// *** main.rs
use std::fmt;
use std::cmp::Ordering;

fn main() {
    // ONLY CHANGE THINGS BELOW THIS LINE
    let champion_number = 11; // e.g. 5 for Kenny, 10 for Felice
    let pet_number = 10; // e.g. 4 for Lake Lizard, 7 for Elephant Fighter
    let pet_level = 2;
    let arena_league = League::Gold; // e.g. Bronze, Silver, Gold, Diamond
    let arena_division = 1;
    let arena_battle = 1;
    // ONLY CHANGE THINGS ABOVE THIS LINE

    let champion = Champion::build_champion(champion_number);
    println!("\n*** Champion stats:");
    champion.print_stats();

    let base_pet = Pet::build_pet(champion.multiplier, pet_number, pet_level);
    println!("\n*** Base pet stats:");
    base_pet.print_stats();

    let arena = Arena::new(arena_league, arena_division, arena_battle);
    println!("\n*** Arena:");
    arena.print_stats();

    let enemy = arena.get_enemy();
    println!("\n*** Enemy stats:");
    enemy.print_stats();

    println!("\n*** Optimising pets:");
    let bps = arena.get_bps();
    println!("{} BPs available to spend", bps);
    let upgraded_pets = PetUpgrader::get_possible_upgraded_pets(&base_pet, bps);
    println!(
        "Found {} possible upgraded pets to check",
        upgraded_pets.len()
    );

    println!("\n*** Optimising battles...");
    optimise_battles(&upgraded_pets, &enemy);
}

fn optimise_battles(pets: &[Pet], enemy: &Enemy) {
    // Try with different combinations of potions in order: ATK & DEF, DEF only, ATK only, neither
    let potion_configs = vec![(true, true), (false, true), (true, false), (false, false)];

    // Try with the first potion config (majority of cases)
    let battle = Battle::new(potion_configs[0].0, potion_configs[0].1);
    let result = battle.get_best_result(pets, enemy);
    if result.0 > 0.25 {
        // We are done
        display_result(potion_configs[0].0, potion_configs[0].1, result);
        return;
    }

    // Now we need to loop through the other potion configs
    let mut prev_result = result;
    for x in 1..4 {
        // Try this potion configuration
        let battle = Battle::new(potion_configs[x].0, potion_configs[x].1);
        let result = battle.get_best_result(pets, enemy);
        if result.0 > 0.25 {
            // We are done - show the previous result
            display_result(
                potion_configs[x - 1].0,
                potion_configs[x - 1].1,
                prev_result,
            );
            return;
        }

        // This is the best yet
        prev_result = result;
    }

    // Display the last result
    display_result(potion_configs[3].0, potion_configs[3].1, prev_result);
}

fn display_result(use_atk_potion: bool, use_def_potion: bool, result: (f32, &Pet)) {
    println!("Use ATK potion  : {}", use_atk_potion);
    println!("Use DEF potion  : {}", use_def_potion);
    println!("HP potions reqd : {:.1}", result.0);
    println!("Optimal pet     : {}", result.1.name);
}

// *** lib.rs
fn print_midas_number(number: f32) -> String {
    if number <= 0.0 {
        number.to_string()
    } else {
        let multiplier = number.log(1000.0).floor() as i32;
        let fraction = number / 1000.0_f32.powi(multiplier);

        let suffix = match multiplier {
            0 => "",
            1 => " K",
            2 => " M",
            3 => " B",
            4 => " T",
            5 => " Qa",
            6 => " Qi",
            7 => " Sx",
            8 => " Sp",
            9 => " Oc",
            10 => " No",
            _ => panic!("Number too big {}", number),
        };

        format!("{:6.2}{}", fraction, suffix)
    }
}

// *** champion.rs
pub struct Champion {
    pub name: String,
    pub multiplier: f32,
}

impl Champion {
    pub fn build_champion(champion_number: i32) -> Champion {
        Champion {
            name: Champion::get_name_for_number(champion_number),
            multiplier: Champion::get_multiplier_for_number(champion_number),
        }
    }

    pub fn print_stats(&self) {
        println!("{}", self.name);
        println!(
            "Multiplier : {} (+{}%)",
            self.multiplier,
            (self.multiplier - 1.0) * 100.0
        );
    }

    fn get_name_for_number(champion_number: i32) -> String {
        match champion_number {
            1 => "Gilligan",
            2 => "Audrey",
            3 => "Scarlet",
            4 => "Irwin",
            5 => "Kenny",
            6 => "Adeline",
            7 => "Valeria",
            8 => "Aurelius",
            9 => "Felix",
            10 => "Felice",
            11 => "Tempestus",
            12 => "Sylvar",
            13 => "Benedict",
            14 => "Lin",
            15 => "Volv",
            _ => panic!("Unknown champion_number: {}", champion_number),
        }.to_string()
    }

    fn get_multiplier_for_number(champion_number: i32) -> f32 {
        match champion_number {
            1 | 2 => 1.0,
            3 => 1.5,
            4 => 3.1,
            5 => 4.6,
            6 => 6.3,
            7 => 8.7,
            8 => 12.2,
            9 => 18.0,
            10 => 27.0,
            11 => 40.8,
            12 => 59.2,
            13 => 90.4,
            14 => 541.0,
            15 => 3201.0,
            _ => panic!("Unknown champion_number: {}", champion_number),
        }
    }
}

// *** pet.rs
pub struct Pet {
    pub name: String,
    pub health: f32,
    pub attack: f32,
    pub defence: f32,
    pub lifesteal: f32,
    pub block: f32,
    pub reflect: f32,
}

impl Pet {
    pub fn build_pet(champion_multiplier: f32, pet_number: i32, pet_level: i32) -> Pet {
        let pet_multiplier = 6_f32.powi(pet_number - 1) * (1.0 + 0.2 * (pet_level as f32 - 1.0));
        let total_multiplier = champion_multiplier * pet_multiplier;

        Pet {
            name: format!(
                "{} (level {})",
                Pet::get_name_for_number(pet_number),
                pet_level
            ),
            health: 720_f32 * total_multiplier,
            attack: 62_f32 * total_multiplier,
            defence: 24_f32 * total_multiplier,
            lifesteal: if pet_number > 1 {
                51_f32 * total_multiplier
            } else {
                0.0
            },
            block: if pet_number > 3 {
                42_f32 * total_multiplier
            } else {
                0.0
            },
            reflect: if pet_number > 6 {
                54_f32 * total_multiplier
            } else {
                0.0
            },
        }
    }

    pub fn print_stats(&self) {
        println!("{}", self.name);
        println!("Health     : {}", print_midas_number(self.health));
        println!("Attack     : {}", print_midas_number(self.attack));
        println!("Defence    : {}", print_midas_number(self.defence));
        println!("Lifesteal  : {}", print_midas_number(self.lifesteal));
        println!("Block      : {}", print_midas_number(self.block));
        println!("Reflect    : {}", print_midas_number(self.reflect));
    }

    fn get_name_for_number(pet_number: i32) -> String {
        match pet_number {
            1 => "Midaeum Gardens Parrot",
            2 => "Wild Mountain Boar",
            3 => "Bonebreaker Python",
            4 => "Lake Lizard",
            5 => "Royal Eagle",
            6 => "Gastonia Defender",
            7 => "Elephant Fighter",
            8 => "Fullmoon Werewolf",
            9 => "Bloodthirsty Tiger",
            10 => "Rhino of the Valley",
            11 => "Flameguard Goblin",
            12 => "Poisonous Hydra",
            13 => "Snowmountain Yeti",
            14 => "Astral Pegasus",
            15 => "Swarm Soldier",
            16 => "Lava Hound",
            17 => "Forest Keeper",
            18 => "Armored Nightmare",
            19 => "Crystal Golem",
            20 => "Dragon of the Void",
            _ => panic!("Unknown pet_number: {}", pet_number),
        }.to_string()
    }
}

// *** arena.rs
pub enum League {
    Bronze,
    Silver,
    Gold,
    Diamond,
}

pub struct Arena {
    league: League,
    division: i32,
    battle: i32,
}

impl Arena {
    pub fn new(league: League, division: i32, battle: i32) -> Arena {
        if division < 1 || division > 5 {
            panic!("Division {} not allowed", division);
        }

        if battle < 1 || battle > Arena::get_total_battles(&league, division) {
            panic!("Battle {} not allowed", battle);
        }

        Arena {
            league: league,
            division: division,
            battle: battle,
        }
    }

    pub fn print_stats(&self) {
        let league_name = match self.league {
            League::Bronze => "Bronze",
            League::Silver => "Silver",
            League::Gold => "Gold",
            League::Diamond => "Diamond",
        };
        let division_name = match self.division {
            1 => "I",
            2 => "II",
            3 => "III",
            4 => "IV",
            5 => "V",
            _ => unreachable!(),
        };

        println!(
            "{} {}     {} / {}",
            league_name,
            division_name,
            self.battle,
            Arena::get_total_battles(&self.league, self.division)
        );
    }

    pub fn get_bps(&self) -> i32 {
        let mut bps = 0;

        let cuumulative_division_num =
            Arena::get_cumulative_division_num(&self.league, self.division);

        // Add BPs from complete divisions
        for div in 1..cuumulative_division_num {
            bps += 2 * div * (div + 3);
        }

        // Add BPs from complete battles in this division
        bps += (self.battle - 1) * cuumulative_division_num;

        bps
    }

    pub fn get_enemy(&self) -> Enemy {
        let all_enemy_healths =
            vec![vec![640.0, 988.0, 1270.0, 1600.0, 4500.0],
                 vec![6000.0, 8500.0, 10500.0, 13000.0, 15000.0, 30000.0],
                 vec![60000.0, 80000.0, 110000.0, 130000.0, 150000.0, 165000.0, 300000.0],
                 vec![6e5, 1e6, 1.2e6, 1.3e6, 1.4e6, 1.6e6, 1.9e6, 4.2e6],
                 vec![7.2e6, 9.2e6, 1.3e7, 1.4e7, 1.5e7, 1.6e7, 1.7e7, 1.9e7, 4.3e7],
                 vec![1.2e8, 1.3e8, 1.5e8, 1.6e8, 1.8e8, 2.1e8, 2.3e8, 2.5e8, 3e8, 6.3e8],
                 vec![1e9, 1.1e9, 1.2e9, 1.5e9, 1.7e9, 1.8e9, 2e9, 2.3e9, 2.8e9, 3e9, 6.2e9],
                 vec![1e10, 1.1e10, 1.2e10, 1.5e10, 1.7e10, 1.8e10, 2e10, 2.3e10, 2.5e10, 2.7e10, 2.8e10, 6.8e10],
                 vec![1e11, 1.1e11, 1.2e11, 1.3e11, 1.5e11, 1.7e11, 1.8e11, 2e11, 2.2e11, 2.3e11, 2.7e11, 3e11, 5e11],
                 vec![6e11, 6.5e11, 7e11, 8.3e11, 9e11, 1e12, 1.1e12, 1.2e12, 1.4e12, 1.5e12, 1.6e12, 1.7e12, 1.9e12, 4e12],
                 vec![5e12, 5.5e12, 6e12, 6.5e12, 7e12, 7.5e12, 8.5e12, 9e12, 1e13, 1.1e13, 1.3e13, 1.4e13, 1.5e13, 1.7e13, 3.7e13],
                 vec![4e13, 4.5e13, 5e13, 5.5e13, 7e13, 7.5e13, 8e13, 8.5e13, 9e13, 9.5e14, 1e14, 1.05e14, 1.1e14, 1.12e14, 1.15e14, 2e14],
                 vec![2.1e14, 2.2e14, 2.3e14, 2.4e14, 2.6e14, 2.8e14, 3e14, 3.5e14, 3.8e14, 4.4e14, 4.6e14, 4.8e14, 5.2e14, 5.4e14, 6.05e14, 6.9e14, 1.3e15],
                 vec![1.7e15, 2.2e15, 2.3e15, 2.7e15, 3.6e15, 4e15, 4.5e15, 4.8e15, 4.9e15, 5e15, 5.1e15, 5.2e15, 5.3e15, 5.4e15, 5.5e15, 5.6e15, 6.1e15, 1.3e16],
                 vec![2e16, 2.2e16, 2.3e16, 2.4e16, 2.5e16, 2.7e16, 2.8e16, 2.9e16, 3.1e16, 3.4e16, 3.6e16, 4.0e16, 4.3e16, 4.6e16, 4.8e16, 5.0e16, 5.5e16, 5.7e16, 1.4e17],
                 vec![2e17, 2.2e17, 2.3e17, 2.4e17, 2.5e17, 2.6e17, 2.7e17, 2.8e17, 2.9e17, 3e17, 3.4e17, 3.6e17, 3.9e17, 4.5e17, 4.7e17, 5.4e17, 5.8e17, 6.4e17, 6.7e17, 1.2e18],
                 vec![1.8e18, 1.9e18, 2e18, 2.2e18, 2.3e18, 2.4e18, 2.5e18, 2.6e18, 2.7e18, 2.8e18, 2.9e18, 3e18, 3.3e18, 3.4e18, 3.9e18, 4e18, 4.4e18, 4.8e18, 5.5e18, 6.6e18, 1.7e19],
                 vec![2e19, 2.2e19, 2.4e19, 2.6e19, 2.8e19, 3e19, 3.3e19, 3.5e19, 3.9e19, 4.4e19, 4.6e19, 4.7e19, 5e19, 5.5e19, 6e19, 6.5e19, 7.5e19, 8e19, 8.5e19, 9e19, 9.5e19, 2e20],
                 vec![2.1e20, 2.2e20, 2.3e20, 2.4e20, 2.5e20, 2.6e20, 2.7e20, 2.8e20, 2.9e20, 3e20, 3.1e20, 3.2e20, 3.3e20, 3.4e20, 3.5e20, 3.6e20, 3.7e20, 3.8e20, 3.9e20, 4e20, 4.1e20, 4.2e20, 6.1e20],
                 vec![6.5e20, 6.8e20, 7.2e20, 7.4e20, 7.6e20, 7.8e20, 8e20, 8.2e20, 8.4e20, 8.6e20, 8.8e20, 9e20, 9.2e20, 9.4e20, 9.8e20, 1e21, 1.05e21, 1.1e21, 1.2e21, 1.3e21, 1.35e21, 1.4e21, 1.5e21, 2.4e21]];

        let cuumulative_division_num =
            Arena::get_cumulative_division_num(&self.league, self.division);
        let enemy_health =
            all_enemy_healths[(cuumulative_division_num - 1) as usize][(self.battle - 1) as usize];

        Enemy::build_enemy(self.battle, enemy_health)
    }

    fn get_cumulative_division_num(league: &League, division: i32) -> i32 {
        let league_num = match *league {
            League::Bronze => 0,
            League::Silver => 1,
            League::Gold => 2,
            League::Diamond => 3,
        };
        5 * league_num + division
    }

    fn get_total_battles(league: &League, division: i32) -> i32 {
        Arena::get_cumulative_division_num(league, division) + 4
    }
}

// *** enemy.rs
pub struct Enemy {
    pub name: String,
    pub health: f32,
    pub damage: f32,
}

impl Enemy {
    pub fn build_enemy(enemy_number: i32, health: f32) -> Enemy {
        Enemy {
            name: Enemy::get_name_for_number(enemy_number),
            health: health,
            damage: health / 8.0,
        }
    }

    pub fn print_stats(&self) {
        println!("{}", self.name);
        println!("Health     : {}", print_midas_number(self.health));
    }

    fn get_name_for_number(enemy_number: i32) -> String {
        match enemy_number {
            1 => "Cave Bug",
            2 => "Sharpbeak",
            3 => "Great Tarantula",
            4 => "Tunnel Minion",
            5 => "Goblin Gladiator",
            6 => "Desert Scorpion",
            7 => "Eyeball Terror",
            8 => "Seashore Goblin",
            9 => "Robotic Gatekeeper",
            10 => "Swarm Beast",
            11 => "Ancient Cyclops",
            12 => "Valhalla Devourer",
            13 => "Druid Hermit",
            14 => "Alien Insect",
            15 => "Fearless Zombie",
            16 => "Mountain Troll King",
            17 => "Undead Warrior",
            18 => "Orc Overlord",
            19 => "Lava Annihilator",
            20 => "The Unbreakable",
            21 => "Evil Shaman",
            22 => "Soul Drainer",
            23 => "Underworld Soulkeeper",
            24 => "Shadow King",
            _ => panic!("Unknown enemy_number: {}", enemy_number),
        }.to_string()
    }
}

// *** pet_upgrader.rs
pub struct PetUpgrader {}

impl PetUpgrader {
    pub fn get_possible_upgraded_pets(pet: &Pet, battle_points: i32) -> Vec<Pet> {
        let upgrades = PetUpgradeGenerator::get_possible_upgrades(pet, battle_points);
        upgrades
            .iter()
            .map(|u| PetUpgrader::upgrade_pet(pet, u))
            .collect()
    }

    fn upgrade_pet(base_pet: &Pet, upgrade: &PetUpgrade) -> Pet {
        Pet {
            name: format!("{} - upgraded with {}", base_pet.name, upgrade),
            health: base_pet.health * (1.0 + 0.1 * upgrade.upgrades[0] as f32),
            attack: base_pet.attack * (1.0 + 0.1 * upgrade.upgrades[1] as f32),
            defence: base_pet.defence * (1.0 + 0.1 * upgrade.upgrades[2] as f32),
            lifesteal: base_pet.lifesteal * (1.0 + 0.1 * upgrade.upgrades[3] as f32),
            block: base_pet.block * (1.0 + 0.1 * upgrade.upgrades[4] as f32),
            reflect: base_pet.reflect * (1.0 + 0.1 * upgrade.upgrades[5] as f32),
        }
    }
}

#[derive(Debug, Clone)]
struct PetUpgrade {
    upgrades: [i32; 6],
}

impl fmt::Display for PetUpgrade {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(
            f,
            "(H:{}, A:{}, D:{}, L:{}, B:{}, R:{})",
            self.upgrades[0],
            self.upgrades[1],
            self.upgrades[2],
            self.upgrades[3],
            self.upgrades[4],
            self.upgrades[5]
        )
    }
}

struct PetUpgradeGenerator {}

impl PetUpgradeGenerator {
    fn get_possible_upgrades(pet: &Pet, battle_points: i32) -> Vec<PetUpgrade> {
        let mut max_depth = 5;
        if pet.reflect == 0.0 {
            max_depth = 4;
        }
        if pet.block == 0.0 {
            max_depth = 3;
        }
        if pet.lifesteal == 0.0 {
            max_depth = 2;
        }
        let (prespend_level, prespend_cost) = PetUpgradeGenerator::get_prespend(battle_points);
        let total_prespend_cost = 2 * prespend_cost;
        if total_prespend_cost > 0 {
            println!("Prespending {} BPs", total_prespend_cost);
        }
        let pet_upgrade = PetUpgrade {
            upgrades: [prespend_level, prespend_level, 0, 0, 0, 0],
        };
        PetUpgradeGenerator::generate_upgrades(
            &pet_upgrade,
            battle_points - total_prespend_cost,
            0,
            max_depth,
        )
    }

    fn get_prespend(battle_points: i32) -> (i32, i32) {
        // No prespend for low BPs
        if battle_points < 300 {
            return (0, 0);
        }

        // Spend upto a quarter or a third of the BPs
        let max_prespend = battle_points / if battle_points < 1000 { 4 } else { 3 };
        let mut level = 0;
        let mut cost = 0;
        loop {
            let upgrade_cost = PetUpgradeGenerator::get_upgrade_cost(level);
            if cost + upgrade_cost > max_prespend {
                return (level, cost);
            }
            level += 1;
            cost += upgrade_cost;
        }
    }

    fn generate_upgrades(
        pet_upgrade: &PetUpgrade,
        battle_points: i32,
        depth: usize,
        max_depth: usize,
    ) -> Vec<PetUpgrade> {
        if depth == max_depth {
            // Just fill it up
            let mut pet_upgrade = pet_upgrade.clone();
            let mut battle_points = battle_points;
            loop {
                let cost = PetUpgradeGenerator::get_upgrade_cost(pet_upgrade.upgrades[depth]);
                if cost > battle_points {
                    break;
                }
                pet_upgrade.upgrades[depth] += 1;
                battle_points -= cost;
            }

            // Need to check that we wouldn't have covered this case before
            for i in 0..max_depth {
                let cost = PetUpgradeGenerator::get_upgrade_cost(pet_upgrade.upgrades[i]);
                if cost <= battle_points {
                    return vec![];
                }
            }

            return vec![pet_upgrade];
        }

        let mut pet_upgrades = vec![];
        let mut pet_upgrade = pet_upgrade.clone();
        let mut battle_points = battle_points;
        loop {
            for pu in PetUpgradeGenerator::generate_upgrades(
                &pet_upgrade,
                battle_points,
                depth + 1,
                max_depth,
            ) {
                pet_upgrades.push(pu);
            }

            let cost = PetUpgradeGenerator::get_upgrade_cost(pet_upgrade.upgrades[depth]);
            if cost > battle_points {
                break;
            }
            pet_upgrade.upgrades[depth] += 1;
            battle_points -= cost;
        }
        pet_upgrades
    }

    fn get_upgrade_cost(current_level: i32) -> i32 {
        if current_level < 10 {
            current_level + 1
        } else {
            current_level + 1 + PetUpgradeGenerator::get_upgrade_cost(current_level - 10)
        }
    }
}

// *** battle.rs
pub struct Battle {
    pub use_attack_potion: bool,
    pub use_defence_potion: bool,
}

impl Battle {
    pub fn new(use_attack_potion: bool, use_defence_potion: bool) -> Battle {
        Battle {
            use_attack_potion: use_attack_potion,
            use_defence_potion: use_defence_potion,
        }
    }

    pub fn get_best_result<'a>(&self, pets: &'a [Pet], enemy: &Enemy) -> (f32, &'a Pet) {
        let results_by_pet = pets.iter().map(|p| (self.do_battle(p, enemy), p)).collect::<Vec<_>>();
        let best_result = results_by_pet.iter().min_by(|a, b| a.0.partial_cmp(&b.0).unwrap_or(Ordering::Equal)).unwrap();

        (if best_result.0 < 0.0 {0.0} else {best_result.0}, best_result.1)
    }

    fn do_battle(&self, pet: &Pet, enemy: &Enemy) -> f32 {
        let pet_hp = pet.health;
        let enemy_hp = enemy.health;
        let potion_hp = 0.25 * pet.health;

        let attack_adjust = if self.use_attack_potion { 1.5 } else { 1.0 };
        let defence_adjust = if self.use_defence_potion { 0.5 } else { 1.0 };

        // Apply ATTACK
        let mut pet_attack_per_round = attack_adjust * pet.attack;

        // Apply LIFESTEAL
        let mut enemy_attack_per_round = -0.25 * pet.lifesteal;

        // Apply DEFENCE
        enemy_attack_per_round += defence_adjust * (enemy.damage * 1.05 - pet.defence);

        // Apply BLOCK
        enemy_attack_per_round -= 0.3 * pet.block;

        // Apply REFLECT
        pet_attack_per_round += 0.3 * pet.reflect;

        // Compute end of battle stats
        let battle_rounds = (enemy_hp / pet_attack_per_round).ceil();
        let pet_hp_after_battle = pet_hp - battle_rounds * enemy_attack_per_round;

        -pet_hp_after_battle / potion_hp
    }
}