/*
    The MIT License (MIT)

    Copyright (c) 2020 Matthias P. Braendli

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE.
*/

use crate::state::*;

use core::fmt;
use core::fmt::Write;

use stm32f1xx_hal::{
    gpio::gpiob::*,
    gpio::gpioc::*,
    gpio::{Input, PullUp, Floating},
};

use embedded_hal::blocking::delay::{DelayMs, DelayUs};
use hd44780_driver::HD44780;

#[derive(PartialEq, Eq, Clone, Copy)]
struct ButtonState {
    pub a : bool,
    pub b : bool,
    pub c : bool,
    pub d : bool,
    pub e : bool,
    pub enc : bool,
}

const VFO_INCR : i32 = 2;

impl ButtonState {
    fn edge_detection(&self, old_state : &ButtonState) -> ButtonState {
        ButtonState {
            a : !old_state.a && self.a,
            b : !old_state.b && self.b,
            c : !old_state.c && self.c,
            d : !old_state.d && self.d,
            e : !old_state.e && self.e,
            enc : !old_state.enc && self.enc,
        }
    }
}

impl Default for ButtonState {
    fn default() -> Self {
        ButtonState {
            a : false,
            b : false,
            c : false,
            d : false,
            e : false,
            enc : false,
        }
    }
}

impl fmt::Display for ButtonState {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}{}{}{}{}{}",
            if self.a { "A" } else { "a" },
            if self.b { "B" } else { "b" },
            if self.c { "C" } else { "c" },
            if self.d { "D" } else { "d" },
            if self.e { "E" } else { "e" },
            if self.enc { "X" } else { "x" })
    }
}

#[derive(Default)]
pub struct ButtonResult {
    pub display_update : bool,
}

pub struct UI {
    btn0 : PB1<Input<Floating>>,
    btn1 : PB0<Input<Floating>>,

    btn2 : PB12<Input<PullUp>>,
    btn3 : PB13<Input<PullUp>>,

    btn_enc : PC15<Input<PullUp>>,

    previous_button_state : ButtonState,
}

impl UI {
    pub fn new(
        pb0: PB0<Input<Floating>>,
        pb1: PB1<Input<Floating>>,
        pb12: PB12<Input<PullUp>>,
        pb13: PB13<Input<PullUp>>,
        pc15 : PC15<Input<PullUp>>) -> UI {

        UI {
            btn0 : pb1,
            btn1 : pb0,
            btn2 : pb12,
            btn3 : pb13,
            btn_enc : pc15,
            previous_button_state : ButtonState::default(),
        }
    }

    fn read_buttons(&mut self) -> ButtonState {
        let mut buttons = ButtonState::default();

        let b0_low = self.btn0.is_low();
        let b1_low = self.btn1.is_low();

        if b0_low && b1_low {
            buttons.e = true;
        }
        else if b0_low {
            buttons.a = true;
        }
        else if b1_low {
            buttons.b = true;
        }

        if self.btn2.is_low() {
            buttons.c = true;
        }

        if self.btn3.is_low() {
            buttons.d = true;
        }

        if self.btn_enc.is_low() {
            buttons.enc = true;
        }

        buttons
    }

    pub fn handle_buttons(&mut self, state: &mut State) -> ButtonResult {
        let mut result = ButtonResult::default();
        let button_state = self.read_buttons();
        let button_updates = button_state.edge_detection(&self.previous_button_state);
        self.previous_button_state = button_state;

        if button_updates.a {
            state.vfo_sel = match (state.ui_sel, state.vfo_sel) {
                (UISelection::VFO, VFOSelection::A) => VFOSelection::B,
                (UISelection::VFO, VFOSelection::B) => VFOSelection::A,
                _ => state.vfo_sel.clone(),
            };
            state.ui_sel = UISelection::VFO;
            result.display_update = true;
        }

        if button_updates.c {
            let (new_ui_sel, new_filter_shift) = match (state.ui_sel, state.mode) {
                (UISelection::Mode, Mode::CW(CWMode::StraightKey)) => (UISelection::Mode, Mode::CW(CWMode::Iambic)),
                (UISelection::Mode, Mode::CW(CWMode::Iambic)) => (UISelection::Mode, Mode::FeldHell),
                (UISelection::Mode, Mode::FeldHell) => (UISelection::Mode, Mode::WSPR),
                (UISelection::Mode, Mode::WSPR) => (UISelection::Mode, Mode::CW(CWMode::StraightKey)),
                (_, f) => (UISelection::Mode, f),
            };

            state.ui_sel = new_ui_sel;
            state.mode = new_filter_shift;

            result.display_update = true;
        }

        if button_updates.d {
            result.display_update = true;
        }

        if button_updates.enc {
            match state.ui_sel {
                UISelection::VFO => {},
                UISelection::Mode => {
                    state.mode = Mode::CW(CWMode::StraightKey);
                },
            }

            result.display_update = true;
        }

        result
    }

    pub fn update_encoder(&mut self, state: &mut State, counter_delta : i32) {

        let delta = (17 * counter_delta + 3 * (counter_delta * counter_delta * counter_delta))/20;

        match state.ui_sel {
            UISelection::VFO => {
                match state.vfo_sel {
                    VFOSelection::A => {
                        state.vfo_a = (state.vfo_a as i32 + delta * VFO_INCR) as u32;
                    },
                    VFOSelection::B => {
                        state.vfo_b = (state.vfo_b as i32 + delta * VFO_INCR) as u32;
                    },
                }
            },
            UISelection::Mode => {
                match state.mode {
                    Mode::CW(CWMode::Iambic) => {
                        let mut new_wpm = state.cw_wpm as i32 + counter_delta / 4;
                        if new_wpm < 1 {
                            new_wpm = 1;
                        }

                        if new_wpm > 40 {
                            new_wpm = 40;
                        }

                        let wpm = new_wpm as u32;
                        state.cw_wpm = wpm;
                        state.mode = Mode::CW(CWMode::Iambic);
                    },
                    _ => { },
                }
            },
        }
    }
}

pub fn update_disp<T: hd44780_driver::bus::DataBus, D: DelayUs<u16> + DelayMs<u8>>(
        lcd: &mut HD44780<T>, state: &State, delay: &mut D)
{
    let mut string = arrayvec::ArrayString::<16>::new();

    let disp_freq = state.vfo_display() as i32;
    write!(string, "{:<05}.{:<03} ", disp_freq / 1000, disp_freq % 1000).unwrap();

    write!(string, " CW{:<02}", state.cw_wpm).unwrap();

    lcd.set_cursor_pos(0, delay).unwrap();
    lcd.write_str(&string, delay).unwrap();

    string.clear();

    match &state.vfo_sel {
        VFOSelection::A => write!(string, "VFOa").unwrap(),
        VFOSelection::B => write!(string, "VFOb").unwrap(),
    }

    write!(string, "    {}", if state.ui_sel == UISelection::Mode { ">" } else { " " }).unwrap();

    let mode = match state.mode {
        Mode::CW(CWMode::StraightKey) => "CWs",
        Mode::CW(CWMode::Iambic) => "CWp",
        Mode::FeldHell => "HEL",
        Mode::WSPR => "WSP",
    };

    write!(string, "{}    ", mode).unwrap();

    lcd.set_cursor_pos(40, delay).unwrap();
    lcd.write_str(&string, delay).unwrap();
}