package driver

import (
	"log"
	"net/rpc"

	"github.com/hashicorp/go-plugin"
	"github.com/hashicorp/nomad/client/driver/executor"
	"github.com/hashicorp/nomad/nomad/structs"
)

type ExecutorRPC struct {
	client *rpc.Client
}

// LaunchCmdArgs wraps a user command and the args for the purposes of RPC
type LaunchCmdArgs struct {
	Cmd *executor.ExecCommand
	Ctx *executor.ExecutorContext
}

func (e *ExecutorRPC) LaunchCmd(cmd *executor.ExecCommand, ctx *executor.ExecutorContext) (*executor.ProcessState, error) {
	var ps *executor.ProcessState
	err := e.client.Call("Plugin.LaunchCmd", LaunchCmdArgs{Cmd: cmd, Ctx: ctx}, &ps)
	return ps, err
}

func (e *ExecutorRPC) Wait() (*executor.ProcessState, error) {
	var ps executor.ProcessState
	err := e.client.Call("Plugin.Wait", new(interface{}), &ps)
	return &ps, err
}

func (e *ExecutorRPC) ShutDown() error {
	return e.client.Call("Plugin.ShutDown", new(interface{}), new(interface{}))
}

func (e *ExecutorRPC) Exit() error {
	return e.client.Call("Plugin.Exit", new(interface{}), new(interface{}))
}

func (e *ExecutorRPC) UpdateLogConfig(logConfig *structs.LogConfig) error {
	return e.client.Call("Plugin.UpdateLogConfig", logConfig, new(interface{}))
}

type ExecutorRPCServer struct {
	Impl executor.Executor
}

func (e *ExecutorRPCServer) LaunchCmd(args LaunchCmdArgs, ps *executor.ProcessState) error {
	state, err := e.Impl.LaunchCmd(args.Cmd, args.Ctx)
	if state != nil {
		*ps = *state
	}
	return err
}

func (e *ExecutorRPCServer) Wait(args interface{}, ps *executor.ProcessState) error {
	state, err := e.Impl.Wait()
	if state != nil {
		*ps = *state
	}
	return err
}

func (e *ExecutorRPCServer) ShutDown(args interface{}, resp *interface{}) error {
	return e.Impl.ShutDown()
}

func (e *ExecutorRPCServer) Exit(args interface{}, resp *interface{}) error {
	return e.Impl.Exit()
}

func (e *ExecutorRPCServer) UpdateLogConfig(args *structs.LogConfig, resp *interface{}) error {
	return e.Impl.UpdateLogConfig(args)
}

type ExecutorPlugin struct {
	logger *log.Logger
	Impl   *ExecutorRPCServer
}

func (p *ExecutorPlugin) Server(*plugin.MuxBroker) (interface{}, error) {
	if p.Impl == nil {
		p.Impl = &ExecutorRPCServer{Impl: executor.NewExecutor(p.logger)}
	}
	return p.Impl, nil
}

func (p *ExecutorPlugin) Client(b *plugin.MuxBroker, c *rpc.Client) (interface{}, error) {
	return &ExecutorRPC{client: c}, nil
}