package main

import (
	"bufio"
	"bytes"
	"encoding/json"
	"fmt"
	"os"
	"os/exec"
	"strings"

	alpm "github.com/jguer/go-alpm"
)

// Verbosity settings for search
const (
	NumberMenu = iota
	Detailed
	Minimal
)

// Describes Sorting method for numberdisplay
const (
	BottomUp = iota
	TopDown
)

type targetMode int

const (
	ModeAUR targetMode = iota
	ModeRepo
	ModeAny
)

// Configuration stores yay's config.
type Configuration struct {
	BuildDir        string `json:"buildDir"`
	Editor          string `json:"editor"`
	EditorFlags     string `json:"editorflags"`
	MakepkgBin      string `json:"makepkgbin"`
	MakepkgConf     string `json:"makepkgconf"`
	PacmanBin       string `json:"pacmanbin"`
	PacmanConf      string `json:"pacmanconf"`
	TarBin          string `json:"tarbin"`
	ReDownload      string `json:"redownload"`
	ReBuild         string `json:"rebuild"`
	AnswerClean     string `json:"answerclean"`
	AnswerDiff      string `json:"answerdiff"`
	AnswerEdit      string `json:"answeredit"`
	AnswerUpgrade   string `json:"answerupgrade"`
	GitBin          string `json:"gitbin"`
	GpgBin          string `json:"gpgbin"`
	GpgFlags        string `json:"gpgflags"`
	MFlags          string `json:"mflags"`
	SortBy          string `json:"sortby"`
	GitFlags        string `json:"gitflags"`
	RequestSplitN   int    `json:"requestsplitn"`
	SearchMode      int    `json:"-"`
	SortMode        int    `json:"sortmode"`
	SudoLoop        bool   `json:"sudoloop"`
	TimeUpdate      bool   `json:"timeupdate"`
	NoConfirm       bool   `json:"-"`
	Devel           bool   `json:"devel"`
	CleanAfter      bool   `json:"cleanAfter"`
	GitClone        bool   `json:"gitclone"`
	Provides        bool   `json:"provides"`
	PGPFetch        bool   `json:"pgpfetch"`
	UpgradeMenu     bool   `json:"upgrademenu"`
	CleanMenu       bool   `json:"cleanmenu"`
	DiffMenu        bool   `json:"diffmenu"`
	EditMenu        bool   `json:"editmenu"`
	CombinedUpgrade bool   `json:"combinedupgrade"`
	UseAsk          bool   `json:"useask"`
}

var version = "7.885"

// configFileName holds the name of the config file.
const configFileName string = "config.json"

// vcsFileName holds the name of the vcs file.
const vcsFileName string = "vcs.json"

// baseURL givers the AUR default address.
const baseURL string = "https://aur.archlinux.org"

// useColor enables/disables colored printing
var useColor bool

// configHome handles config directory home
var configHome string

// cacheHome handles cache home
var cacheHome string

// savedInfo holds the current vcs info
var savedInfo vcsInfo

// configfile holds yay config file path.
var configFile string

// vcsfile holds yay vcs info file path.
var vcsFile string

// shouldSaveConfig holds whether or not the config should be saved
var shouldSaveConfig bool

// YayConf holds the current config values for yay.
var config Configuration

// AlpmConf holds the current config values for pacman.
var alpmConf alpm.PacmanConfig

// AlpmHandle is the alpm handle used by yay.
var alpmHandle *alpm.Handle

// Mode is used to restrict yay to AUR or repo only modes
var mode targetMode = ModeAny

func readAlpmConfig(pacmanconf string) (conf alpm.PacmanConfig, err error) {
	file, err := os.Open(pacmanconf)
	if err != nil {
		return
	}
	conf, err = alpm.ParseConfig(file)
	if err != nil {
		return
	}
	return
}

// SaveConfig writes yay config to file.
func (config *Configuration) saveConfig() error {
	marshalledinfo, _ := json.MarshalIndent(config, "", "\t")
	in, err := os.OpenFile(configFile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
	if err != nil {
		return err
	}
	defer in.Close()
	_, err = in.Write(marshalledinfo)
	if err != nil {
		return err
	}
	err = in.Sync()
	return err
}

func defaultSettings(config *Configuration) {
	config.BuildDir = cacheHome
	config.CleanAfter = false
	config.Editor = ""
	config.EditorFlags = ""
	config.Devel = false
	config.MakepkgBin = "makepkg"
	config.MakepkgConf = ""
	config.NoConfirm = false
	config.PacmanBin = "pacman"
	config.PGPFetch = true
	config.PacmanConf = "/etc/pacman.conf"
	config.GpgFlags = ""
	config.MFlags = ""
	config.GitFlags = ""
	config.SortMode = BottomUp
	config.SortBy = "votes"
	config.SudoLoop = false
	config.TarBin = "bsdtar"
	config.GitBin = "git"
	config.GpgBin = "gpg"
	config.TimeUpdate = false
	config.RequestSplitN = 150
	config.ReDownload = "no"
	config.ReBuild = "no"
	config.AnswerClean = ""
	config.AnswerDiff = ""
	config.AnswerEdit = ""
	config.AnswerUpgrade = ""
	config.GitClone = true
	config.Provides = true
	config.UpgradeMenu = true
	config.CleanMenu = true
	config.DiffMenu = true
	config.EditMenu = false
	config.UseAsk = false
	config.CombinedUpgrade = false
}

// Editor returns the preferred system editor.
func editor() (string, []string) {
	switch {
	case config.Editor != "":
		editor, err := exec.LookPath(config.Editor)
		if err != nil {
			fmt.Println(err)
		} else {
			return editor, strings.Fields(config.EditorFlags)
		}
		fallthrough
	case os.Getenv("EDITOR") != "":
		editorArgs := strings.Fields(os.Getenv("EDITOR"))
		editor, err := exec.LookPath(editorArgs[0])
		if err != nil {
			fmt.Println(err)
		} else {
			return editor, editorArgs[1:]
		}
		fallthrough
	case os.Getenv("VISUAL") != "":
		editorArgs := strings.Fields(os.Getenv("VISUAL"))
		editor, err := exec.LookPath(editorArgs[0])
		if err != nil {
			fmt.Println(err)
		} else {
			return editor, editorArgs[1:]
		}
		fallthrough
	default:
		fmt.Println()
		fmt.Println(bold(red(arrow)), bold(cyan("$EDITOR")), bold("is not set"))
		fmt.Println(bold(red(arrow)) + bold(" Please add ") + bold(cyan("$EDITOR")) + bold(" or ") + bold(cyan("$VISUAL")) + bold(" to your environment variables."))

		for {
			fmt.Print(green(bold(arrow + " Edit PKGBUILD with: ")))
			editorInput, err := getInput("")
			if err != nil {
				fmt.Println(err)
				continue
			}

			editorArgs := strings.Fields(editorInput)

			editor, err := exec.LookPath(editorArgs[0])
			if err != nil {
				fmt.Println(err)
				continue
			}
			return editor, editorArgs[1:]
		}
	}
}

// ContinueTask prompts if user wants to continue task.
//If NoConfirm is set the action will continue without user input.
func continueTask(s string, def string) (cont bool) {
	if config.NoConfirm {
		return true
	}
	var postFix string

	if def == "nN" {
		postFix = " [Y/n] "
	} else {
		postFix = " [y/N] "
	}

	var response string
	fmt.Print(bold(green(arrow)+" "+s), bold(postFix))

	n, err := fmt.Scanln(&response)
	if err != nil || n == 0 {
		return true
	}

	if response == string(def[0]) || response == string(def[1]) {
		return false
	}

	return true
}

func getInput(defaultValue string) (string, error) {
	if defaultValue != "" || config.NoConfirm {
		fmt.Println(defaultValue)
		return defaultValue, nil
	}

	reader := bufio.NewReader(os.Stdin)

	buf, overflow, err := reader.ReadLine()
	if err != nil {
		return "", err
	}

	if overflow {
		return "", fmt.Errorf("Input too long")
	}

	return string(buf), nil
}

func (config Configuration) String() string {
	var buf bytes.Buffer
	enc := json.NewEncoder(&buf)
	enc.SetIndent("", "\t")
	if err := enc.Encode(config); err != nil {
		fmt.Println(err)
	}
	return buf.String()
}