package getopt

import (
	"fmt"
	"log"
	"os"
	"regexp"
	"strconv"
)

func (self *Getopt) usageOption(flagToStringify flag) []string {
	var printArgument bool
	switch flagToStringify.value.(interface{}).(type) {
	case *bool:
		printArgument = false
	default:
		printArgument = true
	}
	var returned []string
	if flagToStringify.shortname != "" {
		returned = append(returned, "-"+flagToStringify.shortname)
	} else {
		returned = append(returned, "")
	}
	if flagToStringify.name != "" {
		returned = append(returned, "--"+flagToStringify.name)
	} else {
		returned = append(returned, "")
	}
	if printArgument {
		returned = append(returned, "<argument>")
	} else {
		returned = append(returned, "")
	}

    if flagToStringify.required {
        returned = append(returned, "(required)")
    } else {
        returned = append(returned, "")
    }

	returned = append(returned, flagToStringify.description)
	return returned
}

func (self *Getopt) maxLen(lol [][]string) []int64 {
	var returned []int64 = make([]int64, 5)
	for _, i_val := range lol {
		for j, j_val := range i_val {
			if returned[j] < int64(len(j_val)) {
				returned[j] = int64(len(j_val))
			}
		}
	}
	return returned
}

func (self *Getopt) parseOptionArgument(value string, expectingFor string, short bool) {
	var gotFlag *flag
	var ok bool
	if short {
		gotFlag, ok = self.flagsByShortname[expectingFor]
	} else {
		gotFlag, ok = self.flags[expectingFor]
	}
	if !ok {
		fmt.Printf("Error retrieving the key, this IS a bug. %s\n", expectingFor)
	}
	self.assignToFlag(gotFlag, value)

}

func (self *Getopt) parseNotOptionArgument(currentIteration string, expectingArgument *bool, expectingFor *string, short *bool) {
	matchName, err := regexp.MatchString("^--", currentIteration)
	if err != nil {
		log.Panic(err)
	}
	matchShortname, err := regexp.MatchString("^-", currentIteration)
	if err != nil {
		log.Panic(err)
	}
	if matchName {
		*short = false
		self.parseOption(currentIteration, expectingFor, expectingArgument, `^--([^=]*)(?:=(.*))?$`, self.flags)
	} else if matchShortname {
		*short = true
		self.parseOption(currentIteration, expectingFor, expectingArgument, `^-(.)(.+)?$`, self.flagsByShortname)
	} else {
		self.commonArgs = append(self.commonArgs, currentIteration)
	}
}

func (self *Getopt) parseOption(currentIteration string, expectingFor *string, expectingArgument *bool, option_regex string, flags map[string]*flag) {
	re := regexp.MustCompile(option_regex)
	listName := re.FindStringSubmatch(currentIteration)
	name := listName[1]
	gotFlag, ok := flags[name]
	if !ok {
		fmt.Printf("%s not in the option list.\n", name)
		self.Usage()
		os.Exit(1)
	}
	var nextParameter bool
	switch gotFlag.value.(interface{}).(type) {
	case *bool:
		nextParameter = false
		*(gotFlag.value.(*bool)) = true
	default:
		nextParameter = true
	}
	if listName[2] != "" {
		if !nextParameter {
			fmt.Printf("%s does not get any parameters.\n", name)
			self.Usage()
			os.Exit(1)
		}
		gotParameter := listName[2]
		self.assignToFlag(gotFlag, gotParameter)
	} else if nextParameter {
		*expectingArgument = true
		*expectingFor = name
	}
}

func (self *Getopt) assignToFlag(toAssignFlag *flag, value string) {
	switch toAssignFlag.value.(interface{}).(type) {
	case **string:
		*(toAssignFlag.value.(**string)) = &value
	case **uint64:
		value_uint, err := strconv.ParseUint(value, 10, 64)
		if err != nil {
			fmt.Printf("%s is not parseable into a unsigned interger of 64 bits.\n", value)
			self.Usage()
			os.Exit(1)
		}
		*(toAssignFlag.value.(**uint64)) = &value_uint
	default:
		fmt.Printf("Unsupported type %v.\n", toAssignFlag.value)
		self.Usage()
		os.Exit(1)
	}
}

func (self *Getopt) nilRuneToEmptyString(input *rune) string {
	if input == nil {
		return ""
	}
	return string(*input)
}

func (self *Getopt) nilToEmptyString(input *string) string {
	if input == nil {
		return ""
	}
	return *input
}