fretboard_layout 0.5.1

#![warn(clippy::all, clippy::pedantic)]
#![allow(clippy::must_use_candidate)]
#![doc = include_str!("../README.md")]

mod config;
mod factors;
mod handedness;
pub mod open;
mod variant;

pub use {
    config::{
        font::{Font, Weight},
        Config, Units,
    },
    factors::Factors,
    handedness::{Handedness, ParseHandednessError},
    rgba_simple::*,
    variant::{MultiscaleBuilder, Variant},
};

use {
    rayon::prelude::*,
    svg::{
        node::element::{path::Data, Description, Group, Path, Text},
        Document,
    },
};

#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};

/// Distance from bridge to fret along each side of the fretboard.
struct Lengths {
    length_bass: f64,
    length_treble: f64,
}

/// A 2-dimensional representation of a point
struct Point(pub f64, pub f64);

/// 2 Points which form a line
struct Line {
    start: Point,
    end: Point,
}

impl Lengths {
    /// Plots the end of a fret, nut or bridge along the bass side of the scale
    fn get_point_bass(&self, specs: &Specs, config: &Config) -> Point {
        let hand = specs.variant.handedness();
        let x = match hand {
            Some(Handedness::Left) => {
                specs.scale - (specs.factors.x_ratio * self.length_bass) + config.border
            }
            _ => (specs.factors.x_ratio * self.length_bass) + config.border,
        };
        let opposite = specs.factors.y_ratio * self.length_bass;
        let y = opposite + config.border;
        Point(x, y)
    }

    /// Plots the end of a fret, nut or bridge along the treble side of the scale
    fn get_point_treble(&self, specs: &Specs, config: &Config) -> Point {
        let hand = specs.variant.handedness();
        let x = match hand {
            Some(Handedness::Left) => {
                specs.scale + config.border
                    - specs.factors.treble_offset
                    - (specs.factors.x_ratio * self.length_treble)
            }
            _ => {
                specs.factors.treble_offset
                    + (specs.factors.x_ratio * self.length_treble)
                    + config.border
            }
        };
        let opposite = specs.factors.y_ratio * self.length_treble;
        let y = specs.bridge - opposite + config.border;
        Point(x, y)
    }

    /// Returns a Point struct containing both ends of a fret, nut or bridge
    /// which will form a line
    fn get_fret_line(&self, specs: &Specs, config: &Config) -> Line {
        let start = self.get_point_bass(specs, config);
        let end = self.get_point_treble(specs, config);
        Line { start, end }
    }
}

impl Line {
    /// Returns an svg Path node representing a single fret
    fn draw_fret(&self, fret: u32, config: &Config) -> Path {
        let id = if fret == 0 {
            "Nut".to_string()
        } else {
            format!("Fret {fret}")
        };
        let data = Data::new()
            .move_to((self.start.0, self.start.1))
            .line_to((self.end.0, self.end.1))
            .close();
        Path::new()
            .set("fill", "none")
            .set("stroke", config.fretline_color.to_hex())
            .set("stroke-opacity", config.fretline_color.alpha)
            .set("stroke-width", config.line_weight)
            .set("id", id)
            .set("d", data)
    }
}

#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
/// This struct contains the user data used to create the svg output file
pub struct Specs {
    /// Scale length. For multiscale designs this is the bass side scale length.
    pub scale: f64,
    /// Number of frets to render
    pub count: u32,
    /// Monoscale or Multiscale Right orLeft handed
    pub variant: Variant,
    /// The width of the fretboard at the nut.
    pub nut: f64,
    /// The string spacing at the bridge. Note that this is not the physical
    /// width of the bridge, but the distance perpendicular to the centerline
    /// between the outer two strings.
    pub bridge: f64,
    factors: Factors,
}

impl Default for Specs {
    /// Returns a default Specs struct
    fn default() -> Self {
        Self::init(655.0, 24, Variant::default(), 43.0, 56.0)
    }
}

impl Specs {
    #[must_use]
    pub fn init(scale: f64, count: u32, variant: Variant, nut: f64, bridge: f64) -> Self {
        let factors = Factors::init(scale, &variant, nut, bridge);
        Self {
            scale,
            count,
            variant,
            nut,
            bridge,
            factors,
        }
    }

    pub fn builder() -> SpecsBuilder {
        SpecsBuilder::new()
    }

    /// Returns a multiscale Specs struct
    #[allow(clippy::must_use_candidate)]
    pub fn multi() -> Self {
        Self::init(655.0, 24, Variant::multi(), 43.0, 56.0)
    }

    #[allow(clippy::must_use_candidate)]
    pub fn scale(&self) -> f64 {
        self.scale
    }

    pub fn set_scale(&mut self, scale: f64) {
        self.scale = scale;
    }

    #[allow(clippy::must_use_candidate)]
    pub fn count(&self) -> u32 {
        self.count
    }

    pub fn set_count(&mut self, count: u32) {
        self.count = count;
    }

    #[allow(clippy::must_use_candidate)]
    pub fn variant(&self) -> Variant {
        self.variant
    }

    pub fn set_multi(&mut self, scale: Option<f64>, pfret: Option<f64>) {
        match scale {
            Some(s) => {
                if let Some(hand) = self.variant.handedness() {
                    self.variant = Variant::Multiscale {
                        scale: s,
                        handedness: hand,
                        pfret: pfret.unwrap_or(8.0),
                    };
                } else {
                    self.variant = Variant::Multiscale {
                        scale: s,
                        handedness: Handedness::Right,
                        pfret: pfret.unwrap_or(8.0),
                    };
                };
            }
            None => self.variant = Variant::Monoscale,
        }
    }

    #[allow(clippy::must_use_candidate)]
    pub fn nut(&self) -> f64 {
        self.nut
    }

    pub fn set_nut(&mut self, nut: f64) {
        self.nut = nut;
    }

    #[allow(clippy::must_use_candidate)]
    pub fn bridge(&self) -> f64 {
        self.bridge
    }

    pub fn set_bridge(&mut self, bridge: f64) {
        self.bridge = bridge;
    }

    /// Returns the distance from bridge to nut on both sides of the fretboard
    fn get_nut(&self) -> Lengths {
        let length_treble = match self.variant {
            Variant::Multiscale { scale: s, .. } => s,
            Variant::Monoscale => self.scale,
        };
        Lengths {
            length_bass: self.scale,
            length_treble,
        }
    }

    /// Returns the length from bridge to fret for a given fret number, along
    /// both bass and treble sides of the board.
    fn get_fret_lengths(&self, fret: u32) -> Lengths {
        let factor = 2.0_f64.powf(f64::from(fret) / 12.0);
        let length_bass = self.scale / factor;
        let length_treble = match self.variant {
            Variant::Monoscale => length_bass,
            Variant::Multiscale { scale: s, .. } => s / factor,
        };
        Lengths {
            length_bass,
            length_treble,
        }
    }

    /// Embeds a text description into the svg
    fn create_description(&self) -> Description {
        let desc = Description::new()
            .set("Scale", self.scale)
            .set("BridgeSpacing", self.bridge - 6.0)
            .set("NutWidth", self.nut)
            .set("FretCount", self.count);
        match self.variant {
            Variant::Multiscale {
                scale: scl,
                handedness: hnd,
                pfret: pf,
            } => desc
                .set("ScaleTreble", scl)
                .set("PerpendicularFret", pf)
                .set("Handedness", hnd.to_string()),
            Variant::Monoscale => desc,
        }
    }

    /// Prints the specs used in the rendered image
    fn print_data(&self, config: &Config) -> Text {
        let units = match config.units {
            Units::Metric => String::from("mm"),
            Units::Imperial => String::from("in"),
        };
        let mut line = match self.variant {
            Variant::Monoscale => format!("Scale: {:.2}{} |", self.scale, &units),
            Variant::Multiscale {
                scale: s, pfret: f, ..
            } => format!(
                "ScaleBass: {:.2}{} | ScaleTreble: {s:.2}{} | PerpendicularFret: {f:.1} |",
                self.scale, &units, &units
            ),
        };
        let font = config.font.clone().unwrap_or_default();
        let font_size = match config.units {
            Units::Metric => "5px",
            Units::Imperial => "0.25px",
        };
        line = format!("{line} NutWidth: {:.2}{} |", self.nut, &units);
        let bridge = match config.units {
            Units::Metric => self.bridge - 6.0,
            Units::Imperial => self.bridge - (6.0 / 20.4),
        };
        line = format!("{line} BridgeSpacing: {bridge:.2}{}", &units);
        svg::node::element::Text::new()
            .set("x", config.border)
            .set("y", (config.border * 1.7) + self.bridge)
            .set("font-family", font.family())
            .set("font-weight", font.weight().css_value())
            .set("font-stretch", font.stretch().css_value())
            .set("font-style", font.style().css_value())
            .set("font-size", font_size)
            .set("id", "Specifications")
            .add(svg::node::Text::new(line))
    }

    /// Adds the centerline to the svg data
    fn draw_centerline(&self, config: &Config) -> Path {
        let start_x = config.border;
        let start_y = (self.bridge / 2.0) + config.border;
        let end_x = config.border + self.scale;
        let end_y = (self.bridge / 2.0) + config.border;
        let (hex, opacity) = match &config.centerline_color {
            Some(c) => (c.to_hex(), f32::from(c.alpha) * 255.0),
            None => (RGBA::<u8>::from(PrimaryColor::Blue).to_hex(), 1.0),
        };
        let dasharray = match config.units {
            Units::Metric => "4.0, 8.0",
            Units::Imperial => "0.2, 0.4",
        };
        let data = Data::new()
            .move_to((start_x, start_y))
            .line_to((end_x, end_y))
            .close();
        Path::new()
            .set("fill", "none")
            .set("stroke", hex)
            .set("stroke-opacity", opacity)
            .set("stroke-dasharray", dasharray)
            .set("stroke-dashoffset", "0")
            .set("stroke-width", config.line_weight)
            .set("id", "Centerline")
            .set("d", data)
    }

    /// adds the bridge as a line between the outer strings
    fn draw_bridge(&self, config: &Config) -> Path {
        let start_x = match self.variant {
            Variant::Monoscale
            | Variant::Multiscale {
                handedness: Handedness::Right,
                ..
            } => config.border,
            Variant::Multiscale {
                handedness: Handedness::Left,
                ..
            } => config.border + self.scale,
        };
        let start_y = config.border;
        let end_x = match self.variant {
            Variant::Monoscale
            | Variant::Multiscale {
                handedness: Handedness::Right,
                ..
            } => config.border + self.factors.treble_offset,
            Variant::Multiscale {
                handedness: Handedness::Left,
                ..
            } => config.border + self.scale - self.factors.treble_offset,
        };
        let end_y = config.border + self.bridge;
        let data = Data::new()
            .move_to((start_x, start_y))
            .line_to((end_x, end_y))
            .close();
        Path::new()
            .set("fill", "none")
            .set("stroke", "black")
            .set("stroke-width", config.line_weight)
            .set("id", "Bridge")
            .set("d", data)
    }

    /// Draws the outline of the fretboard
    fn draw_fretboard(&self, config: &Config) -> Path {
        let nut = self.get_nut().get_fret_line(self, config);
        let end = self
            .get_fret_lengths(self.count + 1)
            .get_fret_line(self, config);
        let (hex, alpha) = (
            config.fretboard_color.to_hex(),
            config.fretboard_color.alpha,
        );
        let data = Data::new()
            .move_to((nut.start.0, nut.start.1))
            .line_to((nut.end.0, nut.end.1))
            .line_to((end.end.0, end.end.1))
            .line_to((end.start.0, end.start.1))
            .line_to((nut.start.0, nut.start.1))
            .close();
        Path::new()
            .set("fill", hex)
            .set("fill-opacity", alpha)
            .set("stroke", "none")
            .set("id", "Fretboard")
            .set("d", data)
    }

    /// draws a single fret
    fn draw_fret(&self, config: &Config, num: u32) -> Path {
        self.get_fret_lengths(num)
            .get_fret_line(self, config)
            .draw_fret(num, config)
    }

    /// Iterates through each fret, returning a group of svg Paths
    fn draw_frets(&self, cfg: &Config) -> Group {
        let frets = Group::new().set("id", "Frets");
        let f: Vec<Path> = (0..=self.count)
            .into_par_iter()
            .map(|fret| self.draw_fret(cfg, fret))
            .collect();
        f.into_iter().fold(frets, Group::add)
    }

    ///Returns the complete svg Document
    ///# Example
    ///
    ///```rust
    ///use fretboard_layout::{Config, Specs};
    ///
    ///fn run() {
    ///    let specs = Specs::default();
    ///    let doc = specs.create_document(Some(Config::default()));
    ///}
    ///```
    #[must_use]
    pub fn create_document(&self, conf: Option<Config>) -> svg::Document {
        let config = conf.unwrap_or_default();
        let width = (config.border * 2.0) + self.scale;
        let units = match config.units {
            Units::Metric => "mm",
            Units::Imperial => "in",
        };
        let widthmm = format!("{width}{units}");
        let height = (config.border * 2.0) + self.bridge;
        let heightmm = format!("{height}{units}");
        // Todo - investigate generating these values async
        let description = self.create_description();
        let fretboard = self.draw_fretboard(&config);
        let bridge = self.draw_bridge(&config);
        let frets = self.draw_frets(&config);
        let document = Document::new()
            .set("width", widthmm)
            .set("height", heightmm)
            .set("preserveAspectRatio", "xMidYMid meet")
            .set("viewBox", (0, 0, width, height))
            .add(description)
            .add(fretboard)
            .add(bridge)
            .add(frets);
        if config.font.is_some() {
            if config.centerline_color.is_some() {
                document
                    .add(self.print_data(&config))
                    .add(self.draw_centerline(&config))
            } else {
                document.add(self.print_data(&config))
            }
        } else if config.centerline_color.is_some() {
            document.add(self.draw_centerline(&config))
        } else {
            document
        }
    }
}

/// A Specs builder
pub struct SpecsBuilder {
    scale: f64,
    count: u32,
    variant: Variant,
    nut: f64,
    bridge: f64,
}

impl Default for SpecsBuilder {
    fn default() -> Self {
        Self {
            scale: 655.0,
            count: 24,
            variant: Variant::Monoscale,
            nut: 43.0,
            bridge: 56.0,
        }
    }
}

impl SpecsBuilder {
    #[must_use]
    pub fn new() -> Self {
        Self::default()
    }

    #[must_use]
    pub fn scale(mut self, scale: f64) -> Self {
        self.scale = scale;
        self
    }

    #[must_use]
    pub fn count(mut self, count: u32) -> Self {
        self.count = count;
        self
    }

    #[must_use]
    pub fn variant(mut self, variant: Variant) -> Self {
        self.variant = variant;
        self
    }

    #[must_use]
    pub fn nut(mut self, nut: f64) -> Self {
        self.nut = nut;
        self
    }

    #[must_use]
    pub fn bridge(mut self, bridge: f64) -> Self {
        self.bridge = bridge;
        self
    }

    #[must_use]
    pub fn build(self) -> Specs {
        Specs::init(self.scale, self.count, self.variant, self.nut, self.bridge)
    }
}

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

    #[test]
    fn lengths() {
        let specs = Specs::default();
        let lengths = specs.get_fret_lengths(12);
        assert_eq!(lengths.length_bass, 327.5);
        assert_eq!(lengths.length_treble, lengths.length_treble);
        let lengths = specs.get_fret_lengths(24);
        assert_eq!(lengths.length_bass, 163.75);
        assert_eq!(lengths.length_bass, lengths.length_treble);
    }
}