use std::string::ToString;
use std::sync::OnceLock;

use indexmap::IndexMap;
use wicked_waifus_protocol::{DFsm, DFsmBlackBoard, EntityComponentPb, EntityFsmComponentPb, FsmCustomBlackboardDatas};
use wicked_waifus_protocol::entity_component_pb::ComponentPb;

use wicked_waifus_data::{ai_base_data, ai_state_machine_config_data, AiStateMachineConfigData, StateMachineJson, StateMachineNode, StateMachineNodeCommon};

use crate::logic::ecs::component::Component;

static COMMON_FSM: OnceLock<AiStateMachineConfigData> = OnceLock::new();

#[derive(Default)]
pub struct Fsm {
    pub hash_code: i32,
    pub common_hash_code: i32,
    pub state_list: Vec<i32>,
    pub node_list: IndexMap<i32, StateMachineNodeCommon>,
}

impl Component for Fsm {
    fn set_pb_data(&self, pb: &mut wicked_waifus_protocol::EntityPb) {
        pb.component_pbs.push(EntityComponentPb {
            component_pb: Some(ComponentPb::EntityFsmComponentPb(EntityFsmComponentPb {
                fsms: self.get_initial_fsm(),
                hash_code: self.hash_code,
                common_hash_code: self.common_hash_code,
                black_board: self.get_black_board(),
                fsm_custom_blackboard_datas: self.get_fsm_custom_blackboard_datas(),
            })),
        })
    }
}

impl Fsm {
    pub fn from_ai_id(ai_id: i32) -> Self {
        let ai_base = ai_base_data::get(&ai_id);
        let Some(base) = ai_base else {
            tracing::error!("Ai Base not found for AI ID: {}", ai_id);
            return Self::default();
        };

        let common_state_machine: &StateMachineJson = &get_common_fsm().state_machine_json;
        // Should always be defined since it comes from bindata
        let Some(state_machine_config_data) = ai_state_machine_config_data::get(&base.state_machine) else {
            tracing::error!("State machine config not found for AI ID: {}", ai_id);
            return Self::default();
        };
        let state_machine_config: &StateMachineJson = &state_machine_config_data.state_machine_json;
        let mut fsm_tree: IndexMap<i32, StateMachineNodeCommon> = IndexMap::with_capacity(state_machine_config.nodes.len());
        for state_machine in &state_machine_config.state_machines {
            for node in &state_machine_config.nodes {
                match node {
                    StateMachineNode::Reference(_node) => {
                        // TODO:
                        // common_state_machine.nodes.iter()
                        //     .filter_map(|state_machine_node| match state_machine_node {
                        //         StateMachineNode::Reference(_) => None,
                        //         StateMachineNode::Override(_) => None,
                        //         StateMachineNode::Custom(custom) => Some(custom)
                        //     })
                        //     .find()
                    }
                    StateMachineNode::Override(node) => {
                        // TODO:
                        tracing::warn!(
                            "FSM: {state_machine} with override node {} for {} unimplemented",
                            node.common.uuid,
                            node.override_common_uuid
                        );
                    }
                    StateMachineNode::Custom(node) => {
                        fsm_tree.insert(node.common.uuid, node.common.clone());
                    }
                }
            }
        }
        Self {
            hash_code: state_machine_config.version as i32,
            common_hash_code: common_state_machine.version as i32,
            state_list: state_machine_config.state_machines.clone(),
            node_list: fsm_tree,
        }
    }

    fn get_initial_fsm(&self) -> Vec<DFsm> {
        self.node_list.iter()
            .filter_map(|(&id, node)| {
                self.state_list.contains(&id).then(|| DFsm {
                    fsm_id: id,
                    current_state: node.children.as_ref()
                        .and_then(|c| c.get(0).cloned())
                        .unwrap_or_default(),
                    flag: 0, // TODO:
                    k_ts: 0, // TODO:
                })
            }).collect::<Vec<_>>()
    }

    fn get_black_board(&self) -> Vec<DFsmBlackBoard> {
        vec![]
    }

    fn get_fsm_custom_blackboard_datas(&self) -> Option<FsmCustomBlackboardDatas> {
        None
    }
}

fn get_common_fsm() -> &'static AiStateMachineConfigData {
    COMMON_FSM.get_or_init(|| {
        let name = "SM_Common".to_string();
        // Common shall be always defined
        ai_state_machine_config_data::get(&name).cloned().unwrap()
    })
}