// Copyright 2016-2018, Pulumi Corporation.
//
// 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 plugin

import (
	"io"

	"github.com/pulumi/pulumi/sdk/go/common/apitype"
	"github.com/pulumi/pulumi/sdk/go/common/resource"
	"github.com/pulumi/pulumi/sdk/go/common/tokens"
	"github.com/pulumi/pulumi/sdk/go/common/workspace"
)

// Analyzer provides a pluggable interface for performing arbitrary analysis of entire projects/stacks/snapshots, and/or
// individual resources, for arbitrary issues.  These might be style, policy, correctness, security, or performance
// related.  This interface hides the messiness of the underlying machinery, since providers are behind an RPC boundary.
type Analyzer interface {
	// Closer closes any underlying OS resources associated with this provider (like processes, RPC channels, etc).
	io.Closer
	// Name fetches an analyzer's qualified name.
	Name() tokens.QName
	// Analyze analyzes a single resource object, and returns any errors that it finds.
	// Is called before the resource is modified.
	Analyze(r AnalyzerResource) ([]AnalyzeDiagnostic, error)
	// AnalyzeStack analyzes all resources after a successful preview or update.
	// Is called after all resources have been processed, and all changes applied.
	AnalyzeStack(resources []AnalyzerStackResource) ([]AnalyzeDiagnostic, error)
	// GetAnalyzerInfo returns metadata about the analyzer (e.g., list of policies contained).
	GetAnalyzerInfo() (AnalyzerInfo, error)
	// GetPluginInfo returns this plugin's information.
	GetPluginInfo() (workspace.PluginInfo, error)
	// Configure configures the analyzer, passing configuration properties for each policy.
	Configure(policyConfig map[string]AnalyzerPolicyConfig) error
}

// AnalyzerResource mirrors a resource that is passed to `Analyze`.
type AnalyzerResource struct {
	URN        resource.URN
	Type       tokens.Type
	Name       tokens.QName
	Properties resource.PropertyMap
	Options    AnalyzerResourceOptions
	Provider   *AnalyzerProviderResource
}

// AnalyzerStackResource mirrors a resource that is passed to `AnalyzeStack`.
type AnalyzerStackResource struct {
	AnalyzerResource
	Parent               resource.URN                            // an optional parent URN for this resource.
	Dependencies         []resource.URN                          // dependencies of this resource object.
	PropertyDependencies map[resource.PropertyKey][]resource.URN // the set of dependencies that affect each property.
}

// AnalyzerResourceOptions mirrors resource options sent to the analyzer.
type AnalyzerResourceOptions struct {
	Protect                 bool                    // true to protect this resource from deletion.
	IgnoreChanges           []string                // a list of property names to ignore during changes.
	DeleteBeforeReplace     *bool                   // true if this resource should be deleted prior to replacement.
	AdditionalSecretOutputs []resource.PropertyKey  // outputs that should always be treated as secrets.
	Aliases                 []resource.URN          // additional URNs that should be aliased to this resource.
	CustomTimeouts          resource.CustomTimeouts // an optional config object for resource options
}

// AnalyzerProviderResource mirrors a resource's provider sent to the analyzer.
type AnalyzerProviderResource struct {
	URN        resource.URN
	Type       tokens.Type
	Name       tokens.QName
	Properties resource.PropertyMap
}

// AnalyzeDiagnostic indicates that resource analysis failed; it contains the property and reason
// for the failure.
type AnalyzeDiagnostic struct {
	PolicyName        string
	PolicyPackName    string
	PolicyPackVersion string
	Description       string
	Message           string
	Tags              []string
	EnforcementLevel  apitype.EnforcementLevel
	URN               resource.URN
}

// AnalyzerInfo provides metadata about a PolicyPack inside an analyzer.
type AnalyzerInfo struct {
	Name           string
	DisplayName    string
	Version        string
	SupportsConfig bool
	Policies       []AnalyzerPolicyInfo
	InitialConfig  map[string]AnalyzerPolicyConfig
}

// AnalyzerPolicyInfo defines the metadata for an individual Policy within a Policy Pack.
type AnalyzerPolicyInfo struct {
	// Unique URL-safe name for the policy.  This is unique to a specific version
	// of a Policy Pack.
	Name        string
	DisplayName string

	// Description is used to provide more context about the purpose of the policy.
	Description      string
	EnforcementLevel apitype.EnforcementLevel

	// Message is the message that will be displayed to end users when they violate
	// this policy.
	Message string

	// ConfigSchema is optional config schema for the policy.
	ConfigSchema *AnalyzerPolicyConfigSchema
}

// JSONSchema represents a JSON schema.
type JSONSchema map[string]interface{}

// AnalyzerPolicyConfigSchema provides metadata about a policy's configuration.
type AnalyzerPolicyConfigSchema struct {
	// Map of config property names to JSON schema.
	Properties map[string]JSONSchema

	// Required config properties
	Required []string
}

// AnalyzerPolicyConfig is the configuration for a policy.
type AnalyzerPolicyConfig struct {
	// Configured enforcement level for the policy.
	EnforcementLevel apitype.EnforcementLevel
	// Configured properties of the policy.
	Properties map[string]interface{}
}
