use std::vec::Vec;
use std::string::String;

struct Sevensegment {
    segments: Vec<bool>,
}

impl Sevensegment {
    pub fn new() -> Sevensegment {
        Sevensegment {
            segments: [false, false, false, false, false, false, false, false].to_vec(),
        }
    }

//     --a--
//    |     |
//    f     b
//    |     |
//     --g--
//    |     |
//    e     c
//    |     |
//     --d--  h

    pub fn encode(&mut self, val: char) {
        self.segments = match val {
            '0' => [true, true, true, true, true, true, false, false].to_vec(),
            '1' => [false, true, true, false, false, false, false, false].to_vec(),
            '2' => [true, true, false, true, true, false, true, false].to_vec(),
            '3' => [true, true, true, true, false, false, true, false].to_vec(),
            '4' => [false, true, true, false, false, true, true, false].to_vec(),
            '5' => [true, false, true, true, false, true, true, false].to_vec(),
            '6' => [true, false, true, true, true, true, true, false].to_vec(),
            '7' => [true, true, true, false, false, false, false, false].to_vec(),
            '8' => [true, true, true, true, true, true, true, false].to_vec(),
            '9' => [true, true, true, true, false, true, true, false].to_vec(),
            'a'|'A' => [true, true, true, false, true, true, true, false].to_vec(),
            'b'|'B' => [false, false, true, true, true, true, true, false].to_vec(),
            'c'|'C' => [true, false, false, true, true, true, false, false].to_vec(),
            'd'|'D' => [false, true, true, true, true, false, true, false].to_vec(),
            'e'|'E' => [true, false, false, true, true, true, true, false].to_vec(),
            'f'|'F' => [true, false, false, false, true, true, true, false].to_vec(),
            'h'|'H' => [false, true, true, false, true, true, true, false].to_vec(),
            'i'|'I' => [false, false, true, false, false, false, false, false].to_vec(),
            'j'|'J' => [false, true, true, true, false, false, false, false].to_vec(),
            'l'|'L' => [false, false, false, true, true, true, false, false].to_vec(),
            'n'|'N' => [false, false, true, false, true, false, true, false].to_vec(),
            'o'|'O' => [false, false, true, true, true, false, true, false].to_vec(),
            'p'|'P' => [true, true, false, false, true, true, true, false].to_vec(),
            't'|'T' => [false, false, false, true, true, true, true, false].to_vec(),
            'u'|'U' => [false, false, true, true, true, false, false, false].to_vec(),
            'y'|'Y' => [false, true, true, true, false, true, true, false].to_vec(),
            _ => [false, false, false, false, false, false, false, false].to_vec(),
        };
    }

    pub fn set_segment(&mut self, index: usize, val: bool) {
        if index < self.segments.len() {
            self.segments[index] = val;
        } else {
            panic!("index out of bounds!");
        }
    }

    pub fn get_segment(&self, index: usize) -> bool {
        if index < self.segments.len() {
            self.segments[index]
        } else {
            panic!("index out of bounds!")
        }
    }
}

pub struct Encodestate {
    current: Sevensegment,
    next: Sevensegment,
}

impl Encodestate {
    pub fn new() -> Encodestate {
        Encodestate {
            current: Sevensegment::new(),
            next: Sevensegment::new(),
        }
    }

    pub fn encode_next_char(&mut self, c: char) -> Vec<String> {
        let mut instructions:Vec<String> = Vec::new();
        self.next.encode(c);
        for i in 0 .. 8 {
            if self.current.get_segment(i) != self.next.get_segment(i) {
                let mut text = String::new();
                text.push_str("set ");
                text.push(std::char::from_u32(('0' as u32) + i as u32).unwrap());
                text.push(' ');
                text.push_str(match self.next.get_segment(i) {
                    true => "0",
                    false => "1",
                });
                self.current.set_segment(i, self.next.get_segment(i));
                instructions.push(text);
            }
        }
        instructions.push(String::from("show"));
        instructions
    }
}