package cfger

import (
	"fmt"
	"os"
	"strconv"
)

type OptionalItem struct {
	key   string
	item  any
	found bool
}

// Required raises a fatal error if the item is not present
func (x OptionalItem) Required() OptionalItem {
	if !x.found {
		FatalErrorHandler(fmt.Errorf("required key %s not found in config", x.key))
		os.Exit(1)
	}
	return x
}

// WithDefault returns the value if it is present, otherwise it returns the provided default value.
func (x OptionalItem) WithDefault(val any) OptionalItem {
	if !x.found {
		x.item = val
		x.found = true
	}
	return x
}

// AsInt returns the value of x as an integer, or 0 if no value is present.
func (x OptionalItem) AsInt() int {
	if !x.found {
		return 0
	}
	return x.item.(int)
}

// ToInt parses x as an integer from a string and returns its value. If no value is present, 0 is returned, and if x is
// unparseable, a fatal error is raised.
func (x OptionalItem) ToInt() int {
	if !x.found {
		return 0
	}

	v, ok := x.item.(string)
	if !ok {
		FatalErrorHandler(fmt.Errorf("cfger: expected %s to be a string, got %T", x.key, x.item))
		os.Exit(1)
	}

	iv, err := strconv.Atoi(v)
	if err != nil {
		FatalErrorHandler(fmt.Errorf("cfger: unable to parse %s as an integer: %w", x.key, err))
	}

	return iv
}

// AsString returns the value of x as a string, or an empty string if no value is present.
func (x OptionalItem) AsString() string {
	if !x.found {
		return ""
	}
	return x.item.(string)
}

// AsBool returns the value of x as a boolean, or an empty string if no value is present.
func (x OptionalItem) AsBool() bool {
	if !x.found {
		return false
	}
	return x.item.(bool)
}

// ToBool parses x as a boolean from a string and returns its value. If no value is present, false is returned, and if x
// is unparseable, a fatal error is raised.
func (x OptionalItem) ToBool() bool {
	if !x.found {
		return false
	}

	v, ok := x.item.(string)
	if !ok {
		FatalErrorHandler(fmt.Errorf("cfger: expected %s to be a string, got %T", x.key, x.item))
		os.Exit(1)
	}

	iv, err := strconv.ParseBool(v)
	if err != nil {
		FatalErrorHandler(fmt.Errorf("cfger: unable to parse %s as an boolean: %w", x.key, err))
	}

	return iv
}