reinstate economics logic

modules/trade-generator.js

@@ -0,0 +1,239 @@
+'use strict';
+
+window.Trade = (function () {
+  const defineCenters = () => {
+    TIME && console.time('defineCenters');
+    pack.trade = {centers: [], deals: []};
+    const {burgs, trade} = pack;
+
+    // min distance between trade centers
+    let minSpacing = (((graphWidth + graphHeight) * 2) / burgs.length ** 0.7) | 0;
+
+    const tradeScore = burgs.map(({i, removed, capital, port, population, produced}) => {
+      if (!i || removed) return {i: 0, score: 0};
+      const totalProduction = d3.sum(Object.values(produced));
+      let score = Math.round(totalProduction - population);
+      if (capital) score *= 2;
+      if (port) score *= 2;
+      return {i, score};
+    });
+
+    const candidatesSorted = tradeScore.sort((a, b) => b.score - a.score);
+    const centersTree = d3.quadtree();
+
+    for (const {i: burgId} of candidatesSorted) {
+      if (!burgId) continue;
+      const burg = burgs[burgId];
+      const {x, y} = burg;
+
+      const tradeCenter = centersTree.find(x, y, minSpacing);
+
+      if (tradeCenter) {
+        const tradeCenterId = tradeCenter[2];
+        burg.tradeCenter = tradeCenterId;
+        trade.centers[tradeCenterId].burgs.push({i: burgId});
+      } else {
+        const tradeCenterId = trade.centers.length;
+        trade.centers.push({i: tradeCenterId, burg: burgId, burgs: [{i: burgId}]});
+        centersTree.add([x, y, tradeCenterId]);
+        burg.tradeCenter = tradeCenterId;
+      }
+
+      minSpacing += 1;
+    }
+
+    // TODO: remove debug rendering
+    for (const burg of burgs) {
+      const {i, x: x1, y: y1, tradeCenter} = burg;
+      if (!i) continue;
+
+      const center = trade.centers[tradeCenter];
+      const {x: x2, y: y2} = burgs[center.burg];
+      debug.append('line').attr('x1', x1).attr('y1', y1).attr('x2', x2).attr('y2', y2).attr('stroke', 'black').attr('stroke-width', 0.2);
+    }
+    for (const {i, score} of candidatesSorted) {
+      if (!i) continue;
+      const {x, y, capital} = burgs[i];
+      debug
+        .append('text')
+        .attr('x', x)
+        .attr('y', y)
+        .style('font-size', capital ? 5 : 3)
+        .style('fill', 'blue')
+        .text(score);
+    }
+    for (const tradeCenter of trade.centers) {
+      const {x, y} = burgs[tradeCenter.burg];
+      debug
+        .append('circle')
+        .attr('cx', x - 4)
+        .attr('cy', y - 4)
+        .attr('r', 2)
+        .style('stroke', '#000')
+        .style('stroke-width', 0.2)
+        .style('fill', 'white');
+      debug
+        .append('text')
+        .attr('x', x - 4)
+        .attr('y', y - 4)
+        .style('font-size', 3)
+        .text(tradeCenter.i);
+    }
+
+    TIME && console.timeEnd('defineCenters');
+  };
+
+  const calculateDistances = () => {
+    TIME && console.time('calculateDistances');
+    const {cells, burgs, trade} = pack;
+    const {centers} = trade;
+
+    const getCost = (dist, sameFeature, sameFeaturePorts) => {
+      if (sameFeaturePorts) return dist / 2;
+      if (sameFeature) return dist;
+      return dist * 1.5;
+    };
+
+    const costs = new Array(centers.length);
+    for (let i = 0; i < centers.length; i++) {
+      costs[i] = new Array(centers.length);
+      const {x: x1, y: y1, port: port1, cell: cell1} = burgs[centers[i].burg];
+
+      for (let j = i + 1; j < centers.length; j++) {
+        const {x: x2, y: y2, port: port2, cell: cell2} = burgs[centers[j].burg];
+        const distance = Math.hypot(x1 - x2, y1 - y2);
+        const sameFeature = cells.f[cell1] === cells.f[cell2];
+        const sameFeaturePorts = port1 && port2 && port1 === port2;
+        costs[i][j] = getCost(distance, sameFeature, sameFeaturePorts) | 0;
+      }
+    }
+
+    for (const center of centers) {
+      // nearers trade centers
+      center.nearest = centers.map(({i}) => {
+        const cost = center.i < i ? costs[center.i][i] : costs[i][center.i];
+        return {i, cost: cost || 0};
+      });
+      center.nearest.sort((a, b) => a.cost - b.cost);
+
+      // distance cost to burgs
+      const {x: x1, y: y1, port: port1, cell: cell1} = burgs[center.burg];
+      center.burgs = center.burgs.map(({i: burgId}) => {
+        const {x: x2, y: y2, port: port2, cell: cell2} = burgs[burgId];
+
+        const distance = Math.hypot(x1 - x2, y1 - y2);
+        const sameFeature = cells.f[cell1] === cells.f[cell2];
+        const sameFeaturePorts = port1 && port2 && port1 === port2;
+        const cost = getCost(distance, sameFeature, sameFeaturePorts) | 0;
+        return {i: burgId, cost};
+      });
+    }
+
+    TIME && console.timeEnd('calculateDistances');
+  };
+
+  const exportGoods = () => {
+    const {burgs, states, trade} = pack;
+    const DEFAULT_TRANSPORT_DIST = (graphWidth + graphHeight) / 20;
+
+    for (const tradeCenter of trade.centers) {
+      const {i: centerId, burgs: centerBurgs} = tradeCenter;
+      const tradeCenterGoods = {};
+
+      for (const {i: burgId, cost: distanceCost} of centerBurgs) {
+        const burg = burgs[burgId];
+        const {i, removed, produced, population, state} = burg;
+        if (!i || removed) continue;
+        const consumption = Math.ceil(population);
+        const exportPool = {};
+
+        const transportFee = (distanceCost / DEFAULT_TRANSPORT_DIST) ** 0.8 || 0.02;
+        const salesTax = states[state].salesTax || 0;
+        let income = 0;
+
+        const categorized = {};
+        for (const resourceId in produced) {
+          const {category} = Resources.get(+resourceId);
+          if (!categorized[category]) categorized[category] = {};
+          categorized[category][resourceId] = produced[resourceId];
+        }
+
+        for (const category in categorized) {
+          const categoryProduction = d3.sum(Object.values(categorized[category]));
+          const exportQuantity = categoryProduction - consumption;
+          if (exportQuantity <= 0) continue;
+
+          for (const resourceId in categorized[category]) {
+            const production = categorized[category][resourceId];
+            const quantity = Math.round((production / categoryProduction) * exportQuantity);
+            if (quantity <= 0) continue;
+
+            const {value, name} = Resources.get(+resourceId);
+
+            const basePrice = value * quantity;
+            const transportCost = rn((value * quantity) ** 0.5 * transportFee, 1);
+            const netPrice = basePrice - transportCost;
+
+            const stateIncome = rn(netPrice * salesTax, 1);
+            const burgIncome = rn(netPrice - stateIncome, 1);
+
+            if (burgIncome < 1 || burgIncome < basePrice / 4) continue;
+
+            trade.deals.push({resourceId: +resourceId, name, quantity, exporter: i, tradeCenter: centerId, basePrice, transportCost, stateIncome, burgIncome});
+            income += burgIncome;
+
+            if (!exportPool[resourceId]) exportPool[resourceId] = quantity;
+            else exportPool[resourceId] += quantity;
+
+            if (!tradeCenterGoods[resourceId]) tradeCenterGoods[resourceId] = quantity;
+            else tradeCenterGoods[resourceId] += quantity;
+          }
+        }
+
+        burg.exported = exportPool;
+        burg.income = income;
+      }
+
+      tradeCenter.supply = tradeCenterGoods;
+    }
+  };
+
+  const importGoods = () => {
+    const {resources, burgs, states, trade} = pack;
+
+    for (const burg of burgs) {
+      const {i, removed, tradeCenter: localTradeCenterId, x, y, produced, population} = burg;
+      if (!i || removed) continue;
+
+      const importPool = {};
+      const localTradeCenter = trade.centers[localTradeCenterId];
+
+      let demand = Math.ceil(population);
+
+      for (const resource of resources) {
+        const {i: resourceId, value, category} = resource;
+        if (produced[resourceId]) continue;
+
+        // check for resource supply on markets starting from closest
+        for (const {i: tradeCenterId, cost: transportCost} of localTradeCenter.nearest) {
+          const tradeCenter = trade.centers[tradeCenterId];
+          const stored = tradeCenter.supply[resourceId];
+          if (!stored) continue;
+
+          const quantity = Math.min(demand, stored);
+          importPool[resourceId] = quantity;
+
+          break;
+
+          tradeCenter.supply[resourceId] -= quantity;
+          demand -= quantity;
+          if (demand <= 0) break;
+        }
+      }
+
+      burg.imported = importPool;
+    }
+  };
+
+  return {defineCenters, calculateDistances, exportGoods, importGoods};
+})();