import { readFile, writeFile } from 'node:fs/promises';
import { createServer } from 'vite';

const server = await createServer({
  server: { middlewareMode: true },
  appType: 'custom',
  optimizeDeps: { noDiscovery: true, include: [] },
});
try {
  const [{ planFlooring }, { planSkirting }, { plannerCases }, metrics] = await Promise.all([
    server.ssrLoadModule('/src/lib/flooring.ts'),
    server.ssrLoadModule('/src/lib/skirting.ts'),
    server.ssrLoadModule('/benchmarks/cases.ts'),
    server.ssrLoadModule('/benchmarks/metrics.ts'),
  ]);
  const cases = plannerCases();
  const random = process.argv.includes('--random');
  if (random) cases.forEach(({ project }) => (project.flooring.optimisation = 'random'));
  const results = [];
  // Warm up the geometry and planners before taking timings.
  planFlooring(cases[0].project.rooms, cases[0].project.flooring, cases[0].project.tolerance);
  for (const { name, project: p } of cases) {
    const start = performance.now();
    const flooring = planFlooring(p.rooms, p.flooring, p.tolerance);
    const floorMs = performance.now() - start;
    const skirtStart = performance.now();
    const skirting = planSkirting(p.rooms, p.skirting, p.tolerance);
    results.push({
      name,
      flooring: metrics.flooringMetrics(flooring, p.flooring),
      skirting: metrics.skirtingMetrics(skirting),
      floorMs: Math.round(floorMs * 10) / 10,
      skirtMs: Math.round((performance.now() - skirtStart) * 10) / 10,
    });
  }
  const baselinePath = new URL('../benchmarks/baseline.json', import.meta.url);
  if (process.argv.includes('--write-baseline')) {
    await writeFile(baselinePath, JSON.stringify(results, null, 2) + '\n');
    console.log(`Recorded ${results.length} baseline cases.`);
  } else {
    const comparison = process.argv
      .find((arg) => arg.startsWith('--compare='))
      ?.slice('--compare='.length);
    const baseline = JSON.parse(await readFile(comparison ?? baselinePath, 'utf8'));
    const sum = (rows, key, metric) => rows.reduce((total, row) => total + row[key][metric], 0);
    const summary = [];
    for (const kind of ['flooring', 'skirting']) {
      const compare =
        kind === 'flooring'
          ? (a, b) => metrics.compareFlooring(a, b, random)
          : metrics.compareSkirting;
      const changes = results.map((result) => {
        const previous = baseline.find((row) => row.name === result.name);
        if (!previous) throw new Error(`No baseline for ${result.name}`);
        return { name: result.name, change: compare(result[kind], previous[kind]) };
      });
      summary.push({
        planner: kind,
        improved: changes.filter((row) => row.change < 0).length,
        tied: changes.filter((row) => row.change === 0).length,
        regressed: changes.filter((row) => row.change > 0).length,
        'cuts before': sum(baseline, kind, 'cuts'),
        'cuts after': sum(results, kind, 'cuts'),
        'boards before': sum(baseline, kind, 'boards'),
        'boards after': sum(results, kind, 'boards'),
        errors: sum(results, kind, 'errors'),
      });
      const regressions = changes.filter((row) => row.change > 0).map((row) => row.name);
      if (regressions.length) console.log(`${kind} regressions: ${regressions.join(', ')}`);
    }
    console.table(summary);
    for (const kind of ['flooring', 'skirting']) {
      const wastePercent = (rows) => {
        const purchased = rows.reduce((total, row) => {
          const { project } = cases.find((c) => c.name === row.name);
          const size =
            kind === 'flooring'
              ? project.flooring.length * project.flooring.width
              : project.skirting.stockLength;
          return total + row[kind].boards * size;
        }, 0);
        return ((sum(rows, kind, 'waste') / purchased) * 100).toFixed(2);
      };
      console.log(
        `${kind} waste: ${wastePercent(baseline)}% → ${wastePercent(results)}% (weighted by purchased stock)`,
      );
    }
    console.table(
      ['shapingCuts', 'ripCuts', 'patternPenalty', 'repeats', 'similarSteps', 'staircases'].map(
        (metric) => ({
          metric,
          before: sum(baseline, 'flooring', metric),
          after: sum(results, 'flooring', metric),
        }),
      ),
    );
  }
  for (const key of ['floorMs', 'skirtMs']) {
    const times = results.map((row) => row[key]).sort((a, b) => a - b);
    console.log(
      `${key}: total ${times.reduce((a, b) => a + b, 0).toFixed(1)} ms; p95 ${times[Math.floor(times.length * 0.95)]} ms; max ${times.at(-1)} ms`,
    );
  }
  const output = process.argv.find((arg) => arg.startsWith('--output='))?.slice('--output='.length);
  if (output) await writeFile(output, JSON.stringify(results, null, 2) + '\n');
} finally {
  await server.close();
}