feat: add Top Holders

website/src/routes/api/coin/[coinSymbol]/holders/+server.ts

@@ -0,0 +1,107 @@
+import { error, json } from '@sveltejs/kit';
+import { db } from '$lib/server/db';
+import { coin, userPortfolio, user } from '$lib/server/db/schema';
+import { eq, desc } from 'drizzle-orm';
+import { validateSearchParams } from '$lib/utils/validation';
+
+function calculateLiquidationValue(tokensToSell: number, poolCoinAmount: number, poolBaseCurrencyAmount: number): number {
+    if (tokensToSell <= 0 || poolCoinAmount <= 0 || poolBaseCurrencyAmount <= 0) {
+        return 0;
+    }
+
+    const maxSellable = poolCoinAmount * 0.995;
+    const actualTokensToSell = Math.min(tokensToSell, maxSellable);
+    const k = poolCoinAmount * poolBaseCurrencyAmount;
+    const newPoolCoin = poolCoinAmount + actualTokensToSell;
+    const newPoolBaseCurrency = k / newPoolCoin;
+    const baseCurrencyReceived = poolBaseCurrencyAmount - newPoolBaseCurrency;
+
+    return Math.max(0, baseCurrencyReceived);
+}
+
+export async function GET({ params, url }) {
+    const coinSymbol = params.coinSymbol?.toUpperCase();
+    const validator = validateSearchParams(url.searchParams);
+    const limit = validator.getPositiveInt('limit', 50);
+
+    if (!coinSymbol) {
+        throw error(400, 'Coin symbol is required');
+    }
+
+    if (limit > 200) {
+        throw error(400, 'Limit cannot exceed 200');
+    }
+
+    try {
+        const [coinData] = await db
+            .select({
+                id: coin.id,
+                symbol: coin.symbol,
+                circulatingSupply: coin.circulatingSupply,
+                poolCoinAmount: coin.poolCoinAmount,
+                poolBaseCurrencyAmount: coin.poolBaseCurrencyAmount,
+                currentPrice: coin.currentPrice
+            })
+            .from(coin)
+            .where(eq(coin.symbol, coinSymbol))
+            .limit(1);
+
+        if (!coinData) {
+            throw error(404, 'Coin not found');
+        }
+
+        const holders = await db
+            .select({
+                userId: user.id,
+                username: user.username,
+                name: user.name,
+                image: user.image,
+                quantity: userPortfolio.quantity
+            })
+            .from(userPortfolio)
+            .innerJoin(user, eq(userPortfolio.userId, user.id))
+            .where(eq(userPortfolio.coinId, coinData.id))
+            .orderBy(desc(userPortfolio.quantity))
+            .limit(limit);
+
+        const totalCirculating = Number(coinData.circulatingSupply);
+        const poolCoinAmount = Number(coinData.poolCoinAmount);
+        const poolBaseCurrencyAmount = Number(coinData.poolBaseCurrencyAmount);
+
+        const processedHolders = holders.map((holder, index) => {
+            const quantity = Number(holder.quantity);
+            const percentage = totalCirculating > 0 ? (quantity / totalCirculating) * 100 : 0;
+            const liquidationValue = calculateLiquidationValue(quantity, poolCoinAmount, poolBaseCurrencyAmount);
+
+            return {
+                rank: index + 1,
+                userId: holder.userId,
+                username: holder.username,
+                name: holder.name,
+                image: holder.image,
+                quantity,
+                percentage,
+                liquidationValue
+            };
+        });
+
+        return json({
+            coinSymbol: coinData.symbol,
+            totalHolders: holders.length,
+            circulatingSupply: totalCirculating,
+            poolInfo: {
+                coinAmount: poolCoinAmount,
+                baseCurrencyAmount: poolBaseCurrencyAmount,
+                currentPrice: Number(coinData.currentPrice)
+            },
+            holders: processedHolders
+        });
+
+    } catch (e) {
+        if (e && typeof e === 'object' && 'status' in e) {
+            throw e;
+        }
+        console.error('Unexpected error in holders API:', e);
+        throw error(500, 'Internal server error');
+    }
+}