import { TestCase } from "./framework/test_case.js";
import { smallState } from "./framework/helpers.js";
import { key } from "../shared/hex.js";
import {
  RESOURCE_IDS,
  RESOURCE_EFFICIENCY_EFFECT,
  TECHNOLOGIES,
} from "../shared/data.js";
import { producerEnergyPerDay } from "../shared/resources.js";

// Puts a resource building on the first free land tile of `civ`.
function placeProducer(state, id, civ = 0) {
  for (const coords of state._territoryByCiv.get(civ) || []) {
    if (state.cityAt(coords)) continue;
    if (!state._isLand(coords)) continue;
    const k = key(coords.x, coords.y);
    if (state.tileImprovements.has(k)) continue;
    state.tileImprovements.set(k, id);
    state.tileImprovementOwner.set(k, civ);
    state.tileImprovementHp.set(k, 1000);
    state._ensureResourceStock(k);
    state._ensureBuildingAgent(k);
    return { coords, k };
  }
  return null;
}

// Studies one level of a repeatable technology for a nation.
function research(state, civ, id) {
  const index = state.technologies.findIndex((tech) => tech.id === id);
  state.researched.get(civ).add(index);
  const counts = state.repeatCounts.get(civ);
  counts.set(id, (counts.get(id) || 0) + 1);
  state._touchModifiers();
}

export class ResourceEfficiencyDataTest extends TestCase {
  test_there_is_exactly_one_efficiency_technology_per_resource() {
    for (const resource of RESOURCE_IDS) {
      const stat = RESOURCE_EFFICIENCY_EFFECT[resource];
      const matching = TECHNOLOGIES.filter(
        (tech) => (tech.effects || []).some((e) => e.stat === stat)
      );
      this.assertSize(matching, 1, `one technology raises ${resource} output per input`);
      this.assertTrue(matching[0].repeatable, `${resource} efficiency is repeatable`);
    }
  }
}

export class ResourceEfficiencyModelTest extends TestCase {
  test_efficiency_is_zero_until_the_technology_is_researched() {
    const state = smallState();
    this.assertApprox(state.resourceEfficiency(0, "steel"), 0);
    research(state, 0, "advanced_metallurgy");
    this.assertApprox(state.resourceEfficiency(0, "steel"), 0.05);
    research(state, 0, "advanced_metallurgy");
    this.assertApprox(state.resourceEfficiency(0, "steel"), 0.10, 1e-9);
    this.assertApprox(state.resourceEfficiency(1, "steel"), 0, 1e-9, "research is national");
  }

  test_steel_efficiency_cuts_the_mill_s_energy_draw() {
    const state = smallState();
    const placed = placeProducer(state, "steel_mill");
    const components = state._resourceLandComponents();
    const componentId = components.get(placed.k);
    const draw = () => state._buildEnergyLedger(components).get(componentId).converters
      .find((entry) => entry.k === placed.k).amount;
    const before = draw();
    this.assertGreater(before, 0);
    research(state, 0, "advanced_metallurgy");
    const after = draw();
    this.assertApprox(before / after, 1.05, 1e-6, "the same steel costs 5% less power");
  }

  test_energy_efficiency_cuts_the_plant_s_fuel() {
    const state = smallState();
    const placed = placeProducer(state, "coal_power_plant");
    const components = state._resourceLandComponents();
    const componentId = components.get(placed.k);
    const fuel = () => state._buildEnergyLedger(components).get(componentId).fuelEnergy;
    const before = fuel();
    this.assertGreater(before, 0);
    research(state, 0, "efficient_generation");
    const after = fuel();
    this.assertApprox(before / after, 1.05, 1e-6, "the same power burns 5% less fuel");
  }

  test_every_efficiency_technology_reads_back_on_its_own_resource() {
    const state = smallState();
    const byResource = {
      energy: "efficient_generation",
      steel: "advanced_metallurgy",
      food: "precision_agriculture",
      luxury: "automated_extraction",
      hightech: "advanced_lithography",
    };
    for (const [resource, tech] of Object.entries(byResource)) {
      research(state, 0, tech);
      this.assertApprox(state.resourceEfficiency(0, resource), 0.05, 1e-9, resource);
    }
  }

  test_food_efficiency_cuts_the_harvest_s_energy() {
    const state = smallState();
    this.assertApprox(
      state._foodHarvestEnergy(0, 1000), producerEnergyPerDay("food", 1000)
    );
    research(state, 0, "precision_agriculture");
    this.assertApprox(
      state._foodHarvestEnergy(0, 1000), producerEnergyPerDay("food", 1000) / 1.05, 1e-6,
      "better farming grows the same food for less power"
    );
  }
}