use super::constant;
use crate::{
    error::Error,
    time::Duration,
    trezorhal::{display, qr, time},
    ui::lerp::Lerp,
};
use core::slice;

use super::geometry::{Offset, Point, Rect};

pub fn backlight() -> i32 {
    display::backlight(-1)
}

pub fn set_backlight(val: i32) {
    display::backlight(val);
}

pub fn fade_backlight(target: i32) {
    const BACKLIGHT_DELAY: Duration = Duration::from_millis(14);
    const BACKLIGHT_STEP: usize = 15;

    let current = backlight();
    if current < target {
        for val in (current..target).step_by(BACKLIGHT_STEP) {
            set_backlight(val);
            time::sleep(BACKLIGHT_DELAY);
        }
    } else {
        for val in (target..current).rev().step_by(BACKLIGHT_STEP) {
            set_backlight(val);
            time::sleep(BACKLIGHT_DELAY);
        }
    }
}

pub fn rect_fill(r: Rect, fg_color: Color) {
    display::bar(r.x0, r.y0, r.width(), r.height(), fg_color.into());
}

pub fn rect_stroke(r: Rect, fg_color: Color) {
    display::bar(r.x0, r.y0, r.width(), 1, fg_color.into());
    display::bar(r.x0, r.y0 + r.height() - 1, r.width(), 1, fg_color.into());
    display::bar(r.x0, r.y0, 1, r.height(), fg_color.into());
    display::bar(r.x0 + r.width() - 1, r.y0, 1, r.height(), fg_color.into());
}

pub fn rect_fill_rounded(r: Rect, fg_color: Color, bg_color: Color, radius: u8) {
    assert!([2, 4, 8, 16].iter().any(|allowed| radius == *allowed));
    display::bar_radius(
        r.x0,
        r.y0,
        r.width(),
        r.height(),
        fg_color.into(),
        bg_color.into(),
        radius,
    );
}

/// NOTE: Cannot start at odd x-coordinate. In this case icon is shifted 1px
/// left.
pub fn icon_top_left(top_left: Point, data: &[u8], fg_color: Color, bg_color: Color) {
    let toif_info = display::toif_info(data).unwrap();
    assert!(toif_info.grayscale);
    display::icon(
        top_left.x,
        top_left.y,
        toif_info.width.into(),
        toif_info.height.into(),
        &data[12..], // Skip TOIF header.
        fg_color.into(),
        bg_color.into(),
    );
}

pub fn icon(center: Point, data: &[u8], fg_color: Color, bg_color: Color) {
    let toif_info = display::toif_info(data).unwrap();
    assert!(toif_info.grayscale);

    let r = Rect::from_center_and_size(
        center,
        Offset::new(toif_info.width.into(), toif_info.height.into()),
    );
    display::icon(
        r.x0,
        r.y0,
        r.width(),
        r.height(),
        &data[12..], // Skip TOIF header.
        fg_color.into(),
        bg_color.into(),
    );
}

pub fn image(center: Point, data: &[u8]) {
    let toif_info = display::toif_info(data).unwrap();
    assert!(!toif_info.grayscale);

    let r = Rect::from_center_and_size(
        center,
        Offset::new(toif_info.width.into(), toif_info.height.into()),
    );
    display::image(
        r.x0,
        r.y0,
        r.width(),
        r.height(),
        &data[12..], // Skip TOIF header.
    );
}

pub fn toif_info(data: &[u8]) -> Option<(Offset, bool)> {
    if let Ok(info) = display::toif_info(data) {
        Some((
            Offset::new(info.width.into(), info.height.into()),
            info.grayscale,
        ))
    } else {
        None
    }
}

// Used on T1 only.
pub fn rect_fill_rounded1(r: Rect, fg_color: Color, bg_color: Color) {
    display::bar(r.x0, r.y0, r.width(), r.height(), fg_color.into());
    let corners = [
        r.top_left(),
        r.top_right() - Offset::x(1),
        r.bottom_right() - Offset::uniform(1),
        r.bottom_left() - Offset::y(1),
    ];
    for p in corners.iter() {
        display::bar(p.x, p.y, 1, 1, bg_color.into());
    }
}

#[derive(Copy, Clone, PartialEq, Eq)]
pub struct TextOverlay<'a> {
    area: Rect,
    text: &'a str,
    font: Font,
}

impl<'a> TextOverlay<'a> {
    pub fn new(text: &'a str, font: Font) -> Self {
        let area = Rect::zero();
        Self { area, text, font }
    }

    pub fn place(&mut self, baseline: Point) {
        let text_width = self.font.text_width(self.text);
        let text_height = self.font.text_height();

        let text_area_start = baseline + Offset::new(-(text_width / 2), -text_height);
        let text_area_end = baseline + Offset::new(text_width / 2, 0);
        let area = Rect::new(text_area_start, text_area_end);

        self.area = area;
    }

    pub fn get_pixel(&self, underlying: Color, fg: Color, p: Point) -> Color {
        if !self.area.contains(p) {
            return underlying;
        }

        let mut tot_adv = 0;

        let p_rel = Point::new(p.x - self.area.x0, p.y - self.area.y0);

        for g in self.text.bytes().filter_map(|c| self.font.get_glyph(c)) {
            let char_area = Rect::new(
                Point::new(tot_adv + g.bearing_x, g.height - g.bearing_y),
                Point::new(tot_adv + g.bearing_x + g.width, g.bearing_y),
            );

            tot_adv += g.adv;

            if !char_area.contains(p_rel) {
                continue;
            }

            let p_inner = p_rel - char_area.top_left();
            let overlay_data = g.get_pixel_data(p_inner);
            return Color::lerp(underlying, fg, overlay_data as f32 / 15_f32);
        }

        underlying
    }
}

/// Gets a color of a pixel on `p` coordinates of rounded rectangle with corner
/// radius 2
fn rect_rounded2_get_pixel(
    p: Offset,
    size: Offset,
    colortable: [Color; 16],
    fill: bool,
    line_width: i32,
) -> Color {
    let border = (p.x >= 0 && p.x < line_width)
        || ((p.x >= size.x - line_width) && p.x <= (size.x - 1))
        || (p.y >= 0 && p.y < line_width)
        || ((p.y >= size.y - line_width) && p.y <= (size.y - 1));

    let corner_lim = 2 * line_width;
    let corner_inner = line_width;

    let corner_all = ((p.x > size.x - (corner_lim + 1)) || p.x < corner_lim)
        && (p.y < corner_lim || p.y > size.y - (corner_lim + 1));

    let corner = corner_all
        && (p.y >= corner_inner)
        && (p.x >= corner_inner)
        && (p.y <= size.y - (corner_inner + 1))
        && (p.x <= size.x - (corner_inner + 1));

    let corner_out = corner_all && !corner;

    if (border || corner || fill) && !corner_out {
        colortable[15]
    } else {
        colortable[0]
    }
}

/// Draws a rounded rectangle with corner radius 2, partially filled
/// according to `fill_from` and `fill_to` arguments.
/// Optionally draws a text inside the rectangle and adjusts its color to match
/// the fill. The coordinates of the text are specified in the TextOverlay
/// struct.
pub fn bar_with_text_and_fill(
    area: Rect,
    overlay: Option<TextOverlay>,
    fg_color: Color,
    bg_color: Color,
    fill_from: i32,
    fill_to: i32,
) {
    let r = area.translate(get_offset());
    let clamped = r.clamp(constant::screen());
    let colortable = get_color_table(fg_color, bg_color);

    set_window(clamped);

    for y_c in clamped.y0..clamped.y1 {
        for x_c in clamped.x0..clamped.x1 {
            let p = Point::new(x_c, y_c);
            let r_offset = p - r.top_left();

            let filled = (r_offset.x >= fill_from
                && fill_from >= 0
                && (r_offset.x <= fill_to || fill_to < fill_from))
                || (r_offset.x < fill_to && fill_to >= 0);

            let underlying_color =
                rect_rounded2_get_pixel(r_offset, r.size(), colortable, filled, 1);

            let final_color = overlay.map_or(underlying_color, |o| {
                let text_color = if filled { bg_color } else { fg_color };
                o.get_pixel(underlying_color, text_color, p)
            });

            pixeldata(final_color);
        }
    }
    pixeldata_dirty();
}

// Used on T1 only.
pub fn dotted_line(start: Point, width: i32, color: Color) {
    for x in (start.x..width).step_by(2) {
        display::bar(x, start.y, 1, 1, color.into());
    }
}

pub const LOADER_MIN: u16 = 0;
pub const LOADER_MAX: u16 = 1000;

pub fn loader(
    progress: u16,
    y_offset: i32,
    fg_color: Color,
    bg_color: Color,
    icon: Option<(&[u8], Color)>,
) {
    display::loader(
        progress,
        false,
        y_offset,
        fg_color.into(),
        bg_color.into(),
        icon.map(|i| i.0),
        icon.map(|i| i.1.into()).unwrap_or(0),
    );
}

pub fn loader_indeterminate(
    progress: u16,
    y_offset: i32,
    fg_color: Color,
    bg_color: Color,
    icon: Option<(&[u8], Color)>,
) {
    display::loader(
        progress,
        true,
        y_offset,
        fg_color.into(),
        bg_color.into(),
        icon.map(|i| i.0),
        icon.map(|i| i.1.into()).unwrap_or(0),
    );
}

pub fn qrcode(center: Point, data: &str, max_size: u32, case_sensitive: bool) -> Result<(), Error> {
    qr::render_qrcode(center.x, center.y, data, max_size, case_sensitive)
}

pub fn text(baseline: Point, text: &str, font: Font, fg_color: Color, bg_color: Color) {
    display::text(
        baseline.x,
        baseline.y,
        text,
        font.0,
        fg_color.into(),
        bg_color.into(),
    );
}

pub fn text_center(baseline: Point, text: &str, font: Font, fg_color: Color, bg_color: Color) {
    let w = font.text_width(text);
    display::text(
        baseline.x - w / 2,
        baseline.y,
        text,
        font.0,
        fg_color.into(),
        bg_color.into(),
    );
}

pub fn text_right(baseline: Point, text: &str, font: Font, fg_color: Color, bg_color: Color) {
    let w = font.text_width(text);
    display::text(
        baseline.x - w,
        baseline.y,
        text,
        font.0,
        fg_color.into(),
        bg_color.into(),
    );
}

#[inline(always)]
pub fn pixeldata(color: Color) {
    display::pixeldata(color.into());
}

pub fn pixeldata_dirty() {
    display::pixeldata_dirty();
}

pub fn get_offset() -> Offset {
    let offset = display::get_offset();
    Offset::new(offset.0, offset.1)
}

pub fn set_window(window: Rect) {
    display::set_window(
        window.x0 as u16,
        window.y0 as u16,
        window.x1 as u16 - 1,
        window.y1 as u16 - 1,
    );
}

pub fn get_color_table(fg_color: Color, bg_color: Color) -> [Color; 16] {
    let mut table: [Color; 16] = [Color::from_u16(0); 16];

    for (i, item) in table.iter_mut().enumerate() {
        *item = Color::lerp(bg_color, fg_color, i as f32 / 15_f32);
    }

    table
}

pub struct Glyph {
    pub width: i32,
    pub height: i32,
    pub adv: i32,
    pub bearing_x: i32,
    pub bearing_y: i32,
    data: &'static [u8],
}

impl Glyph {
    /// Construct a `Glyph` from a raw pointer.
    ///
    /// # Safety
    ///
    /// This function is unsafe because the caller has to guarantee that `data`
    /// is pointing to a memory containing a valid glyph data, that is:
    /// - contains valid glyph metadata
    /// - data has appropriate size
    /// - data must have static lifetime
    pub unsafe fn load(data: *const u8) -> Self {
        unsafe {
            let width = *data.offset(0) as i32;
            let height = *data.offset(1) as i32;

            let data_bits = constant::FONT_BPP * width * height;

            let data_bytes = if data_bits % 8 == 0 {
                data_bits / 8
            } else {
                (data_bits / 8) + 1
            };

            Glyph {
                width,
                height,
                adv: *data.offset(2) as i32,
                bearing_x: *data.offset(3) as i32,
                bearing_y: *data.offset(4) as i32,
                data: slice::from_raw_parts(data.offset(5), data_bytes as usize),
            }
        }
    }

    pub fn print(&self, pos: Point, colortable: [Color; 16]) -> i32 {
        let bearing = Offset::new(self.bearing_x, -self.bearing_y);
        let size = Offset::new(self.width, self.height);
        let pos_adj = pos + bearing;
        let r = Rect::from_top_left_and_size(pos_adj, size);

        let area = r.translate(get_offset());
        let window = area.clamp(constant::screen());

        set_window(window);

        for y in window.y0..window.y1 {
            for x in window.x0..window.x1 {
                let p = Point::new(x, y);
                let r = p - pos_adj;
                let c = self.get_pixel_data(r);
                pixeldata(colortable[c as usize]);
            }
        }
        self.adv
    }

    pub fn unpack_bpp1(&self, a: i32) -> u8 {
        let c_data = self.data[(a / 8) as usize];
        ((c_data >> (7 - (a % 8))) & 0x01) * 15
    }

    pub fn unpack_bpp2(&self, a: i32) -> u8 {
        let c_data = self.data[(a / 4) as usize];
        ((c_data >> (6 - (a % 4) * 2)) & 0x03) * 5
    }

    pub fn unpack_bpp4(&self, a: i32) -> u8 {
        let c_data = self.data[(a / 2) as usize];
        (c_data >> (4 - (a % 2) * 4)) & 0x0F
    }

    pub fn unpack_bpp8(&self, a: i32) -> u8 {
        let c_data = self.data[a as usize];
        c_data >> 4
    }

    pub fn get_pixel_data(&self, p: Offset) -> u8 {
        let a = p.x + p.y * self.width;

        match constant::FONT_BPP {
            1 => self.unpack_bpp1(a),
            2 => self.unpack_bpp2(a),
            4 => self.unpack_bpp4(a),
            8 => self.unpack_bpp8(a),
            _ => 0,
        }
    }
}

#[derive(Copy, Clone, PartialEq, Eq)]
pub struct Font(i32);

impl Font {
    pub const fn new(id: i32) -> Self {
        Self(id)
    }

    pub fn text_width(self, text: &str) -> i32 {
        display::text_width(text, self.0)
    }

    pub fn char_width(self, ch: char) -> i32 {
        display::char_width(ch, self.0)
    }

    pub fn text_height(self) -> i32 {
        display::text_height(self.0)
    }

    pub fn line_height(self) -> i32 {
        constant::LINE_SPACE + self.text_height()
    }

    pub fn get_glyph(self, char_byte: u8) -> Option<Glyph> {
        let gl_data = display::get_char_glyph(char_byte, self.0);

        if gl_data.is_null() {
            return None;
        }
        unsafe { Some(Glyph::load(gl_data)) }
    }

    pub fn display_text(self, text: &str, baseline: Point, fg_color: Color, bg_color: Color) {
        let colortable = get_color_table(fg_color, bg_color);
        let mut adv_total = 0;
        for c in text.bytes() {
            let g = self.get_glyph(c);
            if let Some(gly) = g {
                let adv = gly.print(baseline + Offset::new(adv_total, 0), colortable);
                adv_total += adv;
            }
        }
    }
}

#[derive(Copy, Clone, PartialEq, Eq)]
pub struct Color(u16);

impl Color {
    pub const fn from_u16(val: u16) -> Self {
        Self(val)
    }

    pub const fn rgb(r: u8, g: u8, b: u8) -> Self {
        let r = (r as u16 & 0xF8) << 8;
        let g = (g as u16 & 0xFC) << 3;
        let b = (b as u16 & 0xF8) >> 3;
        Self(r | g | b)
    }

    pub const fn r(self) -> u8 {
        (self.0 >> 8) as u8 & 0xF8
    }

    pub const fn g(self) -> u8 {
        (self.0 >> 3) as u8 & 0xFC
    }

    pub const fn b(self) -> u8 {
        (self.0 << 3) as u8 & 0xF8
    }

    pub fn to_u16(self) -> u16 {
        self.0
    }

    pub fn negate(self) -> Self {
        Self(!self.0)
    }
}

impl Lerp for Color {
    fn lerp(a: Self, b: Self, t: f32) -> Self {
        let r = u8::lerp(a.r(), b.r(), t);
        let g = u8::lerp(a.g(), b.g(), t);
        let b = u8::lerp(a.b(), b.b(), t);
        Color::rgb(r, g, b)
    }
}

impl From<u16> for Color {
    fn from(val: u16) -> Self {
        Self(val)
    }
}

impl From<Color> for u16 {
    fn from(val: Color) -> Self {
        val.to_u16()
    }
}