acts-of-gods/src/parser.rs

use crate::prelude::*;

#[derive(Error, Debug)]
pub(crate) enum SaveEntityParseError {
    #[error("Failed to parse `{0}`")]
    Component(String),
    #[error("Failed to parse Entity")]
    Nom(nom::Err<nom::error::Error<Box<str>>>),
}

// Convert Nom error to parse error
// https://stackoverflow.com/a/77974858/3096574
impl From<nom::Err<nom::error::Error<&str>>> for SaveEntityParseError {
    fn from(err: nom::Err<nom::error::Error<&str>>) -> Self {
        SaveEntityParseError::Nom(err.map_input(|input| input.into()))
    }
}

#[derive(Debug, PartialEq)]
pub(crate) enum Token {
    Tag(String),
    Str(String),
    Num(f32),
    Comment(String),
    Etc,
}

///
/// Simple function to tokenize a string into an array of Token values
///
pub(crate) fn tokenize(line: &str) -> Vec<Token> {
    let mut l = line;
    let mut tokens = Vec::new();

    // Check for comment
    if let Ok((_, (_start, content))) = tuple((char::<&str, ()>('#'), not_line_ending))(line) {
        tokens.push(Token::Comment(content.strip_prefix(" ").unwrap().into()));
    } else {
        // Check for all other token types in a loop
        while l.len() > 0 {
            if let Ok((rem, (_, s, _))) = tuple((
                char::<&str, ()>('"'),
                take_until("\""),
                char::<&str, ()>('"'),
            ))(l)
            {
                debug!("Parsed string {:?}", s);
                tokens.push(Token::Str(s.into()));
                l = rem;
            } else if let Ok((rem, num)) = float::<&str, ()>(l) {
                debug!("Parsed float {:?}", num);
                tokens.push(Token::Num(num.into()));
                l = rem;
            } else if let Ok((rem, (_, etc, _))) =
                tuple((space0, tag::<&str, &str, ()>("..."), space0))(l)
            {
                debug!("Parsed etc. {:?}", etc);
                tokens.push(Token::Etc);
                l = rem;
            } else if let Ok((rem, (_, tag, _))) =
                tuple((space0, alphanumeric1::<&str, ()>, space0))(l)
            {
                debug!("Parsed tag {:?}", tag);
                tokens.push(Token::Tag(tag.into()));
                l = rem;
            } else {
                debug!("Breaking loop");
                break;
            }
        }
    }

    debug!("Parsed tokens: {:?}", tokens);

    tokens
}

#[test]
fn test_tokenize() {
    let line = "foo \"bar\" 1.23 baz -3.45 \"asdf\" \"multi word string\" etc";
    assert_eq!(
        tokenize(line),
        vec![
            Token::Tag("foo".into()),
            Token::Str("bar".into()),
            Token::Num(1.23),
            Token::Tag("baz".into()),
            Token::Num(-3.45),
            Token::Str("asdf".into()),
            Token::Str("multi word string".into()),
            Token::Tag("etc".into())
        ]
    );
}

///
/// Returns reflected `Transform`
///
pub(crate) fn parse_save_transform(
    tokens: &Vec<Token>,
) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
    // Tag(Transform),
    //      Tag(Translation), Number, Number, Number
    //      Tag(Rotation), Number, Number, Number, Number
    //      Tag(Scale), Number, Number, Number

    // return Err(SaveEntityParseError::Transform);

    todo!("parse_save_transform");
}

#[test]
fn test_parse_transform() {
    let line = "transform translation 1.0 2.0 3.0 rotation 0.1 0.2 0.3 1.0 scale 1.1 1.2 1.3";
    let tokens = tokenize(line);
    let parsed = parse_save_transform(&tokens).unwrap();
    let expected = Transform {
        translation: Vec3::new(1.0, 2.0, 3.0),
        rotation: Quat::from_xyzw(0.1, 0.2, 0.3, 1.0),
        scale: Vec3::new(1.1, 1.2, 1.3),
    };

    assert!(expected
        .clone_value()
        .reflect_partial_eq(parsed.as_reflect())
        .unwrap());
}

///
/// Returns a reflected `Name`
///
pub(crate) fn parse_save_name(
    tokens: &Vec<Token>,
) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
    if let Some((Token::Tag(t), &[Token::Str(ref s)])) = tokens.split_first()
        && *t == String::from("name")
    {
        Ok(Name::new(s.clone()).clone_value())
    } else {
        Err(SaveEntityParseError::Component("Name".into()))
    }
}

#[test]
fn test_parse_name() {
    {
        let line = "name Van";
        let tokens = tokenize(line);
        let parsed = parse_save_name(&tokens).unwrap();
        let expected = Name::new("Van");

        assert!(expected
            .clone_value()
            .reflect_partial_eq(parsed.as_reflect())
            .unwrap());
    }
    {
        let line = "name Big Mike";
        let tokens = tokenize(line);
        let parsed = parse_save_name(&tokens).unwrap();
        let expected = Name::new("Big Mike");

        assert!(expected
            .clone_value()
            .reflect_partial_eq(parsed.as_reflect())
            .unwrap());
    }
}

#[derive(Debug, Default, Reflect, PartialEq)]
#[reflect(Component, PartialEq)]
pub(crate) struct SaveModel {
    gltf_file: PathBuf,
    scene_name: String,
}

impl Component for SaveModel {
    const STORAGE_TYPE: StorageType = StorageType::Table;

    fn register_component_hooks(hooks: &mut ComponentHooks) {
        todo!("Assign Scene Handle for SaveModel")
    }
}

///
/// Returns a reflected `SaveModel`
///
pub(crate) fn parse_save_model(
    tokens: &Vec<Token>,
) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
    todo!("parse_save_model");

    /*
    Ok(SaveModel {
        gltf_file: gltf_path.into(),
        scene_name: scene_name.into(),
    }
    .clone_value())
    */
}

#[test]
fn test_parse_model() {
    let line = "model \"models/foo.glb\" \"My Scene\"";
    let tokens = tokenize(line);
    let parsed = parse_save_model(&tokens).unwrap();
    let expected = SaveModel {
        gltf_file: "models/foo.glb".into(),
        scene_name: "My Scene".into(),
    };

    assert!(expected
        .clone_value()
        .reflect_partial_eq(parsed.as_reflect())
        .unwrap());
}

#[derive(Debug, Default, PartialEq, Reflect, Clone)]
#[reflect_value(Component, Default, PartialEq)]
pub(crate) enum SaveCameraRenderTarget {
    #[default]
    Default,
    Window(PathBuf),
}

impl Component for SaveCameraRenderTarget {
    const STORAGE_TYPE: StorageType = StorageType::Table;

    fn register_component_hooks(hooks: &mut ComponentHooks) {
        todo!("Assign Render Target")
    }
}

///
/// Returns a reflected `SaveCameraRenderTarget
///
pub(crate) fn parse_save_camera(
    tokens: &Vec<Token>,
) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
    todo!("parse_save_camera");

    // Nothing parsed well
    // Err(SaveEntityParseError::Camera)
}

#[test]
fn test_parse_camera() {
    {
        let line = "camera";
        let tokens = tokenize(line);
        let parsed = parse_save_camera(&tokens).unwrap();
        let expected = SaveCameraRenderTarget::Default;
        assert!(expected
            .clone_value()
            .reflect_partial_eq(parsed.as_reflect())
            .unwrap());
    }
    {
        let line = "camera target window";
        let tokens = tokenize(line);
        let parsed = parse_save_camera(&tokens).unwrap();
        let expected = SaveCameraRenderTarget::Default;
        assert!(expected
            .clone_value()
            .reflect_partial_eq(parsed.as_reflect())
            .unwrap());
    }
    {
        let line = "camera target";
        let tokens = tokenize(line);
        let parsed = parse_save_camera(&tokens);
        assert!(parsed.is_err());
    }
    {
        let line = "camera target window \"some.entity\"";
        let tokens = tokenize(line);
        let parsed = parse_save_camera(&tokens).unwrap();
        let expected = SaveCameraRenderTarget::Window("some.entity".into());
        assert!(expected
            .clone_value()
            .reflect_partial_eq(parsed.as_reflect())
            .unwrap());
    }
    {
        let line = "notcamera";
        let tokens = tokenize(line);
        let parsed = parse_save_camera(&tokens);
        assert!(parsed.is_err());
    }
}

/// SaveParent entity which is a reference to which entity this is a child of
/// A run-time system converts this to a bevy Parent component
#[derive(PartialEq, Debug, Reflect, Clone)]
#[reflect_value(Component, PartialEq)]
pub(crate) struct SaveParent(String);

impl Component for SaveParent {
    const STORAGE_TYPE: StorageType = StorageType::Table;

    fn register_component_hooks(hooks: &mut ComponentHooks) {
        todo!("Assign parent for entity")
    }
}

///
/// Parses a parent entity with this format:
/// ```text
/// parent some_other_file.entity
/// ```
///
/// Returns a reflected `SaveParent`
///
pub(crate) fn parse_save_parent(
    tokens: &Vec<Token>,
) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
    todo!("parse_save_parent");

    // Ok(SaveParent(parent_file.into()).clone_value())
}

#[test]
fn test_parse_parent() {
    let line = "parent \"some_other_file.entity\"";
    let tokens = tokenize(line);
    let parsed = parse_save_parent(&tokens).unwrap();
    let expected = SaveParent("some_other_file.entity".into());
    assert!(expected
        .clone_value()
        .reflect_partial_eq(parsed.as_reflect())
        .unwrap());
}

///
/// Parse the Window component (which is very big!)
/// We only sparsely define the bits that we want to edit (for now)
///
/// Returns a reflected `Window`
///
pub(crate) fn parse_save_window(
    tokens: &Vec<Token>,
) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
    todo!("parse_save_window");

    /*
    Ok(Window {
        title: window_title.into(),
        visible: visibility,
        ..default()
    }
    .clone_value())
    */
}

#[test]
fn test_parse_window() {
    let line = "window \"Editor\" visible false";
    let tokens = tokenize(line);
    let parsed = parse_save_window(&tokens).unwrap();
    let expected = Window {
        visible: false,
        title: "Editor".into(),
        ..default()
    };
    assert!(expected
        .clone_value()
        .reflect_partial_eq(parsed.as_reflect())
        .unwrap());
}

///
/// The UI Text bundle specified as a sparse subset of a bundle
/// ```text
/// uiText "This is the text" color #abc123 size 12.34
/// ```
///
/// Returns a reflected `Text`
///
pub(crate) fn parse_save_ui_text(
    tokens: &Vec<Token>,
) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
    todo!("parse_save_ui_text");

    /*
    let style = TextStyle {
        color: Color::Srgba(Srgba::hex(hex_color).unwrap()),
        font_size,
        ..default()
    };
    Ok(Text::from_section(text, style).clone_value())
    */
}

#[test]
fn test_save_ui_text() {
    let line = "uiText \"This is the text\" color #caffee size 14.6";
    let tokens = tokenize(line);
    let parsed = parse_save_ui_text(&tokens).unwrap();
    let expected = Text::from_section(
        "This is the text",
        TextStyle {
            color: Srgba::hex("#caffee").unwrap().into(),
            font_size: 14.6,
            ..default()
        },
    );
    assert!(expected
        .clone_value()
        .reflect_partial_eq(parsed.as_reflect())
        .unwrap());
}

///
/// Returns a parser function for a basic stand-alone tag
/// e.g., "editor_tag" or "ui_node"
///
pub(crate) fn parse_save_tag<T: Component + Reflect + Default>(
    t: &str,
) -> impl FnOnce(&Vec<Token>) -> Result<Box<dyn Reflect>, SaveEntityParseError> + '_ {
    move |tokens: &Vec<Token>| -> Result<Box<dyn Reflect>, SaveEntityParseError> {
        todo!("parse_save_tag")
    }
}

#[derive(Component, Reflect, PartialEq, Debug, Default)]
#[reflect(Component)]
struct TestingTag;

#[test]
fn test_save_tag() {
    let line = "testing";
    let tokens = tokenize(line);
    let parsed = parse_save_tag::<TestingTag>("testing")(&tokens).unwrap();
    let expected = TestingTag;
    assert!(expected
        .clone_value()
        .reflect_partial_eq(parsed.as_reflect())
        .unwrap());
}

#[derive(Clone, Debug, Reflect, PartialEq)]
#[reflect(Component)]
pub(crate) struct SaveTargetCamera(String);

impl Component for SaveTargetCamera {
    const STORAGE_TYPE: StorageType = StorageType::Table;

    fn register_component_hooks(hooks: &mut ComponentHooks) {
        todo!("Assign target camera")
    }
}

/// Parses the a SaveTargetCamera which at runtime is converted to a TargetCamera
/// ```text
/// targetCamera "./level-camera.entity"
/// ```
///
/// Returns reflected `SaveTargetCamera`
pub(crate) fn parse_save_target_camera(
    tokens: &Vec<Token>,
) -> Result<Box<dyn Reflect>, SaveEntityParseError> {
    todo!("parse_save_target_camera")
}

#[test]
fn test_target_camera() {
    let line = "targetCamera \"./level-camera.entity\"";
    let tokens = tokenize(line);
    let parsed = parse_save_target_camera(&tokens).unwrap();
    let expected = SaveTargetCamera("./level-camera.entity".into());

    assert!(expected
        .clone_value()
        .reflect_partial_eq(parsed.as_reflect())
        .unwrap());
}