/*
Copyright 2020 Cortex Labs, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package configreader

import (
	"github.com/cortexlabs/cortex/pkg/lib/cast"
	"github.com/cortexlabs/cortex/pkg/lib/errors"
)

type IntListValidation struct {
	Required          bool
	Default           []int
	AllowExplicitNull bool
	AllowEmpty        bool
	CastSingleItem    bool
	MinLength         int
	MaxLength         int
	InvalidLengths    []int
	Validator         func([]int) ([]int, error)
}

func IntList(inter interface{}, v *IntListValidation) ([]int, error) {
	casted, castOk := cast.InterfaceToIntSlice(inter)
	if !castOk {
		if v.CastSingleItem {
			castedItem, castOk := cast.InterfaceToInt(inter)
			if !castOk {
				return nil, ErrorInvalidPrimitiveType(inter, PrimTypeInt, PrimTypeIntList)
			}
			casted = []int{castedItem}
		} else {
			return nil, ErrorInvalidPrimitiveType(inter, PrimTypeIntList)
		}
	}
	return ValidateIntListProvided(casted, v)
}

func IntListFromInterfaceMap(key string, iMap map[string]interface{}, v *IntListValidation) ([]int, error) {
	inter, ok := ReadInterfaceMapValue(key, iMap)
	if !ok {
		val, err := ValidateIntListMissing(v)
		if err != nil {
			return nil, errors.Wrap(err, key)
		}
		return val, nil
	}
	val, err := IntList(inter, v)
	if err != nil {
		return nil, errors.Wrap(err, key)
	}
	return val, nil
}

func ValidateIntListMissing(v *IntListValidation) ([]int, error) {
	if v.Required {
		return nil, ErrorMustBeDefined()
	}
	return validateIntList(v.Default, v)
}

func ValidateIntListProvided(val []int, v *IntListValidation) ([]int, error) {
	if !v.AllowExplicitNull && val == nil {
		return nil, ErrorCannotBeNull(v.Required)
	}
	return validateIntList(val, v)
}

func validateIntList(val []int, v *IntListValidation) ([]int, error) {
	if !v.AllowEmpty {
		if val != nil && len(val) == 0 {
			return nil, ErrorCannotBeEmpty()
		}
	}

	if v.MinLength != 0 {
		if len(val) < v.MinLength {
			return nil, ErrorTooFewElements(v.MinLength)
		}
	}

	if v.MaxLength != 0 {
		if len(val) > v.MaxLength {
			return nil, ErrorTooManyElements(v.MaxLength)
		}
	}

	for _, invalidLength := range v.InvalidLengths {
		if len(val) == invalidLength {
			return nil, ErrorWrongNumberOfElements(v.InvalidLengths)
		}
	}

	if v.Validator != nil {
		return v.Validator(val)
	}
	return val, nil
}
