import { readdir, readFile } from "node:fs/promises";
import { join } from "node:path";
import { type Db, researchTemplates } from "@autoscholar/db";
import { eq } from "drizzle-orm";

const TEMPLATE_META: Record<string, { name: string; mode: string; description: string }> = {
  general: {
    name: "General research brief",
    mode: "empirical",
    description: "Discipline-agnostic starter covering every section a good research instruction needs.",
  },
  empirical: {
    name: "Empirical study",
    mode: "empirical",
    description: "Data-driven analysis with provenance, executed code, identification limits and robustness.",
  },
  theoretical: {
    name: "Theoretical result",
    mode: "theoretical",
    description: "Definitions, propositions, derivations, counterexample search and optional formal proof.",
  },
  computational: {
    name: "Computational / AI study",
    mode: "computational",
    description: "Executable benchmark with baselines, seeds, ablations and resource budgets.",
  },
  review: {
    name: "Literature review",
    mode: "review",
    description: "Systematic or narrative synthesis with search protocol, screening and verified references.",
  },
};

/** Loads research/templates/<slug>/CLAUDE.md into the DB (idempotent; bumps version when content changes). */
export async function syncTemplates(db: Db, templatesDir: string): Promise<string[]> {
  const synced: string[] = [];
  let dirs: string[] = [];
  try {
    dirs = (await readdir(templatesDir, { withFileTypes: true }))
      .filter((d) => d.isDirectory() && TEMPLATE_META[d.name])
      .map((d) => d.name);
  } catch {
    return synced;
  }
  for (const slug of dirs) {
    let content: string;
    try {
      content = await readFile(join(templatesDir, slug, "CLAUDE.md"), "utf8");
    } catch {
      continue;
    }
    const meta = TEMPLATE_META[slug]!;
    const [existing] = await db
      .select()
      .from(researchTemplates)
      .where(eq(researchTemplates.slug, slug))
      .limit(1);
    if (!existing) {
      await db
        .insert(researchTemplates)
        .values({ slug, name: meta.name, mode: meta.mode, description: meta.description, content });
      synced.push(slug);
    } else if (existing.content !== content) {
      await db
        .update(researchTemplates)
        .set({
          content,
          version: existing.version + 1,
          updatedAt: new Date(),
          name: meta.name,
          description: meta.description,
          mode: meta.mode,
        })
        .where(eq(researchTemplates.id, existing.id));
      synced.push(slug);
    }
  }
  return synced;
}

export async function listTemplates(db: Db) {
  return db.select().from(researchTemplates).orderBy(researchTemplates.slug);
}