/**
 * Migration — 2026-07-25-add-ai-insights-fields.ts
 *
 * Adds the four JSON fields the n8n AI agent writes to when it generates
 * insights for a quote/order or for an individual line item.
 *
 * ## Why JSON, not a typed schema
 *
 * The AI produces whatever it can find — the shape is fluid per record
 * (sometimes we have historical pricing, sometimes not; sometimes the
 * model surfaces a duplicate warning, sometimes a margin one). Locking
 * the schema down fights the model. We keep the field as a single
 * `json` blob and let the UI be a smart renderer (see
 * `src/components/ai-insights-renderer.tsx`) that handles whatever
 * keys come back.
 *
 * The only contract between n8n and the UI is: a top-level `summary`
 * string. Everything else is opportunistic.
 *
 * ## The four fields
 *
 *  - quotes.ai_insights         (json) — document-level card
 *  - orders.ai_insights         (json) — document-level card
 *  - quote_items.ai_item_insights (json) — line-item popover
 *  - order_items.ai_item_insights (json) — line-item popover
 *
 * Snapshot-once: n8n writes the field when the parent record is
 * created. The UI never overwrites it; the "Regenerate" button on the
 * card triggers a re-run of the n8n flow which then PATCHes the same
 * field.
 *
 * Idempotent — safe to re-run. Skips fields that already exist.
 *
 * Run with:
 *   npx tsx scripts/migrations/2026-07-25-add-ai-insights-fields.ts
 */
import PocketBase from "pocketbase";
import { readFileSync } from "node:fs";
import { resolve } from "node:path";

function loadEnvFile(name: string) {
  try {
    const raw = readFileSync(resolve(process.cwd(), name), "utf8");
    for (const line of raw.split("\n")) {
      const trimmed = line.trim();
      if (!trimmed || trimmed.startsWith("#")) continue;
      const m = trimmed.match(/^([A-Z0-9_]+)\s*=\s*(.+)$/i);
      if (m && !process.env[m[1]]) {
        process.env[m[1]] = m[2].replace(/^["']|["']$/g, "").trim();
      }
    }
  } catch {
    /* fine — rely on shell env */
  }
}
loadEnvFile(".env");
loadEnvFile(".env.local");

function getAdminPocketBase(): PocketBase {
  const url = process.env.NEXT_PUBLIC_POCKETBASE_URL;
  const email = process.env.PB_ADMIN_EMAIL;
  const password = process.env.PB_ADMIN_PASSWORD;
  if (!url || !email || !password) {
    throw new Error(
      "Set NEXT_PUBLIC_POCKETBASE_URL, PB_ADMIN_EMAIL, PB_ADMIN_PASSWORD (sourced from .env.local).",
    );
  }
  return new PocketBase(url);
}

async function authedPb(): Promise<PocketBase> {
  const pb = getAdminPocketBase();
  await pb
    .collection("_superusers")
    .authWithPassword(
      process.env.PB_ADMIN_EMAIL!,
      process.env.PB_ADMIN_PASSWORD!,
    );
  return pb;
}

type AnyField = {
  name: string;
  type?: string;
  required?: boolean;
  maxSize?: number;
  [k: string]: unknown;
};

/**
 * PB's `json` field shape: name + type + optional maxSize (in bytes).
 * No `options` wrapper — same flat shape as `select` / `file` fields,
 * see memory gotcha "PB select fields… create-collection API uses
 * `fields`, not `schema`".
 */
function jsonField(name: string): AnyField {
  return {
    name,
    type: "json",
    required: false,
    // 64KB ceiling — way more than the AI will write, but small enough
    // to keep PB's per-field validation snappy. Bump if the model ever
    // produces a legitimate >64KB insight blob.
    maxSize: 65_536,
    presentable: false,
  };
}

const TARGETS: Array<{ collection: string; field: AnyField }> = [
  { collection: "quotes", field: jsonField("ai_insights") },
  { collection: "orders", field: jsonField("ai_insights") },
  { collection: "quote_items", field: jsonField("ai_item_insights") },
  { collection: "order_items", field: jsonField("ai_item_insights") },
];

export async function run(): Promise<void> {
  const pb = await authedPb();

  // Build a per-collection name → collectionId map once, so we can
  // resolve by name even though the SDK wants the id.
  const collections = await pb.collections.getFullList();
  const byName = new Map(collections.map((c) => [c.name, c]));

  for (const { collection, field } of TARGETS) {
    const col = byName.get(collection);
    if (!col) {
      console.warn(
        `[migration:ai-insights] skip — collection "${collection}" not found`,
      );
      continue;
    }

    const existing = ((col.fields ?? []) as AnyField[]).map((f) => f.name);
    if (existing.includes(field.name)) {
      console.log(
        `[migration:ai-insights] ${collection}.${field.name} already exists — skip`,
      );
      continue;
    }

    const next = [...((col.fields ?? []) as AnyField[]), field];
    await pb.collections.update(col.id, { fields: next });
    console.log(
      `[migration:ai-insights] ✓ added ${collection}.${field.name} (json, 64KB)`,
    );
  }

  // Verify
  console.log("\n[migration:ai-insights] Verifying...");
  const fresh = await pb.collections.getFullList();
  const freshByName = new Map(fresh.map((c) => [c.name, c]));
  const checks: Array<[string, boolean]> = [];
  for (const { collection, field } of TARGETS) {
    const c = freshByName.get(collection);
    const f = ((c?.fields ?? []) as AnyField[]).find((x) => x.name === field.name);
    checks.push([
      `${collection}.${field.name} is json`,
      f?.type === "json",
    ]);
  }
  let allOk = true;
  for (const [label, ok] of checks) {
    console.log(`  ${ok ? "✓" : "✗"} ${label}`);
    if (!ok) allOk = false;
  }
  if (!allOk) {
    throw new Error("[migration:ai-insights] verification failed");
  }
  console.log("[migration:ai-insights] Migration complete.");
}

if (require.main === module) {
  run().catch((err) => {
    console.error("[migration:ai-insights] fatal:", err);
    process.exit(1);
  });
}