use super::{Event, Home, Screens};
use crate::{eeprom, lcd::Lcd, Input, BACKLIGHT, CONTRAST};
use nb::block;

enum Selection {
    Backlight,
    BacklightEdit,
    Contrast,
    ContrastEdit,
    Back,
}

pub struct Setup {
    active: Selection,
    backlight: u8,
    contrast: u8,
}

impl Setup {
    pub fn new() -> Self {
        Self {
            active: Selection::Backlight,
            backlight: block!(eeprom::read_byte(&BACKLIGHT)).unwrap(),
            contrast: block!(eeprom::read_byte(&CONTRAST)).unwrap(),
        }
    }

    pub fn input(&mut self, input: &Input) -> Event {
        self.active = match self.active {
            Selection::Backlight => match input {
                Input::Next => Selection::Contrast,
                Input::Previous => Selection::Back,
                Input::Select => Selection::BacklightEdit,
                Input::Back => return Event::Screen(Screens::Home(Home::new())),
            },
            Selection::BacklightEdit => match input {
                Input::Next => {
                    self.backlight = if self.backlight == u8::MAX {
                        u8::MAX
                    } else {
                        self.backlight + 1
                    };

                    return Event::Backlight(self.backlight);
                }
                Input::Previous => {
                    self.backlight = if self.backlight == u8::MIN {
                        u8::MIN
                    } else {
                        self.backlight - 1
                    };

                    return Event::Backlight(self.backlight);
                }
                Input::Select => {
                    block!(eeprom::write_byte(&BACKLIGHT, self.backlight)).unwrap();
                    Selection::Backlight
                }
                Input::Back => {
                    self.active = Selection::Backlight;
                    self.backlight = block!(eeprom::read_byte(&BACKLIGHT)).unwrap();
                    return Event::Backlight(self.backlight);
                }
            },
            Selection::Contrast => match input {
                Input::Next => Selection::Back,
                Input::Previous => Selection::Backlight,
                Input::Select => Selection::ContrastEdit,
                Input::Back => return Event::Screen(Screens::Home(Home::new())),
            },
            Selection::ContrastEdit => match input {
                Input::Next => {
                    self.contrast = if self.contrast >= 63 {
                        63
                    } else {
                        self.contrast + 1
                    };

                    return Event::Contrast(self.contrast);
                }
                Input::Previous => {
                    self.contrast = if self.contrast == u8::MIN {
                        u8::MIN
                    } else {
                        self.contrast - 1
                    };

                    return Event::Contrast(self.contrast);
                }
                Input::Select => {
                    block!(eeprom::write_byte(&CONTRAST, self.contrast)).unwrap();
                    Selection::Contrast
                }
                Input::Back => {
                    self.active = Selection::Contrast;
                    self.contrast = block!(eeprom::read_byte(&CONTRAST)).unwrap();
                    return Event::Contrast(self.contrast);
                }
            },
            Selection::Back => match input {
                Input::Next => Selection::Backlight,
                Input::Previous => Selection::Contrast,
                _ => return Event::Screen(Screens::Home(Home::new())),
            },
        };

        Event::None
    }

    pub fn draw(&self, lcd: &mut Lcd) {
        lcd.fill_area(0, 0, 33, 2, 0xFF);
        lcd.print(33, 0, true, "SETUP");
        lcd.fill_area(69, 0, 33, 2, 0xFF);

        match &self.active {
            Selection::Contrast => {
                lcd.print(0, 2, false, "BACKLIGHT:");
                lcd.print_u8(81, 2, 3, false, self.backlight);
                lcd.print(0, 4, true, "CONTRAST:");
                lcd.print_u8(87, 4, 2, false, self.contrast);
                lcd.print(36, 6, false, "BACK");
            }
            Selection::ContrastEdit => {
                lcd.print(0, 2, false, "BACKLIGHT:");
                lcd.print_u8(81, 2, 3, false, self.backlight);
                lcd.print(0, 4, false, "CONTRAST:");
                lcd.print_u8(87, 4, 2, true, self.contrast);
                lcd.print(36, 6, false, "BACK");
            }
            Selection::Backlight => {
                lcd.print(0, 2, true, "BACKLIGHT:");
                lcd.print_u8(81, 2, 3, false, self.backlight);
                lcd.print(0, 4, false, "CONTRAST:");
                lcd.print_u8(87, 4, 2, false, self.contrast);
                lcd.print(36, 6, false, "BACK");
            }
            Selection::BacklightEdit => {
                lcd.print(0, 2, false, "BACKLIGHT:");
                lcd.print_u8(81, 2, 3, true, self.backlight);
                lcd.print(0, 4, false, "CONTRAST:");
                lcd.print_u8(87, 4, 2, false, self.contrast);
                lcd.print(36, 6, false, "BACK");
            }
            Selection::Back => {
                lcd.print(0, 2, false, "BACKLIGHT:");
                lcd.print_u8(81, 2, 3, false, self.backlight);
                lcd.print(0, 4, false, "CONTRAST:");
                lcd.print_u8(87, 4, 2, false, self.contrast);
                lcd.print(36, 6, true, "BACK");
            }
        }
    }
}