// Research tree. A technology costs research points and may require earlier
// technologies before it can be started.
//
// Research is focused: a nation picks one technology, and every research point
// it creates is applied to it, month on month, until it is discovered. A
// `repeatable` technology may be researched again and again, each level costing
// `repeatCostGrowth` more than the last, and unlike a discovery it raises no
// news event (it only notifies the player).

import {
  EFFECT_PRODUCTION,
  EFFECT_RESEARCH,
  EFFECT_CULTURE,
  EFFECT_INFANTRY_ATTACK,
  EFFECT_INFANTRY_DEFENSE,
  EFFECT_ARTILLERY_ATTACK,
  EFFECT_CONSTRUCTION_SPEED,
  EFFECT_RAIL_SPEED,
  EFFECT_ENERGY_EFFICIENCY,
  EFFECT_STEEL_EFFICIENCY,
  EFFECT_FOOD_EFFICIENCY,
  EFFECT_LUXURY_EFFICIENCY,
  EFFECT_HIGHTECH_EFFICIENCY,
  effect,
} from "./effects.js";

// The tabs the technology panel groups research under.
export const TECH_THEMES = [
  { id: "science", name: "Science" },
  { id: "economy", name: "Economy" },
  { id: "society", name: "Society" },
  { id: "military", name: "Military" },
];

export const TECHNOLOGIES = [
  {
    id: "scientific_method",
    name: "Scientific Method",
    description: "A disciplined approach to experiment and evidence. Lays the groundwork for every later technology.",
    theme: "science",
    cost: 20,
    prerequisites: [],
    effects: [effect(EFFECT_RESEARCH, 1.0, 1.0), effect(EFFECT_PRODUCTION, 0.02, 1.0)],
  },
  {
    id: "industrial_automation",
    name: "Industrial Automation",
    description: "Robotics and control systems take over the factory floor, lifting national production.",
    theme: "economy",
    repeatable: true,
    cost: 60,
    prerequisites: ["scientific_method"],
    effects: [effect(EFFECT_PRODUCTION, 0.08, 1.0)],
  },
  {
    id: "renewable_energy",
    name: "Renewable Energy",
    description: "Clean generation cuts waste and lifts national production.",
    theme: "economy",
    cost: 80,
    prerequisites: ["scientific_method"],
    effects: [effect(EFFECT_PRODUCTION, 0.03, 1.0)],
  },
  {
    id: "quantum_computing",
    name: "Quantum Computing",
    description: "Machines that reason in superposition. A step change in the pace of discovery.",
    theme: "science",
    cost: 120,
    prerequisites: ["scientific_method"],
    effects: [effect(EFFECT_RESEARCH, 4.0, 1.0)],
  },
  {
    id: "space_program",
    name: "Space Program",
    description: "Reaching orbit inspires the nation and spins off technology across the economy.",
    theme: "science",
    cost: 300,
    prerequisites: ["industrial_automation", "quantum_computing"],
    effects: [effect(EFFECT_CULTURE, 3.0, 1.0), effect(EFFECT_PRODUCTION, 0.05, 1.0)],
  },
  {
    id: "fusion_power",
    name: "Fusion Power",
    description: "Controlled fusion. The key to the fusion power plant, and the most expensive research a nation can undertake.",
    theme: "science",
    // 500,000 research points, a lifetime's work for a mature nation.
    cost: 5_000,
    prerequisites: ["space_program", "quantum_computing"],
    effects: [effect(EFFECT_RESEARCH, 8.0, 1.0)],
  },

  // Repeatable levels. Each raises a single stat by 1% of its base value.
  {
    id: "infantry_weapons",
    name: "Infantry Weapons",
    description: "Better small arms and training raise the damage infantry deal.",
    theme: "military",
    cost: 40,
    repeatable: true,
    repeatCostGrowth: 0.02,
    prerequisites: ["scientific_method"],
    effects: [effect(EFFECT_INFANTRY_ATTACK, 0.01, 1.0)],
  },
  {
    id: "body_armour",
    name: "Body Armour",
    description: "Personal protection raises infantry base defense.",
    theme: "military",
    cost: 40,
    repeatable: true,
    repeatCostGrowth: 0.02,
    prerequisites: ["scientific_method"],
    effects: [effect(EFFECT_INFANTRY_DEFENSE, 0.01, 1.0)],
  },
  {
    id: "artillery_shells",
    name: "Artillery Shells",
    description: "Improved propellant and shells raise the damage artillery deal.",
    theme: "military",
    cost: 50,
    repeatable: true,
    repeatCostGrowth: 0.02,
    prerequisites: ["scientific_method"],
    effects: [effect(EFFECT_ARTILLERY_ATTACK, 0.01, 1.0)],
  },
  {
    id: "construction_technology",
    name: "Construction Technology",
    description: "Better methods and machines speed every building and unit the nation produces.",
    theme: "economy",
    cost: 50,
    repeatable: true,
    repeatCostGrowth: 0.02,
    prerequisites: ["scientific_method"],
    effects: [effect(EFFECT_CONSTRUCTION_SPEED, 0.01, 1.0)],
  },
  {
    id: "trains_technology",
    name: "Trains Technology",
    description: "Faster locomotives raise movement speed along railways.",
    theme: "economy",
    cost: 50,
    repeatable: true,
    repeatCostGrowth: 0.02,
    prerequisites: ["scientific_method"],
    effects: [effect(EFFECT_RAIL_SPEED, 0.01, 1.0)],
  },

  // Efficiency research: one repeatable technology per commodity that raises the
  // output the nation gets from each unit of energy. Each level adds 5% to that
  // commodity's output per input, so the power drawn to make it falls.
  {
    id: "efficient_generation",
    name: "Efficient Generation",
    description: "Better turbines and heat recovery wring more electricity from every tonne of fuel.",
    theme: "economy",
    cost: 50,
    repeatable: true,
    repeatCostGrowth: 0.03,
    prerequisites: ["renewable_energy"],
    effects: [effect(EFFECT_ENERGY_EFFICIENCY, 0.05, 1.0)],
  },
  {
    id: "advanced_metallurgy",
    name: "Advanced Metallurgy",
    description: "Continuous casting and heat recycling smelt more steel for less power.",
    theme: "economy",
    cost: 50,
    repeatable: true,
    repeatCostGrowth: 0.03,
    prerequisites: ["industrial_automation"],
    effects: [effect(EFFECT_STEEL_EFFICIENCY, 0.05, 1.0)],
  },
  {
    id: "precision_agriculture",
    name: "Precision Agriculture",
    description: "Climate-controlled growing and tailored feed raise the food won from each unit of power, on the land and in synthesis.",
    theme: "economy",
    cost: 50,
    repeatable: true,
    repeatCostGrowth: 0.03,
    prerequisites: ["scientific_method"],
    effects: [effect(EFFECT_FOOD_EFFICIENCY, 0.05, 1.0)],
  },
  {
    id: "automated_extraction",
    name: "Automated Extraction",
    description: "Automated mines and sorting win more gold and diamonds for the same power.",
    theme: "economy",
    cost: 50,
    repeatable: true,
    repeatCostGrowth: 0.03,
    prerequisites: ["industrial_automation"],
    effects: [effect(EFFECT_LUXURY_EFFICIENCY, 0.05, 1.0)],
  },
  {
    id: "advanced_lithography",
    name: "Advanced Lithography",
    description: "Finer process nodes pack more chips onto every wafer, cutting the power each component costs.",
    theme: "science",
    cost: 80,
    repeatable: true,
    repeatCostGrowth: 0.03,
    prerequisites: ["quantum_computing"],
    effects: [effect(EFFECT_HIGHTECH_EFFICIENCY, 0.05, 1.0)],
  },
];

export function technologyById(id) {
  return TECHNOLOGIES.find((t) => t.id === id) || null;
}

// Research is deliberately expensive: the catalogue lists the thematic base
// price, and every effective cost is scaled by this factor. Keeping the scale
// in one place lets the whole tree be retuned without touching each entry.
export const RESEARCH_COST_MULTIPLIER = 100;

// The cost of the next level of a technology given how many times it has been
// researched already. Non-repeatable technologies cost the same either way.
export function technologyCost(proto, repeatCount = 0) {
  if (!proto) return 0;
  const base = proto.cost * RESEARCH_COST_MULTIPLIER;
  if (!proto.repeatable) return base;
  const growth = proto.repeatCostGrowth || 0;
  return base * Math.pow(1 + growth, Math.max(0, repeatCount));
}