package args

import (
	"fmt"
	"strconv"
	"strings"
	"time"
)

type Arg struct {
	Env     string
	Flag    string
	Help    string
	Default interface{}
	Value   interface{}
	ArgType Type
}

func NewArg(argType Type, key, help string, def interface{}) *Arg {
	return &Arg{
		Env:     strings.ToUpper(key),
		Flag:    strings.ToLower(key),
		Help:    help,
		Default: def,
		Value:   def,
		ArgType: argType,
	}
}

func (a *Arg) GetInt() int {
	if a.ArgType != INT {
		return -1
	}
	if _, ok := a.Value.(int); !ok {
		return -1
	}
	return a.Value.(int)
}

func (a *Arg) GetString() string {
	if a.ArgType != STRING {
		return ""
	}
	if _, ok := a.Value.(string); !ok {
		return ""
	}
	return a.Value.(string)
}

func (a *Arg) GetBool() bool {
	if a.ArgType != BOOL {
		return false
	}
	if _, ok := a.Value.(bool); !ok {
		return false
	}
	return a.Value.(bool)
}

func (a *Arg) GetDuration() time.Duration {
	if a.ArgType != DURATION {
		return time.Duration(-1)
	}
	if _, ok := a.Value.(time.Duration); !ok {
		return time.Duration(-1)
	}
	return a.Value.(time.Duration)
}

func (a *Arg) Set(value interface{}) error {
	err := fmt.Errorf("incompatible set of type %T for arg $%v/-%v type %v", value, a.Env, a.Flag, a.ArgType)
	switch a.ArgType {
	case INT:
		i, ok := value.(int)
		if ok {
			a.Value = i
			err = nil
		} else if s, ok := value.(string); !ok {
		} else if i, err = strconv.Atoi(s); err == nil {
			a.Value = i
			err = nil
		}
	case STRING:
		i, ok := value.(string)
		if ok {
			a.Value = i
			err = nil
		}
	case BOOL:
		i, ok := value.(bool)
		if ok {
			a.Value = i
			err = nil
		} else if s, ok := value.(string); !ok {
		} else if i, err = strconv.ParseBool(s); err == nil {
			a.Value = i
			err = nil
		}
	case DURATION:
		i, ok := value.(time.Duration)
		if ok {
			a.Value = i
			err = nil
		} else if s, ok := value.(string); !ok {
		} else if i, err = time.ParseDuration(s); err == nil {
			a.Value = i
			err = nil
		}
	}
	return err
}