// Orders from the hand: "attack" sends the fighting creatures nearby at an enemy unit or tower,
// "guard" posts a few creatures in a room. Right click with an order tool cancels the orders.

use crate::game::*;
use crate::map::*;

const ORDER_RADIUS: f32 = 18.0;
const GUARDS: usize = 3;

fn ready(e: &Ent) -> bool {
    e.alive && !e.held && e.creature() && !matches!(e.job, Job::Leave | Job::Register | Job::MakeBed(_)) && e.hp > e.max_hp * 0.25
}

impl Game {
    // attack: the enemy (unit, or tower) at (wx, wy)
    pub fn order_attack(&mut self, picked: Option<usize>, wx: f32, wy: f32) {
        let unit = picked.filter(|&j| j < self.ents.len() && self.is_hostile(&self.ents[j])).or_else(|| {
            self.ents.iter().position(|e| self.is_hostile(e) && (e.x - wx).powi(2) + (e.y - wy).powi(2) < 1.5 * 1.5)
        });
        let tower = if unit.is_none() {
            self.towers.iter().find(|t| t.hero && (t.pos().0 - wx).powi(2) + (t.pos().1 - wy).powi(2) < 1.2 * 1.2).map(|t| (t.id, t.pos()))
        } else {
            None
        };
        let (tx, ty) = match (unit, tower) {
            (Some(j), _) => (self.ents[j].x, self.ents[j].y),
            (None, Some((_, p))) => p,
            _ => {
                self.hint(31, "hint.order_attack");
                self.sfx_ui(Sfx::Error);
                return;
            }
        };
        let mut n = 0;
        for e in self.ents.iter_mut().filter(|e| ready(e) && (e.x - tx).powi(2) + (e.y - ty).powi(2) < ORDER_RADIUS * ORDER_RADIUS) {
            e.job = match (unit, tower) {
                (Some(_), _) => Job::Attack(0),
                (None, Some((id, _))) => Job::AttackTower(id),
                _ => continue,
            };
            e.path.clear();
            e.repath = 0.0;
            n += 1;
        }
        if let Some(j) = unit {
            let id = self.ents[j].id;
            for e in self.ents.iter_mut() {
                if e.job == Job::Attack(0) {
                    e.job = Job::Attack(id);
                }
            }
        }
        if n == 0 {
            self.hint(31, "hint.order_nobody");
            return;
        }
        self.fx(7, tx, ty, 0.0, 0.0, 0.6, 0xff3040ff);
        self.sfx_ui(Sfx::FlagSet);
        self.msg("msg.order_attack", vec![n.to_string()]);
    }

    // guard: a few creatures take positions in the room at (x, y)
    pub fn order_guard(&mut self, x: i32, y: i32) {
        if !inb(x, y) {
            return;
        }
        let i = idx(x, y);
        let kind = self.map.t[i].kind;
        if self.map.t[i].owner != self.me || room_index(kind).is_none() && kind != Kind::Floor {
            self.hint(31, "hint.order_guard");
            self.sfx_ui(Sfx::Error);
            return;
        }
        // the spots: tiles of the same room (or floor) around the click
        let mut spots: Vec<usize> = Vec::new();
        for dy in -3..=3 {
            for dx in -3..=3 {
                if let Some(t) = self.map.get(x + dx, y + dy) {
                    let j = idx(x + dx, y + dy);
                    if t.kind == kind && t.owner == self.me && t.reserved == 0 && !self.ents.iter().any(|e| e.job == Job::Guard(j)) {
                        spots.push(j);
                    }
                }
            }
        }
        spots.sort_by_key(|&j| {
            let (sx, sy) = xy(j);
            (sx - x).pow(2) + (sy - y).pow(2)
        });
        let (fx, fy) = (x as f32 + 0.5, y as f32 + 0.5);
        let mut cands: Vec<usize> = (0..self.ents.len()).filter(|&j| ready(&self.ents[j]) && !matches!(self.ents[j].job, Job::Attack(_) | Job::Guard(_))).collect();
        cands.sort_by(|&a, &b| {
            let da = (self.ents[a].x - fx).powi(2) + (self.ents[a].y - fy).powi(2);
            let db = (self.ents[b].x - fx).powi(2) + (self.ents[b].y - fy).powi(2);
            da.partial_cmp(&db).unwrap_or(std::cmp::Ordering::Equal)
        });
        let mut n = 0;
        for (&j, &spot) in cands.iter().zip(spots.iter()).take(GUARDS) {
            let cur = self.ents[j].tile();
            let Some(p) = self.map.creature_path(flies(self.ents[j].kind), cur, spot) else { continue };
            let me = self.ents[j].id + 1;
            self.unreserve(me);
            self.map.t[spot].reserved = me;
            let e = &mut self.ents[j];
            e.job = Job::Guard(spot);
            e.path = p;
            e.timer = 120.0;
            n += 1;
        }
        if n == 0 {
            self.hint(31, "hint.order_nobody");
            return;
        }
        self.fx(8, fx, fy, 0.0, 0.0, 0.6, 0xff40d0ff);
        self.sfx_ui(Sfx::FlagSet);
        self.msg("msg.order_guard", vec![n.to_string()]);
    }

    // right click with an order tool: everybody stands down
    pub fn cancel_orders(&mut self) {
        let mut n = 0;
        for k in 0..self.ents.len() {
            if matches!(self.ents[k].job, Job::Guard(_)) && self.ents[k].creature() {
                let me = self.ents[k].id + 1;
                self.unreserve(me);
                self.ents[k].job = Job::None;
                n += 1;
            }
        }
        if n > 0 {
            self.msg("msg.orders_cancelled", vec![]);
            self.sfx_ui(Sfx::Click);
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn creatures_follow_attack_and_guard_orders() {
        let mut g = Game::new(14, 64, 64);
        let (cx, cy) = g.map.core;
        let ids: Vec<u32> = (0..4).map(|k| g.spawn(EK::Ogre, false, cx as f32 - 0.5, cy as f32 + 0.5 + k as f32 * 0.3, 2)).collect();
        let knight = g.spawn(EK::Knight, true, cx as f32 + 2.5, cy as f32 - 1.5, 1);
        let j = g.find(knight).unwrap();
        g.order_attack(Some(j), 0.0, 0.0);
        assert!(ids.iter().all(|&id| g.ents[g.find(id).unwrap()].job == Job::Attack(knight)));
        // guard the treasury ring around the core
        for &id in &ids {
            let j = g.find(id).unwrap();
            g.ents[j].job = Job::None;
        }
        g.order_guard(cx - 1, cy - 1);
        let guards = g.ents.iter().filter(|e| matches!(e.job, Job::Guard(_))).count();
        assert_eq!(guards, 3);
        g.cancel_orders();
        assert_eq!(g.ents.iter().filter(|e| matches!(e.job, Job::Guard(_))).count(), 0);
    }
}