// Copyright erfenjiao, 630166475@qq.com.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package wasm

import (
	"fmt"
	"path/filepath"
	"sync"

	"github.com/lf-edge/ekuiper/internal/conf"
	"github.com/lf-edge/ekuiper/internal/plugin"
)

type registry struct {
	sync.RWMutex
	plugins   map[string]*PluginInfo
	functions map[string]string
}

// Set prerequisite: the pluginInfo must have been validated that the names are valid
func (r *registry) Set(name string, pi *PluginInfo) {
	r.Lock()
	defer r.Unlock()
	pluginDir, err := conf.GetPluginsLoc()
	if err != nil {
		fmt.Println("[internal][wasm] cannot find plugins folder:", err)
	}
	wasmPath := filepath.Join(pluginDir, "wasm", name, name+".wasm")
	pi.WasmFile = wasmPath
	r.plugins[name] = pi
	for _, s := range pi.Functions {
		r.functions[s] = name
	}
}

func (r *registry) Get(name string) (*PluginInfo, bool) {
	r.RLock()
	defer r.RUnlock()
	result, ok := r.plugins[name]
	return result, ok
}

func (r *registry) GetSymbol(pt plugin.PluginType, symbolName string) (string, bool) {
	switch pt {
	case plugin.FUNCTION:
		s, ok := r.functions[symbolName]
		return s, ok
	default:
		return "", false
	}
}

func (r *registry) List() []*PluginInfo {
	r.RLock()
	defer r.RUnlock()
	// return empty slice instead of nil to help json marshal
	result := make([]*PluginInfo, 0, len(r.plugins))
	for _, v := range r.plugins {
		result = append(result, v)
	}
	return result
}

func (r *registry) Delete(name string) {
	r.Lock()
	defer r.Unlock()
	pi, ok := r.plugins[name]
	if !ok {
		return
	}
	delete(r.plugins, name)
	for _, s := range pi.Functions {
		delete(r.functions, s)
	}
}