import type { FastifyInstance, FastifyRequest } from 'fastify';
import { ScreenerEngine } from './ScreenerEngine';
import { CatalystCache, SignalSnapshotRepository, YahooFinanceClient } from '../../domains/shared';
import type { DataHealth, LiveAssetResult, ScreenerResult } from '../../domains/shared';
import type { NewsRepository } from '../news/NewsRepository';
import { screenSchema } from '../../domains/shared/types/schemas';

export class ScreenerController {
  /** Company profiles change rarely — cache for an hour. */
  private static readonly PROFILE_TTL_MS = 60 * 60 * 1000;
  private profileCache = new Map<string, { data: unknown; expiresAt: number }>();

  /** Sector pulse — SPDR sector ETFs as the standard proxy, cached 15 min. */
  private static readonly SECTOR_TTL_MS = 15 * 60 * 1000;
  private static readonly SECTOR_ETFS: Array<{ etf: string; sector: string; name: string }> = [
    { etf: 'XLK', sector: 'TECHNOLOGY', name: 'Technology' },
    { etf: 'XLF', sector: 'FINANCIAL', name: 'Financials' },
    { etf: 'XLE', sector: 'ENERGY', name: 'Energy' },
    { etf: 'XLV', sector: 'HEALTHCARE', name: 'Healthcare' },
    { etf: 'XLC', sector: 'COMMUNICATION', name: 'Communication' },
    { etf: 'XLP', sector: 'CONSUMER_STAPLES', name: 'Staples' },
    { etf: 'XLY', sector: 'CONSUMER_DISCRETIONARY', name: 'Discretionary' },
    { etf: 'XLRE', sector: 'REIT', name: 'Real Estate' },
    { etf: 'XLI', sector: 'GENERAL', name: 'Industrials' },
    { etf: 'XLU', sector: 'GENERAL', name: 'Utilities' },
  ];
  private sectorCache: { data: unknown; expiresAt: number } | null = null;

  /** Sector drill-down (holdings + screen + news) — cached 30 min per sector. */
  private static readonly SECTOR_DETAIL_TTL_MS = 30 * 60 * 1000;
  private sectorDetailCache = new Map<string, { data: unknown; expiresAt: number }>();

  constructor(
    private readonly engine: ScreenerEngine,
    private readonly catalystCache: CatalystCache,
    // Optional so tests and minimal setups work without a database.
    private readonly snapshots?: SignalSnapshotRepository,
    private readonly yahoo?: YahooFinanceClient,
    private readonly news?: NewsRepository,
  ) {}

  register(app: FastifyInstance): void {
    app.post(
      '/api/screen',
      { schema: screenSchema, config: { rateLimit: { max: 10, timeWindow: '1 minute' } } },
      this.screen.bind(this),
    );
    app.get(
      '/api/screen/catalysts',
      { config: { rateLimit: { max: 10, timeWindow: '1 minute' } } },
      this.catalysts.bind(this),
    );
    app.get('/api/screen/history/:ticker', this.history.bind(this));
    app.get('/api/screen/profile/:ticker', this.profile.bind(this));
    app.get('/api/screen/chart/:ticker', this.chart.bind(this));
    app.get('/api/screen/sectors', this.sectors.bind(this));
    app.get('/api/screen/sector/:sector', this.sectorDetail.bind(this));
  }

  /**
   * Sector drill-down: the sector ETF's top 10 holdings, freshly screened
   * (signal + advice-ready rows), plus recent news for those tickers and
   * macro stories — "what's in this sector and why is it moving".
   */
  private async sectorDetail(req: FastifyRequest) {
    const sector = (req.params as { sector: string }).sector.toUpperCase();
    const entry = ScreenerController.SECTOR_ETFS.find((s) => s.sector === sector);
    if (!entry || !this.yahoo) return { sector, etf: null, stocks: [], news: [] };

    const cached = this.sectorDetailCache.get(sector);
    if (cached && Date.now() < cached.expiresAt) return cached.data;

    const holdings = await this.yahoo.fetchTopHoldings(entry.etf, 10);
    const results = holdings.length > 0 ? await this.engine.screenTickers(holdings) : null;
    const stocks = results
      ? ScreenerController.serializeAssets(results.STOCK as LiveAssetResult[])
      : [];

    // News: stored stories for these tickers (last 3 days), deduped by URL
    const newsSince = new Date(Date.now() - 3 * 24 * 60 * 60 * 1000).toISOString().slice(0, 10);
    const byUrl = new Map<string, unknown>();
    if (this.news) {
      for (const ticker of holdings) {
        for (const row of this.news.newsForTicker(ticker, newsSince)) {
          byUrl.set(row.url, {
            headline: row.headline,
            tickers: JSON.parse(row.ticker_list),
            source: row.source,
            catalyst: row.catalyst,
            url: row.url,
            publishedAt: row.published_at,
          });
        }
      }
    }

    const data = {
      sector,
      etf: entry.etf,
      name: entry.name,
      stocks,
      news: [...byUrl.values()],
    };
    this.sectorDetailCache.set(sector, {
      data,
      expiresAt: Date.now() + ScreenerController.SECTOR_DETAIL_TTL_MS,
    });
    return data;
  }

  /**
   * Sector pulse — today's % change per sector via SPDR sector ETFs (the
   * standard proxy). Returns sectors sorted best→worst plus the leader.
   */
  private async sectors() {
    if (this.sectorCache && Date.now() < this.sectorCache.expiresAt) {
      return this.sectorCache.data;
    }
    if (!this.yahoo) return { asOf: null, leader: null, sectors: [] };

    const results = await Promise.all(
      ScreenerController.SECTOR_ETFS.map(async ({ etf, sector, name }) => {
        try {
          const summary = await this.yahoo!.fetchSummary(etf);
          const pr = summary?.price ?? {};
          const price = pr.regularMarketPrice ?? null;
          const prev = pr.regularMarketPreviousClose ?? null;
          const changePct =
            price != null && prev != null && prev > 0
              ? +(((price - prev) / prev) * 100).toFixed(2)
              : null;
          return { etf, sector, name, changePct };
        } catch {
          return { etf, sector, name, changePct: null };
        }
      }),
    );

    const sectors = results
      .filter((s) => s.changePct != null)
      .sort((a, b) => (b.changePct as number) - (a.changePct as number));

    const data = {
      asOf: new Date().toISOString(),
      leader: sectors[0] ?? null,
      sectors,
    };
    this.sectorCache = { data, expiresAt: Date.now() + ScreenerController.SECTOR_TTL_MS };
    return data;
  }

  /** Company profile for the ticker modal — name, description, sector. */
  private async profile(req: FastifyRequest) {
    const ticker = (req.params as { ticker: string }).ticker.toUpperCase();
    if (!this.yahoo) return { ticker, profile: null };

    const cached = this.profileCache.get(ticker);
    if (cached && Date.now() < cached.expiresAt) return cached.data;

    try {
      const summary = await this.yahoo.fetchSummary(ticker);
      const ap = summary?.assetProfile ?? {};
      const pr = summary?.price ?? {};
      const fd = summary?.financialData ?? {};
      const price = pr.regularMarketPrice ?? null;
      const targetMean = fd.targetMeanPrice ?? null;
      const data = {
        ticker,
        profile: {
          name: pr.longName ?? pr.shortName ?? ticker,
          summary: ap.longBusinessSummary ?? null,
          sector: ap.sector ?? null,
          industry: ap.industry ?? null,
          website: ap.website ?? null,
          employees: ap.fullTimeEmployees ?? null,
          marketCap: pr.marketCap ?? null,
          currentPrice: price,
          // Analyst price targets (Yahoo sell-side consensus)
          targets: {
            mean: targetMean,
            high: fd.targetHighPrice ?? null,
            low: fd.targetLowPrice ?? null,
            analysts: fd.numberOfAnalystOpinions ?? null,
            recommendationMean: fd.recommendationMean ?? null, // 1=Strong Buy … 5=Strong Sell
            upsidePct:
              targetMean != null && price != null && price > 0
                ? +(((targetMean - price) / price) * 100).toFixed(1)
                : null,
          },
        },
      };
      this.profileCache.set(ticker, {
        data,
        expiresAt: Date.now() + ScreenerController.PROFILE_TTL_MS,
      });
      return data;
    } catch {
      return { ticker, profile: null };
    }
  }

  /** Closes for the ticker modal chart. ?range=1d|5d|1mo|3mo|6mo|1y. */
  private async chart(req: FastifyRequest) {
    const ticker = (req.params as { ticker: string }).ticker.toUpperCase();
    const raw = (req.query as { range?: string }).range ?? '6mo';
    const range = raw in YahooFinanceClient.CHART_RANGES ? raw : '6mo';
    if (!this.yahoo) return { ticker, range, points: [] };
    return { ticker, range, points: await this.yahoo.fetchCloses(ticker, range) };
  }

  /** Signal snapshot history for one ticker (P0.1 ledger read side). */
  private async history(req: FastifyRequest) {
    if (!this.snapshots) return { ticker: null, snapshots: [] };
    const { ticker } = req.params as { ticker: string };
    return {
      ticker: ticker.toUpperCase(),
      snapshots: this.snapshots.history(ticker).map((row) => ({
        date: row.snapshot_date,
        signal: row.signal,
        price: row.price,
        fundamental: { tier: row.fundamental_tier, score: row.fundamental_score },
        inflated: { tier: row.inflated_tier, score: row.inflated_score },
        coverage:
          row.coverage_active != null
            ? { active: row.coverage_active, total: row.coverage_total }
            : null,
        riskFlags: row.risk_flags ? JSON.parse(row.risk_flags) : [],
        rateRegime: row.rate_regime,
      })),
    };
  }

  private static serializeAssets(arr: LiveAssetResult[]) {
    return arr.map((r) => ({
      ...r,
      asset: {
        ticker: r.asset.ticker,
        type: r.asset.type,
        currentPrice: r.asset.currentPrice,
        metrics: r.asset.metrics,
        displayMetrics: r.asset.getDisplayMetrics(),
      },
    }));
  }

  private async screen(req: FastifyRequest) {
    const tickers = (req.body as { tickers: string[] }).tickers.map((t) => t.toUpperCase());
    const results = await this.engine.screenTickers(tickers);
    this.recordSnapshots(results, req);
    this.flagTurnarounds(results);
    const dataHealth = ScreenerController.assessDataHealth(results);
    if (dataHealth.degraded) {
      req.log?.warn?.({ dataHealth }, 'screen batch returned degraded fundamentals data');
    }
    return {
      ...results,
      STOCK: ScreenerController.serializeAssets(results.STOCK as LiveAssetResult[]),
      ETF: ScreenerController.serializeAssets(results.ETF as LiveAssetResult[]),
      BOND: ScreenerController.serializeAssets(results.BOND as LiveAssetResult[]),
      dataHealth,
    };
  }

  /**
   * Turnaround-watch (candidate flag, NOT a prediction): the stock's style is
   * already Turnaround (earnings down, revenue holding) AND its fundamental
   * score improved vs the previous snapshot in the ledger. Both legs must
   * hold — style alone is static, improvement alone is noise.
   */
  private flagTurnarounds(results: ScreenerResult): void {
    if (!this.snapshots) return;
    for (const row of results.STOCK as LiveAssetResult[]) {
      const metrics = row.asset.metrics as { growthCategory?: string };
      if (metrics?.growthCategory !== 'Turnaround') continue;
      if (row.fundamental.tier === 'REJECT' || row.fundamental.score == null) continue;

      try {
        // History includes today's snapshot (recorded just above) — compare
        // today's score against the most recent prior day with a score.
        const history = this.snapshots.history(row.asset.ticker);
        const prior = [...history]
          .reverse()
          .find((h) => h.snapshot_date < history[history.length - 1]?.snapshot_date);
        if (prior?.fundamental_score != null && row.fundamental.score > prior.fundamental_score) {
          row.turnaroundWatch = true;
        }
      } catch {
        // best-effort — never fail the screen for a highlight
      }
    }
  }

  /**
   * P0.4 data-sanity sentinel — if a large share of screened stocks come back
   * with null core fundamentals (P/E, ROE), the upstream source has likely
   * changed schema or is throttling. Surface it loudly instead of letting
   * everything silently degrade to "No Data" rows.
   */
  private static assessDataHealth(results: ScreenerResult): DataHealth {
    const THRESHOLD = 0.3; // >30% nulls = degraded
    const MIN_SAMPLE = 3; // don't alarm on tiny batches

    const stocks = results.STOCK as LiveAssetResult[];
    const metrics = stocks.map(
      (r) => r.asset.metrics as { peRatio?: number | null; returnOnEquity?: number | null },
    );
    const nullPeRatio = metrics.filter((m) => m.peRatio == null).length;
    const nullRoe = metrics.filter((m) => m.returnOnEquity == null).length;
    const total = metrics.length;

    const degraded =
      total >= MIN_SAMPLE && (nullPeRatio / total > THRESHOLD || nullRoe / total > THRESHOLD);

    return {
      degraded,
      stocksChecked: total,
      nullPeRatio,
      nullRoe,
      message: degraded
        ? `${Math.max(nullPeRatio, nullRoe)} of ${total} stocks returned no core fundamentals — data source may be degraded; treat this screen with caution`
        : null,
    };
  }

  /**
   * P0.1 signal track record — persist one snapshot per asset per day.
   * Best-effort: a snapshot failure must never fail the screen response.
   */
  private recordSnapshots(results: ScreenerResult, req: FastifyRequest): void {
    if (!this.snapshots) return;
    try {
      const rateRegime = results.marketContext?.rateRegime ?? null;
      const inputs = [...results.STOCK, ...results.ETF, ...results.BOND].map((r) => ({
        ticker: r.asset.ticker,
        assetType: r.asset.type,
        price: r.asset.currentPrice ?? null,
        signal: r.signal,
        fundamental: r.fundamental,
        inflated: r.inflated,
        rateRegime,
      }));
      this.snapshots.recordBatch(inputs);
    } catch (err) {
      req.log?.warn?.({ err }, 'signal snapshot recording failed');
    }
  }

  private async catalysts() {
    const { tickers, stories } = await this.catalystCache.get();
    return { tickers, stories };
  }
}