/*
* Copyright (C) 2022 Brian Evans
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
package local

import (
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"sort"
	"strings"
)

func Open(address string) (string, []string, error) {
	links := make([]string, 0, 10)

	if !pathExists(address) {
		return "", links, fmt.Errorf("Invalid system path: %s", address)
	}

	file, err := os.Open(address)
	if err != nil {
		return "", links, err
	}
	defer file.Close()

	if pathIsDir(address) {
		offset := 1
		fileList, err := file.Readdir(0)
		if err != nil {
			return "", links, err
		}
		var out strings.Builder
		out.WriteString(fmt.Sprintf("Current directory: %s\n\n", address))

		// Handle 'addres/..' display
		offset = 2
		upFp := filepath.Join(address, "..")
		upOneLevel, _ := filepath.Abs(upFp)
		info, err := os.Stat(upOneLevel)
		if err == nil {
			out.WriteString("[1]   ")
			out.WriteString(fmt.Sprintf("%-12s   ", info.Mode().String()))
			out.WriteString("../\n")
			links = append(links, upOneLevel)
		}

		// Sort the directory contents alphabetically
		sort.Slice(fileList, func(i, j int) bool {
			return fileList[i].Name() < fileList[j].Name()
		})

		// Handle each item in the directory
		for i, obj := range fileList {
			linkNum := fmt.Sprintf("[%d]", i+offset)
			out.WriteString(fmt.Sprintf("%-5s ", linkNum))
			out.WriteString(fmt.Sprintf("%-12s   ", obj.Mode().String()))
			out.WriteString(obj.Name())
			if obj.IsDir() {
				out.WriteString("/")
			}
			out.WriteString("\n")
			fp := filepath.Join(address, obj.Name())
			links = append(links, fp)
		}
		return out.String(), links, nil
	}

	bytes, err := ioutil.ReadAll(file)
	if err != nil {
		return "", links, err
	}
	return string(bytes), links, nil
}

func pathExists(p string) bool {
	exists := true

	if _, err := os.Stat(p); os.IsNotExist(err) {
		exists = false
	}

	return exists
}

func pathIsDir(p string) bool {
	info, err := os.Stat(p)
	if err != nil {
		return false
	}
	return info.IsDir()
}