package pflag

import (

	"bytes"

	"encoding/csv"

	"fmt"

	"strings"

)

// -- stringToString Value

type stringToStringValue struct {

	value   *map[string]string

	changed bool

}

func newStringToStringValue(val map[string]string, p *map[string]string) *stringToStringValue {

	ssv := new(stringToStringValue)

	ssv.value = p

	*ssv.value = val

	return ssv

}

// Format: a=1,b=2

func (s *stringToStringValue) Set(val string) error {

	var ss []string

	n := strings.Count(val, "=")

	switch n {

	case 0:

		return fmt.Errorf("%s must be formatted as key=value", val)

	case 1:

		ss = append(ss, strings.Trim(val, `"`))

	default:

		r := csv.NewReader(strings.NewReader(val))

		var err error

		ss, err = r.Read()

		if err != nil {

			return err

		}

	}

	out := make(map[string]string, len(ss))

	for _, pair := range ss {

		kv := strings.SplitN(pair, "=", 2)

		if len(kv) != 2 {

			return fmt.Errorf("%s must be formatted as key=value", pair)

		}

		out[kv[0]] = kv[1]

	}

	if !s.changed {

		*s.value = out

	} else {

		for k, v := range out {

			(*s.value)[k] = v

		}

	}

	s.changed = true

	return nil

}

func (s *stringToStringValue) Type() string {

	return "stringToString"

}

func (s *stringToStringValue) String() string {

	records := make([]string, 0, len(*s.value)>>1)

	for k, v := range *s.value {

		records = append(records, k+"="+v)

	}

	var buf bytes.Buffer

	w := csv.NewWriter(&buf)

	if err := w.Write(records); err != nil {

		panic(err)

	}

	w.Flush()

	return "[" + strings.TrimSpace(buf.String()) + "]"

}

func stringToStringConv(val string) (interface{}, error) {

	val = strings.Trim(val, "[]")

	// An empty string would cause an empty map

	if len(val) == 0 {

		return map[string]string{}, nil

	}

	r := csv.NewReader(strings.NewReader(val))

	ss, err := r.Read()

	if err != nil {

		return nil, err

	}

	out := make(map[string]string, len(ss))

	for _, pair := range ss {

		kv := strings.SplitN(pair, "=", 2)

		if len(kv) != 2 {

			return nil, fmt.Errorf("%s must be formatted as key=value", pair)

		}

		out[kv[0]] = kv[1]

	}

	return out, nil

}

// GetStringToString return the map[string]string value of a flag with the given name

func (f *FlagSet) GetStringToString(name string) (map[string]string, error) {

	val, err := f.getFlagType(name, "stringToString", stringToStringConv)

	if err != nil {

		return map[string]string{}, err

	}

	return val.(map[string]string), nil

}

// StringToStringVar defines a string flag with specified name, default value, and usage string.

// The argument p points to a map[string]string variable in which to store the values of the multiple flags.

// The value of each argument will not try to be separated by comma

func (f *FlagSet) StringToStringVar(p *map[string]string, name string, value map[string]string, usage string) {

	f.VarP(newStringToStringValue(value, p), name, "", usage)

}

// StringToStringVarP is like StringToStringVar, but accepts a shorthand letter that can be used after a single dash.

func (f *FlagSet) StringToStringVarP(p *map[string]string, name, shorthand string, value map[string]string, usage string) {

	f.VarP(newStringToStringValue(value, p), name, shorthand, usage)

}

// StringToStringVar defines a string flag with specified name, default value, and usage string.

// The argument p points to a map[string]string variable in which to store the value of the flag.

// The value of each argument will not try to be separated by comma

func StringToStringVar(p *map[string]string, name string, value map[string]string, usage string) {

	CommandLine.VarP(newStringToStringValue(value, p), name, "", usage)

}

// StringToStringVarP is like StringToStringVar, but accepts a shorthand letter that can be used after a single dash.

func StringToStringVarP(p *map[string]string, name, shorthand string, value map[string]string, usage string) {

	CommandLine.VarP(newStringToStringValue(value, p), name, shorthand, usage)

}

// StringToString defines a string flag with specified name, default value, and usage string.

// The return value is the address of a map[string]string variable that stores the value of the flag.

// The value of each argument will not try to be separated by comma

func (f *FlagSet) StringToString(name string, value map[string]string, usage string) *map[string]string {

	p := map[string]string{}

	f.StringToStringVarP(&p, name, "", value, usage)

	return &p

}

// StringToStringP is like StringToString, but accepts a shorthand letter that can be used after a single dash.

func (f *FlagSet) StringToStringP(name, shorthand string, value map[string]string, usage string) *map[string]string {

	p := map[string]string{}

	f.StringToStringVarP(&p, name, shorthand, value, usage)

	return &p

}

// StringToString defines a string flag with specified name, default value, and usage string.

// The return value is the address of a map[string]string variable that stores the value of the flag.

// The value of each argument will not try to be separated by comma

func StringToString(name string, value map[string]string, usage string) *map[string]string {

	return CommandLine.StringToStringP(name, "", value, usage)

}

// StringToStringP is like StringToString, but accepts a shorthand letter that can be used after a single dash.

func StringToStringP(name, shorthand string, value map[string]string, usage string) *map[string]string {

	return CommandLine.StringToStringP(name, shorthand, value, usage)

}