use std::fmt::Debug;
use std::sync::Arc;

use crate::dynamic_data::{ItemScript, Script, ScriptOwnerData};
use crate::static_data::Item;
use crate::{PkmnResult, StringKey};

/// A script resolver deals with the resolving of scripts. These scripts are non-hardcoded
/// implementations of different effects in Pokemon. This allows for things such as generational
/// differences, and custom implementations.
pub trait ScriptResolver: Debug {
    /// Loads a standard script with a given unique combination of category and key. If no script
    /// can be created with this combination, returns None.
    fn load_script(
        &self,
        owner: ScriptOwnerData,
        category: ScriptCategory,
        script_key: &StringKey,
    ) -> PkmnResult<Option<Arc<dyn Script>>>;

    /// Loads an item script with the given unique key. If no script can be created with this
    /// combinations, returns None. Note that ItemScripts are immutable, as their script should be
    /// shared between all different usages.
    fn load_item_script(&self, _key: &Item) -> PkmnResult<Option<Arc<dyn ItemScript>>>;
}

/// A script category defines a sub-group of scripts. This can be used to have multiple scripts with
/// the same name, but a different script. It should be completely valid for a move to have the same
/// name as an ability, or more commonly: for a script attached to a Pokemon to have the same name as
/// a move that placed it there.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
#[repr(u8)]
pub enum ScriptCategory {
    /// A script that belongs to a move. This generally is only the script that is attached to a
    /// [`MoveChoice`](crate::dynamic_data::MoveChoice) and [`ExecutingMove`](crate::dynamic_data::ExecutingMove)
    Move = 0,
    /// An ability script. Scripts in this category are always abilities, and therefore always
    /// attached to a Pokemon.
    Ability = 1,
    /// A non volatile status script. Scripts in this category are always non volatile statuses, and
    /// therefore always attached to a Pokemon.
    Status = 2,
    /// A volatile status script. Scripts in this category are always volatile status effects, and
    /// therefore always attached to a Pokemon.
    Pokemon = 3,
    /// A script that can be attached to an entire side.
    Side = 4,
    /// A script that can be attached to the entire battle.
    Battle = 5,
    /// A special script for held items. As they're part of a held item, they're attached to a Pokemon.
    ItemBattleTrigger = 6,
}

/// A basic empty script resolver, that always returns None.
#[derive(Debug)]
pub struct EmptyScriptResolver {}

impl ScriptResolver for EmptyScriptResolver {
    fn load_script(
        &self,
        _owner: ScriptOwnerData,
        _category: ScriptCategory,
        _script_key: &StringKey,
    ) -> PkmnResult<Option<Arc<dyn Script>>> {
        Ok(None)
    }

    fn load_item_script(&self, _key: &Item) -> PkmnResult<Option<Arc<dyn ItemScript>>> {
        Ok(None)
    }
}