import path from "node:path";
import { SourceMapConsumer } from "source-map";
const getBytesPerFileUsingSourceMap = (bundleId, code, map, dir) => {
    const modules = {};
    const modulesBySource = new Map();
    const bundleDir = path.dirname(path.join(dir, bundleId));
    let line = 1;
    let lineStart = 0;
    let lineEnd = 0;
    let previous;
    const countSpan = (next) => {
        if (previous?.source == null)
            return;
        // Columns and string offsets both use UTF-16; only the size uses UTF-8.
        const start = Math.min(lineStart + previous.generatedColumn, lineEnd);
        const end = next?.generatedLine === previous.generatedLine
            ? Math.min(lineStart + next.generatedColumn, lineEnd)
            : lineEnd;
        if (end <= start)
            return;
        let module = modulesBySource.get(previous.source);
        if (module == null) {
            const id = path.resolve(bundleDir, previous.source);
            module = modules[id] ??= { id, renderedLength: 0 };
            modulesBySource.set(previous.source, module);
        }
        module.renderedLength += Buffer.byteLength(code.slice(start, end));
    };
    // Rollup and Rolldown emit flat maps. Stream their generated mappings without
    // materializing characters or retaining the generated code for each module.
    map.eachMapping((mapping) => {
        // Original positions within the same source do not affect module sizes.
        if (previous?.generatedLine === mapping.generatedLine && previous.source === mapping.source) {
            return;
        }
        countSpan(mapping);
        while (line < mapping.generatedLine && lineStart < code.length) {
            const newline = code.indexOf("\n", lineStart);
            lineStart = newline === -1 ? code.length : newline + 1;
            line++;
        }
        if (previous?.generatedLine !== mapping.generatedLine) {
            const newline = code.indexOf("\n", lineStart);
            // Preserve the existing policy: include a mapped line's terminating LF,
            // but do not extend its final mapping into an unmapped following line.
            lineEnd = newline === -1 ? code.length : newline + 1;
        }
        previous = mapping;
    }, null, SourceMapConsumer.GENERATED_ORDER);
    countSpan();
    return modules;
};
export const getSourcemapModules = (id, outputChunk, dir) => {
    if (outputChunk.map == null) {
        return Promise.resolve({});
    }
    return SourceMapConsumer.with(outputChunk.map, null, (map) => {
        return getBytesPerFileUsingSourceMap(id, outputChunk.code, map, dir);
    });
};