// Copyright 2025 The Gogs 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 database

import (
	"context"
	"encoding/json"
	"time"

	"github.com/pkg/errors"
	"gorm.io/gorm"
)

// GPGKey represents a GPG key for commit signature verification.
type GPGKey struct {
	ID          int64  `gorm:"primaryKey"`
	OwnerID     int64  `gorm:"index;not null"`
	KeyID       string `gorm:"type:VARCHAR(16);unique;not null"` // Short key ID (8 or 16 chars)
	Fingerprint string `gorm:"type:VARCHAR(40);not null"`        // Full 40-character fingerprint
	Content     string `gorm:"type:TEXT;not null"`               // ASCII-armored public key
	CanSign     bool   `gorm:"not null;default:false"`
	CanEncrypt  bool   `gorm:"not null;default:false"`
	Emails      string `gorm:"type:TEXT"` // JSON array of email addresses

	Created           time.Time `gorm:"-"`
	CreatedUnix       int64
	Updated           time.Time `gorm:"-"`
	UpdatedUnix       int64
	Expired           time.Time `gorm:"-"`
	ExpiredUnix       int64
	HasRecentActivity bool `gorm:"-" json:"-"`
}

// BeforeCreate implements the GORM create hook.
func (k *GPGKey) BeforeCreate(tx *gorm.DB) error {
	if k.CreatedUnix == 0 {
		k.CreatedUnix = tx.NowFunc().Unix()
	}
	if k.UpdatedUnix == 0 {
		k.UpdatedUnix = k.CreatedUnix
	}
	return nil
}

// BeforeUpdate implements the GORM update hook.
func (k *GPGKey) BeforeUpdate(tx *gorm.DB) error {
	k.UpdatedUnix = tx.NowFunc().Unix()
	return nil
}

// AfterFind implements the GORM query hook.
func (k *GPGKey) AfterFind(tx *gorm.DB) error {
	k.Created = time.Unix(k.CreatedUnix, 0).Local()
	k.Updated = time.Unix(k.UpdatedUnix, 0).Local()
	if k.ExpiredUnix > 0 {
		k.Expired = time.Unix(k.ExpiredUnix, 0).Local()
	}
	return nil
}

// GetEmails returns the list of email addresses associated with this GPG key.
func (k *GPGKey) GetEmails() ([]string, error) {
	if k.Emails == "" {
		return []string{}, nil
	}
	var emails []string
	err := json.Unmarshal([]byte(k.Emails), &emails)
	if err != nil {
		return nil, errors.Wrap(err, "unmarshal emails")
	}
	return emails, nil
}

// SetEmails sets the list of email addresses for this GPG key.
func (k *GPGKey) SetEmails(emails []string) error {
	data, err := json.Marshal(emails)
	if err != nil {
		return errors.Wrap(err, "marshal emails")
	}
	k.Emails = string(data)
	return nil
}

// IsExpired returns true if the key has expired.
func (k *GPGKey) IsExpired() bool {
	return k.ExpiredUnix > 0 && time.Now().Unix() > k.ExpiredUnix
}

// GPGKeysStore is the storage layer for GPG keys.
type GPGKeysStore struct {
	db *gorm.DB
}

func newGPGKeysStore(db *gorm.DB) *GPGKeysStore {
	return &GPGKeysStore{db: db}
}

// Create creates a new GPG key for the given user.
func (s *GPGKeysStore) Create(ctx context.Context, ownerID int64, keyID, fingerprint, content string, emails []string, canSign, canEncrypt bool, expiredUnix int64) (*GPGKey, error) {
	key := &GPGKey{
		OwnerID:     ownerID,
		KeyID:       keyID,
		Fingerprint: fingerprint,
		Content:     content,
		CanSign:     canSign,
		CanEncrypt:  canEncrypt,
		ExpiredUnix: expiredUnix,
	}

	if err := key.SetEmails(emails); err != nil {
		return nil, errors.Wrap(err, "set emails")
	}

	err := s.db.WithContext(ctx).Create(key).Error
	if err != nil {
		return nil, errors.Wrap(err, "create")
	}

	return key, nil
}

// GetByID returns the GPG key with the given ID.
func (s *GPGKeysStore) GetByID(ctx context.Context, id int64) (*GPGKey, error) {
	var key GPGKey
	err := s.db.WithContext(ctx).Where("id = ?", id).First(&key).Error
	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, ErrGPGKeyNotExist{args: map[string]any{"keyID": id}}
		}
		return nil, errors.Wrap(err, "get")
	}
	return &key, nil
}

// GetByKeyID returns the GPG key with the given key ID.
func (s *GPGKeysStore) GetByKeyID(ctx context.Context, keyID string) (*GPGKey, error) {
	var key GPGKey
	err := s.db.WithContext(ctx).Where("key_id = ?", keyID).First(&key).Error
	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, ErrGPGKeyNotExist{args: map[string]any{"keyID": keyID}}
		}
		return nil, errors.Wrap(err, "get")
	}
	return &key, nil
}

// GetByFingerprint returns the GPG key with the given fingerprint.
func (s *GPGKeysStore) GetByFingerprint(ctx context.Context, fingerprint string) (*GPGKey, error) {
	var key GPGKey
	err := s.db.WithContext(ctx).Where("fingerprint = ?", fingerprint).First(&key).Error
	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, ErrGPGKeyNotExist{args: map[string]any{"fingerprint": fingerprint}}
		}
		return nil, errors.Wrap(err, "get")
	}
	return &key, nil
}

// List returns all GPG keys for the given user.
func (s *GPGKeysStore) List(ctx context.Context, ownerID int64) ([]*GPGKey, error) {
	var keys []*GPGKey
	err := s.db.WithContext(ctx).Where("owner_id = ?", ownerID).Order("created_unix DESC").Find(&keys).Error
	if err != nil {
		return nil, errors.Wrap(err, "list")
	}
	return keys, nil
}

// Delete deletes the GPG key with the given ID.
func (s *GPGKeysStore) Delete(ctx context.Context, id int64) error {
	result := s.db.WithContext(ctx).Where("id = ?", id).Delete(&GPGKey{})
	if result.Error != nil {
		return errors.Wrap(result.Error, "delete")
	}
	if result.RowsAffected == 0 {
		return ErrGPGKeyNotExist{args: map[string]any{"keyID": id}}
	}
	return nil
}

// DeleteByOwnerID deletes all GPG keys for the given user.
func (s *GPGKeysStore) DeleteByOwnerID(ctx context.Context, ownerID int64) error {
	return s.db.WithContext(ctx).Where("owner_id = ?", ownerID).Delete(&GPGKey{}).Error
}