package main

import (
//	"os/exec"
	"fmt"
	"log"
	"os"
	"strings"
	"io"
	"bufio"
//	"path/filepath"
	"text/template"
	"cdhist/dir"
)

func histAdd(histFile string, newPath string) (error) {

	paths, err := ReadLines(histFile)
	if err != nil {
		if os.IsNotExist(err) != true {
			log.Printf("Error reading cd history file: %v", err)
		}
	}
 	file, err := os.OpenFile(histFile, os.O_RDWR|os.O_CREATE, 0660)
	if err != nil {
		return err
	}
	defer file.Close()

	if err := file.Truncate(0); err != nil {
		return err
	}
	if len(paths) == 0 {
		path, _ := os.Getwd()
		if err == nil {
			paths = append(paths, path)
		}
	}
	for _, path := range paths {
		if strings.Compare(path, newPath) != 0 {
			_, err := file.Write([]byte(fmt.Sprintf("%s\n", path)))
			if err != nil {
				log.Printf("Error writing cd history file: %v", err)
				return err
			}
		}
	 }
	_, err = file.Write([]byte(fmt.Sprintf("%s\n", newPath)))
	 if err != nil {
		log.Printf("Error writing cd history file: %v", err)
		return err
	}
	return nil
}

func histList(histFile string) error {
	paths, err := ReadLines(histFile)
	if err != nil {
		return err
	}
	m := len(paths) - 1
	for i := 0; i < m; i++ {
		s := fmt.Sprintf("%d: %s\n",m - i, paths[i])
		os.Stderr.WriteString(s)
	}

	var in int
	os.Stderr.WriteString("> ")
	fmt.Scanln(&in)
	if in >= 1 && in <= m {
		path := paths[m - in]
		cd(histFile, aliasFile, "", path)
	}
	return nil
}

func histListNoPrompt(histFile string) error {
	paths, err := ReadLines(histFile)
	if err != nil {
		return err
	}
	for _, p := range(paths) {
		os.Stdout.WriteString(p)
		os.Stdout.WriteString("\n")
	}
	return nil
}

func DirAliases(aliasFile string) map[string]string {
		d, err := ReadLines(aliasFile)
		if err != nil {
			log.Printf("Error reading cd alias file: %s", err)
		}
		aliases := make(map[string]string)
		for _, line := range d {
			l := strings.Split(line, "=")
			if len(l) == 2 {
				aliases[strings.TrimSpace(l[0])] = strings.TrimSpace(l[1])
			}
		}
	return aliases
}

func cd(histFile, aliasFile, outString, path string) {
	cleanPath, err := dir.Sanitize(path)
	if ! dir.Exist(cleanPath) {
		a := DirAliases(aliasFile)
		p, prs := a[path]
		if prs {
			cleanPath, err = dir.Sanitize(p)
		}
	}
	if err != nil {
		log.Printf("%s: %s", path, err)
		os.Exit(3)
	}
	histAdd(histFile, cleanPath)
	fmt.Printf("%s %s", outString, cleanPath)
	os.Exit(0)
}

func ReadLines(fileName string) ([]string, error) {
	file, err := os.OpenFile(fileName, os.O_RDWR|os.O_CREATE, 0660)
	if err != nil {
	//	log.Print(err)
		return nil, err
	}
	defer file.Close()

	reader := bufio.NewReader(file)
	lines := make([]string,0)
	for {
		line, _, err := reader.ReadLine()
		if err != nil {
			if err == io.EOF {
				err = nil
			}
			break
		}
		lines = append(lines, string(line))
	}
	return lines, err
}



// makeBashFunc prints the wrapper function to be sourced by bash
// Copied from https://github.com/bulletmark/cdhist/blob/master/cdhist/cdhist.py
func printBashFunc(opts BashFuncOpts) {
	f := `{{.FuncName}}() {
	local d
	local r
	d=$({{.Command}} "$@")
	r=$?
	if [[ $r == 0 ]]; then
		builtin cd $d
	elif [[ $r == 2 ]]; then
		echo -e "$d"
	fi
	}`
	t, err := template.New("t").Parse(f)
	if err != nil {
		log.Printf("Error parsing template, %s", err)
		os.Exit(3)
	}
	err = t.Execute(os.Stdout, opts)
	if err != nil {
		log.Printf("Error executing template, %s", err)
		os.Exit(3)
	}
	return
}

/*
func sanitizePath(path string) string {
	switch path {
	case "-":
		path = os.Getenv("OLDPWD")
	case "":
		var err error // need to do this because the next line won't work using :=
		path, err = os.UserHomeDir()
		if err != nil {
			log.Printf("No home directory: %s", err)
		}
	}

	path = strings.TrimSpace(path)
	path, err := filepath.Abs(path)
	if err != nil {
		log.Printf("Invalid path:, %s", err)
		os.Exit(2)
	}
	if _, err := os.Stat(path); os.IsNotExist(err) {
		log.Printf("%s: No such directory.", path)
		log.Printf("%v", DirAliases(aliasFile))
		os.Exit(2)
	}

	return path
}*/

// func cdableVars() bool {
// 	v := exec.Command("bash", "-i", "-c", "echo $var")
// 	o, _ := v.Output()
// 	os.Stderr.WriteString(string(o))
//
// 	c := exec.Command("bash", "-i", "-c", "shopt cdable_vars")
// 	out, _ := c.Output()
// 	os.Stderr.WriteString(string(out))
//
// 	return strings.Contains(string(out), "on")
// }