package main

import (
	"bufio"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
	"time"
)

var cmdArgs = makeArguments()

func usage() {
	fmt.Println(`Usage:
    yay <operation> [...]
    yay <package(s)>

operations:
    yay {-h --help}
    yay {-V --version}
    yay {-D --database}    <options> <package(s)>
    yay {-F --files}       [options] [package(s)]
    yay {-Q --query}       [options] [package(s)]
    yay {-R --remove}      [options] <package(s)>
    yay {-S --sync}        [options] [package(s)]
    yay {-T --deptest}     [options] [package(s)]
    yay {-U --upgrade}     [options] <file(s)>

New operations:
    yay {-Y --yay}         [options] [package(s)]
    yay {-G --getpkgbuild} [package(s)]

Permanent configuration options:
    --topdown            Shows repository's packages first and then aur's
    --bottomup           Shows aur's packages first and then repository's
    --devel              Check -git/-svn/-hg development version
    --nodevel            Disable development version checking
    --afterclean         Clean package sources after successful build
    --noafterclean       Disable package sources cleaning after successful build
    --timeupdate         Check package's modification date and version
    --notimeupdate       Check only package version change

Yay specific options:
    --printconfig        Prints current yay configuration
    --stats              Displays system information
    --cleandeps          Remove unneeded dependencies
    --gendb              Generates development package DB used for updating.

If no operation is provided -Y will be assumed
`)
}

func initYay() (err error) {
	var configHome string // configHome handles config directory home
	var cacheHome string  // cacheHome handles cache home

	if 0 == os.Geteuid() {
		fmt.Println("Please avoid running yay as root/sudo.")
	}

	if configHome = os.Getenv("XDG_CONFIG_HOME"); configHome != "" {
		if info, err := os.Stat(configHome); err == nil && info.IsDir() {
			configHome = configHome + "/yay"
		} else {
			configHome = os.Getenv("HOME") + "/.config/yay"
		}
	} else {
		configHome = os.Getenv("HOME") + "/.config/yay"
	}

	if cacheHome = os.Getenv("XDG_CACHE_HOME"); cacheHome != "" {
		if info, err := os.Stat(cacheHome); err == nil && info.IsDir() {
			cacheHome = cacheHome + "/yay"
		} else {
			cacheHome = os.Getenv("HOME") + "/.cache/yay"
		}
	} else {
		cacheHome = os.Getenv("HOME") + "/.cache/yay"
	}

	configFile = configHome + "/config.json"
	vcsFile = configHome + "/yay_vcs.json"
	completionFile = cacheHome + "/aur_"

	////////////////
	// yay config //
	////////////////
	defaultSettings(&config)

	if _, err = os.Stat(configFile); os.IsNotExist(err) {
		err = os.MkdirAll(filepath.Dir(configFile), 0755)
		if err != nil {
			err = fmt.Errorf("Unable to create config directory:\n%s\n"+
				"The error was:\n%s", filepath.Dir(configFile), err)
			return
		}
		// Save the default config if nothing is found
		config.saveConfig()
	} else {
		cfile, errf := os.OpenFile(configFile, os.O_RDWR|os.O_CREATE, 0644)
		if errf != nil {
			fmt.Printf("Error reading config: %s\n", err)
		} else {
			defer cfile.Close()
			decoder := json.NewDecoder(cfile)
			err = decoder.Decode(&config)
			if err != nil {
				fmt.Println("Loading default Settings.\nError reading config:",
					err)
				defaultSettings(&config)
			}
		}
	}

	/////////////////
	// vcs config //
	////////////////
	updated = false

	vfile, err := os.OpenFile(vcsFile, os.O_RDONLY|os.O_CREATE, 0644)
	if err == nil {
		defer vfile.Close()
		decoder := json.NewDecoder(vfile)
		_ = decoder.Decode(&savedInfo)
	}

	return
}

func initAlpm() (err error) {
	/////////////////
	// alpm config //
	/////////////////

	var value string
	var exists bool
	//var double bool

	value, _, exists = cmdArgs.getArg("config")
	if exists {
		config.PacmanConf = value
	}

	alpmConf, err = readAlpmConfig(config.PacmanConf)
	if err != nil {
		err = fmt.Errorf("Unable to read Pacman conf: %s", err)
		return
	}

	value, _, exists = cmdArgs.getArg("dbpath", "b")
	if exists {
		alpmConf.DBPath = value
	}

	value, _, exists = cmdArgs.getArg("root", "r")
	if exists {
		alpmConf.RootDir = value
	}

	value, _, exists = cmdArgs.getArg("arch")
	if exists {
		alpmConf.Architecture = value
	}

	//TODO
	//current system does not allow duplicate arguments
	//but pacman allows multiple cachdirs to be passed
	//for now only hanle one cache dir
	value, _, exists = cmdArgs.getArg("cachdir")
	if exists {
		alpmConf.CacheDir = []string{value}
	}

	value, _, exists = cmdArgs.getArg("gpgdir")
	if exists {
		alpmConf.GPGDir = value
	}

	alpmHandle, err = alpmConf.CreateHandle()
	if err != nil {
		err = fmt.Errorf("Unable to CreateHandle: %s", err)
		return
	}

	return
}

func main() {
	var status int
	var err error
	var changedConfig bool

	err = cmdArgs.parseCommandLine()
	if err != nil {
		fmt.Println(err)
		status = 1
		goto cleanup
	}

	err = initYay()
	if err != nil {
		fmt.Println(err)
		status = 1
		goto cleanup
	}

	err = initAlpm()
	if err != nil {
		fmt.Println(err)
		status = 1
		goto cleanup
	}

	changedConfig, err = handleCmd()
	if err != nil {
		fmt.Println(err)
		status = 1
		goto cleanup
	}

	//ive used a goto here
	//i think its the best way to do this sort of thing
cleanup:
	//cleanup
	//from here on out dont exit if an error occurs
	//if we fail to save the configuration
	//atleast continue on and try clean up other parts

	if updated {
		err = saveVCSInfo()

		if err != nil {
			fmt.Println(err)
			status = 1
		}
	}

	if changedConfig {
		err = config.saveConfig()

		if err != nil {
			fmt.Println(err)
			status = 1
		}
	}

	if alpmHandle != nil {
		err = alpmHandle.Release()
		if err != nil {
			fmt.Println(err)
			status = 1
		}
	}

	os.Exit(status)
}

func handleCmd() (changedConfig bool, err error) {
	changedConfig = false

	for option := range cmdArgs.options {
		changedConfig = changedConfig || handleConfig(option)
	}

	for option := range cmdArgs.globals {
		changedConfig = changedConfig || handleConfig(option)
	}

	switch cmdArgs.op {
	case "V", "version":
		handleVersion()
	case "D", "database":
		passToPacman(cmdArgs)
	case "F", "files":
		passToPacman(cmdArgs)
	case "Q", "query":
		passToPacman(cmdArgs)
	case "R", "remove":
		handleRemove()
	case "S", "sync":
		err = handleSync()
	case "T", "deptest":
		passToPacman(cmdArgs)
	case "U", "upgrade":
		passToPacman(cmdArgs)
	case "G", "getpkgbuild":
		err = handleGetpkgbuild()
	case "Y", "--yay":
		err = handleYay()
	default:
		//this means we allowed an op but not implement it
		//if this happens it an error in the code and not the usage
		err = fmt.Errorf("unhandled operation")
	}

	return
}

//this function should only set config options
//but currently still uses the switch left over from old code
//eventuall this should be refactored out futher
//my current plan is to have yay specific operations in its own operator
//e.g. yay -Y --gendb
//e.g yay -Yg
func handleConfig(option string) (changedConfig bool) {
	switch option {
	case "afterclean":
		config.CleanAfter = true
	case "noafterclean":
		config.CleanAfter = false
		//		case "printconfig":
		//			fmt.Printf("%#v", config)
		//			os.Exit(0)
		//		case "gendb":
		//			err = createDevelDB()
		//			if err != nil {
		//				fmt.Println(err)
		//			}
		//			err = saveVCSInfo()
		//			if err != nil {
		//				fmt.Println(err)
		//			}
		//			os.Exit(0)
	case "devel":
		config.Devel = true
	case "nodevel":
		config.Devel = false
	case "timeupdate":
		config.TimeUpdate = true
	case "notimeupdate":
		config.TimeUpdate = false
	case "topdown":
		config.SortMode = TopDown
	case "--bottomup":
		config.SortMode = BottomUp
		//		case "complete":
		//			config.Shell = "sh"
		//			complete()
		//			os.Exit(0)
		//		case "fcomplete":
		//			config.Shell = fishShell
		//			complete()
		//			os.Exit(0)
		//		case "help":
		//			usage()
		//			os.Exit(0)
		//		case "version":
		//			fmt.Printf("yay v%s\n", version)
		//			os.Exit(0)
	case "noconfirm":
		config.NoConfirm = true
	default:
		return
	}

	changedConfig = true
	return
}

func handleVersion() {
	fmt.Printf("yay v%s\n", version)
}

func handleYay() (err error) {
	//_, options, targets := cmdArgs.formatArgs()
	if cmdArgs.existsArg("h", "help") {
		usage()
	} else if cmdArgs.existsArg("printconfig") {
		fmt.Printf("%#v", config)
	} else if cmdArgs.existsArg("gendb") {
		err = createDevelDB()
		if err != nil {
			return
		}
		err = saveVCSInfo()
		if err != nil {
			return
		}
	} else if cmdArgs.existsArg("complete") {
		config.Shell = "sh"
		complete()
	} else if cmdArgs.existsArg("fcomplete") {
		config.Shell = "fish"
		complete()
	} else if cmdArgs.existsArg("stats") {
		err = localStatistics()
	} else if cmdArgs.existsArg("cleandeps") {
		err = cleanDependencies()
	} else if len(cmdArgs.targets) > 0 {
		err = handleYogurt()
	}

	return
}

func handleGetpkgbuild() (err error) {
	for pkg := range cmdArgs.targets {
		err = getPkgbuild(pkg)
		if err != nil {
			//we print the error instead of returning it
			//seems as we can handle multiple errors without stoping
			//theres no easy way arround this right now
			fmt.Println(pkg+":", err)
		}
	}

	return
}

func handleYogurt() (err error) {
	options := cmdArgs.formatArgs()
	targets := cmdArgs.formatTargets()

	config.SearchMode = NumberMenu
	err = numberMenu(targets, options)

	return
}

func handleSync() (err error) {
	targets := cmdArgs.formatTargets()
	options := cmdArgs.formatArgs()

	if cmdArgs.existsArg("y", "refresh") {
		arguments := cmdArgs.copy()
		arguments.delArg("u", "sysupgrade")
		arguments.targets = make(stringSet)
		err = passToPacman(arguments)
		if err != nil {
			return
		}
	}

	if cmdArgs.existsArg("s", "search") {
		if cmdArgs.existsArg("q", "quiet") {
			config.SearchMode = Minimal
		} else {
			config.SearchMode = Detailed
		}

		err = syncSearch(targets)
	} else if cmdArgs.existsArg("c", "clean") {
		err = passToPacman(cmdArgs)
	} else if cmdArgs.existsArg("u", "sysupgrade") {
		err = upgradePkgs(make([]string, 0))
	} else if cmdArgs.existsArg("i", "info") {
		err = syncInfo(targets, options)
	} else if len(cmdArgs.targets) > 0 {
		err = install(cmdArgs)
	}

	return
}

func handleRemove() (err error) {
	removeVCSPackage(cmdArgs.formatTargets())
	err = passToPacman(cmdArgs)
	return
}

// BuildIntRange build the range from start to end
func BuildIntRange(rangeStart, rangeEnd int) []int {
	if rangeEnd-rangeStart == 0 {
		// rangeEnd == rangeStart, which means no range
		return []int{rangeStart}
	}
	if rangeEnd < rangeStart {
		swap := rangeEnd
		rangeEnd = rangeStart
		rangeStart = swap
	}

	final := make([]int, 0)
	for i := rangeStart; i <= rangeEnd; i++ {
		final = append(final, i)
	}
	return final
}

// BuildRange construct a range of ints from the format 1-10
func BuildRange(input string) ([]int, error) {
	multipleNums := strings.Split(input, "-")
	if len(multipleNums) != 2 {
		return nil, errors.New("Invalid range")
	}

	rangeStart, err := strconv.Atoi(multipleNums[0])
	if err != nil {
		return nil, err
	}
	rangeEnd, err := strconv.Atoi(multipleNums[1])
	if err != nil {
		return nil, err
	}

	return BuildIntRange(rangeStart, rangeEnd), err
}

// Contains returns wheter e is present in s
func contains(s []string, e string) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

// RemoveIntListFromList removes all src's elements that are present in target
func removeListFromList(src, target []string) []string {
	max := len(target)
	for i := 0; i < max; i++ {
		if contains(src, target[i]) {
			target = append(target[:i], target[i+1:]...)
			max--
			i--
		}
	}
	return target
}

// NumberMenu presents a CLI for selecting packages to install.
func numberMenu(pkgS []string, flags []string) (err error) {
	//func numberMenu(cmdArgs *arguments) (err error) {
	var num int

	aurQ, err := narrowSearch(pkgS, true)
	if err != nil {
		fmt.Println("Error during AUR search:", err)
	}
	numaq := len(aurQ)
	repoQ, numpq, err := queryRepo(pkgS)
	if err != nil {
		return
	}

	if numpq == 0 && numaq == 0 {
		return fmt.Errorf("no packages match search")
	}

	if config.SortMode == BottomUp {
		aurQ.printSearch(numpq + 1)
		repoQ.printSearch()
	} else {
		repoQ.printSearch()
		aurQ.printSearch(numpq + 1)
	}

	fmt.Printf("\x1b[32m%s %s\x1b[0m\nNumbers: ",
		"Type the numbers or ranges (e.g. 1-10) you want to install.",
		"Separate each one of them with a space.")
	reader := bufio.NewReader(os.Stdin)
	numberBuf, overflow, err := reader.ReadLine()
	if err != nil || overflow {
		fmt.Println(err)
		return
	}

	numberString := string(numberBuf)
	var aurI, aurNI, repoNI, repoI []string
	result := strings.Fields(numberString)
	for _, numS := range result {
		negate := numS[0] == '^'
		if negate {
			numS = numS[1:]
		}
		var numbers []int
		num, err = strconv.Atoi(numS)
		if err != nil {
			numbers, err = BuildRange(numS)
			if err != nil {
				continue
			}
		} else {
			numbers = []int{num}
		}

		// Install package
		for _, x := range numbers {
			var target string
			if x > numaq+numpq || x <= 0 {
				continue
			} else if x > numpq {
				if config.SortMode == BottomUp {
					target = aurQ[numaq+numpq-x].Name
				} else {
					target = aurQ[x-numpq-1].Name
				}
				if negate {
					aurNI = append(aurNI, target)
				} else {
					aurI = append(aurI, target)
				}
			} else {
				if config.SortMode == BottomUp {
					target = repoQ[numpq-x].Name()
				} else {
					target = repoQ[x-1].Name()
				}
				if negate {
					repoNI = append(repoNI, target)
				} else {
					repoI = append(repoI, target)
				}
			}
		}
	}

	if len(repoI) == 0 && len(aurI) == 0 &&
		(len(aurNI) > 0 || len(repoNI) > 0) {
		// If no package was specified, only exclusions, exclude from all the
		// packages
		for _, pack := range aurQ {
			aurI = append(aurI, pack.Name)
		}
		for _, pack := range repoQ {
			repoI = append(repoI, pack.Name())
		}
	}
	aurI = removeListFromList(aurNI, aurI)
	repoI = removeListFromList(repoNI, repoI)

	arguments := makeArguments()
	arguments.addTarget(repoI...)
	arguments.addTarget(aurI...)
	err = install(arguments)

	return err
}

// Complete provides completion info for shells
func complete() error {
	path := completionFile + config.Shell + ".cache"
	info, err := os.Stat(path)
	if os.IsNotExist(err) || time.Since(info.ModTime()).Hours() > 48 {
		os.MkdirAll(filepath.Dir(completionFile), 0755)
		out, errf := os.Create(path)
		if errf != nil {
			return errf
		}

		if createAURList(out) != nil {
			defer os.Remove(path)
		}
		erra := createRepoList(out)

		out.Close()
		return erra
	}

	in, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 0644)
	if err != nil {
		return err
	}
	defer in.Close()

	_, err = io.Copy(os.Stdout, in)
	return err
}

// passToPacman outsorces execution to pacman binary without modifications.
func passToPacman(args *arguments) error {
	var cmd *exec.Cmd
	argArr := make([]string, 0)

	if args.needRoot() {
		argArr = append(argArr, "sudo")
	}

	argArr = append(argArr, "pacman")
	argArr = append(argArr, cmdArgs.formatGlobals()...)
	argArr = append(argArr, args.formatArgs()...)
	argArr = append(argArr, args.formatTargets()...)

	cmd = exec.Command(argArr[0], argArr[1:]...)

	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
	err := cmd.Run()
	return err
}

// passToMakepkg outsorces execution to makepkg binary without modifications.
func passToMakepkg(dir string, args ...string) (err error) {
	cmd := exec.Command(config.MakepkgBin, args...)
	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
	cmd.Dir = dir
	err = cmd.Run()
	if err == nil {
		_ = saveVCSInfo()
		if config.CleanAfter {
			fmt.Println("\x1b[1;32m==> CleanAfter enabled. Deleting source folder.\x1b[0m")
			os.RemoveAll(dir)
		}
	}
	return
}