/**
 * result-packager — assemble result.zip for benchmark deliverables
 * (Task #176, Wave A).
 *
 * Produces a zip with:
 *   - result.csv     wide table (task_id, ligand_id, score) for
 *                    DUD-E / LIT-PCBA virtual-screening benchmarks.
 *   - result.log     human-readable log referencing the Blueprint id +
 *                    per-task EF1% (or proxy) numbers.
 *   - manifest.json  machine summary (network name, variant id,
 *                    blueprint id, totals, evaluator hint).
 */
import { createWriteStream } from "node:fs";
import { mkdir, writeFile } from "node:fs/promises";
import path from "node:path";
import archiver from "archiver";

export interface ResultRow {
  taskId: string;
  ligandId: string;
  score: number;
}

export interface TaskSummary {
  taskId: string;
  numLigands: number;
  topScore: number;
  evaluatorMetric?: number | null;
  notes?: string;
}

export interface PackageResultInput {
  outDir: string;
  /** Filename of the produced zip (without directory). */
  zipName: string;
  blueprintId: string;
  networkName: string;
  variantId: string;
  rows: ResultRow[];
  taskSummaries: TaskSummary[];
  /** Aggregate proxy / true EF1% across all tasks if available. */
  aggregateMetric?: number | null;
  /** Free-form notes appended to result.log. */
  extraLogLines?: string[];
}

function csvEscape(v: string | number): string {
  const s = String(v);
  if (/[",\n]/.test(s)) return `"${s.replace(/"/g, '""')}"`;
  return s;
}

export async function packageResult(
  input: PackageResultInput,
): Promise<{ zipPath: string; csvBytes: number; logBytes: number }> {
  await mkdir(input.outDir, { recursive: true });
  const stage = path.join(input.outDir, `_stage_${input.blueprintId}`);
  await mkdir(stage, { recursive: true });

  // result.csv
  const csvLines: string[] = ["task_id,ligand_id,score"];
  for (const r of input.rows) {
    csvLines.push(
      [csvEscape(r.taskId), csvEscape(r.ligandId), r.score.toFixed(6)].join(","),
    );
  }
  const csvBody = csvLines.join("\n") + "\n";
  await writeFile(path.join(stage, "result.csv"), csvBody, "utf8");

  // result.log
  const logLines: string[] = [];
  logLines.push(`# DoAtlas benchmark result`);
  logLines.push(`blueprint_id: ${input.blueprintId}`);
  logLines.push(`network: ${input.networkName}`);
  logLines.push(`variant_id: ${input.variantId}`);
  logLines.push(`generated_at: ${new Date().toISOString()}`);
  logLines.push(`total_tasks: ${input.taskSummaries.length}`);
  logLines.push(`total_rows: ${input.rows.length}`);
  if (input.aggregateMetric != null) {
    logLines.push(`aggregate_metric: ${input.aggregateMetric.toFixed(6)}`);
  }
  logLines.push(``);
  logLines.push(`## per-task summary`);
  for (const s of input.taskSummaries) {
    logLines.push(
      `- ${s.taskId} ligands=${s.numLigands} top=${s.topScore.toFixed(6)}` +
        (s.evaluatorMetric != null
          ? ` metric=${s.evaluatorMetric.toFixed(6)}`
          : "") +
        (s.notes ? ` notes=${s.notes}` : ""),
    );
  }
  if (input.extraLogLines && input.extraLogLines.length > 0) {
    logLines.push(``);
    logLines.push(`## notes`);
    for (const ln of input.extraLogLines) logLines.push(ln);
  }
  const logBody = logLines.join("\n") + "\n";
  await writeFile(path.join(stage, "result.log"), logBody, "utf8");

  // manifest.json
  const manifest = {
    blueprintId: input.blueprintId,
    networkName: input.networkName,
    variantId: input.variantId,
    generatedAt: new Date().toISOString(),
    totals: {
      tasks: input.taskSummaries.length,
      rows: input.rows.length,
    },
    aggregateMetric: input.aggregateMetric ?? null,
    perTask: input.taskSummaries,
  };
  await writeFile(
    path.join(stage, "manifest.json"),
    JSON.stringify(manifest, null, 2),
    "utf8",
  );

  // zip
  const zipPath = path.join(input.outDir, input.zipName);
  await new Promise<void>((resolve, reject) => {
    const out = createWriteStream(zipPath);
    const arch = archiver("zip", { zlib: { level: 9 } });
    out.on("close", () => resolve());
    out.on("error", reject);
    arch.on("error", reject);
    arch.pipe(out);
    arch.file(path.join(stage, "result.csv"), { name: "result.csv" });
    arch.file(path.join(stage, "result.log"), { name: "result.log" });
    arch.file(path.join(stage, "manifest.json"), { name: "manifest.json" });
    void arch.finalize();
  });

  return {
    zipPath,
    csvBytes: Buffer.byteLength(csvBody, "utf8"),
    logBytes: Buffer.byteLength(logBody, "utf8"),
  };
}