// Copyright 2021 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package models

import (
	"strings"

	"code.gitea.io/gitea/modules/log"

	"github.com/keybase/go-crypto/openpgp"
)

//   __________________  ________   ____  __.
//  /  _____/\______   \/  _____/  |    |/ _|____ ___.__.
// /   \  ___ |     ___/   \  ___  |      <_/ __ <   |  |
// \    \_\  \|    |   \    \_\  \ |    |  \  ___/\___  |
//  \______  /|____|    \______  / |____|__ \___  > ____|
//         \/                  \/          \/   \/\/
//    _____       .___  .___
//   /  _  \    __| _/__| _/
//	/  /_\  \  / __ |/ __ |
// /    |    \/ /_/ / /_/ |
// \____|__  /\____ \____ |
//         \/      \/    \/

// This file contains functions relating to adding GPG Keys

// addGPGKey add key, import and subkeys to database
func addGPGKey(e Engine, key *GPGKey, content string) (err error) {
	// Add GPGKeyImport
	if _, err = e.Insert(GPGKeyImport{
		KeyID:   key.KeyID,
		Content: content,
	}); err != nil {
		return err
	}
	// Save GPG primary key.
	if _, err = e.Insert(key); err != nil {
		return err
	}
	// Save GPG subs key.
	for _, subkey := range key.SubsKey {
		if err := addGPGSubKey(e, subkey); err != nil {
			return err
		}
	}
	return nil
}

// addGPGSubKey add subkeys to database
func addGPGSubKey(e Engine, key *GPGKey) (err error) {
	// Save GPG primary key.
	if _, err = e.Insert(key); err != nil {
		return err
	}
	// Save GPG subs key.
	for _, subkey := range key.SubsKey {
		if err := addGPGSubKey(e, subkey); err != nil {
			return err
		}
	}
	return nil
}

// AddGPGKey adds new public key to database.
func AddGPGKey(ownerID int64, content, token, signature string) ([]*GPGKey, error) {
	ekeys, err := checkArmoredGPGKeyString(content)
	if err != nil {
		return nil, err
	}

	sess := x.NewSession()
	defer sess.Close()
	if err = sess.Begin(); err != nil {
		return nil, err
	}
	keys := make([]*GPGKey, 0, len(ekeys))

	verified := false
	// Handle provided signature
	if signature != "" {
		signer, err := openpgp.CheckArmoredDetachedSignature(ekeys, strings.NewReader(token), strings.NewReader(signature))
		if err != nil {
			signer, err = openpgp.CheckArmoredDetachedSignature(ekeys, strings.NewReader(token+"\n"), strings.NewReader(signature))
		}
		if err != nil {
			signer, err = openpgp.CheckArmoredDetachedSignature(ekeys, strings.NewReader(token+"\r\n"), strings.NewReader(signature))
		}
		if err != nil {
			log.Error("Unable to validate token signature. Error: %v", err)
			return nil, ErrGPGInvalidTokenSignature{
				ID:      ekeys[0].PrimaryKey.KeyIdString(),
				Wrapped: err,
			}
		}
		ekeys = []*openpgp.Entity{signer}
		verified = true
	}

	for _, ekey := range ekeys {
		// Key ID cannot be duplicated.
		has, err := sess.Where("key_id=?", ekey.PrimaryKey.KeyIdString()).
			Get(new(GPGKey))
		if err != nil {
			return nil, err
		} else if has {
			return nil, ErrGPGKeyIDAlreadyUsed{ekey.PrimaryKey.KeyIdString()}
		}

		// Get DB session

		key, err := parseGPGKey(ownerID, ekey, verified)
		if err != nil {
			return nil, err
		}

		if err = addGPGKey(sess, key, content); err != nil {
			return nil, err
		}
		keys = append(keys, key)
	}
	return keys, sess.Commit()
}