use crate::{
    models::{
        item::Item,
        task::{
            Task,
            TaskMeta,
            TaskDetails,
        }
    },
        
    DResult,
    static_content::{
        possession_type::UseEffect,
    },
    regular_tasks::{
        TaskHandler,
        TaskRunContext,
    }
};
use super::{
    broadcast_to_room,
    combat::change_health,
};
use async_trait::async_trait;
use std::time;
use serde::{Serialize, Deserialize};
use std::collections::{BTreeMap, VecDeque};
use chrono::Utc;
use log::info;
use mockall_double::double;
#[double] use crate::db::DBTrans;

#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq, Ord, PartialOrd)]
pub struct DelayedHealthEffect {
    magnitude: i64,
    delay: u64,
    message: String,
    message_nonexp: String
}

pub struct DelayedHealthTaskHandler;
#[async_trait]
impl TaskHandler for DelayedHealthTaskHandler {
    async fn do_task(&self, ctx: &mut TaskRunContext) -> DResult<Option<time::Duration>> {
        let ref mut item_effect_series = match &mut ctx.task.details {
            TaskDetails::DelayedHealth { item, ref mut effect_series } => (item, effect_series),
            _ => Err("Expected DelayedHealth type")?
        };
        let (item_type, item_code) = match item_effect_series.0.split_once("/") {
            None => {
                info!("Invalid item {} to DelayedHealthTaskHandler", item_effect_series.0);
                return Ok(None);
            }
            Some((item_type, item_code)) => (item_type, item_code)
        };
        let item = match ctx.trans.find_item_by_type_code(item_type, item_code).await? {
            None => {
                return Ok(None);
            }
            Some(it) => it
        };
        if item.is_dead {
            return Ok(None);
        }
        match item_effect_series.1.pop_front() {
            None => Ok(None),
            Some(DelayedHealthEffect { magnitude, message, message_nonexp, .. }) => {
                let mut item_mut = (*item).clone();
                change_health(ctx.trans, magnitude, &mut item_mut, &message, &message_nonexp).await?;
                ctx.trans.save_item_model(&item_mut).await?;
                Ok(item_effect_series.1.front().map(|it| time::Duration::from_secs(it.delay)))
            }
        }
    }
}
pub static DELAYED_HEALTH_HANDLER: &'static (dyn TaskHandler + Sync + Send) = &DelayedHealthTaskHandler;

pub async fn run_effects(
    trans: &DBTrans, effects: &Vec<UseEffect>,
    player: &mut Item,
    item: &Item,
    // None if target is player
    target: &mut Option<Item>,
    level: f64,
    task_ref: &str
) -> DResult<()> {
    let mut target_health_series = BTreeMap::<String, VecDeque<DelayedHealthEffect>>::new();
    for effect in effects {
        match effect {
            UseEffect::BroadcastMessage { messagef } => {
                let (msg_exp, msg_nonexp) = messagef(player, item, target.as_ref().unwrap_or(player));
                broadcast_to_room(trans, &player.location, None, &msg_exp,
                                  Some(&msg_nonexp)).await?;                    
            },
            UseEffect::ChangeTargetHealth { delay_secs, base_effect, skill_multiplier, max_effect,
                                            message } => {
                let health_impact =
                    (*base_effect + ((skill_multiplier * level) as i64).min(*max_effect)) as i64;
                let (msg, msg_nonexp) = message(target.as_ref().unwrap_or(player));
                if *delay_secs == 0 {
                    change_health(trans, health_impact, target.as_mut().unwrap_or(player), &msg,
                                  &msg_nonexp).await?;
                } else {
                    let target_it = target.as_ref().unwrap_or(player);
                    let fx = DelayedHealthEffect {
                        magnitude: health_impact,
                        delay: *delay_secs,
                        message: msg,
                        message_nonexp: msg_nonexp
                    };
                    target_health_series
                        .entry(format!("{}/{}", target_it.item_type, target_it.item_code))
                        .and_modify(|l| l.push_back(fx.clone()))
                        .or_insert(VecDeque::from([fx]));
                }
            }
        }
    }

    for (eff_item, l) in target_health_series.into_iter() {
      trans.upsert_task(&Task {
          meta: TaskMeta {
              task_code: format!("{}/{}", eff_item, task_ref),
              next_scheduled: Utc::now() + chrono::Duration::seconds(l[0].delay as i64),
              ..Default::default()
          },
          details: TaskDetails::DelayedHealth {
              effect_series: l,
              item: eff_item,
          }
      }).await?;
    }

    Ok(())
}