// Copyright 2022 EMQ Technologies Co., Ltd.
//
// 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.

//go:build (plugin || !core) && (ui || !core)
// +build plugin !core
// +build ui !core

package server

import (
	"fmt"
	"github.com/gorilla/mux"
	"github.com/lf-edge/ekuiper/internal/conf"
	"github.com/lf-edge/ekuiper/internal/plugin"
	"net/http"
	"runtime"
	"strings"
)

// This must be and will be run after meta_init.go init()
func init() {
	metaEndpoints = append(metaEndpoints, func(r *mux.Router) {
		r.HandleFunc("/plugins/sources/prebuild", prebuildSourcePlugins).Methods(http.MethodGet)
		r.HandleFunc("/plugins/sinks/prebuild", prebuildSinkPlugins).Methods(http.MethodGet)
		r.HandleFunc("/plugins/functions/prebuild", prebuildFuncsPlugins).Methods(http.MethodGet)
	})
}

func prebuildSourcePlugins(w http.ResponseWriter, r *http.Request) {
	prebuildPluginsHandler(w, r, plugin.SOURCE)
}

func prebuildSinkPlugins(w http.ResponseWriter, r *http.Request) {
	prebuildPluginsHandler(w, r, plugin.SINK)
}

func prebuildFuncsPlugins(w http.ResponseWriter, r *http.Request) {
	prebuildPluginsHandler(w, r, plugin.FUNCTION)
}

func prebuildPluginsHandler(w http.ResponseWriter, _ *http.Request, t plugin.PluginType) {
	emsg := "It's strongly recommended to install plugins at linux. If you choose to proceed to install plugin, please make sure the plugin is already validated in your own build."
	if runtime.GOOS == "linux" {
		osrelease, err := Read()
		if err != nil {
			handleError(w, err, "", logger)
			return
		}
		prettyName := strings.ToUpper(osrelease["PRETTY_NAME"])
		var os = "debian"
		if strings.Contains(prettyName, "ALPINE") {
			os = "alpine"
		}

		hosts := conf.Config.Basic.PluginHosts
		if err, plugins := fetchPluginList(t, hosts, os, runtime.GOARCH); err != nil {
			handleError(w, err, "", logger)
		} else {
			jsonResponse(plugins, w, logger)
		}
	} else {
		handleError(w, fmt.Errorf(emsg), "", logger)
	}
}

var NativeSourcePlugin = []string{"random", "zmq", "sql"}
var NativeSinkPlugin = []string{"file", "image", "influx", "tdengine", "zmq", "sql"}
var NativeFunctionPlugin = []string{"accumulateWordCount", "countPlusOne", "echo", "geohash", "image", "labelImage"}

func fetchPluginList(t plugin.PluginType, hosts, os, arch string) (err error, result map[string]string) {
	ptype := "sources"
	plugins := NativeSourcePlugin
	if t == plugin.SINK {
		ptype = "sinks"
		plugins = NativeSinkPlugin
	} else if t == plugin.FUNCTION {
		ptype = "functions"
		plugins = NativeFunctionPlugin
	}

	if hosts == "" || ptype == "" || os == "" {
		logger.Errorf("Invalid parameter value: hosts %s, ptype %s or os: %s should not be empty.", hosts, ptype, os)
		return fmt.Errorf("invalid configruation for plugin host in kuiper.yaml"), nil
	}
	result = make(map[string]string)
	hostsArr := strings.Split(hosts, ",")
	for _, host := range hostsArr {
		host := strings.Trim(host, " ")
		tmp := []string{host, "kuiper-plugins", version, os, ptype}
		//The url is similar to http://host:port/kuiper-plugins/0.9.1/debian/sinks/
		url := strings.Join(tmp, "/")

		for _, p := range plugins {
			result[p] = url + "/" + p + "_" + arch + ".zip"
		}
	}
	return
}