package repository

import (
	"context"

	"gorm.io/gorm"

	"github.com/gochat/gochat/internal/model"
)

// PermissibleRepo provides data access for Permissible (polymorphic permission records).
// Reference: Chatwoot PlatformAppPermissible + P2B M12 spec
//
// Each Permissible record means "PlatformApp X can operate on Resource Y".
// Resource types (PermissibleType) include: Account, User, AgentBot.
type PermissibleRepo struct {
	db *gorm.DB
}

// NewPermissibleRepo creates a new Permissible repository.
func NewPermissibleRepo(db *gorm.DB) *PermissibleRepo {
	return &PermissibleRepo{db: db}
}

// Create inserts a new Permissible record.
func (r *PermissibleRepo) Create(ctx context.Context, permissible *model.Permissible) error {
	return r.db.WithContext(ctx).Create(permissible).Error
}

// GetByID retrieves a Permissible by primary key.
func (r *PermissibleRepo) GetByID(ctx context.Context, id uint) (*model.Permissible, error) {
	var permissible model.Permissible
	if err := r.db.WithContext(ctx).First(&permissible, id).Error; err != nil {
		return nil, err
	}
	return &permissible, nil
}

// FindByPlatformAppID retrieves all Permissible records for a given PlatformApp.
// Returns all permissions granted to a specific platform app.
func (r *PermissibleRepo) FindByPlatformAppID(ctx context.Context, platformAppID uint) ([]model.Permissible, error) {
	var permissibles []model.Permissible
	if err := r.db.WithContext(ctx).
		Where("platform_app_id = ?", platformAppID).
		Find(&permissibles).Error; err != nil {
		return nil, err
	}
	return permissibles, nil
}

// FindByResource retrieves all Permissible records for a given resource (polymorphic).
// Returns which platform apps can access a specific resource (e.g. "which apps can access Account X").
func (r *PermissibleRepo) FindByResource(ctx context.Context, permissibleType string, permissibleID uint) ([]model.Permissible, error) {
	var permissibles []model.Permissible
	if err := r.db.WithContext(ctx).
		Where("permissible_type = ? AND permissible_id = ?", permissibleType, permissibleID).
		Find(&permissibles).Error; err != nil {
		return nil, err
	}
	return permissibles, nil
}

// FindByPlatformAppAndResource checks if a specific PlatformApp has permission on a specific resource.
// Returns the Permissible record if it exists, or nil if no permission is granted.
func (r *PermissibleRepo) FindByPlatformAppAndResource(ctx context.Context, platformAppID uint, permissibleType string, permissibleID uint) (*model.Permissible, error) {
	var permissible model.Permissible
	if err := r.db.WithContext(ctx).
		Where("platform_app_id = ? AND permissible_type = ? AND permissible_id = ?", platformAppID, permissibleType, permissibleID).
		First(&permissible).Error; err != nil {
		return nil, err
	}
	return &permissible, nil
}

// Delete removes a Permissible record by primary key (hard delete — no soft delete on Permissible).
func (r *PermissibleRepo) Delete(ctx context.Context, id uint) error {
	return r.db.WithContext(ctx).Delete(&model.Permissible{}, id).Error
}

// DeleteByPlatformAppAndResource removes a specific permission for a PlatformApp on a resource.
func (r *PermissibleRepo) DeleteByPlatformAppAndResource(ctx context.Context, platformAppID uint, permissibleType string, permissibleID uint) error {
	return r.db.WithContext(ctx).
		Where("platform_app_id = ? AND permissible_type = ? AND permissible_id = ?", platformAppID, permissibleType, permissibleID).
		Delete(&model.Permissible{}).Error
}

// DeleteByPlatformAppID removes all Permissible records for a given PlatformApp.
// Used for cleanup when a PlatformApp is deleted.
func (r *PermissibleRepo) DeleteByPlatformAppID(ctx context.Context, platformAppID uint) error {
	return r.db.WithContext(ctx).
		Where("platform_app_id = ?", platformAppID).
		Delete(&model.Permissible{}).Error
}