import type {
  AbilityAiHints,
  AbilityDefinition,
  AbilityRuneCost,
  AbilityTargetingRules,
} from "./abilityCatalog";

const CHAIN_ABILITIES = new Set(["chain heal", "chain lightning", "multi-shot", "prayer of mending"]);
const GROUND_ABILITIES = new Set([
  "blizzard", "rain of fire", "flamestrike", "death and decay", "consecration",
  "volley", "hurricane", "earthquake", "meteor", "healing rain",
]);
const CONE_ABILITIES = new Set([
  "cone of cold", "dragon's breath", "dragons breath", "shockwave", "cleave",
  "swipe", "swipe (cat)", "whirlwind",
]);
const BEHIND_ABILITIES = new Set(["backstab", "ambush", "garrote", "ravage", "shred", "pounce", "blind spot", "sneak attack"]);
const MOVEMENT_CAST_ABILITIES = new Set(["scorch", "steady shot", "spiritwalker's grace"]);
const EMERGENCY_HEAL_ABILITIES = new Set([
  "flash heal", "flash of light", "swiftmend", "lay on hands", "nature's swiftness",
]);
const AREA_HEAL_ABILITIES = new Set([
  "chain heal", "circle of healing", "divine hymn", "holy nova", "prayer of healing",
  "prayer of mending", "tranquility", "wild growth",
]);

const RUNE_COSTS_BY_SPELL_ID: Readonly<Record<number, AbilityRuneCost>> = Object.freeze({
  49909: { frost: 1 }, 45524: { frost: 1 }, 49184: { frost: 1 }, 47528: { frost: 1 },
  49921: { unholy: 1 }, 55271: { unholy: 1 }, 49222: { unholy: 1 }, 51052: { unholy: 1 },
  49930: { blood: 1 }, 55262: { blood: 1 }, 49941: { blood: 1 }, 50842: { blood: 1 },
  48982: { blood: 1 }, 49005: { blood: 1 },
  49924: { frost: 1, unholy: 1 }, 51425: { frost: 1, unholy: 1 },
  49938: { blood: 1, frost: 1, unholy: 1 },
});
const RUNE_COSTS_BY_NAME: Readonly<Record<string, AbilityRuneCost>> = Object.freeze({
  "icy touch": { frost: 1 }, "chains of ice": { frost: 1 }, "howling blast": { frost: 1 }, "mind freeze": { frost: 1 },
  "plague strike": { unholy: 1 }, "scourge strike": { unholy: 1 }, "bone shield": { unholy: 1 }, "anti-magic zone": { unholy: 1 },
  "blood strike": { blood: 1 }, "heart strike": { blood: 1 }, "blood boil": { blood: 1 }, "pestilence": { blood: 1 },
  "rune tap": { blood: 1 }, "mark of blood": { blood: 1 },
  "death strike": { frost: 1, unholy: 1 }, "obliterate": { frost: 1, unholy: 1 },
  "death and decay": { blood: 1, frost: 1, unholy: 1 },
});

export function targetingRulesForAbility(ability: AbilityDefinition): AbilityTargetingRules {
  if (ability.targeting) return ability.targeting;
  const name = ability.name.toLowerCase();
  const shape = CHAIN_ABILITIES.has(name)
    ? "chain"
    : GROUND_ABILITIES.has(name) || name.endsWith(" trap")
      ? "ground"
      : CONE_ABILITIES.has(name) || name.endsWith(" breath")
        ? "cone"
        : ability.radius && ability.radius > 0
          ? "circle"
          : "unit";
  const hostile = ability.target === "hostile" || ability.target === "any";
  return Object.freeze({
    shape,
    requiresLineOfSight: ability.target !== "self",
    // WoW friendly spells are deliberately facing independent.
    requiresFacing: hostile && shape !== "circle" && shape !== "ground",
    requiresBehindTarget: hostile && BEHIND_ABILITIES.has(name),
    attackArcRadians: shape === "cone" ? Math.PI / 2 : Math.PI,
    ...(ability.radius ? { radius: ability.radius } : {}),
    ...(shape === "chain" ? { maximumTargets: 3, jumpRange: name === "multi-shot" ? 10 : 12 } : {}),
    ...(shape === "ground" ? { groundRange: ability.range.max > 0 ? ability.range.max : name.endsWith(" trap") || name === "consecration" ? 0 : 30, radius: ability.radius ?? 8 } : {}),
  });
}

export function canAbilityCastWhileMoving(ability: AbilityDefinition): boolean {
  return ability.castRules?.canCastWhileMoving ?? MOVEMENT_CAST_ABILITIES.has(ability.name.toLowerCase());
}

export function abilityRequiresOutOfCombat(ability: AbilityDefinition): boolean {
  return (ability.source === "runewaker" || ability.source === "wow335-progression")
    && /\bcannot be used (?:when already )?in combat\b/i.test(ability.description);
}

export function abilityPushbackResistance(ability: AbilityDefinition): number {
  if (ability.castRules?.pushbackImmune) return 1;
  return Math.max(0, Math.min(1, ability.castRules?.pushbackResistance ?? 0));
}

/** WotLK 3.3.5 rune costs for the active DK toolkit imported by the game. */
export function runeCostForAbility(ability: AbilityDefinition): AbilityRuneCost | null {
  if (ability.runeCost) return ability.runeCost;
  return RUNE_COSTS_BY_SPELL_ID[ability.dbcSpellId]
    ?? RUNE_COSTS_BY_NAME[ability.name.toLowerCase()]
    ?? null;
}

export function aiHintsForAbility(ability: AbilityDefinition): AbilityAiHints {
  if (ability.ai) return ability.ai;
  const name = ability.name.toLowerCase();
  const categories = new Set<AbilityAiHints["categories"][number]>();
  for (const effect of ability.effects) {
    if (["damage", "dot", "finisher-damage"].includes(effect.kind)) categories.add("damage");
    if (effect.kind === "execute") categories.add("execute");
    if (effect.kind === "heal" || effect.kind === "hot" || effect.kind === "sacrifice-minion") categories.add("heal");
    if (effect.kind === "shield") categories.add("mitigation");
    if (effect.kind === "taunt") categories.add("taunt");
    if (effect.kind === "interrupt") categories.add("interrupt");
    if (effect.kind === "dispel" || effect.kind === "dispel-mechanic") categories.add("dispel");
    if (effect.kind === "resurrection") categories.add("resurrection");
    if (effect.kind === "status") {
      categories.add(effect.status === "interrupt" ? "interrupt" : "control");
    }
    if (effect.kind === "dot" || (effect.kind === "apply-aura" && effect.aura.disposition === "debuff")) categories.add("debuff");
    if (effect.kind === "apply-aura" && effect.aura.disposition === "buff") categories.add("buff");
    if (effect.kind === "apply-aura" && (
      effect.aura.absorbs?.length
      || effect.aura.modifiers?.some((modifier) => modifier.kind === "damage"
        && modifier.direction === "taken" && modifier.value < 0)
      || effect.aura.modifiers?.some((modifier) => modifier.kind === "stat"
        && ["block", "dodge", "parry"].includes(modifier.stat)
        && modifier.value > 0)
    )) categories.add("mitigation");
    if (effect.kind === "apply-aura" && effect.aura.modifiers?.some((modifier) => (
      modifier.kind === "stat" && modifier.stat === "threat"
    ))) categories.add("threat");
    if (effect.kind === "apply-aura" && effect.aura.modifiers?.some((modifier) => modifier.kind === "resource")) {
      categories.add("resource");
    }
    if (effect.kind === "resource" || effect.kind === "rune") categories.add("resource");
    if (effect.kind === "summon" || effect.kind === "totem") categories.add("summon");
    if (effect.kind === "pet") categories.add("pet");
    if (effect.kind === "movement" || effect.kind === "pull") categories.add("movement");
    if (effect.kind === "threat") categories.add("threat");
  }
  if (EMERGENCY_HEAL_ABILITIES.has(name)) categories.add("emergency-heal");
  if (((ability.radius ?? 0) > 0 || AREA_HEAL_ABILITIES.has(name)) && categories.has("heal")) categories.add("area-heal");
  const targeting = targetingRulesForAbility(ability);
  if (categories.has("damage") && (
    targeting.shape !== "unit"
    || (targeting.maximumTargets ?? 1) > 1
    || (targeting.radius ?? ability.radius ?? 0) > 0
  )) categories.add("area-damage");
  return Object.freeze({ categories: Object.freeze([...categories]) });
}