// SPDX-FileCopyrightText: 2026 Milovann Yanatchkov
// SPDX-License-Identifier: MIT

//! bimr-wasm — browser adapter for the [`bimr-engine`](https://git.rvba.fr/rvba/bimr-engine) eval.
//!
//! **Whole-source only**: the adapter exposes exactly one export —
//! `compile(src)`. There is no session layer, no per-call construction, and
//! no side queries: Python emits `.bimr` text and calls `compile()` once,
//! the same path as the CLI. The `.bimr` intermediate is the compatibility
//! layer; whole-source is the single entry point for the CLI, web Python,
//! and LLM paths.
//!
//! Errors return `{"error": "..."}` JSON strings.

use wasm_bindgen::prelude::*;

fn parse_or_error(src: &str) -> Result<parser::ast::Program, String> {
    parser::parse(src).map_err(|errors| {
        let msg = errors
            .iter()
            .map(|e| format!("{e:?}"))
            .collect::<Vec<_>>()
            .join("; ");
        format!("{{\"error\": \"{}\"}}", msg.replace('"', "'"))
    })
}

/// Compile a `.bimr` source string to IFCX JSON.
///
/// Returns a JSON string — either an IFCX document on success, or
/// `{"error": "..."}` on parse/eval failure.
#[wasm_bindgen]
pub fn compile(src: &str) -> String {
    let program = match parse_or_error(src) {
        Ok(p) => p,
        Err(e) => return e,
    };
    match eval::eval_program(&program, "model.bimr") {
        Ok(store) => eval::to_ifcx(&store),
        Err(e) => format!("{{\"error\": \"{e}\"}}"),
    }
}

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

    const WALL_SRC: &str = "\
p1 = Point(0,0,0)
p2 = Point(500,0,0)
l1 = Line(p1,p2)
w1 = Wall(l1,20,300)";

    #[test]
    fn compile_wall_to_ifcx() {
        let out = compile(WALL_SRC);
        assert!(out.contains("wall-001"), "missing wall-001: {out}");
        assert!(out.contains("ifcx_alpha"));
        assert!(out.contains("faceVertexIndices"));
    }

    #[test]
    fn compile_errors_are_error_json() {
        let out = compile("w1 = Wall(missing)");
        assert!(out.contains("error"), "expected error json: {out}");
    }
}