// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// +build java android

package security

import (
	"fmt"
	"log"
	"runtime"

	"v.io/v23/security"
	jutil "v.io/x/jni/util"
)

// #include "jni.h"
import "C"

// JavaPrincipal converts the provided Go Principal into a Java VPrincipal
// object.
func JavaPrincipal(env jutil.Env, principal security.Principal) (jutil.Object, error) {
	if principal == nil {
		return jutil.NullObject, nil
	}
	ref := jutil.GoNewRef(&principal) // Un-refed when the Java VPrincipalImpl is finalized.
	jPrincipal, err := jutil.NewObject(env, jVPrincipalImplClass, []jutil.Sign{jutil.LongSign, signerSign, blessingStoreSign, blessingRootsSign}, int64(ref), jutil.NullObject, jutil.NullObject, jutil.NullObject)
	if err != nil {
		jutil.GoDecRef(ref)
		return jutil.NullObject, err
	}
	return jPrincipal, nil
}

// GoPrincipal converts the provided Java VPrincipal object into a Go Principal.
func GoPrincipal(env jutil.Env, jPrincipal jutil.Object) (security.Principal, error) {
	if jPrincipal.IsNull() {
		return nil, nil
	}
	if jutil.IsInstanceOf(env, jPrincipal, jVPrincipalImplClass) {
		// Called with our implementation of VPrincipal, which maintains a Go reference - use it.
		ref, err := jutil.CallLongMethod(env, jPrincipal, "nativeRef", nil)
		if err != nil {
			return nil, err
		}
		return (*(*security.Principal)(jutil.GoRefValue(jutil.Ref(ref)))), nil
	}

	// Reference Java VPrincipal; it will be de-referenced when the Go Principal
	// created below is garbage-collected (through the finalizer callback we
	// setup just below).
	jPrincipal = jutil.NewGlobalRef(env, jPrincipal)
	// Create Go Principal.
	p := &principal{
		jPrincipal: jPrincipal,
	}
	runtime.SetFinalizer(p, func(p *principal) {
		env, freeFunc := jutil.GetEnv()
		defer freeFunc()
		jutil.DeleteGlobalRef(env, p.jPrincipal)
	})
	return p, nil
}

type principal struct {
	jPrincipal jutil.Object
}

func (p *principal) Bless(key security.PublicKey, with security.Blessings, extension string, caveat security.Caveat, additionalCaveats ...security.Caveat) (security.Blessings, error) {
	env, freeFunc := jutil.GetEnv()
	defer freeFunc()

	jKey, err := JavaPublicKey(env, key)
	if err != nil {
		return security.Blessings{}, err
	}
	jWith, err := JavaBlessings(env, with)
	if err != nil {
		return security.Blessings{}, err
	}
	jCaveat, err := JavaCaveat(env, caveat)
	if err != nil {
		return security.Blessings{}, err
	}
	jAdditionalCaveats, err := JavaCaveatArray(env, additionalCaveats)
	if err != nil {
		return security.Blessings{}, err
	}
	jBlessings, err := jutil.CallObjectMethod(env, p.jPrincipal, "bless", []jutil.Sign{publicKeySign, blessingsSign, jutil.StringSign, caveatSign, jutil.ArraySign(caveatSign)}, blessingsSign, jKey, jWith, extension, jCaveat, jAdditionalCaveats)
	if err != nil {
		return security.Blessings{}, err
	}
	return GoBlessings(env, jBlessings)
}

func (p *principal) BlessSelf(name string, caveats ...security.Caveat) (security.Blessings, error) {
	env, freeFunc := jutil.GetEnv()
	defer freeFunc()
	jCaveats, err := JavaCaveatArray(env, caveats)
	if err != nil {
		return security.Blessings{}, err
	}
	jBlessings, err := jutil.CallObjectMethod(env, p.jPrincipal, "blessSelf", []jutil.Sign{jutil.StringSign, jutil.ArraySign(caveatSign)}, blessingsSign, name, jCaveats)
	if err != nil {
		return security.Blessings{}, err
	}
	return GoBlessings(env, jBlessings)
}

func (p *principal) Sign(message []byte) (security.Signature, error) {
	env, freeFunc := jutil.GetEnv()
	defer freeFunc()
	jSig, err := jutil.CallObjectMethod(env, p.jPrincipal, "sign", []jutil.Sign{jutil.ArraySign(jutil.ByteSign)}, signatureSign, message)
	if err != nil {
		return security.Signature{}, err
	}
	return GoSignature(env, jSig)
}

func (p *principal) MintDischarge(forThirdPartyCaveat, caveatOnDischarge security.Caveat, additionalCaveatsOnDischarge ...security.Caveat) (security.Discharge, error) {
	return security.Discharge{}, fmt.Errorf("MintDischarge not yet implemented")
}

func (p *principal) PublicKey() security.PublicKey {
	env, freeFunc := jutil.GetEnv()
	defer freeFunc()
	jPublicKey, err := jutil.CallObjectMethod(env, p.jPrincipal, "publicKey", nil, publicKeySign)
	if err != nil {
		log.Printf("Couldn't get Java public key: %v", err)
		return nil
	}
	key, err := GoPublicKey(env, jPublicKey)
	if err != nil {
		log.Printf("Couldn't convert Java public key to Go: %v", err)
		return nil
	}
	return key
}

func (p *principal) BlessingStore() security.BlessingStore {
	env, freeFunc := jutil.GetEnv()
	defer freeFunc()
	jBlessingStore, err := jutil.CallObjectMethod(env, p.jPrincipal, "blessingStore", nil, blessingStoreSign)
	if err != nil {
		log.Printf("Couldn't get Java Blessing Store: %v", err)
		return nil
	}
	store, err := GoBlessingStore(env, jBlessingStore)
	if err != nil {
		log.Printf("Couldn't convert Java Blessing Store to Go: %v", err)
		return nil
	}
	return store
}

func (p *principal) Roots() security.BlessingRoots {
	env, freeFunc := jutil.GetEnv()
	defer freeFunc()
	jBlessingRoots, err := jutil.CallObjectMethod(env, p.jPrincipal, "roots", nil, blessingRootsSign)
	if err != nil {
		log.Printf("Couldn't get Java Blessing Roots: %v", err)
		return nil
	}
	roots, err := GoBlessingRoots(env, jBlessingRoots)
	if err != nil {
		log.Printf("Couldn't convert Java Blessing Roots to Go: %v", err)
		return nil
	}
	return roots
}