/*
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"
	"github.com/cortexlabs/cortex/pkg/lib/files"
	"github.com/cortexlabs/cortex/pkg/lib/prompt"
	s "github.com/cortexlabs/cortex/pkg/lib/strings"
)

type StringPtrValidation struct {
	Required                             bool
	Default                              *string
	AllowExplicitNull                    bool
	AllowEmpty                           bool
	AllowedValues                        []string
	DisallowedValues                     []string
	Prefix                               string
	InvalidPrefixes                      []string
	MaxLength                            int
	MinLength                            int
	DisallowLeadingWhitespace            bool
	DisallowTrailingWhitespace           bool
	AlphaNumericDashDotUnderscoreOrEmpty bool
	AlphaNumericDashDotUnderscore        bool
	AlphaNumericDashUnderscore           bool
	AWSTag                               bool
	DNS1035                              bool
	DNS1123                              bool
	CastInt                              bool
	CastNumeric                          bool
	CastScalar                           bool
	AllowCortexResources                 bool
	RequireCortexResources               bool
	DockerImageOrEmpty                   bool
	Validator                            func(string) (string, error)
}

func makeStringValValidation(v *StringPtrValidation) *StringValidation {
	return &StringValidation{
		AllowEmpty:                           v.AllowEmpty,
		AllowedValues:                        v.AllowedValues,
		DisallowedValues:                     v.DisallowedValues,
		Prefix:                               v.Prefix,
		InvalidPrefixes:                      v.InvalidPrefixes,
		MaxLength:                            v.MaxLength,
		MinLength:                            v.MinLength,
		DisallowLeadingWhitespace:            v.DisallowLeadingWhitespace,
		DisallowTrailingWhitespace:           v.DisallowTrailingWhitespace,
		AlphaNumericDashDotUnderscoreOrEmpty: v.AlphaNumericDashDotUnderscoreOrEmpty,
		AlphaNumericDashDotUnderscore:        v.AlphaNumericDashDotUnderscore,
		AlphaNumericDashUnderscore:           v.AlphaNumericDashUnderscore,
		AWSTag:                               v.AWSTag,
		DNS1035:                              v.DNS1035,
		DNS1123:                              v.DNS1123,
		CastInt:                              v.CastInt,
		CastNumeric:                          v.CastNumeric,
		CastScalar:                           v.CastScalar,
		AllowCortexResources:                 v.AllowCortexResources,
		RequireCortexResources:               v.RequireCortexResources,
		DockerImageOrEmpty:                   v.DockerImageOrEmpty,
	}
}

func StringPtr(inter interface{}, v *StringPtrValidation) (*string, error) {
	if inter == nil {
		return ValidateStringPtrProvided(nil, v)
	}
	casted, castOk := inter.(string)
	if !castOk {
		if v.CastScalar {
			if !cast.IsScalarType(inter) {
				return nil, ErrorInvalidPrimitiveType(inter, PrimTypeString, PrimTypeInt, PrimTypeFloat, PrimTypeBool)
			}
			casted = s.ObjFlatNoQuotes(inter)
		} else if v.CastNumeric {
			if !cast.IsNumericType(inter) {
				return nil, ErrorInvalidPrimitiveType(inter, PrimTypeString, PrimTypeInt, PrimTypeFloat)
			}
			casted = s.ObjFlatNoQuotes(inter)
		} else if v.CastInt {
			if !cast.IsIntType(inter) {
				return nil, ErrorInvalidPrimitiveType(inter, PrimTypeString, PrimTypeInt)
			}
			casted = s.ObjFlatNoQuotes(inter)
		} else {
			return nil, ErrorInvalidPrimitiveType(inter, PrimTypeString)
		}
	}

	return ValidateStringPtrProvided(&casted, v)
}

func StringPtrFromInterfaceMap(key string, iMap map[string]interface{}, v *StringPtrValidation) (*string, error) {
	inter, ok := ReadInterfaceMapValue(key, iMap)
	if !ok {
		val, err := ValidateStringPtrMissing(v)
		if err != nil {
			return nil, errors.Wrap(err, key)
		}
		return val, nil
	}
	val, err := StringPtr(inter, v)
	if err != nil {
		return nil, errors.Wrap(err, key)
	}
	return val, nil
}

func StringPtrFromStrMap(key string, sMap map[string]string, v *StringPtrValidation) (*string, error) {
	valStr, ok := sMap[key]
	if !ok {
		val, err := ValidateStringPtrMissing(v)
		if err != nil {
			return nil, errors.Wrap(err, key)
		}
		return val, nil
	}
	val, err := StringPtrFromStr(valStr, v)
	if err != nil {
		return nil, errors.Wrap(err, key)
	}
	return val, nil
}

func StringPtrFromStr(str string, v *StringPtrValidation) (*string, error) {
	return ValidateStringPtrProvided(&str, v)
}

func StringPtrFromEnv(envVarName string, v *StringPtrValidation) (*string, error) {
	valStr := ReadEnvVar(envVarName)
	if valStr == nil {
		val, err := ValidateStringPtrMissing(v)
		if err != nil {
			return nil, errors.Wrap(err, EnvVar(envVarName))
		}
		return val, nil
	}
	val, err := StringPtrFromStr(*valStr, v)
	if err != nil {
		return nil, errors.Wrap(err, EnvVar(envVarName))
	}
	return val, nil
}

func StringPtrFromFile(filePath string, v *StringPtrValidation) (*string, error) {
	if !files.IsFile(filePath) {
		val, err := ValidateStringPtrMissing(v)
		if err != nil {
			return nil, errors.Wrap(err, filePath)
		}
		return val, nil
	}

	valStr, err := files.ReadFile(filePath)
	if err != nil {
		return nil, err
	}
	if len(valStr) == 0 {
		val, err := ValidateStringPtrMissing(v)
		if err != nil {
			return nil, errors.Wrap(err, filePath)
		}
		return val, nil
	}

	val, err := StringPtrFromStr(valStr, v)
	if err != nil {
		return nil, errors.Wrap(err, filePath)
	}
	return val, nil
}

func StringPtrFromEnvOrFile(envVarName string, filePath string, v *StringPtrValidation) (*string, error) {
	valStr := ReadEnvVar(envVarName)
	if valStr != nil {
		return StringPtrFromEnv(envVarName, v)
	}
	return StringPtrFromFile(filePath, v)
}

func StringPtrFromPrompt(promptOpts *prompt.Options, v *StringPtrValidation) (*string, error) {
	if v.Default != nil && promptOpts.DefaultStr == "" {
		promptOpts.DefaultStr = *v.Default
	}
	valStr := prompt.Prompt(promptOpts)
	if valStr == "" { // Treat empty prompt value as missing
		return ValidateStringPtrMissing(v)
	}
	return StringPtrFromStr(valStr, v)
}

func ValidateStringPtrMissing(v *StringPtrValidation) (*string, error) {
	if v.Required {
		return nil, ErrorMustBeDefined(v.AllowedValues)
	}
	return validateStringPtr(v.Default, v)
}

func ValidateStringPtrProvided(val *string, v *StringPtrValidation) (*string, error) {
	if !v.AllowExplicitNull && val == nil {
		return nil, ErrorCannotBeNull(v.Required)
	}
	return validateStringPtr(val, v)
}

func validateStringPtr(val *string, v *StringPtrValidation) (*string, error) {
	if val != nil {
		err := ValidateStringVal(*val, makeStringValValidation(v))
		if err != nil {
			return nil, err
		}
	}

	if val == nil {
		return val, nil
	}

	if v.Validator != nil {
		validated, err := v.Validator(*val)
		if err != nil {
			return nil, err
		}
		return &validated, nil
	}

	return val, nil
}
