import { hydrateFilingTaxonomySnapshot } from '@/lib/server/taxonomy/engine';
import { listFilingsRecords, updateFilingMetricsById } from '@/lib/server/repos/filings';
import {
  getFilingTaxonomySnapshotByFilingId,
  normalizeFilingTaxonomySnapshotPayload,
  upsertFilingTaxonomySnapshot
} from '@/lib/server/repos/filing-taxonomy';

type ScriptOptions = {
  apply: boolean;
  ticker: string | null;
  window: '10y' | 'all';
  limit: number | null;
  refresh: boolean;
};

type ScriptSummary = {
  scanned: number;
  wouldWrite: number;
  written: number;
  skippedFresh: number;
  failed: number;
};

type FilingRow = {
  id: number;
  ticker: string;
  cik: string;
  accessionNumber: string;
  filingDate: string;
  filingType: '10-K' | '10-Q';
  filingUrl: string | null;
  primaryDocument: string | null;
  updatedAt: string;
};

const REQUEST_DELAY_MS = 120;

function parseOptions(argv: string[]): ScriptOptions {
  const options: ScriptOptions = {
    apply: false,
    ticker: null,
    window: '10y',
    limit: null,
    refresh: false
  };

  for (const arg of argv) {
    if (arg === '--apply') {
      options.apply = true;
      continue;
    }

    if (arg === '--refresh') {
      options.refresh = true;
      continue;
    }

    if (arg.startsWith('--ticker=')) {
      const value = arg.slice('--ticker='.length).trim().toUpperCase();
      options.ticker = value.length > 0 ? value : null;
      continue;
    }

    if (arg.startsWith('--window=')) {
      const value = arg.slice('--window='.length).trim().toLowerCase();
      options.window = value === 'all' ? 'all' : '10y';
      continue;
    }

    if (arg.startsWith('--limit=')) {
      const parsed = Number.parseInt(arg.slice('--limit='.length), 10);
      if (Number.isFinite(parsed) && parsed > 0) {
        options.limit = parsed;
      }
      continue;
    }

    if (arg === '--help' || arg === '-h') {
      console.log('Backfill filing taxonomy snapshots (Financial Statements V3).');
      console.log('');
      console.log('Usage:');
      console.log('  bun run scripts/backfill-taxonomy-snapshots.ts [--apply] [--ticker=SYMBOL] [--window=10y|all] [--limit=N] [--refresh]');
      process.exit(0);
    }
  }

  return options;
}

function tenYearsAgoIso() {
  const date = new Date();
  date.setUTCFullYear(date.getUTCFullYear() - 10);
  return date.toISOString().slice(0, 10);
}

async function loadFilings(options: ScriptOptions): Promise<FilingRow[]> {
  const rows: FilingRow[] = [];
  let cursor = 0;

  while (true) {
    const page = await listFilingsRecords({
      ticker: options.ticker ?? undefined,
      limit: 250
    });

    const normalizedPage = page
      .filter((filing): filing is typeof filing & { filing_type: '10-K' | '10-Q' } => {
        return filing.filing_type === '10-K' || filing.filing_type === '10-Q';
      })
      .filter((filing) => {
        if (options.window === 'all') {
          return true;
        }

        return filing.filing_date >= tenYearsAgoIso();
      })
      .slice(cursor);

    if (normalizedPage.length === 0) {
      break;
    }

    for (const filing of normalizedPage) {
      rows.push({
        id: filing.id,
        ticker: filing.ticker,
        cik: filing.cik,
        accessionNumber: filing.accession_number,
        filingDate: filing.filing_date,
        filingType: filing.filing_type,
        filingUrl: filing.filing_url,
        primaryDocument: filing.primary_document ?? null,
        updatedAt: filing.updated_at
      });

      if (options.limit && rows.length >= options.limit) {
        return rows;
      }
    }

    cursor += normalizedPage.length;
  }

  return rows;
}

async function runBackfill(options: ScriptOptions): Promise<ScriptSummary> {
  const rows = await loadFilings(options);
  const summary: ScriptSummary = {
    scanned: 0,
    wouldWrite: 0,
    written: 0,
    skippedFresh: 0,
    failed: 0
  };

  console.log(`[backfill-taxonomy-snapshots] mode=${options.apply ? 'apply' : 'dry-run'} window=${options.window} filings=${rows.length}`);
  if (options.ticker) {
    console.log(`[backfill-taxonomy-snapshots] ticker=${options.ticker}`);
  }

  for (const [index, row] of rows.entries()) {
    summary.scanned += 1;
    console.log(`[backfill-taxonomy-snapshots] [${index + 1}/${rows.length}] ${row.ticker} ${row.filingType} ${row.filingDate} ${row.accessionNumber}`);

    const existing = await getFilingTaxonomySnapshotByFilingId(row.id);
    const isFresh = existing && Date.parse(existing.updated_at) >= Date.parse(row.updatedAt);

    if (isFresh && !options.refresh) {
      summary.skippedFresh += 1;
      continue;
    }

    try {
      const snapshot = await hydrateFilingTaxonomySnapshot({
        filingId: row.id,
        ticker: row.ticker,
        cik: row.cik,
        accessionNumber: row.accessionNumber,
        filingDate: row.filingDate,
        filingType: row.filingType,
        filingUrl: row.filingUrl,
        primaryDocument: row.primaryDocument
      });

      summary.wouldWrite += 1;

      if (options.apply) {
        const normalizedSnapshot = {
          ...snapshot,
          ...normalizeFilingTaxonomySnapshotPayload(snapshot)
        };
        await upsertFilingTaxonomySnapshot(normalizedSnapshot);
        await updateFilingMetricsById(row.id, normalizedSnapshot.derived_metrics);
        summary.written += 1;
      }
    } catch (error) {
      summary.failed += 1;
      const reason = error instanceof Error ? error.message : 'unknown error';
      console.error(`[backfill-taxonomy-snapshots] failed for ${row.accessionNumber}: ${reason}`);
    }

    await Bun.sleep(REQUEST_DELAY_MS);
  }

  return summary;
}

async function main() {
  const options = parseOptions(process.argv.slice(2));
  const startedAt = Date.now();

  try {
    const summary = await runBackfill(options);
    const durationSec = ((Date.now() - startedAt) / 1000).toFixed(1);

    console.log('[backfill-taxonomy-snapshots] summary');
    console.log(`  scanned=${summary.scanned}`);
    console.log(`  wouldWrite=${summary.wouldWrite}`);
    console.log(`  written=${summary.written}`);
    console.log(`  skippedFresh=${summary.skippedFresh}`);
    console.log(`  failed=${summary.failed}`);
    console.log(`  durationSec=${durationSec}`);
  } catch (error) {
    const message = error instanceof Error ? error.message : String(error);
    console.error(`[backfill-taxonomy-snapshots] fatal: ${message}`);
    process.exitCode = 1;
  }
}

void main();