import type { Command } from 'commander';
import type { MigrationSource } from './migrate-tier.js';
import { redactErrMsg } from './redact-error.js';

/**
 * Reads the DATABASE_URL environment variable and redacts the password portion.
 */
function redactedConnectionString(): string | null {
  const url = process.env['DATABASE_URL'];
  if (!url) return null;
  try {
    const parsed = new URL(url);
    if (parsed.password) {
      parsed.password = '***';
    }
    return parsed.toString();
  } catch {
    // Not a valid URL — redact anything that looks like :password@
    return url.replace(/:([^@/]+)@/, ':***@');
  }
}

/**
 * Determine the active storage tier from the environment.
 * Looks at DATABASE_URL; if absent or set to a pglite path, treats tier as pglite.
 */
function activeTier(): 'postgres' | 'pglite' {
  const url = process.env['DATABASE_URL'];
  if (url && url.startsWith('postgres')) return 'postgres';
  return 'pglite';
}

/**
 * Return a human-readable config source description.
 */
function configSource(): string {
  if (process.env['DATABASE_URL']) return 'env:DATABASE_URL';
  const pgliteDir = process.env['PGLITE_DATA_DIR'];
  if (pgliteDir) return `env:PGLITE_DATA_DIR (${pgliteDir})`;
  return 'default (no DATABASE_URL set)';
}

/**
 * Register storage subcommands on an existing Commander program.
 * Follows the registerQualityRails pattern — uses the caller's Command
 * instance to avoid cross-package Commander version mismatches.
 */
export function registerStorageCommand(parent: Command): void {
  const storage = parent
    .command('storage')
    .description('Inspect and manage Mosaic storage configuration');

  // ── storage status ───────────────────────────────────────────────────────

  storage
    .command('status')
    .description('Show the configured storage tier and whether the adapter is reachable')
    .action(async () => {
      const tier = activeTier();
      const source = configSource();
      const connStr = tier === 'postgres' ? redactedConnectionString() : null;

      console.log(`[storage] tier: ${tier}`);
      console.log(`[storage] config source: ${source}`);

      if (tier === 'postgres' && connStr) {
        console.log(`[storage] connection: ${connStr}`);
        try {
          const { createDb, sql } = await import('@mosaicstack/db');
          const url = process.env['DATABASE_URL'] ?? '';
          const handle = createDb(url);
          await handle.db.execute(sql`SELECT 1`);
          await handle.close();
          console.log('[storage] reachable: yes');
        } catch (err) {
          console.log(
            `[storage] reachable: no (${redactErrMsg(err instanceof Error ? err.message : String(err))})`,
          );
        }
      } else {
        const dataDir = process.env['PGLITE_DATA_DIR'] ?? ':memory:';
        console.log(`[storage] data dir: ${dataDir}`);
        console.log('[storage] reachable: pglite is always local — no network check needed');
      }
    });

  // ── storage tier ─────────────────────────────────────────────────────────

  const tier = storage.command('tier').description('Inspect or switch the storage tier');

  tier
    .command('show')
    .description('Print the active storage tier and its config source')
    .action(() => {
      const activeTierValue = activeTier();
      const source = configSource();
      console.log(`[storage] active tier: ${activeTierValue}`);
      console.log(`[storage] config source: ${source}`);
    });

  tier
    .command('switch <tier>')
    .description('Switch storage tier between pglite and postgres')
    .action((newTier: string) => {
      const validTiers = ['pglite', 'postgres'];
      if (!validTiers.includes(newTier)) {
        console.error(
          `[storage] unknown tier: ${newTier}. Valid options: ${validTiers.join(', ')}`,
        );
        process.exitCode = 1;
        return;
      }

      console.log(`[storage] tier switch requested: ${newTier}`);
      console.log('');
      console.log('Mosaic storage tier is controlled by environment variables.');
      console.log('Automatic config-file mutation is not supported — set the variable manually.');
      console.log('');

      if (newTier === 'postgres') {
        console.log('To switch to postgres:');
        console.log('  1. Set DATABASE_URL in your environment or .env file:');
        console.log('       export DATABASE_URL="postgresql://user:pass@localhost:5432/mosaic"');
        console.log('  2. Run migrations:');
        console.log('       pnpm --filter @mosaicstack/db db:migrate');
        console.log('  3. Restart the gateway.');
      } else {
        console.log('To switch to pglite:');
        console.log('  1. Unset DATABASE_URL (or set it to a pglite path):');
        console.log('       unset DATABASE_URL');
        console.log('       # optionally: export PGLITE_DATA_DIR=/path/to/pglite/data');
        console.log('  2. Restart the gateway.');
        console.log('  Note: pglite uses an in-process database — no migrations needed.');
      }
    });

  // ── storage export ───────────────────────────────────────────────────────

  storage
    .command('export <path>')
    .description('Dump the active storage contents to a file')
    .action((outputPath: string) => {
      const currentTier = activeTier();

      if (currentTier === 'postgres') {
        const redacted = redactedConnectionString() ?? '<DATABASE_URL>';
        console.log('[storage] export for postgres tier');
        console.log('');
        console.log('postgres export is not yet wired in the CLI — use pg_dump directly:');
        console.log('');
        console.log(`  pg_dump "${redacted}" > ${outputPath}`);
        console.log('');
        console.log('Or with Docker:');
        console.log(
          `  docker exec <postgres-container> pg_dump -U <user> <dbname> > ${outputPath}`,
        );
        process.exitCode = 0;
      } else {
        const dataDir = process.env['PGLITE_DATA_DIR'];
        console.log('[storage] export for pglite tier');
        console.log('');
        console.log(
          'pglite export is not yet wired in the CLI — copy the data directory directly:',
        );
        console.log('');
        if (dataDir) {
          console.log(`  cp -r ${dataDir} ${outputPath}`);
        } else {
          console.log(
            '  PGLITE_DATA_DIR is not set; the database is in-memory and cannot be exported.',
          );
          console.log('  Set PGLITE_DATA_DIR to a persistent path before running export.');
        }
        process.exitCode = 0;
      }
    });

  // ── storage import ───────────────────────────────────────────────────────

  storage
    .command('import <path>')
    .description('Restore storage contents from a previously exported file')
    .action((inputPath: string) => {
      const currentTier = activeTier();

      if (currentTier === 'postgres') {
        const redacted = redactedConnectionString() ?? '<DATABASE_URL>';
        console.log('[storage] import for postgres tier');
        console.log('');
        console.log('postgres import is not yet wired in the CLI — use psql directly:');
        console.log('');
        console.log(`  psql "${redacted}" < ${inputPath}`);
        process.exitCode = 0;
      } else {
        const dataDir = process.env['PGLITE_DATA_DIR'];
        console.log('[storage] import for pglite tier');
        console.log('');
        console.log(
          'pglite import is not yet wired in the CLI — restore the data directory directly:',
        );
        console.log('');
        if (dataDir) {
          console.log(`  rm -rf ${dataDir} && cp -r ${inputPath} ${dataDir}`);
          console.log('  Then restart the gateway.');
        } else {
          console.log(
            '  PGLITE_DATA_DIR is not set; set it to a persistent path before running import.',
          );
        }
        process.exitCode = 0;
      }
    });

  // ── storage migrate-tier ─────────────────────────────────────────────────

  storage
    .command('migrate-tier')
    .description('Migrate data from tier: local/standalone → tier: federated (Postgres + pgvector)')
    .requiredOption(
      '--to <tier>',
      'Target tier to migrate to (only "federated" is supported)',
      'federated',
    )
    .requiredOption('--target-url <url>', 'Target federated Postgres connection string (required)')
    .option(
      '--source-config <path>',
      'Path to mosaic.config.json (default: cwd/mosaic.config.json)',
    )
    .option('--dry-run', 'Print what would be migrated without writing anything')
    .option('--yes', 'Skip interactive confirmation prompt (required for non-TTY environments)')
    .option('--batch-size <n>', 'Rows per transaction batch', '1000')
    .option('--allow-non-empty', 'Allow writing to a non-empty target (upsert — idempotent)')
    .action(
      async (opts: {
        to: string;
        targetUrl: string;
        sourceConfig?: string;
        dryRun?: boolean;
        yes?: boolean;
        batchSize?: string;
        allowNonEmpty?: boolean;
      }) => {
        if (opts.to !== 'federated') {
          console.error(
            `[migrate-tier] --to "${opts.to}" is not supported. Only "federated" is allowed.`,
          );
          process.exitCode = 1;
          return;
        }

        const batchSize = parseInt(opts.batchSize ?? '1000', 10);
        if (isNaN(batchSize) || batchSize < 1) {
          console.error('[migrate-tier] --batch-size must be a positive integer.');
          process.exitCode = 1;
          return;
        }

        // Redact target URL password for display.
        function redactUrl(url: string): string {
          try {
            const parsed = new URL(url);
            if (parsed.password) parsed.password = '***';
            return parsed.toString();
          } catch {
            return url.replace(/:([^@/]+)@/, ':***@');
          }
        }

        const redactedTarget = redactUrl(opts.targetUrl);
        const isDryRun = opts.dryRun ?? false;
        const allowNonEmpty = opts.allowNonEmpty ?? false;

        // Determine source tier from environment.
        const sourceTier = activeTier();
        const sourceDesc = configSource();

        console.log('');
        console.log('[migrate-tier] ─────────────────────────────────────────');
        console.log(`[migrate-tier] Source tier:  ${sourceTier}`);
        console.log(`[migrate-tier] Source:       ${sourceDesc}`);
        console.log(`[migrate-tier] Target tier:  federated (Postgres + pgvector)`);
        console.log(`[migrate-tier] Target:       ${redactedTarget}`);
        console.log(`[migrate-tier] Batch size:   ${batchSize.toString()}`);
        console.log(`[migrate-tier] Dry run:      ${isDryRun.toString()}`);
        console.log(`[migrate-tier] Allow non-empty: ${allowNonEmpty.toString()}`);
        console.log('[migrate-tier] ─────────────────────────────────────────');
        console.log('');

        // Lazy-import core migration logic to keep the CLI thin.
        const {
          runMigrateTier,
          PostgresMigrationTarget,
          DrizzleMigrationSource,
          getMigrationOrder,
        } = await import('./migrate-tier.js');

        // Build source adapter using Drizzle-backed DrizzleMigrationSource.
        // Both local (PGlite) and standalone (Postgres) sources expose the same
        // normalized Drizzle schema — this is where the actual domain data lives.
        let sourceAdapter: MigrationSource;
        if (sourceTier === 'pglite') {
          const { createPgliteDb } = await import('@mosaicstack/db');
          const pgliteDataDir = process.env['PGLITE_DATA_DIR'];
          if (!pgliteDataDir) {
            console.error(
              '[migrate-tier] PGLITE_DATA_DIR is not set. ' +
                'Cannot open PGlite source — set it to the data directory path.',
            );
            process.exitCode = 1;
            return;
          }
          const handle = createPgliteDb(pgliteDataDir);
          // Local/PGlite sources do not have pgvector registered — the embedding
          // column is omitted from the insights SELECT and set to null on target.
          sourceAdapter = new DrizzleMigrationSource(handle.db, /* sourceHasVector= */ false);
        } else {
          const { createDb } = await import('@mosaicstack/db');
          const url = process.env['DATABASE_URL'];
          if (!url) {
            console.error('[migrate-tier] DATABASE_URL is not set for postgres source.');
            process.exitCode = 1;
            return;
          }
          const handle = createDb(url);
          // Standalone Postgres may or may not have pgvector — assume it does not
          // (it is a non-federated tier) so embedding is treated as null.
          sourceAdapter = new DrizzleMigrationSource(handle.db, /* sourceHasVector= */ false);
        }

        // Print per-table row counts for the confirmation prompt.
        const tablesToMigrate = getMigrationOrder();
        const counts: Array<{ table: string; count: number }> = [];
        for (const table of tablesToMigrate) {
          const n = await sourceAdapter.count(table);
          counts.push({ table, count: n });
        }

        console.log('[migrate-tier] Source row counts:');
        for (const { table, count } of counts) {
          console.log(`  ${table}: ${count.toString()}`);
        }
        console.log('  sessions: SKIPPED (ephemeral)');
        console.log('  verifications: SKIPPED (ephemeral)');
        console.log('  admin_tokens: SKIPPED (environment-specific)');
        console.log('');

        // Interactive confirmation unless --yes or dry-run.
        const isTTY = process.stdin.isTTY;
        if (!isDryRun) {
          if (!opts.yes && !isTTY) {
            console.error(
              '[migrate-tier] Not running in a TTY and --yes was not passed. ' +
                'Pass --yes to confirm in headless environments.',
            );
            process.exitCode = 1;
            await sourceAdapter.close();
            return;
          }

          if (!opts.yes) {
            const { createInterface } = await import('node:readline');
            const rl = createInterface({ input: process.stdin, output: process.stdout });
            const answer = await new Promise<string>((resolve) => {
              rl.question(`This will WRITE to ${redactedTarget}. Continue? [y/N] `, (ans) => {
                rl.close();
                resolve(ans);
              });
            });
            if (answer.trim().toLowerCase() !== 'y') {
              console.log('[migrate-tier] Aborted.');
              await sourceAdapter.close();
              return;
            }
          }
        }

        const target = new PostgresMigrationTarget(opts.targetUrl);

        try {
          const result = await runMigrateTier(
            sourceAdapter,
            target,
            {
              targetUrl: opts.targetUrl,
              dryRun: isDryRun,
              allowNonEmpty,
              batchSize,
              onProgress: (msg) => console.log(msg),
            },
            /* sourceHasVector= */ sourceTier === 'postgres',
          );

          if (result.dryRun) {
            console.log('[migrate-tier] Dry run complete. No data was written.');
          } else {
            console.log(
              `[migrate-tier] Migration complete. ${result.totalRows.toString()} rows migrated.`,
            );
          }
        } catch (err) {
          console.error(
            `[migrate-tier] ERROR: ${redactErrMsg(err instanceof Error ? err.message : String(err))}`,
          );
          process.exitCode = 1;
        } finally {
          await Promise.all([sourceAdapter.close(), target.close()]);
        }
      },
    );

  // ── storage migrate ──────────────────────────────────────────────────────

  storage
    .command('migrate')
    .description(
      'Run database migrations (thin wrapper — delegates to pnpm db:migrate or prints the command)',
    )
    .option('--run', 'Actually execute the migration command via shell')
    .action(async (opts: { run?: boolean }) => {
      const currentTier = activeTier();

      if (currentTier === 'pglite') {
        console.log('[storage] pglite tier detected');
        console.log(
          'pglite runs schema setup automatically on first connection via adapter.migrate().',
        );
        console.log('No separate migration step is required.');
        return;
      }

      const migrateCmd = 'pnpm --filter @mosaicstack/db db:migrate';
      console.log('[storage] postgres tier detected');
      console.log(`Migration command: ${migrateCmd}`);
      console.log('');

      if (opts.run) {
        console.log('Running migrations...');
        const { execSync } = await import('node:child_process');
        try {
          execSync(migrateCmd, { stdio: 'inherit' });
          console.log('[storage] migrations complete.');
        } catch (err) {
          console.error(
            `[storage] migration failed: ${err instanceof Error ? err.message : String(err)}`,
          );
          process.exitCode = 1;
        }
      } else {
        console.log('To run migrations, execute:');
        console.log(`  ${migrateCmd}`);
        console.log('');
        console.log('Or pass --run to have this command execute it for you.');
      }
    });
}