// lib/pdf-render.ts
// SERVER-ONLY — bridges the Workflow app to the patched minimax-pdf skill.
//
// Why: minimax-pdf produces print-quality branded PDFs (Playfair Display, navy
// accent rules, alternating row tints). The skill lives in the ysterbaard
// profile at ~/.hermes/profiles/ysterbaard/skills/minimax-pdf — installed with
// auto h2 keepWithNext (no orphan headings) + an explicit `keep_together`
// block type.
//
// Fallback order:
//   1. Profile skill path (preferred, has David's edits).
//   2. Default skill path (~/.hermes/skills/minimax-pdf, symlinked in this env).
//   3. Throw with a clear "skill not installed" error.

import "server-only";
import { spawn } from "child_process";
import { promises as fs } from "fs";
import os from "os";
import path from "path";

const HOME = os.homedir();
const SKILL_PATHS = [
  path.join(HOME, ".hermes/profiles/ysterbaard/skills/minimax-pdf"),
  path.join(HOME, ".hermes/skills/minimax-pdf"),
];

export interface RenderPdfOptions {
  /** Title shown on the cover page. */
  title: string;
  /** Subtitle / company-or-director name shown on the cover. */
  author: string;
  /** Date string for the cover (e.g. "30 August 2026"). */
  date: string;
  /** Hex color, e.g. "#1C3A5E". Deep navy = legal/compliance. */
  accent: string;
  /** Document type — see skill (report/proposal/etc). "report" is the default. */
  type?: "report" | "proposal" | "general" | "minimal";
  /** minimax-pdf content.json: a flat array of blocks. */
  blocks: unknown[];
  /** Absolute path for the rendered PDF. */
  outPath: string;
}

function pickSkill(): string {
  for (const p of SKILL_PATHS) {
    try {
      // eslint-disable-next-line @typescript-eslint/no-require-imports
      require("fs").accessSync(path.join(p, "scripts/make.sh"));
      return p;
    } catch { /* try next */ }
  }
  throw new Error(
    `minimax-pdf skill not installed at any of: ${SKILL_PATHS.join(", ")}. ` +
    "Copy the skill into the ysterbaard profile and re-deploy."
  );
}

function run(cmd: string, args: string[], cwd: string): Promise<{ ok: boolean; stderr: string }> {
  return new Promise((resolve) => {
    const child = spawn(cmd, args, { cwd });
    let stderr = "";
    child.stderr.on("data", (b) => (stderr += b.toString()));
    child.on("error", (err) => resolve({ ok: false, stderr: err.message }));
    child.on("close", (code) => resolve({ ok: code === 0, stderr }));
  });
}

export async function renderPdf(opts: RenderPdfOptions): Promise<Buffer> {
  const skillRoot = pickSkill();
  const makeSh = path.join(skillRoot, "scripts/make.sh");

  // Write content.json to a temp file in the skill's working dir
  // (make.sh reads it relative to cwd).
  const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "wf-report-"));
  const contentPath = path.join(tmpDir, "content.json");
  await fs.writeFile(contentPath, JSON.stringify(opts.blocks, null, 2));

  try {
    const result = await run("bash", [
      makeSh, "run",
      "--title", opts.title,
      "--type", opts.type || "report",
      "--author", opts.author,
      "--date", opts.date,
      "--accent", opts.accent,
      "--content", contentPath,
      "--out", opts.outPath,
    ], tmpDir);

    if (!result.ok) {
      throw new Error(`minimax-pdf render failed: ${result.stderr.slice(0, 800)}`);
    }

    return await fs.readFile(opts.outPath);
  } finally {
    await fs.unlink(contentPath).catch(() => {});
    await fs.rmdir(tmpDir).catch(() => {});
  }
}