lini 0.5.0

mod ast;
mod desugar;
mod error;
mod fmt;
mod layout;
mod lexer;
mod lint;
mod render;
mod resolve;
mod serve;
mod span;
mod syntax;
mod theme;

pub use error::{Diagnostic, Error, Level};
pub use fmt::format as format_source;

/// Lower a source file's sugar to primitives + `.lini-*` classes and print canonical
/// `.lini` — what `lini desugar` shows: every typed instance becomes a `|primitive|`
/// wearing its `.lini-*` chain, defines and templates collapse into generated
/// `.lini-*` class defs, scene/wire defaults fill the global block, and labels /
/// `along:` become explicit. Comments are dropped. The lowered form re-renders
/// identically and is a fixed point of desugar.
pub fn desugar_source(src: &str) -> Result<String, Error> {
    let tokens = lexer::lex(src)?;
    let file = syntax::parser::parse(&tokens)?;
    Ok(fmt::print_file(&desugar::desugar(&file)?))
}
pub use layout::{Rule, Severity, Violation};
pub use serve::{ServeTarget, serve};
pub use theme::extract_lini_vars;

/// Top-level compile options threaded through every phase. Build with
/// `Options::default()` and override fields with the struct-update syntax —
/// future versions may add knobs.
#[derive(Clone, Debug, Default)]
pub struct Options {
    /// Emit `var()` values inline as their resolved literal so renderers
    /// without CSS-variable support (resvg, librsvg, image converters) still
    /// display the diagram correctly. The structural class rules stay; only the
    /// `@layer` variable defaults are dropped (their values are inlined).
    pub bake_vars: bool,
    /// Output wrapper format.
    pub format: OutputFormat,
    /// Raw CSS text whose `--lini-*` declarations override built-in defaults
    /// before the `defaults {}` block. `extract_lini_vars` does the parse.
    pub theme_css: Option<String>,
}

#[derive(Default, Clone, Copy, Debug, PartialEq, Eq)]
pub enum OutputFormat {
    #[default]
    Svg,
    Html,
}

pub fn compile_str(src: &str) -> Result<String, Error> {
    compile_str_with(src, &Options::default())
}

pub fn compile_str_with(src: &str, opts: &Options) -> Result<String, Error> {
    let program = resolve_pipeline(src, opts)?;
    let laid_out = layout::layout(&program)?;
    Ok(finish_svg(&laid_out, opts))
}

/// Compile to SVG **and** collect the routing diagnostics in a single layout
/// pass. The CLI's default path needs both (the SVG to emit, the diagnostics
/// to warn); routing through here runs the wire router once instead of twice.
pub fn compile_str_checked(src: &str, opts: &Options) -> Result<(String, Vec<Diagnostic>), Error> {
    let program = resolve_pipeline(src, opts)?;
    let laid_out = layout::layout(&program)?;
    let diags = routing_diagnostics_of(layout::validate_routing(&laid_out));
    Ok((finish_svg(&laid_out, opts), diags))
}

fn finish_svg(laid_out: &layout::LaidOut, opts: &Options) -> String {
    let svg = render::render(laid_out, opts);
    match opts.format {
        OutputFormat::Svg => svg,
        OutputFormat::Html => wrap_html(&svg),
    }
}

/// Lex and parse only — verifies syntactic correctness without running
/// resolve/layout/render.
pub fn check_parse(src: &str) -> Result<(), Error> {
    let tokens = lexer::lex(src)?;
    let _file = syntax::parser::parse(&tokens)?;
    Ok(())
}

/// Lex, parse, and run the lint pass. Returns warnings (no errors).
/// Parse errors are surfaced as `Err`; missing lints just return an empty Vec.
pub fn lint_str(src: &str) -> Result<Vec<Diagnostic>, Error> {
    let tokens = lexer::lex(src)?;
    let file = syntax::parser::parse(&tokens)?;
    Ok(lint::lint(&file))
}

/// Lex, parse, and resolve. Verifies semantic correctness without running
/// layout or render. The CLI's `--check` flag goes through here.
pub fn check(src: &str) -> Result<(), Error> {
    check_with(src, &Options::default())
}

pub fn check_with(src: &str, opts: &Options) -> Result<(), Error> {
    let _ = resolve_pipeline(src, opts)?;
    Ok(())
}

/// Lex, parse, resolve, lay out, route, then validate the routing against the
/// contract in WIRING.md. Returns the violations found (empty = clean). Parse
/// and resolve errors surface as `Err`.
pub fn validate_str(src: &str) -> Result<Vec<Violation>, Error> {
    let program = resolve_pipeline(src, &Options::default())?;
    let laid_out = layout::layout(&program)?;
    Ok(layout::validate_routing(&laid_out))
}

/// Surface routing violations as user-facing diagnostics. Crossings are normal,
/// counted output (`Info`) and stay silent here; everything else — an impossible
/// wire, or a law breach (which would mean an engine bug) — is flagged, never
/// silent. The CLI prints these as warnings; `--strict` makes them fail the build.
fn routing_diagnostics_of(violations: Vec<Violation>) -> Vec<Diagnostic> {
    violations
        .into_iter()
        .filter(|v| v.severity != Severity::Info)
        .map(|v| {
            Diagnostic::warn(
                v.span,
                format!("{} ({}): {}", v.rule.id(), v.wires.join(", "), v.detail),
            )
        })
        .collect()
}

fn resolve_pipeline(src: &str, opts: &Options) -> Result<resolve::Program, Error> {
    let tokens = lexer::lex(src)?;
    let file = syntax::parser::parse(&tokens)?;
    let lowered = desugar::desugar(&file)?;
    let theme = match &opts.theme_css {
        Some(css) => theme::extract_lini_vars(css),
        None => Vec::new(),
    };
    resolve::resolve_with_theme(&lowered, &theme)
}

fn wrap_html(svg: &str) -> String {
    format!(
        "<!doctype html>\n<html>\n<head>\n  <meta charset=\"utf-8\">\n  <title>lini</title>\n</head>\n<body>\n{}</body>\n</html>\n",
        svg
    )
}

/// Test-only hooks for the wire-routing parameter sweep (see `tests/wiring_sweep.rs`).
/// Not part of the public API.
#[doc(hidden)]
pub mod testing {
    use crate::Options;
    use crate::layout;
    use crate::resolve::ResolvedValue;

    pub use crate::layout::LaidOut;

    /// A node's absolute rect by full dot-path, for geometric assertions.
    pub fn node_rect(laid: &LaidOut, path: &str) -> Option<(f64, f64, f64, f64)> {
        layout::node_rect(&laid.nodes, path)
    }

    /// Compile `src` to a laid-out scene with `clearance` forced on every wire,
    /// overriding whatever the source set. Gap growth runs as in production —
    /// starved corridors may widen the layout.
    pub fn route_sample(src: &str, clearance: f64) -> LaidOut {
        layout::layout(&forced(src, clearance)).expect("layout")
    }

    /// [`route_sample`] with gap growth disabled: the raw router's result, the
    /// one the clearance sweep measures. `clearance` does not move nodes here,
    /// so the node geometry — and hence which wires are routable — is
    /// identical across values.
    pub fn route_sample_raw(src: &str, clearance: f64) -> LaidOut {
        layout::layout_raw(&forced(src, clearance)).expect("layout")
    }

    fn forced(src: &str, clearance: f64) -> crate::resolve::Program {
        let mut prog = super::resolve_pipeline(src, &Options::default()).expect("resolve");
        for w in &mut prog.wires {
            w.attrs
                .insert("clearance", ResolvedValue::Number(clearance));
        }
        prog
    }

    /// The number of routable edges the source declares (fans/chains already expanded
    /// at resolve into one `ResolvedWire` per edge-chain).
    pub fn declared_edges(src: &str) -> usize {
        let prog = super::resolve_pipeline(src, &Options::default()).expect("resolve");
        prog.wires
            .iter()
            .map(|w| w.endpoints.len().saturating_sub(1))
            .sum()
    }

    /// Judge a laid-out scene against the four laws (the independent validator).
    pub fn laws(laid: &LaidOut) -> Vec<crate::Violation> {
        layout::validate_routing(laid)
    }
}