package ape

import (
	"context"
	"errors"
	"fmt"

	objectV2 "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object"
	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/session"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/container"
	frostfsidcore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/frostfsid"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/netmap"
	checkercore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/common/ape"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
	policyengine "git.frostfs.info/TrueCloudLab/policy-engine/pkg/engine"
	nativeschema "git.frostfs.info/TrueCloudLab/policy-engine/schema/native"
	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
)

type checkerImpl struct {
	checkerCore     checkercore.CheckCore
	frostFSIDClient frostfsidcore.SubjectProvider
	headerProvider  HeaderProvider
	nm              netmap.Source
	cnrSource       container.Source
	nodePK          []byte
}

func NewChecker(localOverrideStorage policyengine.LocalOverrideStorage, morphChainStorage policyengine.MorphRuleChainStorageReader, headerProvider HeaderProvider, frostFSIDClient frostfsidcore.SubjectProvider, nm netmap.Source, st netmap.State, cnrSource container.Source, nodePK []byte) Checker {
	return &checkerImpl{
		checkerCore:     checkercore.New(localOverrideStorage, morphChainStorage, frostFSIDClient, st),
		frostFSIDClient: frostFSIDClient,
		headerProvider:  headerProvider,
		nm:              nm,
		cnrSource:       cnrSource,
		nodePK:          nodePK,
	}
}

type Prm struct {
	Namespace string

	Container cid.ID

	// Object ID is omitted for some methods.
	Object *oid.ID

	// If Header is set, then object attributes and properties will be parsed from
	// a request/response's header.
	Header *objectV2.Header

	// Method must be represented only as a constant represented in native schema.
	Method string

	// Role must be representedonly as a constant represented in native schema.
	Role string

	// An encoded sender's public key string.
	SenderKey string

	// An encoded container's owner user ID.
	ContainerOwner user.ID

	// If SoftAPECheck is set to true, then NoRuleFound is interpreted as allow.
	SoftAPECheck bool

	// If true, object headers will not retrieved from storage engine.
	WithoutHeaderRequest bool

	// The request's bearer token. It is used in order to check APE overrides with the token.
	BearerToken *bearer.Token

	// XHeaders from the request.
	XHeaders []session.XHeader
}

var errMissingOID = errors.New("object ID is not set")

// CheckAPE prepares an APE-request and checks if it is permitted by policies.
func (c *checkerImpl) CheckAPE(ctx context.Context, prm Prm) error {
	// APE check is ignored for some inter-node requests.
	if prm.Role == nativeschema.PropertyValueContainerRoleContainer {
		return nil
	} else if prm.Role == nativeschema.PropertyValueContainerRoleIR {
		switch prm.Method {
		case nativeschema.MethodGetObject,
			nativeschema.MethodHeadObject,
			nativeschema.MethodSearchObject,
			nativeschema.MethodRangeObject,
			nativeschema.MethodHashObject:
			return nil
		default:
		}
	}

	r, err := c.newAPERequest(ctx, prm)
	if err != nil {
		return fmt.Errorf("failed to create ape request: %w", err)
	}
	pub, err := keys.NewPublicKeyFromString(prm.SenderKey)
	if err != nil {
		return err
	}

	return c.checkerCore.CheckAPE(checkercore.CheckPrm{
		Request:        r,
		PublicKey:      pub,
		Namespace:      prm.Namespace,
		Container:      prm.Container,
		ContainerOwner: prm.ContainerOwner,
		BearerToken:    prm.BearerToken,
		SoftAPECheck:   prm.SoftAPECheck,
	})
}