
}

// CreateHostRequest contains the arguments to the
// CreateHost RPC method.
//
// All fields are required.
type CreateHostRequest struct {
	HostName nebula.HostName
	Opts     CreateHostOpts
}

// CreateHostResult wraps the results from the CreateHost RPC method.
type CreateHostResult struct {
	JoiningBootstrap JoiningBootstrap
}

// CreateNebulaCertificateRequest contains the arguments to the
// CreateNebulaCertificate RPC method.
//
// All fields are required.
type CreateNebulaCertificateRequest struct {
	HostName                nebula.HostName
	HostEncryptingPublicKey nebula.EncryptingPublicKey
}

// CreateNebulaCertificateResult wraps the results from the
// CreateNebulaCertificate RPC method.
type CreateNebulaCertificateResult struct {
	HostNebulaCertifcate nebula.Certificate
}

// RPC exposes all RPC methods which are available to be called over the RPC
// interface.
type RPC interface {
	// CreateNetwork passes through to the Daemon method of the same name.
	//
	// name: Human-readable name of the network.
	// domain: Primary domain name that network services are served under.
	// ipNet:
	//   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.
	// hostName: The name of this first host in the network.
	CreateNetwork(
		ctx context.Context,
		name string,
		domain string,
		ipNet nebula.IPNet,
		hostName nebula.HostName,
	) (
		struct{}, error,
	)

	// JoinNetwork passes through to the Daemon method of the same name.
	JoinNetwork(
		ctx context.Context, req JoiningBootstrap,
	) (
		struct{}, error,
	)

	// GetHosts returns all hosts known to the network, sorted by their name.
	GetHosts(ctx context.Context) (GetHostsResult, error)

	// GetGarageClientParams passes the call through to the Daemon method of the
	// same name.
	GetGarageClientParams(ctx context.Context) (GarageClientParams, error)

	// GetNebulaCAPublicCredentials returns the CAPublicCredentials for the
	// network.
	GetNebulaCAPublicCredentials(
		ctx context.Context,
	) (
		nebula.CAPublicCredentials, error,
	)

	// RemoveHost passes the call through to the Daemon method of the same name.
	RemoveHost(
		ctx context.Context, req RemoveHostRequest,
	) (
		struct{}, error,
	)

	// CreateHost passes the call through to the Daemon method of the same name.
	CreateHost(
		ctx context.Context, req CreateHostRequest,
	) (
		CreateHostResult, error,
	)

	// CreateNebulaCertificate passes the call through to the Daemon method of
	// the same name.
	CreateNebulaCertificate(
		ctx context.Context, req CreateNebulaCertificateRequest,
	) (
		CreateNebulaCertificateResult, error,
	)
}

type rpcImpl struct {
	daemon Daemon
}

// NewRPC initializes and returns an RPC instance.
func NewRPC(daemon Daemon) RPC {
	return &rpcImpl{daemon}
}

func (r *rpcImpl) CreateNetwork(
	ctx context.Context,
	name string,
	domain string,
	ipNet nebula.IPNet,
	hostName nebula.HostName,
) (
	struct{}, error,
) {
	return struct{}{}, r.daemon.CreateNetwork(
		ctx, name, domain, ipNet, hostName,
	)
}

func (r *rpcImpl) JoinNetwork(
	ctx context.Context, req JoiningBootstrap,
) (
	struct{}, error,
) {
	return struct{}{}, r.daemon.JoinNetwork(ctx, req)
}

func (r *rpcImpl) GetHosts(ctx context.Context) (GetHostsResult, error) {
	b, err := r.daemon.GetBootstrap(ctx)
	if err != nil {
		return GetHostsResult{}, fmt.Errorf("retrieving bootstrap: %w", err)
	}

	hosts := maps.Values(b.Hosts)
	slices.SortFunc(hosts, func(a, b bootstrap.Host) int {
		return cmp.Compare(a.Name, b.Name)
	})

	return GetHostsResult{hosts}, nil
}

func (r *rpcImpl) GetGarageClientParams(
	ctx context.Context,
) (
	GarageClientParams, error,
) {
	return r.daemon.GetGarageClientParams(ctx)
}

func (r *rpcImpl) GetNebulaCAPublicCredentials(
	ctx context.Context,
) (
	nebula.CAPublicCredentials, error,
) {
	b, err := r.daemon.GetBootstrap(ctx)
	if err != nil {
		return nebula.CAPublicCredentials{}, fmt.Errorf(
			"retrieving bootstrap: %w", err,
		)
	}

	return b.CAPublicCredentials, nil
}

func (r *rpcImpl) RemoveHost(
	ctx context.Context, req RemoveHostRequest,
) (
	struct{}, error,
) {
	return struct{}{}, r.daemon.RemoveHost(ctx, req.HostName)
}

func (r *rpcImpl) CreateHost(
	ctx context.Context, req CreateHostRequest,
) (
	CreateHostResult, error,
) {
	joiningBootstrap, err := r.daemon.CreateHost(
		ctx, req.HostName, req.Opts,
	)
	if err != nil {
		return CreateHostResult{}, err
	}

	return CreateHostResult{JoiningBootstrap: joiningBootstrap}, nil
}

func (r *rpcImpl) CreateNebulaCertificate(
	ctx context.Context, req CreateNebulaCertificateRequest,
) (
	CreateNebulaCertificateResult, error,
) {
	cert, err := r.daemon.CreateNebulaCertificate(
		ctx, req.HostName, req.HostEncryptingPublicKey,
	)
	if err != nil {
		return CreateNebulaCertificateResult{}, err
	}

	return CreateNebulaCertificateResult{
		HostNebulaCertifcate: cert,
	}, nil
}