// Copyright 2024 The Casdoor Authors. All Rights Reserved.
//
// 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 controllers

import (
	"encoding/json"
	"fmt"
	"os"
	"os/exec"
	"strings"
)

func processArgsToTempFiles(args []string) ([]string, []string, error) {
	tempFiles := []string{}
	newArgs := []string{}
	for i := 0; i < len(args); i++ {
		if (args[i] == "-m" || args[i] == "-p") && i+1 < len(args) {
			pattern := fmt.Sprintf("casbin_temp_%s_*.conf", args[i])
			tempFile, err := os.CreateTemp("", pattern)
			if err != nil {
				return nil, nil, fmt.Errorf("failed to create temp file: %v", err)
			}

			_, err = tempFile.WriteString(args[i+1])
			if err != nil {
				tempFile.Close()
				return nil, nil, fmt.Errorf("failed to write to temp file: %v", err)
			}

			tempFile.Close()
			tempFiles = append(tempFiles, tempFile.Name())
			newArgs = append(newArgs, args[i], tempFile.Name())
			i++
		} else {
			newArgs = append(newArgs, args[i])
		}
	}
	return tempFiles, newArgs, nil
}

// RunCasbinCommand
// @Title RunCasbinCommand
// @Tag Enforcer API
// @Description Call Casbin CLI commands
// @Success 200 {object} controllers.Response The Response object
// @router /run-casbin-command [get]
func (c *ApiController) RunCasbinCommand() {
	language := c.Input().Get("language")
	argString := c.Input().Get("args")

	if language == "" {
		language = "go"
	}
	// use "casbin-go-cli" by default, can be also "casbin-java-cli", "casbin-node-cli", etc.
	// the pre-built binary of "casbin-go-cli" can be found at: https://github.com/casbin/casbin-go-cli/releases
	binaryName := fmt.Sprintf("casbin-%s-cli", language)

	_, err := exec.LookPath(binaryName)
	if err != nil {
		c.ResponseError(fmt.Sprintf("executable file: %s not found in PATH", binaryName))
		return
	}

	// RBAC model & policy example:
	// https://door.casdoor.com/api/run-casbin-command?language=go&args=["enforce", "-m", "[request_definition]\nr = sub, obj, act\n\n[policy_definition]\np = sub, obj, act\n\n[role_definition]\ng = _, _\n\n[policy_effect]\ne = some(where (p.eft == allow))\n\n[matchers]\nm = g(r.sub, p.sub) %26%26 r.obj == p.obj %26%26 r.act == p.act", "-p", "p, alice, data1, read\np, bob, data2, write\np, data2_admin, data2, read\np, data2_admin, data2, write\ng, alice, data2_admin", "alice", "data1", "read"]
	// Casbin CLI usage:
	// https://github.com/jcasbin/casbin-java-cli?tab=readme-ov-file#get-started
	var args []string
	err = json.Unmarshal([]byte(argString), &args)
	if err != nil {
		c.ResponseError(err.Error())
		return
	}

	tempFiles, processedArgs, err := processArgsToTempFiles(args)
	defer func() {
		for _, file := range tempFiles {
			os.Remove(file)
		}
	}()
	if err != nil {
		c.ResponseError(err.Error())
		return
	}

	command := exec.Command(binaryName, processedArgs...)
	outputBytes, err := command.CombinedOutput()
	if err != nil {
		errorString := err.Error()
		if outputBytes != nil {
			output := string(outputBytes)
			errorString = fmt.Sprintf("%s, error: %s", output, err.Error())
		}

		c.ResponseError(errorString)
		return
	}

	output := string(outputBytes)
	output = strings.TrimSuffix(output, "\n")
	c.ResponseOk(output)
}