package models

import (
	"database/sql/driver"
	"fmt"
)

// OrganizationPermission represents a bitmask of permissions for organization members.
//
// The DB column is SMALLINT (signed int16), but this type is uint16 so the
// full 16-bit space is usable (RoleOwner == 0xFFFF). The Value/Scan pair
// reinterprets the bits between int16 and uint16 so a high-bit-set value
// like 0xFFFF round-trips as -1 on disk and back, without pgx rejecting
// either direction.
type OrganizationPermission uint16

// Value implements driver.Valuer. Reinterpret the uint16 bits as int16 so
// pgx accepts values > 32767 when writing into a SMALLINT column.
func (p OrganizationPermission) Value() (driver.Value, error) {
	return int64(int16(p)), nil
}

// Scan implements sql.Scanner. The SMALLINT column comes back as int (any
// width depending on driver); reinterpret the low 16 bits as uint16 so a
// stored -1 reads as 0xFFFF.
func (p *OrganizationPermission) Scan(src any) error {
	switch v := src.(type) {
	case nil:
		*p = 0
	case int64:
		*p = OrganizationPermission(uint16(v))
	case int32:
		*p = OrganizationPermission(uint16(v))
	case int16:
		*p = OrganizationPermission(uint16(v))
	default:
		return fmt.Errorf("OrganizationPermission.Scan: unsupported type %T", src)
	}
	return nil
}

const (
	// PermManageTeam allows inviting/removing members
	PermManageTeam OrganizationPermission = 1 << iota
	// PermManageBilling allows viewing invoices and upgrading plans
	PermManageBilling
	// PermManageCampaigns allows creating/editing campaigns
	PermManageCampaigns
	// PermManageContacts allows creating/editing contacts
	PermManageContacts
	// PermManageEmails allows connecting email accounts
	PermManageEmails
	// PermViewAnalytics allows viewing reports
	PermViewAnalytics
	// PermSendCampaigns allows starting campaigns
	PermSendCampaigns
	// PermAccessUnibox allows using unified inbox
	PermAccessUnibox
	// PermManageSequences allows creating/editing sequences
	PermManageSequences
	// PermManageSettings allows changing org settings
	PermManageSettings
	// PermViewCampaigns allows read-only campaign access
	PermViewCampaigns
	// PermViewContacts allows read-only contact access
	PermViewContacts
	// PermTransferOwnership allows transferring org ownership
	PermTransferOwnership
	// PermManageAPIKeys allows managing organization API keys
	PermManageAPIKeys
)

// Role represents predefined permission sets
type Role string

const (
	RoleOwner   Role = "owner"
	RoleAdmin   Role = "admin"
	RoleManager Role = "manager"
	RoleViewer  Role = "viewer"
)

// AllPermissions represents all permissions combined
const AllPermissions OrganizationPermission = 0xFFFF

// RolePermissions maps roles to their default permissions
var RolePermissions = map[Role]OrganizationPermission{
	RoleOwner: AllPermissions,
	RoleAdmin: AllPermissions ^ PermTransferOwnership ^ 0, // Admin gets all except transfer
	RoleManager: PermManageCampaigns | PermManageContacts | PermManageEmails |
		PermSendCampaigns | PermManageSequences | PermViewAnalytics |
		PermViewCampaigns | PermViewContacts | PermAccessUnibox,
	RoleViewer: PermViewCampaigns | PermViewContacts | PermViewAnalytics,
}

// GetRolePermissions returns the default permissions for a role
func GetRolePermissions(role Role) OrganizationPermission {
	if perms, ok := RolePermissions[role]; ok {
		return perms
	}
	return RolePermissions[RoleViewer]
}

// HasPermission checks if the permission set includes a specific permission
func (p OrganizationPermission) HasPermission(perm OrganizationPermission) bool {
	return p&perm == perm
}

// AddPermission adds a permission to the set
func (p OrganizationPermission) AddPermission(perm OrganizationPermission) OrganizationPermission {
	return p | perm
}

// RemovePermission removes a permission from the set
func (p OrganizationPermission) RemovePermission(perm OrganizationPermission) OrganizationPermission {
	return p &^ perm
}

// IsValidRole checks if a role string is valid
func IsValidRole(role string) bool {
	switch Role(role) {
	case RoleOwner, RoleAdmin, RoleManager, RoleViewer:
		return true
	default:
		return false
	}
}