// Phase 2 dart-sass recompile (ARCHITECTURE.md 7.5). Lazy and defensive: the
// `sass` dependency and the vendored Bootstrap SCSS under ../scss are Phase-2
// only, so a missing dep or compile error degrades to the Phase-1 overlay
// rather than white-screening. Only ever reached for engine:"sass" themes.

const path = require("path");
const { sanitizeValue } = require("./sanitize");        // shared guard (folded fix)


function compileSass(tokens, opts = {}) {
    const warnings = [];
    try {
        const sass = require("sass");                       // lazy; Phase-2 dep
        const flat = require("./compile").flattenTokens(tokens);
        const varBlock = Object.entries(flat)
            .filter(([k]) => /^[-a-zA-Z0-9_]{1,64}$/.test(k))
            .map(([k, v]) => {
                const sv = sanitizeValue(v, warnings);
                return sv == null ? "" : `$${k}: ${sv};`;
            })
            .filter(Boolean)
            .join("\n");
        const scssDir = path.join(__dirname, "..", "scss");
        // relative module id resolved via loadPaths; no absolute @import string.
        const entry = `@use "bootstrap/bootstrap" with (\n${varBlock}\n);\n`;
        const result = sass.compileString(entry, {
            loadPaths: [scssDir],
            style: "compressed",
            logger: { warn: (m) => warnings.push(m), debug: () => {} },
        });
        return { css: result.css, warnings };
    } catch (e) {
        warnings.push("sass compile unavailable/failed: " + e.message);
        // fall back to the overlay; never white-screen.
        const overlay = require("./compile").emitOverlayCss(tokens);
        return { css: overlay.css, warnings: warnings.concat(overlay.warnings || []) };
    }
}


module.exports = { compileSass };