//! Data model structs and enums

use serde::{Serialize, Deserialize};
use std::borrow::Cow;
use super::ID;
use super::data::TypedValue;
use std::fmt::{Display, Formatter};
use std::fmt;

/// Get a description of a struct
pub trait Describe {
    /// Short but informative description for error messages
    fn describe(&self) -> String;
}

/// Object template
#[derive(Debug,Clone,Serialize,Deserialize)]
pub struct ObjectModel {
    /// PK
    pub id : ID,
    /// Template name, unique within the database
    pub name: String,
    /// Parent object template ID
    pub parent_tpl_id: Option<ID>,
}

/// Relation between templates
#[derive(Debug,Clone,Serialize,Deserialize)]
pub struct RelationModel {
    /// PK
    pub id: ID,
    /// Object template ID
    pub object_tpl_id: ID,
    /// Relation name, unique within the parent object
    pub name: String,
    /// Relation is optional
    pub optional: bool,
    /// Relation can be multiple
    pub multiple: bool,
    /// Related object template ID
    pub related_tpl_id: ID,
}

/// Property definition
#[derive(Debug,Clone,Serialize,Deserialize)]
pub struct PropertyModel {
    /// PK
    pub id: ID,
    /// Object or Reference template ID
    pub parent_tpl_id: ID,
    /// Property name, unique within the parent object or reference
    pub name: String,
    /// Property is optional
    pub optional: bool,
    /// Property can be multiple
    pub multiple: bool,
    /// Property data type
    pub data_type: DataType,
    /// Default value, used for newly created objects
    pub default: Option<TypedValue>,
}

/// Value data type
#[derive(Debug,Clone,Copy,Serialize,Deserialize,Eq,PartialEq)]
pub enum DataType {
    /// Text
    String,
    /// Integer
    Integer,
    /// Floating point number
    Decimal,
    /// Boolean yes/no
    Boolean,
}

impl Display for ObjectModel {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        write!(f, "object \"{}\" ({})", self.name, self.id)
    }
}

impl Display for RelationModel {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        write!(f, "relation \"{}\" ({})", self.name, self.id)
    }
}

impl Display for PropertyModel {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        write!(f, "property \"{}\" ({})", self.name, self.id)
    }
}