use crate::prelude::*;

#[derive(Debug)]
pub struct Point {
    x: i32,
    y: i32,
}

pub struct Population {
    pub start_infected_ratio: i32,
    pub start_immune_ratio: i32,
    pub start_dead_ratio: i32,
    pub humans: Vec<Human>,
    pub width: i32,
    pub height: i32,
    pub age: i32,
    pub plague: Disease,
    pub size: usize,
}

pub fn human_idx(x: i32, y: i32, width: i32) -> usize {
    ((y * width) + x) as usize
}

impl Population {
    pub fn new(
        start_infected_ratio: i32,
        start_immune_ratio: i32,
        start_dead_ratio: i32,
        width: i32,
        height: i32,
        plague: Disease,
    ) -> Self {
        let mut rng = rand::thread_rng();

        let size: usize = (width * height) as usize;

        let mut the_humans: Vec<Human> = vec![
            Human {
                x: 0,
                y: 0,
                present_state: State::Normal
            };
            size
        ];
        for x in 0..width {
            for y in 0..height {
                let idx = human_idx(x, y, width);
                let mut present_state = State::Normal;
                if (start_infected_ratio > 0)
                    && (rng.gen_range(0..CORRECTED_PERCENTAGE) <= start_infected_ratio)
                {
                    present_state = State::Infected;
                } else if (start_immune_ratio > 0)
                    && (rng.gen_range(0..CORRECTED_PERCENTAGE) <= start_immune_ratio)
                {
                    present_state = State::Immune;
                } else if (start_dead_ratio > 0)
                    && (rng.gen_range(0..CORRECTED_PERCENTAGE) <= start_dead_ratio)
                {
                    present_state = State::Dead;
                }
                the_humans[idx] = Human{x: x, y: y, present_state: present_state};
            }
        }
        Self {
            start_infected_ratio: start_infected_ratio,
            start_immune_ratio: start_immune_ratio,
            start_dead_ratio: start_dead_ratio,
            width: width,
            height: height,
            plague: plague,
            age: 0,
            humans: the_humans,
            size: size,
        }
    }
    // pub fn change_disease(&mut self, plague:Disease){
    //     self.plague = plague;
    // }

    fn is_inside(&self, pos: &Point) -> bool {
        if pos.x >= 0 && pos.x < self.width && pos.y >= 0 && pos.y < self.height {
            true
        } else {
            false
        }
    }

    fn is_inside_and_infected(&self, point: Point) -> bool {
        if self.is_inside(&point) {
            let idx = human_idx(point.x, point.y, self.width);
            if self.humans[idx].present_state == State::Infected {
                roll(self.plague.infection_rate)
            } else {
                false
            }
        } else {
            false
        }
    }

    pub fn propagate(&mut self) -> [i32; 4] {
        let mut people_to_check: Vec<Point> =
            Vec::with_capacity(self.size);
        let mut possible_infected: Vec<Point> =
            Vec::with_capacity(self.size);
        let mut people_to_infect: Vec<Point> =
            Vec::with_capacity(self.size);
        let mut people_to_cure: Vec<Point> =
            Vec::with_capacity(self.size);
        let mut people_to_kill: Vec<Point> =
            Vec::with_capacity(self.size);
        let mut stats: [i32; 4] = [0, 0, 0, 0];
        // stats[0] Normal stats[1] Infected stats[2] Immune stats[3] Dead

        for h in self.humans.iter() {
            match h.present_state {
                State::Normal => {
                    possible_infected.push(Point{ x: h.x, y: h.y});
                    stats[0] += 1;
                }
                State::Infected => {
                    people_to_check.push(Point { x: h.x, y: h.y });
                    stats[1] += 1;
                }
                State::Immune => {
                    stats[2] += 1;
                }
                State::Dead => {
                    stats[3] += 1;
                }
            }
        }
        //        for pos in &people_to_check {
        for pos in people_to_check.iter() {
            //people_to_check.iter().map(|pos|{
            //get all the other people next to me and check if i die cure or infect
            //now we can start to check if people would be infected or not
            //let idx = human_idx(pos.x as i32, pos.y as i32, self.width as i32);
            if roll(self.plague.curing_rate) {
                //checks if the man recovers
                people_to_cure.push(Point { x: pos.x, y: pos.y });
            } else {
                if roll(self.plague.death_rate) {
                    //cheks if the man dies
                    people_to_kill.push(Point { x: pos.x, y: pos.y });
                }
            }
        }
        for pos in possible_infected.iter() {
            let infected: bool = self.is_inside_and_infected(
                Point {
                    x: pos.x - 1,
                    y: pos.y - 1,
                },
            ) || //Top Left
            self.is_inside_and_infected(
                Point {
                    x: pos.x,
                    y: pos.y - 1,
                },
            ) || //Top
            self.is_inside_and_infected(
                Point {
                    x: pos.x + 1,
                    y: pos.y - 1,
                },
            ) || //Top Right
            self.is_inside_and_infected(
                Point {
                    x: pos.x - 1,
                    y: pos.y,
                },
            ) || //Left
            self.is_inside_and_infected(
                Point {
                    x: pos.x + 1,
                    y: pos.y,
                },
            ) || //Right
            self.is_inside_and_infected(
                Point {
                    x: pos.x - 1,
                    y: pos.y + 1,
                },
            ) || //Bottom Left
            self.is_inside_and_infected(
                Point {
                    x: pos.x,
                    y: pos.y + 1,
                },
            ) || //Bottom
            self.is_inside_and_infected(
                Point {
                    x: pos.x + 1,
                    y: pos.y + 1,
                },
            ); //Bottom Right
            if infected {
                people_to_infect.push(Point { x: pos.x, y: pos.y });
            }
        }

        for infected_position in people_to_infect.iter() {
            // println!("To infect: {:?}", infected_position);
            //people_to_infect.iter().map(|infected_position|{
            let infected_index = human_idx(infected_position.x, infected_position.y, self.width);
            // let _ = infected_position.x;
            //DEBUG
            //println!("x: {} y: {} index: {}",infected_position.x,infected_position.y,infected_index);
            self.humans[infected_index].present_state = State::Infected;
            //DEBUG
            //println!("Infected someone");
        }

        for cured_position in people_to_cure.iter() {
            //people_to_cure.iter().map(|cured_position|{
            let cured_index = human_idx(cured_position.x, cured_position.y, self.width);
            if self.humans[cured_index].present_state != State::Infected {
                println!("not infected");
            }
            self.humans[cured_index].present_state = State::Immune;
            //DEBUG
            //println!("Cured someone");
        }

        for dead_position in people_to_kill.iter() {
            //people_to_kill.iter().map(|dead_position|{
            let dead_index = human_idx(dead_position.x, dead_position.y, self.width);
            if self.humans[dead_index].present_state == State::Dead {
                // println!("Already dead");
            } else {
                self.humans[dead_index].present_state = State::Dead;
            }
            //DEBUG
        }
        assert_eq!(
            stats[0] + stats[1] + stats[2] + stats[3],
            self.size as i32
        );
        stats
    }

    // pub fn display(&mut self){
    //     let sprite = "#";
    //     print!("\n");
    //     for x in 0..self.width{
    //         for y in 0..self.height{
    //             let index = human_idx(x as i32,y as i32,self.width as i32);
    //             match self.humans[index].present_state {
    //                 State::Normal => print!("{}",style(sprite).green()),
    //                 State::Dead => print!("{}",style(sprite).black()),
    //                 State::Infected => print!("{}",style(sprite).red()),
    //                 State::Immune => print!("{}",style(sprite).blue()),
    //                 _ => print!("{}",style(sprite).white()),
    //             }
    //         }
    //         print!("\n");
    //     }
    // }

    pub fn propagate_new(&mut self) -> [i32; 4] {
        let mut stats: [i32; 4] = [0, 0, 0, 0];
        let mut humans_n_plus_1: Vec<Human> = Vec::with_capacity(self.humans.len());

        for human in self.humans.iter() {
            let mut neighbors: Vec<&Human> = Vec::with_capacity(8);
            if human.present_state == State::Normal {
                let possible = [
                    (human.x - 1, human.y - 1), (human.x, human.y - 1), (human.x + 1, human.y - 1),
                    (human.x - 1, human.y)    ,                         (human.x + 1, human.y),
                    (human.x - 1, human.y + 1), (human.x, human.y + 1), (human.x + 1, human.y + 1),
                ];
                for neigh_coords in possible.iter() {
                    let neigh_idx = point_to_index(neigh_coords.0, neigh_coords.1, self.width, self.height);
                    match neigh_idx {
                        Some(x) => neighbors.push(&self.humans[x]),
                        None => {},
                    }
                }
            }
            let new_human = evolve(human, neighbors, self.plague.infection_rate, self.plague.curing_rate, self.plague.death_rate);
            match human.present_state {
                State::Normal => { stats[0] += 1; }
                State::Infected => { stats[1] += 1; }
                State::Immune => { stats[2] += 1; }
                State::Dead => { stats[3] += 1; }
            }
            humans_n_plus_1.push(new_human);
        }

        self.humans = humans_n_plus_1;
        stats
    }
}

fn evolve(human: &Human, neighbors: Vec<&Human>, infection_rate: i32, curing_rate: i32, death_rate: i32) -> Human {
    let mut new_human = human.clone();
    match human.present_state {
        State::Normal => {
            new_human.present_state = infect_by_neighbors(neighbors, infection_rate);
        }
        State::Infected => {
            new_human.present_state = die_or_cure(curing_rate, death_rate);
        }
        State::Immune => {}
        State::Dead => {}
    }
    new_human
}

fn infect_by_neighbors(neighbors: Vec<&Human>, infection_rate: i32) -> State {
    for neighbor in neighbors.iter() {
        if neighbor.present_state == State::Infected {
            if roll(infection_rate) {
                return State::Infected;
            }
        }
    }
    State::Normal
}

fn die_or_cure(curing_rate: i32, death_rate: i32) -> State {
    if roll(curing_rate) {
        State::Immune
    } else if roll(death_rate) {
        State::Dead
    } else {
        State::Infected
    }
}

fn point_to_index(x: i32, y: i32, width: i32, height: i32) -> Option<usize> {
    if (x >= 0) && (x < width) && (y >= 0) && (y < height) {
        Some(human_idx(x, y, width))
    } else {
        None
    }
}

pub fn roll(probability: i32) -> bool {
    if probability > 0 {
        let mut rng = rand::thread_rng();
        rng.gen_range(0..CORRECTED_PERCENTAGE) <= probability
    } else {
        false
    }
}

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

    #[derive(Debug)]
    struct Stats {
        normal: i32,
        infected: i32,
        immune: i32,
        dead: i32,
    }

    impl Stats {
        fn new() -> Stats {
            Stats {
                normal: 0,
                infected: 0,
                immune: 0,
                dead: 0,
            }
        }
    }

    fn humans_stats(humans: &Vec<Human>) -> Stats {
        let mut stats: Stats = Stats::new();
        for human in humans.iter() {
            match human.present_state {
                State::Normal => {
                    stats.normal += 1;
                }
                State::Infected => {
                    stats.infected += 1;
                }
                State::Immune => {
                    stats.immune += 1;
                }
                State::Dead => {
                    stats.dead += 1;
                }
            }
        }
        stats
    }

    #[parameterized(x = {
        2, 3, 5
    }, y = {
        1, 4, 0
    }, width = {
        3, 5, 7
    }, res = {
        5, 23, 5
    })]
    fn test_human_idx(x: i32, y: i32, width: i32, res: usize) {
        assert_eq!(human_idx(x, y, width), res);
    }

    #[test]
    fn test_human_stats() {
        let mut humans: Vec<Human> = Vec::with_capacity(10);
        let mut stats: Stats;

        for _ in 0..10 {
            humans.push(Human {
                present_state: State::Normal,
                x: 0,
                y: 0,
            });
        }
        stats = humans_stats(&humans);
        assert_eq!(stats.normal, 10);

        for x in 0..2 {
            humans[x].present_state = State::Infected;
        }
        for x in 2..5 {
            humans[x].present_state = State::Immune;
        }
        for x in 5..9 {
            humans[x].present_state = State::Dead;
        }
        stats = humans_stats(&humans);
        assert_eq!(stats.normal, 1);
        assert_eq!(stats.infected, 2);
        assert_eq!(stats.immune, 3);
        assert_eq!(stats.dead, 4);
    }

    #[test]
    fn population_new() {
        let disease = Disease::new(20, 10, 5, String::from("Covid 44"));
        let (width, height) = (5, 7);
        let population = Population::new(20, 10, 5, 5, 7, disease);
        assert_eq!(population.humans.len(), 5 * 7);
        for h in population.humans.iter() {
            let idx = human_idx(h.x, h.y, width);
            assert_eq!(population.humans[idx].x, h.x, "coordinates should match");
            assert_eq!(population.humans[idx].y, h.y, "coordinates should match");
        }
        assert_eq!(population.humans.len(), (width * height) as usize);
    }

    #[test]
    fn population_gen() {
        let disease = Disease::new(20, 10, 5, String::from("Covid 44"));
        let (width, height) = (5, 7);
        let population = Population::new(20, 10, 5, 5, 7, disease);

        let stats: Stats = humans_stats(&population.humans);
        println!("Stats: {:?}", stats);

        assert_eq!(
            stats.normal + stats.infected + stats.immune + stats.dead,
            width * height
        );
    }

    #[test]
    fn plague_init_stats() {
        let mut disease: Disease;
        let mut population: Population;
        let mut stats: Stats;
        let (width, height) = (5, 7);

        disease = Disease::new(0, 0, 0, String::from("Test"));
        population = Population::new(0, 0, 0, width, height, disease);
        stats = humans_stats(&population.humans);
        println!("should be normal: {:?}", stats);
        assert_eq!(stats.normal, width * height);

        disease = Disease::new(0, 0, 0, String::from("Test"));
        population = Population::new(100, 0, 0, width, height, disease);
        stats = humans_stats(&population.humans);
        println!("should be infected: {:?}", stats);
        assert_eq!(stats.infected, width * height);

        disease = Disease::new(0, 0, 0, String::from("Test"));
        population = Population::new(0, 100, 0, width, height, disease);
        stats = humans_stats(&population.humans);
        println!("should be immune: {:?}", stats);
        assert_eq!(stats.immune, width * height);

        disease = Disease::new(0, 0, 0, String::from("Test"));
        population = Population::new(0, 0, 100, width, height, disease);
        stats = humans_stats(&population.humans);
        println!("should be dead: {:?}", stats);
        assert_eq!(stats.dead, width * height);
    }

    #[parameterized(rate = {0, 100}, expected = {false, true})]
    fn roll_test(rate: i32, expected: bool) {
        let tries = 100000;
        let mut result = 0;
        println!("Testing roll, rate {}, expected {}", rate, expected);
        for _x in 0..tries {
            if roll(rate) == expected {
                result += 1;
            }
        }
        assert_eq!(result, tries);
    }

    #[test]
    fn propagate_simple() {
        let disease: Disease = Disease::new(0, 0, 100, String::from("Deadly"));
        let mut population: Population = Population::new(100, 0, 0, 10, 10, disease);
        let mut stats: Stats;
        let mut propagate_stats: [i32; 4];

        // infect every one
        stats = humans_stats(&population.humans);
        println!("stats after init: {:?}", stats);
        assert_eq!(stats.infected, 100, "everybody should be infected");

        // kill every one
        propagate_stats = population.propagate_new();
        stats = humans_stats(&population.humans);
        println!("propate_stats: {:?}", propagate_stats);
        assert_eq!(propagate_stats, [0, 100, 0, 0]);
        assert_eq!(stats.normal, 0);
        assert_eq!(stats.infected, 0);
        assert_eq!(stats.immune, 0);
        assert_eq!(stats.dead, 100);

        for _x in 0..100 {
            propagate_stats = population.propagate_new();
            stats = humans_stats(&population.humans);
            println!("propate_stats: {:?}", propagate_stats);
            assert_eq!(propagate_stats, [0, 0, 0, 100]);
            assert_eq!(stats.normal, 0);
            assert_eq!(stats.infected, 0);
            assert_eq!(stats.immune, 0);
            assert_eq!(stats.dead, 100);
        }
    }

    #[test]
    fn propagate_infect_all() {
        let disease: Disease = Disease::new(100, 0, 0, String::from("Deadly"));
        let mut population: Population = Population::new(0, 0, 0, 3, 3, disease);
        let mut stats: Stats;
        let mut propagate_stats: [i32; 4];

        // start with normal population
        population.humans = vec![
            Human {
                present_state: State::Normal,
                x: 0,
                y: 0,
            },
            Human {
                present_state: State::Normal,
                x: 1,
                y: 0,
            },
            Human {
                present_state: State::Normal,
                x: 2,
                y: 0,
            },
            Human {
                present_state: State::Normal,
                x: 0,
                y: 1,
            },
            Human {
                present_state: State::Infected,
                x: 1,
                y: 1,
            },
            Human {
                present_state: State::Normal,
                x: 2,
                y: 1,
            },
            Human {
                present_state: State::Normal,
                x: 0,
                y: 2,
            },
            Human {
                present_state: State::Normal,
                x: 1,
                y: 2,
            },
            Human {
                present_state: State::Normal,
                x: 2,
                y: 2,
            },
        ];
        stats = humans_stats(&population.humans);
        println!("stats after init: {:?}", stats);
        assert_eq!(stats.normal, 8);

        // kill every one
        propagate_stats = population.propagate_new();
        stats = humans_stats(&population.humans);
        println!("propate_stats: {:?}", propagate_stats);
        assert_eq!(propagate_stats, [8, 1, 0, 0]);
        assert_eq!(stats.normal, 0);
        assert_eq!(stats.infected, 9);
        assert_eq!(stats.immune, 0);
        assert_eq!(stats.dead, 0);

        for _x in 0..100 {
            propagate_stats = population.propagate_new();
            stats = humans_stats(&population.humans);
            println!("propate_stats: {:?}", propagate_stats);
            assert_eq!(propagate_stats, [0, 9, 0, 0]);
            assert_eq!(stats.normal, 0);
            assert_eq!(stats.infected, 9);
            assert_eq!(stats.immune, 0);
            assert_eq!(stats.dead, 0);
        }
    }

    #[test]
    fn propagate_infect_cure_all() {
        let disease: Disease = Disease::new(100, 100, 0, String::from("Deadly"));
        let mut population: Population = Population::new(0, 0, 0, 3, 3, disease);
        let mut stats: Stats;
        let mut propagate_stats: [i32; 4];

        // start with normal population
        population.humans = vec![
            Human {
                present_state: State::Normal,
                x: 0,
                y: 0,
            },
            Human {
                present_state: State::Normal,
                x: 1,
                y: 0,
            },
            Human {
                present_state: State::Normal,
                x: 2,
                y: 0,
            },
            Human {
                present_state: State::Normal,
                x: 0,
                y: 1,
            },
            Human {
                present_state: State::Infected,
                x: 1,
                y: 1,
            },
            Human {
                present_state: State::Normal,
                x: 2,
                y: 1,
            },
            Human {
                present_state: State::Normal,
                x: 0,
                y: 2,
            },
            Human {
                present_state: State::Normal,
                x: 1,
                y: 2,
            },
            Human {
                present_state: State::Normal,
                x: 2,
                y: 2,
            },
        ];
        stats = humans_stats(&population.humans);
        println!("stats after init: {:?}", stats);
        assert_eq!(stats.normal, 8);

        // infect every one
        propagate_stats = population.propagate_new();
        stats = humans_stats(&population.humans);
        println!("propate_stats: {:?}", propagate_stats);
        println!("population: {:?}", stats);
        assert_eq!(propagate_stats, [8, 1, 0, 0]);
        assert_eq!(stats.normal, 0);
        assert_eq!(stats.infected, 8);
        assert_eq!(stats.immune, 1);
        assert_eq!(stats.dead, 0);

        // cure every one
        propagate_stats = population.propagate_new();
        stats = humans_stats(&population.humans);
        println!("propate_stats: {:?}", propagate_stats);
        println!("population: {:?}", stats);
        assert_eq!(propagate_stats, [0, 8, 1, 0]);
        assert_eq!(stats.normal, 0);
        assert_eq!(stats.infected, 0);
        assert_eq!(stats.immune, 9);
        assert_eq!(stats.dead, 0);

        // then
        for _x in 0..100 {
            propagate_stats = population.propagate_new();
            stats = humans_stats(&population.humans);
            println!("propate_stats: {:?}", propagate_stats);
            println!("population: {:?}", stats);
            assert_eq!(propagate_stats, [0, 0, 9, 0]);
            assert_eq!(stats.normal, 0);
            assert_eq!(stats.infected, 0);
            assert_eq!(stats.immune, 9);
            assert_eq!(stats.dead, 0);
        }
    }

    #[parameterized(infection_start = {0, 50, 100})]
    fn propagate_harmless(infection_start: i32) {
        let disease: Disease = Disease::new(0, 0, 0, String::from("Harmless"));
        let (width, height) = (100, 100);
        let mut population: Population = Population::new(infection_start, 0, 0, width, height, disease);
        let stats_before: Stats;
        let stats_after: Stats;

        stats_before = humans_stats(&population.humans);
        let should_be_infected = population.size as i32 * infection_start / 100;
        let tolerance = (should_be_infected as f32 * 0.20) as i32;
        println!("{:?}", stats_before);
        assert!(stats_before.infected <= should_be_infected + tolerance, "{} infected, should be less than {}", stats_before.infected, should_be_infected + tolerance);
        assert!(stats_before.infected >= should_be_infected - tolerance, "{} infected, should be more than {}", stats_before.infected, should_be_infected - tolerance);

        population.propagate_new();

        stats_after = humans_stats(&population.humans);
        assert_eq!(stats_before.infected, stats_after.infected, "no one should have been infected");
    }

    #[parameterized(infection_rate = {0, 100, 0}, death_rate = {0, 0, 100}, infected_expected = {0, 1, 0})]
    fn propagate_test(infection_rate: i32, death_rate: i32, infected_expected: i32) {
        let disease: Disease;
        let mut population: Population;
        let mut stats: Stats;
        let (width, height) = (100, 100);
        let start_infected = 50;

        println!(
            "infection rate: {}, death_rate: {}",
            infection_rate, death_rate
        );

        disease = Disease::new(infection_rate, 0, death_rate, String::from("Test"));
        population = Population::new(start_infected, 0, 0, width, height, disease);

        stats = humans_stats(&population.humans);
        println!("Population after init: {:?}", stats);

        // total * proba - 20% < infected < total * proba + 20%
        let infected_at_start_proba = width * height * start_infected / 100;
        let infected_tolerance = ((width * height) as f32 * 0.2) as i32;
        assert!(stats.infected <= infected_at_start_proba + infected_tolerance);
        assert!(stats.infected >= infected_at_start_proba - infected_tolerance);
        assert_eq!(stats.dead, 0);

        let infected_at_start = stats.infected;
        let dead_at_start = stats.dead;

        let propa_stats: [i32; 4] = population.propagate_new();

        assert!(propa_stats[3] >= dead_at_start);

        if death_rate == 0 {
            assert_eq!(propa_stats[3], 0, "no human should have died");
        }

        stats = humans_stats(&population.humans);
        println!("Population after propagate: {:?}", stats);

        assert!(stats.infected <= infected_at_start + width * height * infected_expected);

        let should_be_dead = infected_at_start * death_rate / 100;
        let dead_tolerance = (should_be_dead as f32 * 0.20) as i32;

        assert!(
            stats.dead <= should_be_dead + dead_tolerance,
            "death count should be less or equal than {}",
            should_be_dead + dead_tolerance
        );
        assert!(stats.dead >= should_be_dead - dead_tolerance);
    }
}