package serverless

import (
	"bytes"
	"encoding/json"
	"fmt"

	"github.com/weaveworks/eksctl/pkg/goformation/cloudformation/types"

	"github.com/weaveworks/eksctl/pkg/goformation/cloudformation/policies"
)

// Function AWS CloudFormation Resource (AWS::Serverless::Function)
// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
type Function struct {

	// AutoPublishAlias AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	AutoPublishAlias *types.Value `json:"AutoPublishAlias,omitempty"`

	// CodeUri AWS CloudFormation Property
	// Required: true
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	CodeUri *Function_CodeUri `json:"CodeUri,omitempty"`

	// DeadLetterQueue AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	DeadLetterQueue *Function_DeadLetterQueue `json:"DeadLetterQueue,omitempty"`

	// DeploymentPreference AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	DeploymentPreference *Function_DeploymentPreference `json:"DeploymentPreference,omitempty"`

	// Description AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Description *types.Value `json:"Description,omitempty"`

	// Environment AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Environment *Function_FunctionEnvironment `json:"Environment,omitempty"`

	// Events AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Events map[string]Function_EventSource `json:"Events,omitempty"`

	// FileSystemConfigs AWS CloudFormation Property
	// Required: false
	// See: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-resource-function.html
	FileSystemConfigs []Function_FileSystemConfig `json:"FileSystemConfigs,omitempty"`

	// FunctionName AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	FunctionName *types.Value `json:"FunctionName,omitempty"`

	// Handler AWS CloudFormation Property
	// Required: true
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Handler *types.Value `json:"Handler,omitempty"`

	// KmsKeyArn AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	KmsKeyArn *types.Value `json:"KmsKeyArn,omitempty"`

	// Layers AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Layers *types.Value `json:"Layers,omitempty"`

	// MemorySize AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	MemorySize *types.Value `json:"MemorySize,omitempty"`

	// PermissionsBoundary AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	PermissionsBoundary *types.Value `json:"PermissionsBoundary,omitempty"`

	// Policies AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Policies *Function_Policies `json:"Policies,omitempty"`

	// ReservedConcurrentExecutions AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	ReservedConcurrentExecutions *types.Value `json:"ReservedConcurrentExecutions,omitempty"`

	// Role AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Role *types.Value `json:"Role,omitempty"`

	// Runtime AWS CloudFormation Property
	// Required: true
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Runtime *types.Value `json:"Runtime,omitempty"`

	// Tags AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Tags map[string]*types.Value `json:"Tags,omitempty"`

	// Timeout AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Timeout *types.Value `json:"Timeout,omitempty"`

	// Tracing AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	Tracing *types.Value `json:"Tracing,omitempty"`

	// VpcConfig AWS CloudFormation Property
	// Required: false
	// See: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
	VpcConfig *Function_VpcConfig `json:"VpcConfig,omitempty"`

	// AWSCloudFormationDeletionPolicy represents a CloudFormation DeletionPolicy
	AWSCloudFormationDeletionPolicy policies.DeletionPolicy `json:"-"`

	// AWSCloudFormationUpdateReplacePolicy represents a CloudFormation UpdateReplacePolicy
	AWSCloudFormationUpdateReplacePolicy policies.UpdateReplacePolicy `json:"-"`

	// AWSCloudFormationDependsOn stores the logical ID of the resources to be created before this resource
	AWSCloudFormationDependsOn []string `json:"-"`

	// AWSCloudFormationMetadata stores structured data associated with this resource
	AWSCloudFormationMetadata map[string]interface{} `json:"-"`

	// AWSCloudFormationCondition stores the logical ID of the condition that must be satisfied for this resource to be created
	AWSCloudFormationCondition string `json:"-"`
}

// AWSCloudFormationType returns the AWS CloudFormation resource type
func (r *Function) AWSCloudFormationType() string {
	return "AWS::Serverless::Function"
}

// MarshalJSON is a custom JSON marshalling hook that embeds this object into
// an AWS CloudFormation JSON resource's 'Properties' field and adds a 'Type'.
func (r Function) MarshalJSON() ([]byte, error) {
	type Properties Function
	return json.Marshal(&struct {
		Type                string
		Properties          Properties
		DependsOn           []string                     `json:"DependsOn,omitempty"`
		Metadata            map[string]interface{}       `json:"Metadata,omitempty"`
		DeletionPolicy      policies.DeletionPolicy      `json:"DeletionPolicy,omitempty"`
		UpdateReplacePolicy policies.UpdateReplacePolicy `json:"UpdateReplacePolicy,omitempty"`
		Condition           string                       `json:"Condition,omitempty"`
	}{
		Type:                r.AWSCloudFormationType(),
		Properties:          (Properties)(r),
		DependsOn:           r.AWSCloudFormationDependsOn,
		Metadata:            r.AWSCloudFormationMetadata,
		DeletionPolicy:      r.AWSCloudFormationDeletionPolicy,
		UpdateReplacePolicy: r.AWSCloudFormationUpdateReplacePolicy,
		Condition:           r.AWSCloudFormationCondition,
	})
}

// UnmarshalJSON is a custom JSON unmarshalling hook that strips the outer
// AWS CloudFormation resource object, and just keeps the 'Properties' field.
func (r *Function) UnmarshalJSON(b []byte) error {
	type Properties Function
	res := &struct {
		Type                string
		Properties          *Properties
		DependsOn           []string
		Metadata            map[string]interface{}
		DeletionPolicy      string
		UpdateReplacePolicy string
		Condition           string
	}{}

	dec := json.NewDecoder(bytes.NewReader(b))
	dec.DisallowUnknownFields() // Force error if unknown field is found

	if err := dec.Decode(&res); err != nil {
		fmt.Printf("ERROR: %s\n", err)
		return err
	}

	// If the resource has no Properties set, it could be nil
	if res.Properties != nil {
		*r = Function(*res.Properties)
	}
	if res.DependsOn != nil {
		r.AWSCloudFormationDependsOn = res.DependsOn
	}
	if res.Metadata != nil {
		r.AWSCloudFormationMetadata = res.Metadata
	}
	if res.DeletionPolicy != "" {
		r.AWSCloudFormationDeletionPolicy = policies.DeletionPolicy(res.DeletionPolicy)
	}
	if res.UpdateReplacePolicy != "" {
		r.AWSCloudFormationUpdateReplacePolicy = policies.UpdateReplacePolicy(res.UpdateReplacePolicy)
	}
	if res.Condition != "" {
		r.AWSCloudFormationCondition = res.Condition
	}
	return nil
}
