#!/usr/bin/env bun
/**
 * One-shot migration: quinn-my.db (SQLite) → prod Postgres (quinn database)
 *
 * Prerequisites:
 *   ssh -L 25436:127.0.0.1:6432 quinn-vps -fN
 *
 * Run from codebase/@features/my/backend-api/ (postgres package lives there):
 *   cd codebase/@features/my/backend-api
 *   bun ../../../../scripts/sqlite-to-pg-migrate.ts
 *
 * Or override env vars:
 *   SQLITE_PATH=/abs/path/quinn-my.db MIGRATE_DB_URL=postgres://... bun ...
 */

import { Database } from 'bun:sqlite';
import postgres from 'postgres';

const SQLITE_PATH =
  process.env.SQLITE_PATH ??
  new URL('../codebase/@features/my/backend-api/data/quinn-my.db', import.meta.url).pathname;

const DB_URL =
  process.env.MIGRATE_DB_URL ??
  'postgres://quinn_my:plxLEliUesG73vnvwAFTefNlEWjSF2QRz1YCk6D7@127.0.0.1:25436/quinn';

const sqlite = new Database(SQLITE_PATH, { readonly: true });
const sql = postgres(DB_URL, { max: 1 });

const out = (msg: string): void => { process.stdout.write(msg + '\n'); };
const err = (msg: string): void => { process.stderr.write(msg + '\n'); };

// ---------------------------------------------------------------------------
// Straight-copy tables: SQLite columns are a subset of prod columns.
// All prod extra NOT NULL columns have safe defaults.
// ---------------------------------------------------------------------------

const BOOL_COLS: Record<string, readonly string[]> = {
  tasks:            ['daily', 'completed'],
  calendar_sources: ['sync_enabled'],
  platforms:        ['account', 'content', 'photos', 'verification_submitted', 'verified'],
  photo_css_traps:  ['inverted'],
};

// FK dependency order: parents before children
const STRAIGHT_TABLES = [
  'admin_auth',
  'projects',
  'calendar_sources',
  'platforms',
  'platform_ad_copies',
  'clients',
  'income_meta',
  'income_sessions',
  'purchases',
  'subscriptions',
  'pending_items',
  'pending_income',
  'inspiration',
  'context_sections',
  'photo_css_traps',
  'vigil_history',
  'tasks',
  'credentials',
] as const;

// city_visits + flights: skipped — data already in tour_stops/tour_legs (newer source)
// calendar_events: migrated via custom mapper below (schema renamed columns)

type Row = Record<string, unknown>;

function coerce(table: string, rows: Row[]): Row[] {
  const bools = BOOL_COLS[table];
  return rows.map(row => {
    const r = { ...row };
    if (bools) {
      for (const col of bools) {
        if (col in r && r[col] !== null) r[col] = Boolean(r[col]);
      }
    }
    // tasks.priority: SQLite had 'medium'; prod allows only normal|high|urgent
    if (table === 'tasks' && r['priority'] === 'medium') r['priority'] = 'normal';
    return r;
  });
}

async function resetSequence(table: string): Promise<void> {
  try {
    await sql.unsafe(
      `SELECT setval(
        pg_get_serial_sequence($1, 'id'),
        COALESCE((SELECT MAX(id) FROM ${table}), 0) + 1,
        false
      )`,
      [table],
    );
  } catch {
    // Table has no serial 'id' column (e.g. platforms uses TEXT name PK, tasks uses TEXT id)
  }
}

async function migrateStraight(table: string): Promise<void> {
  const rows = sqlite.prepare(`SELECT * FROM ${table}`).all() as Row[];
  if (rows.length === 0) { out(`SKIP   ${table}: empty in SQLite`); return; }

  const [{ c }] = await sql<[{ c: number }]>`SELECT count(*)::int as c FROM ${sql(table)}`;
  if (c > 0) { out(`SKIP   ${table}: prod already has ${c} rows`); return; }

  await sql`INSERT INTO ${sql(table)} ${sql(coerce(table, rows))} ON CONFLICT DO NOTHING`;
  out(`INSERT ${table}: ${rows.length} rows`);
  await resetSequence(table);
}

// ---------------------------------------------------------------------------
// Custom mapper: calendar_events
// Prod schema renamed: uid→external_id, summary→title, dtstart→start_at,
// dtend→end_at, description→notes. calendar_name derived from source.
// ---------------------------------------------------------------------------

function toTimestamp(date: unknown): string | null {
  if (!date) return null;
  const s = String(date).trim();
  return s.includes('T') || s.includes(' ') ? s : `${s}T00:00:00`;
}

async function migrateCalendarEvents(): Promise<void> {
  const [{ c }] = await sql<[{ c: number }]>`SELECT count(*)::int as c FROM calendar_events`;
  if (c > 0) { out(`SKIP   calendar_events: prod already has ${c} rows`); return; }

  type SourceRow = { id: number; display_name: string };
  const sourceNames = new Map<number, string>(
    (sqlite.prepare('SELECT id, display_name FROM calendar_sources').all() as SourceRow[])
      .map(r => [r.id, r.display_name]),
  );

  type EventRow = {
    id: number; source_id: number | null; uid: string | null; summary: string | null;
    description: string | null; location: string | null; dtstart: string | null;
    dtend: string | null; all_day: number; created_at: string; updated_at: string;
    project_id: number | null; client_id: number | null;
  };
  const rows = sqlite.prepare('SELECT * FROM calendar_events').all() as EventRow[];

  const mapped: Row[] = rows.map(r => ({
    id:            r.id,
    external_id:   r.uid ?? null,
    title:         r.summary ?? '',
    start_at:      toTimestamp(r.dtstart),
    end_at:        toTimestamp(r.dtend) ?? toTimestamp(r.dtstart),
    all_day:       Boolean(r.all_day),
    location:      r.location ?? null,
    notes:         r.description ?? null,
    calendar_name: r.source_id != null ? (sourceNames.get(r.source_id) ?? null) : null,
    provider_slug: 'quinn',
    synced_at:     r.updated_at,
    created_at:    r.created_at,
    updated_at:    r.updated_at,
    project_id:    r.project_id ?? null,
    client_id:     r.client_id ?? null,
  }));

  await sql`INSERT INTO calendar_events ${sql(mapped)} ON CONFLICT DO NOTHING`;
  out(`INSERT calendar_events: ${mapped.length} rows`);
  await resetSequence('calendar_events');
}

// ---------------------------------------------------------------------------
// Main
// ---------------------------------------------------------------------------

async function main(): Promise<void> {
  out(`Source: ${SQLITE_PATH}`);
  out(`Target: ${DB_URL.replace(/:\/\/[^@]+@/, '://<creds>@')}\n`);

  for (const table of STRAIGHT_TABLES) {
    await migrateStraight(table);
  }

  await migrateCalendarEvents();

  out('\nDone.');
}

main().catch(e => {
  err(String(e));
  process.exit(1);
}).finally(() => {
  sqlite.close();
  return sql.end();
});