recipes/db/build.rs

use std::fs;
use std::io::{BufWriter, Write};

use serde::Deserialize;

#[derive(Deserialize, Debug)]
pub struct Main {
    ingredients: Option<Vec<Ingredient>>,
    recipes: Option<Vec<Recipe>>,
}

#[derive(Deserialize, Debug)]
pub struct Ingredient {
    key: String,
    translates: IngredientTranslate,
}

#[derive(Deserialize, Debug)]
pub struct IngredientTranslate {
    ru: String,
    en: Option<String>,
}

#[derive(Deserialize, Debug)]
pub struct Recipe {
    key: String,
    ingredients: Vec<RecipeIngredient>,
    steps: u8,
    translates: RecipeTranslates,
}

#[derive(Deserialize, Debug)]
pub struct RecipeIngredient {
    key: String,
    #[serde(flatten)]
    measure: RecipeIngredientMeasure,
}

#[derive(Deserialize, Debug)]
pub enum RecipeIngredientMeasure {
    #[serde(rename = "g")]
    Gram(u32),
    #[serde(rename = "kg")]
    KiloGram(u32),
    #[serde(rename = "ml")]
    MilliLiter(u32),
    #[serde(rename = "l")]
    Liter(u32),
}

#[derive(Deserialize, Debug)]
pub struct RecipeTranslates {
    ru: RecipeTranslate,
    en: Option<RecipeTranslate>,
}

#[derive(Deserialize, Debug)]
pub struct RecipeTranslate {
    name: String,
    instructions: Vec<String>,
}

fn write_structs(file: &mut BufWriter<fs::File>) -> Result<(), std::io::Error> {
    writeln!(file, "#[derive(Debug)]")?;
    writeln!(file, "pub struct Ingredient {{")?;
    writeln!(file, "    pub key: &'static str,")?;
    writeln!(file, "    translates: IngredientTranslate,")?;
    writeln!(file, "}}")?;

    writeln!(file, "#[derive(Debug)]")?;
    writeln!(file, "pub struct IngredientTranslate {{")?;
    writeln!(file, "    ru: &'static str,")?;
    writeln!(file, "    en: Option<&'static str>,")?;
    writeln!(file, "}}")?;

    writeln!(file, "#[derive(Debug)]")?;
    writeln!(file, "pub struct Recipe {{")?;
    writeln!(file, "    key: &'static str,")?;
    writeln!(file, "    ingredients: Vec<RecipeIngredient>,")?;
    writeln!(file, "    steps: u8,")?;
    writeln!(file, "    translates: RecipeTranslates,")?;
    writeln!(file, "}}")?;

    writeln!(file, "#[derive(Debug)]")?;
    writeln!(file, "pub struct RecipeIngredient {{")?;
    writeln!(file, "    key: &'static str,")?;
    writeln!(file, "    measure: RecipeIngredientMeasure,")?;
    writeln!(file, "}}")?;

    writeln!(file, "#[derive(Debug)]")?;
    writeln!(file, "pub enum RecipeIngredientMeasure {{")?;
    writeln!(file, "    Gram(u32),")?;
    writeln!(file, "    KiloGram(u32),")?;
    writeln!(file, "    MilliLiter(u32),")?;
    writeln!(file, "    Liter(u32),")?;
    writeln!(file, "}}")?;

    writeln!(file, "#[derive(Debug)]")?;
    writeln!(file, "pub struct RecipeTranslates {{")?;
    writeln!(file, "    ru: RecipeTranslate,")?;
    writeln!(file, "    en: Option<RecipeTranslate>,")?;
    writeln!(file, "}}")?;

    writeln!(file, "#[derive(Debug)]")?;
    writeln!(file, "pub struct RecipeTranslate {{")?;
    writeln!(file, "    name: &'static str,")?;
    writeln!(file, "    instructions: Vec<&'static str>,")?;
    writeln!(file, "}}")?;
    Ok(())
}

fn write_ingredients(file: &mut BufWriter<fs::File>) -> Result<(), std::io::Error> {
    // fs::read_dir("data/ingredients")
    let fruit = fs::read_to_string("data/ingredients/fruit.toml")?;
    let cfg: Main = toml::from_str(&fruit).unwrap();

    let mut ins: usize = 0;

    writeln!(
        file,
        "pub const INGREDIENTS: [Ingredient; {}] = [",
        cfg.ingredients
            .as_ref()
            .map(|i| i.len())
            .unwrap_or_default()
    )?;
    ins += 1;
    if let Some(ingredients) = cfg.ingredients {
        for ingredient in ingredients {
            writeln!(file, "{}Ingredient {{", indent(ins))?;
            ins += 1;
            writeln!(file, "{}key: {:?},", indent(ins), to_str(ingredient.key))?;
            writeln!(file, "{}translates: IngredientTranslate {{", indent(ins))?;
            ins += 1;
            writeln!(
                file,
                "{}ru: {:?},",
                indent(ins),
                to_str(ingredient.translates.ru)
            )?;
            writeln!(
                file,
                "{}en: {:?},",
                indent(ins),
                ingredient.translates.en.map(to_str)
            )?;
            ins -= 1;
            writeln!(file, "{}}}", indent(ins))?;
            ins -= 1;
            writeln!(file, "{}}},", indent(ins))?;
        }
    }
    ins -= 1;
    writeln!(file, "{}];", indent(ins))?;

    Ok(())
}

fn gen_data_mod() -> Result<(), std::io::Error> {
    let file = fs::File::create("src/data.rs")?;
    let mut buf = BufWriter::new(file);
    write_structs(&mut buf)?;
    println!("cargo:rerun-if-changed=data");
    write_ingredients(&mut buf)?;
    Ok(())
}

fn indent(indent_size: usize) -> String {
    std::iter::repeat(" ").take(indent_size * 4).collect()
}

fn to_str(string: String) -> &'static str {
    Box::leak(string.into_boxed_str())
}

fn main() {
    println!("cargo:rerun-if-changed=build.rs");
    if let Err(e) = gen_data_mod() {
        eprintln!("Error: {}", e);
    }
}