'use server';

import { db } from '@/db';
import { portfolioSnapshots } from '@/db/schema';
import { getPortfolioPositions } from './portfolio';
import { eq, sql } from 'drizzle-orm';
import Big from 'big.js';

function getTodayInShanghai(): string {
  const now = new Date();
  const utcStr = now.toLocaleString('en-US', { timeZone: 'UTC' });
  const utcDate = new Date(utcStr);
  const shanghaiOffset = 8 * 60 * 60 * 1000;
  const shanghaiDate = new Date(utcDate.getTime() + shanghaiOffset);
  const year = shanghaiDate.getFullYear();
  const month = String(shanghaiDate.getMonth() + 1).padStart(2, '0');
  const day = String(shanghaiDate.getDate()).padStart(2, '0');
  return `${year}-${month}-${day}`;
}

export async function recordDailySnapshot() {
  const positions = await getPortfolioPositions();

  const totalValueCny = positions.reduce(
    (sum, pos) => sum.plus(pos.cnyValue || '0'),
    new Big(0)
  ).toString();

  const totalCostCny = positions.reduce(
    (sum, pos) => sum.plus(pos.totalCostCny || '0'),
    new Big(0)
  ).toString();

  const dateStr = getTodayInShanghai();

  const existing = await db
    .select()
    .from(portfolioSnapshots)
    .where(eq(portfolioSnapshots.date, dateStr))
    .limit(1);

  const now = new Date();

  if (existing.length > 0) {
    await db
      .update(portfolioSnapshots)
      .set({
        totalValueCny,
        totalCostCny,
        updatedAt: now,
      })
      .where(eq(portfolioSnapshots.date, dateStr));

    return {
      success: true,
      action: 'updated',
      date: dateStr,
      totalValueCny,
      totalCostCny,
    };
  }

  await db
    .insert(portfolioSnapshots)
    .values({
      date: dateStr,
      totalValueCny,
      totalCostCny,
      createdAt: now,
      updatedAt: now,
    });

  return {
    success: true,
    action: 'inserted',
    date: dateStr,
    totalValueCny,
    totalCostCny,
  };
}

export async function getSnapshots(params?: {
  limit?: number;
  startDate?: string;
  endDate?: string;
}) {
  const { limit = 365, startDate, endDate } = params || {};

  let query = db
    .select()
    .from(portfolioSnapshots)
    .orderBy(sql`"${date}" DESC`);

  if (startDate) {
    query = query.where(sql`"${date}" >= ${startDate}`);
  }
  if (endDate) {
    query = query.where(sql`"${date}" <= ${endDate}`);
  }

  const snapshots = await query.limit(limit);

  return snapshots.reverse();
}