/**
 * Seed `chat_session_models` for conversations that existed before the table did.
 *
 * Runs from `postdb:push`, so every machine gets it on the next schema push rather than needing a manual
 * step per server. Bun fires `pre`/`post` hooks for colon-named scripts — verified on 1.3.14 against
 * `db:push`, because a `post` hook that silently never runs is the worst outcome for a migration.
 *
 * ── Why a family guess is good enough here ──
 *
 * A transcript records the API model (`claude-opus-5`), and Officer's picker offers CLI aliases
 * (`claude-code/opus`, `claude-code/opus[1m]`). The mapping is one-way: the 1M variant and `opusplan` are
 * not recoverable after the fact. So this seeds the FAMILY, which is right about which model answered and
 * silent about the variant — and the first real turn afterwards replaces it with the exact alias.
 *
 * Compare the alternative, which is what this exists to prevent: with no row at all, resuming a session
 * falls back to the first entry in the catalogue. That looked correct for as long as the first entry
 * happened to be `opus`, and started showing every old conversation as `fable` the day `fable` was added
 * above it.
 *
 * ── Rules it follows ──
 *
 * INSERT ONLY. `seedMissingChatSessionModels` never overwrites, so a session that has already recorded its
 * exact alias keeps it, and re-running this is a no-op rather than a downgrade.
 *
 * NEVER FAILS THE PUSH. Every failure path exits 0 with a printed reason. A schema push that has already
 * applied must not report failure because a cosmetic backfill could not read a transcript — and `postdb:push`
 * failing would make `bun db:push` look like it had not worked.
 *
 * OWNER ONLY, for now. Members' transcripts are readable (`listTranscriptsAs` goes through `sudo`), but the
 * platform's own user is not guaranteed to have that permission from a bare CLI invocation, and a member's
 * sessions fill in on their next turn anyway. Stated here rather than silently scoped.
 */
import { listTranscriptModels } from '../src/servers/api/chat/claude-sessions';
import { officerModelForApiModel } from '../src/servers/api/chat/model-aliases';
import { chatSessionModelsTableExists, seedMissingChatSessionModels } from 'officerdb';
import { homedir } from 'node:os';

const done = (message: string): never => {
  console.log(`[backfill:session-models] ${message}`);
  process.exit(0);
};

try {
  // The push may have been a no-op, or aimed at a database where this table is commented out of
  // `src/schema.ts`. Checking beats assuming — and beats a confusing "relation does not exist".
  if (!(await chatSessionModelsTableExists())) done('chat_session_models is not there yet — nothing to do');

  const owner = { email: '', home: homedir(), osUser: null, isOwner: true };
  const transcripts = listTranscriptModels(owner);
  if (!transcripts.length) done('no transcripts found — nothing to do');

  // Drop what cannot be named honestly: `<synthetic>` is filtered upstream, and mythos and OpenCode models
  // have no Officer id. A dropped session shows no model rather than a wrong one.
  const entries = transcripts.flatMap(({ sessionId, apiModel }) => {
    const model = officerModelForApiModel(apiModel);
    return model ? [{ sessionId, model }] : [];
  });

  const unmapped = transcripts.length - entries.length;
  if (!entries.length) done(`${transcripts.length} transcript(s), none with a model Officer offers`);

  const inserted = await seedMissingChatSessionModels(entries);
  const skipped = entries.length - inserted;

  done(
    `${inserted} seeded` +
      (skipped ? `, ${skipped} already recorded` : '') +
      (unmapped ? `, ${unmapped} with no Officer equivalent` : '') +
      ` (of ${transcripts.length} transcript(s))`,
  );
} catch (err) {
  // Deliberately exit 0. See the header: the push has already applied, and this is bookkeeping.
  done(`skipped — ${err instanceof Error ? err.message : String(err)}`);
}