package pluginInternal

import (
	"os"
	"os/exec"

	"github.com/hashicorp/go-hclog"
	"github.com/hashicorp/go-plugin"
	"github.com/rs/zerolog/log"
)

var client *plugin.Client

// HashicorpPlugin implements hashicorp/go-plugin
type HashicorpPlugin struct {
	logOn bool // turn on plugin log
	FuncCaller
	cachedFunctions map[string]bool // cache loaded functions to improve performance
}

func (p *HashicorpPlugin) Init(path string) error {
	loggerOptions := &hclog.LoggerOptions{
		Name:   PluginName,
		Output: os.Stdout,
	}
	if p.logOn {
		loggerOptions.Level = hclog.Debug
	} else {
		loggerOptions.Level = hclog.Info
	}
	// launch the plugin process
	client = plugin.NewClient(&plugin.ClientConfig{
		HandshakeConfig: HandshakeConfig,
		Plugins: map[string]plugin.Plugin{
			PluginName: &HRPPlugin{},
		},
		Cmd:    exec.Command(path),
		Logger: hclog.New(loggerOptions),
	})

	// Connect via RPC
	rpcClient, err := client.Client()
	if err != nil {
		log.Error().Err(err).Msg("connect plugin via RPC failed")
		return err
	}

	// Request the plugin
	raw, err := rpcClient.Dispense(PluginName)
	if err != nil {
		log.Error().Err(err).Msg("request plugin failed")
		return err
	}

	// We should have a Function now! This feels like a normal interface
	// implementation but is in fact over an RPC connection.
	p.FuncCaller = raw.(FuncCaller)

	p.cachedFunctions = make(map[string]bool)
	log.Info().Str("path", path).Msg("load hashicorp go plugin success")
	return nil
}

func (p *HashicorpPlugin) Has(funcName string) bool {
	flag, ok := p.cachedFunctions[funcName]
	if ok {
		return flag
	}

	funcNames, err := p.GetNames()
	if err != nil {
		return false
	}

	for _, name := range funcNames {
		if name == funcName {
			p.cachedFunctions[funcName] = true // cache as exists
			return true
		}
	}

	p.cachedFunctions[funcName] = false // cache as not exists
	return false
}

func (p *HashicorpPlugin) Call(funcName string, args ...interface{}) (interface{}, error) {
	return p.FuncCaller.Call(funcName, args...)
}

func (p *HashicorpPlugin) Quit() error {
	// kill hashicorp plugin process
	log.Info().Msg("quit hashicorp plugin process")
	client.Kill()
	return nil
}