fn main() {
    println!("Hello, world!");
}

pub const DEBUG : bool = true;

pub struct Trail {
    waypoints: Vec<Point>,
    directions: Vec<Direction>,
}

impl Trail {
    pub fn new() -> Trail {
        Trail {
            waypoints: Vec::new(),
            directions: Vec::new(),
        }
    }

    pub fn start(&mut self, way: String) -> DistArea {
        if !way.is_empty() {
            let mut da = DistArea{dist: 0, area: 0, size: 0};
            let split = way.split_whitespace();
            let mut plan : Vec<String> = Vec::new();
            for s in split {
                plan.push(String::from(s));
            }
            let steps = match plan.remove(0).parse::<i32>() {
                Err(_) => 0,
                Ok(i) => i,
            };

            self.directions.push(Direction::North);
            self.waypoints.push(Point{x: 0, y: 0});

            da.dist = self.walk(plan, steps);

            let mut min = Point{x: 0, y: 0};
            let mut max = Point{x: 0, y: 0};
            for i in &self.waypoints {
                if i.x < min.x {
                    min.x = i.x;
                }
                if i.y < min.y {
                    min.y = i.y;
                }
                if i.x > max.x {
                    max.x = i.x;
                }
                if i.y > max.y {
                    max.y = i.y;
                }
            }
            da.area = (max.x - min.x) * (max.y - min.y);
            da
        } else {
            DistArea{dist:0, area:0, size:0}
        }
    }

    fn walk(&mut self, mut plan: Vec<String>, steps: i32) -> i32 {
        if steps == 0 {
            0
        } else {
            let mut stepcount = 0;
            let part = plan.remove(0);
            let count = match plan.remove(0).parse::<i32>() {
                Err(_) => 0,
                Ok(i) => i,
            };
            let mut dir = self.directions.last().unwrap().clone();
            let mut pos = self.waypoints.last().unwrap().clone();
            for _i in 0 .. count {
                for c in part.chars() {
                    match c {
                        'F' => {
                            pos.add(dir, 1);
                            if DEBUG {
                                println!("F, pos: x={} y={}, dir: {:?}", pos.x, pos.y, dir);
                            }
                            stepcount += 1;
                        },
                        'L' => {
                            dir = Direction::turn_left(dir);
                            if DEBUG {
                                print!("L");
                            }
                        },
                        'R' => {
                            dir = Direction::turn_right(dir);
                            if DEBUG {
                                print!("R");
                            }
                        },
                        _ => (),
                    }
                    self.directions.push(dir);
                    self.waypoints.push(pos);
                }
            }

            stepcount += self.walk(plan, steps - 1);

            stepcount
        }
    }
}

#[derive(Copy, Clone, Debug)]
pub enum Direction {
    North,
    East,
    South,
    West,
}

impl Direction {
    pub fn turn_right(dir: Direction) -> Direction {
        match dir {
            Direction::North => Direction::East,
            Direction::East => Direction::South,
            Direction::South => Direction::West,
            Direction::West => Direction::North,
        }
    }
    pub fn turn_left(dir: Direction) -> Direction {
        match dir {
            Direction::North => Direction::West,
            Direction::East => Direction::North,
            Direction::South => Direction::East,
            Direction::West => Direction::South,
        }
    }
}

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

impl Point {
    pub fn add(&mut self, dir: Direction, len: i32) {
        match dir {
            Direction::North => self.y += len,
            Direction::East => self.x += len,
            Direction::South => self.y -= len,
            Direction::West => self.x -= len,
        };
    }
}

#[derive(Copy, Clone, Debug)]
pub struct DistArea {
    pub dist: i32,
    pub area: i32,
    pub size: i32,
}

impl PartialEq for DistArea {
    fn eq(&self, other: &DistArea) -> bool {
        let mut res = self.dist == other.dist;
        res &= self.area == other.area;
        res &= self.size == other.size;
        res
    }
}

impl Eq for DistArea {}

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

    #[test]
    fn level1_1() {
        let input = String::from("1 FFFR 4");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.dist, 12);
    }

    #[test]
    fn level1_2() {
        let input = String::from("9 F 6 R 1 F 4 RFF 2 LFF 1 LFFFR 1 F 2 R 1 F 5");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.dist, 26);
    }

    #[test]
    fn level1_3() {
        let input = String::from("14 L 1 FR 1 FFFFFL 1 FFFFL 1 F 12 L 1 F 12 L 1 F 12 L 1 FFFFL 1 FFFFFFFFR 1 FFFR 1 FFFL 1");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.dist, 64);
    }

    #[test]
    fn level1_4() {
        let input = String::from("32 FFRFLFLFFRFRFLFF 3 R 1 FFLFRFRFLFFF 3 R 1 FFFFFF 3 L 1 FFFRFLFLFRFF 2 R 1 FFFRFLFLFRFF 3 R 1 FFFFFF 1 L 1 FFRFLFLFFRFRFLFF 3 R 1 FFLFRFRFFLFLFRFF 2 L 1 FFLFRFRFFLFLFRFF 3 R 1 FFRFLFLFFRFRFLFF 2 R 1 FFRFLFLFFRFRFLFF 2 L 1 FFFFFF 3 R 1 FFFRFLFLFRFF 5 R 1 FFLFRFRFLFFF 1 L 1 FFLFRFRFFLFLFRFF 2 R 1 FFRFLFLFFRFRFLFF 2 L 1");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.dist, 344);
    }

    #[test]
    fn level1_5() {
        let input = String::from("10 FFLFRFRFFLFLFRFF 5 L 1 FFFRFLFLFRFF 4 L 1 FFLFRFRFFLFLFRFF 8 L 1 FFLFRFRFFLFLFRFF 4 L 1 FFFFFF 3 R 1");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.dist, 220);
    }

    #[test]
    fn level2_1() {
        let input = String::from("1 FFFR 4");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.area, 9);
    }

    #[test]
    fn level2_2() {
        let input = String::from("9 F 6 R 1 F 4 RFF 2 LFF 1 LFFFR 1 F 2 R 1 F 5");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.area, 30);
    }

    #[test]
    fn level2_3() {
        let input = String::from("14 L 1 FR 1 FFFFFL 1 FFFFL 1 F 12 L 1 F 12 L 1 F 12 L 1 FFFFL 1 FFFFFFFFR 1 FFFR 1 FFFL 1");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.area, 144);
    }

    #[test]
    fn level2_4() {
        let input = String::from("32 FFRFLFLFFRFRFLFF 3 R 1 FFLFRFRFLFFF 3 R 1 FFFFFF 3 L 1 FFFRFLFLFRFF 2 R 1 FFFRFLFLFRFF 3 R 1 FFFFFF 1 L 1 FFRFLFLFFRFRFLFF 3 R 1 FFLFRFRFFLFLFRFF 2 L 1 FFLFRFRFFLFLFRFF 3 R 1 FFRFLFLFFRFRFLFF 2 R 1 FFRFLFLFFRFRFLFF 2 L 1 FFFFFF 3 R 1 FFFRFLFLFRFF 5 R 1 FFLFRFRFLFFF 1 L 1 FFLFRFRFFLFLFRFF 2 R 1 FFRFLFLFFRFRFLFF 2 L 1");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.area, 3552);
    }

    #[test]
    fn level2_5() {
        let input = String::from("10 FFLFRFRFFLFLFRFF 5 L 1 FFFRFLFLFRFF 4 L 1 FFLFRFRFFLFLFRFF 8 L 1 FFLFRFRFFLFLFRFF 4 L 1 FFFFFF 3 R 1");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.area, 1300);
    }

    #[test]
    fn level3_1() {
        let input = String::from("1 FFFR 4");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.size, 12);
    }

    #[test]
    fn level3_2() {
        let input = String::from("9 F 6 R 1 F 4 RFF 2 LFF 1 LFFFR 1 F 2 R 1 F 5");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.size, 12);
    }

    #[test]
    fn level3_3() {
        let input = String::from("14 L 1 FR 1 FFFFFL 1 FFFFL 1 F 12 L 1 F 12 L 1 F 12 L 1 FFFFL 1 FFFFFFFFR 1 FFFR 1 FFFL 1");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.size, 12);
    }

    #[test]
    fn level3_4() {
        let input = String::from("32 FFRFLFLFFRFRFLFF 3 R 1 FFLFRFRFLFFF 3 R 1 FFFFFF 3 L 1 FFFRFLFLFRFF 2 R 1 FFFRFLFLFRFF 3 R 1 FFFFFF 1 L 1 FFRFLFLFFRFRFLFF 3 R 1 FFLFRFRFFLFLFRFF 2 L 1 FFLFRFRFFLFLFRFF 3 R 1 FFRFLFLFFRFRFLFF 2 R 1 FFRFLFLFFRFRFLFF 2 L 1 FFFFFF 3 R 1 FFFRFLFLFRFF 5 R 1 FFLFRFRFLFFF 1 L 1 FFLFRFRFFLFLFRFF 2 R 1 FFRFLFLFFRFRFLFF 2 L 1");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.size, 12);
    }

    #[test]
    fn level3_5() {
        let input = String::from("10 FFLFRFRFFLFLFRFF 5 L 1 FFFRFLFLFRFF 4 L 1 FFLFRFRFFLFLFRFF 8 L 1 FFLFRFRFFLFLFRFF 4 L 1 FFFFFF 3 R 1");
        let mut trail = Trail::new();
        let mut res = trail.start(input);

        assert_eq!(res.size, 12);
    }
}