import "dotenv/config";
import cors from "cors";
import express from "express";
import { existsSync, readFileSync } from "node:fs";
import { join } from "node:path";
import { generateDailyReport } from "../agent/report";
import { createProvider } from "../agent/provider";
import { normalizeSymbol } from "../agent/symbols";
import { StockDataCache } from "../agent/stockDataCache";
import { WatchlistStore } from "../agent/watchlistStore";
import { loadIpadsConfig } from "./ipadsConfig";
import type { ChartPeriod, WatchStock } from "../shared/types";
import type { BacktestConfig } from "../shared/strategyTypes";
import { listStrategies, runBacktest, getCachedResult, getLiveStrategies } from "./strategyService";

const port = Number(process.env.PORT ?? 8787);
const host = process.env.HOST ?? "127.0.0.1";
const dataDir = process.env.STOCK_AGENT_DATA_DIR ?? join(process.cwd(), "data");

const watchlistStore = new WatchlistStore(join(dataDir, "watchlist.json"));
const dataProvider = createProvider(loadIpadsConfig().apiKey);
const stockDataCache = new StockDataCache(join(dataDir, "cache"), dataProvider);
const app = express();

let cachedReportUpdatedAt = 0;
let cachedReport: Awaited<ReturnType<typeof generateDailyReport>> | undefined;

app.use(cors());
app.use(express.json());

app.get("/api/health", async (_request, response) => {
  const config = loadIpadsConfig();
  response.json({
    ok: true,
    providerConfigured: config.apiKeyConfigured,
    baseUrl: config.baseUrl,
    wireApi: config.wireApi,
    scheduler: "24h"
  });
});

app.get("/api/watchlist", async (_request, response) => {
  response.json(await watchlistStore.list());
});

app.post("/api/watchlist", async (request, response, next) => {
  try {
    response.status(201).json(await watchlistStore.add(String(request.body?.symbol ?? ""), request.body?.name, parseTags(request.body?.tags)));
    cachedReport = undefined;
  } catch (error) {
    next(error);
  }
});

app.put("/api/watchlist/:symbol/tags", async (request, response, next) => {
  try {
    const updated = await watchlistStore.updateTags(request.params.symbol, parseTags(request.body?.tags));
    cachedReport = undefined;
    response.json(updated);
  } catch (error) {
    next(error);
  }
});

app.delete("/api/watchlist/:symbol", async (request, response, next) => {
  try {
    await watchlistStore.remove(request.params.symbol);
    cachedReport = undefined;
    response.status(204).end();
  } catch (error) {
    next(error);
  }
});

app.get("/api/stocks/:symbol/chart", async (request, response, next) => {
  try {
    const stock = await findWatchStock(request.params.symbol);
    response.json(
      request.query.refresh === "1"
        ? await stockDataCache.refreshChart(stock, parsePeriod(request.query.period))
        : await stockDataCache.chart(stock, parsePeriod(request.query.period))
    );
  } catch (error) {
    next(error);
  }
});

app.get("/api/stocks/:symbol/fundamentals", async (request, response, next) => {
  try {
    response.json(await stockDataCache.fundamentals(await findWatchStock(request.params.symbol), request.query.refresh === "1"));
  } catch (error) {
    next(error);
  }
});

app.get("/api/stocks/:symbol/related", async (request, response, next) => {
  try {
    response.json(await stockDataCache.relatedData(await findWatchStock(request.params.symbol), request.query.refresh === "1"));
  } catch (error) {
    next(error);
  }
});

app.get("/api/stocks/:symbol/analysis", async (request, response, next) => {
  try {
    const stock = await findWatchStock(request.params.symbol);
    if (request.query.refresh !== "1" && (await stockDataCache.hasAnalysis(stock))) {
      const analysis = await stockDataCache.quantAnalysis(stock);
      if (await stockDataCache.analysisNeedsRefresh(stock)) {
        void stockDataCache.quantAnalysis(stock, true).catch((error) => {
          console.error(`background analysis refresh failed for ${stock.display}`, error);
        });
      }
      response.json(analysis);
      return;
    }
    if (request.query.refresh !== "1") {
      void stockDataCache.quantAnalysis(stock, true).catch((error) => {
        console.error(`background analysis generation failed for ${stock.display}`, error);
      });
      response.json(stockDataCache.placeholderAnalysis(stock));
      return;
    }
    response.json(await stockDataCache.quantAnalysis(stock, request.query.refresh === "1"));
  } catch (error) {
    next(error);
  }
});

app.get("/api/report/daily", async (_request, response, next) => {
  try {
    response.json(await getDailyReport());
  } catch (error) {
    next(error);
  }
});

app.post("/api/report/daily/refresh", async (_request, response, next) => {
  try {
    cachedReport = undefined;
    response.json(await getDailyReport(true));
  } catch (error) {
    next(error);
  }
});

// ---------------------------------------------------------------------------
// Strategy / Quant endpoints
// ---------------------------------------------------------------------------

app.get("/api/strategies", async (_request, response, next) => {
  try {
    response.json(await listStrategies());
  } catch (error) {
    next(error);
  }
});

function loadPrecomputedFile() {
  const precomputedPath = join(dataDir, "precomputed", "backtest_results.json");
  if (!existsSync(precomputedPath)) {
    throw new Error("Pre-computed results not available. Run precompute_backtest.py first.");
  }
  return JSON.parse(readFileSync(precomputedPath, "utf-8"));
}

// Newer files expose `scenarios`; legacy files expose `markets` at the top level.
function resolveScenarios(raw: { scenarios?: Record<string, unknown>; markets?: Record<string, unknown> }) {
  if (raw.scenarios && typeof raw.scenarios === "object") {
    return raw.scenarios as Record<string, {
      id: string;
      label: string;
      description?: string;
      capital: number;
      capitalByMarket?: Record<string, number>;
      injectionSchedule: unknown;
      markets: Record<string, unknown>;
    }>;
  }
  // Backward compat — wrap legacy single-scenario file as one anonymous scenario.
  if (raw.markets) {
    return {
      legacy: {
        id: "legacy",
        label: "默认",
        capital: 100000,
        injectionSchedule: null,
        markets: raw.markets,
      },
    } as Record<string, {
      id: string;
      label: string;
      description?: string;
      capital: number;
      capitalByMarket?: Record<string, number>;
      injectionSchedule: unknown;
      markets: Record<string, unknown>;
    }>;
  }
  throw new Error("Pre-computed file is missing both `scenarios` and `markets`.");
}

app.get("/api/strategies/precomputed/index", (_request, response, next) => {
  try {
    const raw = loadPrecomputedFile();
    const scenarios = resolveScenarios(raw);
    const list = Object.values(scenarios).map((sc) => ({
      id: sc.id,
      label: sc.label,
      description: sc.description,
      capital: sc.capital,
      capitalByMarket: sc.capitalByMarket,
      injectionSchedule: sc.injectionSchedule ?? null,
      availableMarkets: Object.keys(sc.markets ?? {}),
    }));
    response.json({ computedAt: raw.computedAt, scenarios: list });
  } catch (error) {
    next(error);
  }
});

app.get("/api/strategies/precomputed", (_request, response, next) => {
  try {
    const market = String(_request.query.market ?? "us");
    const requestedScenario = _request.query.scenario ? String(_request.query.scenario) : undefined;
    const raw = loadPrecomputedFile();
    const scenarios = resolveScenarios(raw);
    const scenarioIds = Object.keys(scenarios);
    // An explicit but unknown scenario is a client error; silently serving
    // another scenario would mislabel the results.
    if (requestedScenario && !Object.hasOwn(scenarios, requestedScenario)) {
      throw new Error(`Unknown pre-computed scenario: ${requestedScenario}`);
    }
    const scenarioId = requestedScenario ?? scenarioIds[0];
    const scenario = scenarios[scenarioId];
    if (!scenario) {
      throw new Error("No pre-computed scenarios available.");
    }
    const marketResult = scenario.markets?.[market];
    if (!marketResult) {
      throw new Error(`No pre-computed results for market: ${market} in scenario ${scenarioId}`);
    }
    response.json({
      id: `precomputed_${scenarioId}_${market}`,
      scenarioId,
      computedAt: raw.computedAt,
      ...(marketResult as object),
    });
  } catch (error) {
    next(error);
  }
});

app.post("/api/strategies/backtest", async (request, response, next) => {
  try {
    const config = request.body as BacktestConfig;
    if (!config.strategies?.length) throw new Error("strategies is required");
    if (!config.market) throw new Error("market is required");
    const result = await runBacktest({
      strategies: config.strategies,
      market: config.market,
      years: config.years ?? 10,
      initialCapital: config.initialCapital ?? 100000,
      fixedFee: config.fixedFee ?? 2.0,
      txCost: config.txCost ?? 0.001,
      injectionSchedule: config.injectionSchedule,
    });
    response.json(result);
  } catch (error) {
    next(error);
  }
});

app.get("/api/strategies/results/:id", async (request, response, next) => {
  try {
    const result = await getCachedResult(request.params.id);
    if (!result) throw new Error("Result not found");
    response.json(result);
  } catch (error) {
    next(error);
  }
});

app.get("/api/strategies/live", async (request, response, next) => {
  try {
    const market = String(request.query.market ?? "us");
    const strategy = request.query.strategy ? String(request.query.strategy) : undefined;
    response.json(await getLiveStrategies(market, strategy));
  } catch (error) {
    next(error);
  }
});

app.use((error: unknown, _request: express.Request, response: express.Response, _next: express.NextFunction) => {
  const message = error instanceof Error ? error.message : "Unknown server error";
  response.status(400).json({ error: message });
});

setInterval(() => {
  void getDailyReport().catch((error) => {
    console.error("daily report refresh failed", error);
  });
}, 24 * 60 * 60 * 1000).unref();

app.listen(port, host, () => {
  console.log(`stock agent api listening at http://${host}:${port}`);
});

async function getDailyReport(forceSnapshots = false) {
  const now = Date.now();
  if (!forceSnapshots && cachedReport && now - cachedReportUpdatedAt < 24 * 60 * 60 * 1000) {
    return cachedReport;
  }

  const watchlist = await watchlistStore.list();
  cachedReport = await generateDailyReport(
    watchlist,
    {
      snapshot: (stock) => stockDataCache.snapshot(stock, forceSnapshots),
      candles: (stock) => dataProvider.candles(stock),
      fundamentals: (stock) => dataProvider.fundamentals(stock),
      relatedData: (stock) => dataProvider.relatedData(stock),
      quantAnalysis: (input) => dataProvider.quantAnalysis(input)
    },
    new Date()
  );
  cachedReportUpdatedAt = now;
  return cachedReport;
}

async function findWatchStock(symbolInput: string): Promise<WatchStock> {
  const normalized = normalizeSymbol(symbolInput);
  const stock = (await watchlistStore.list()).find((item) => item.display === normalized.display);
  if (!stock) {
    throw new Error("Stock is not in watchlist");
  }
  return stock;
}

function parseTags(value: unknown): string[] {
  if (Array.isArray(value)) {
    return value.map(String);
  }
  if (typeof value === "string") {
    return value.split(",");
  }
  return [];
}

function parsePeriod(value: unknown): ChartPeriod {
  return value === "W" || value === "M" || value === "Y" ? value : "D";
}