import {
  abilitiesForCharacter,
  learnedAbilityForBuild,
  type AbilityDefinition,
  type AbilityEffect,
  type ResourceType,
} from "./abilityCatalog";
import { aiHintsForAbility, runeCostForAbility } from "./abilityRules";
import {
  evaluateCombatRotation,
  type RotationDecision,
  type RotationFriendlyTarget,
} from "./combatRotation";
import { spendDeathKnightRunes } from "./combatResources";
import { equipmentAdjustedCombatAmount, type MobCombatState } from "./combatStore";
import type { PartyMember } from "./partyStore";
import { baseResourcesFor } from "./wotlkStats";
import { companionResourceMaximum } from "./combatActorAuthority";

export interface PartyAbilityContext {
  readonly now: number;
  readonly target: MobCombatState | null;
  readonly targetIsLoose?: boolean;
  readonly hasDangerousThreat?: boolean;
  readonly requiredControl?: boolean;
  readonly allyNeedsDispel?: boolean;
  readonly fallenAlly?: boolean;
  readonly injuredAllies?: number;
  readonly lowestHealthFraction?: number;
  readonly hostileCount?: number;
  readonly friendlyTargets?: readonly RotationFriendlyTarget[];
  readonly maintainedAbilityIds?: ReadonlySet<string>;
  readonly activeAuraExclusiveGroups?: ReadonlySet<string>;
  readonly activeSummonAbilityIds?: ReadonlySet<string>;
  readonly hasActivePet?: boolean;
  readonly canUseAbility?: (ability: AbilityDefinition) => boolean;
}

function currentResource(member: PartyMember, type: ResourceType): number {
  return member.resourcePools[type] ?? (type === member.resourceType ? member.resource : 0);
}

function abilityCosts(member: PartyMember, ability: AbilityDefinition): readonly { resource: ResourceType; amount: number }[] {
  return (ability.costs?.length ? ability.costs : [ability.cost]).map((cost) => ({
    resource: cost.resource,
    amount: cost.percentage ? cost.amount / 100 * (cost.percentageBasis === "base-mana"
      ? baseResourcesFor(member.classId, member.level).mana
      : cost.resource === "health" ? member.maxHealth : companionResourceMaximum(member, cost.resource)) : cost.amount,
  }));
}

export function partyAbilityIsReady(member: PartyMember, ability: AbilityDefinition, now: number): boolean {
  if (ability.passive || !learnedAbilityForBuild(ability, member.level, member.talentRanks)) return false;
  if (member.globalCooldownEndsAt > now || (member.cooldowns[ability.id] ?? 0) > now) return false;
  if ((member.schoolLockedUntil[ability.castRules?.school ?? "physical"] ?? 0) > now) return false;
  if (aiHintsForAbility(ability).categories.includes("taunt") && member.tauntReadyAt > now) return false;
  if (abilityCosts(member, ability).some(cost => cost.resource === "health"
    ? member.health <= cost.amount : currentResource(member, cost.resource) < cost.amount)) return false;
  const runeCost = member.classId === "death-knight" ? runeCostForAbility(ability) : null;
  return !runeCost || spendDeathKnightRunes(member.runes, runeCost, now) !== null;
}

function candidateAbilities(member: PartyMember, now: number): readonly AbilityDefinition[] {
  return abilitiesForCharacter(member.classId, member.secondaryClassId)
    .map((ability) => learnedAbilityForBuild(ability, member.level, member.talentRanks))
    .filter((ability): ability is AbilityDefinition => ability !== null)
    .filter((ability) => partyAbilityIsReady(member, ability, now));
}

export function choosePartyRotationDecision(
  member: PartyMember,
  context: PartyAbilityContext,
): RotationDecision | null {
  const friendlyTargets = context.friendlyTargets ?? (context.fallenAlly || context.allyNeedsDispel
    || (context.lowestHealthFraction ?? 1) < 1
    ? [{
        id: "rotation-friendly-target",
        health: (context.lowestHealthFraction ?? 1) * 100,
        maxHealth: 100,
        fallen: context.fallenAlly,
        needsDispel: context.allyNeedsDispel,
      }]
    : []);
  const maximumResources = Object.fromEntries(
    [...new Set([...Object.keys(member.resourcePools), member.resourceType])]
      .map((resource) => [resource, companionResourceMaximum(member, resource)]),
  );
  return evaluateCombatRotation({
    now: context.now,
    classId: member.classId,
    secondaryClassId: member.secondaryClassId,
    specializationId: member.specializationId,
    specialization: member.specialization,
    role: member.role,
    level: member.level,
    health: member.health,
    maxHealth: member.maxHealth,
    selfId: member.id,
    resources: member.resourcePools,
    maximumResources,
    primaryResource: member.resourceType,
    comboPoints: member.comboPoints,
    comboTargetId: member.comboTargetId,
    runes: member.runes,
    abilities: candidateAbilities(member, context.now),
    hostileTarget: context.target,
    friendlyTargets,
    hostileCount: context.hostileCount,
    targetIsLoose: context.targetIsLoose,
    hasDangerousThreat: context.hasDangerousThreat,
    requiredControl: context.requiredControl,
    maintainedAbilityIds: context.maintainedAbilityIds,
    activeAuraExclusiveGroups: context.activeAuraExclusiveGroups,
    activeSummonAbilityIds: context.activeSummonAbilityIds,
    hasActivePet: context.hasActivePet,
    canUseAbility: context.canUseAbility,
  });
}

export function choosePartyAbility(
  member: PartyMember,
  context: PartyAbilityContext,
): AbilityDefinition | null {
  return choosePartyRotationDecision(member, context)?.ability ?? null;
}

export function commitPartyAbilityUse(
  member: PartyMember,
  ability: AbilityDefinition,
  now: number,
): PartyMember | null {
  if (!partyAbilityIsReady(member, ability, now)) return null;
  const resourcePools = { ...member.resourcePools };
  const lastResourceSpentAt = { ...member.lastResourceSpentAt };
  let resource = member.resource;
  let health = member.health;
  for (const cost of abilityCosts(member, ability)) {
    const amount = cost.amount;
    if (cost.resource === "health") { health -= amount; continue; }
    const current = currentResource(member, cost.resource);
    resourcePools[cost.resource] = Math.max(0, current - amount);
    if (amount > 0) lastResourceSpentAt[cost.resource] = now;
    if (cost.resource === member.resourceType) resource = resourcePools[cost.resource] ?? resource;
  }
  const runeCost = member.classId === "death-knight" ? runeCostForAbility(ability) : null;
  const runes = runeCost ? spendDeathKnightRunes(member.runes, runeCost, now) : member.runes;
  if (!runes) return null;
  return {
    ...member,
    health,
    resource,
    resourcePools,
    lastResourceSpentAt,
    runes,
    cooldowns: ability.cooldownMs > 0
      ? { ...member.cooldowns, [ability.id]: now + ability.cooldownMs }
      : member.cooldowns,
    globalCooldownEndsAt: now + ability.gcdMs,
    tauntReadyAt: aiHintsForAbility(ability).categories.includes("taunt")
      ? now + Math.max(8_000, ability.cooldownMs)
      : member.tauntReadyAt,
  };
}

export function partyAbilityAmount(
  member: PartyMember,
  ability: AbilityDefinition,
  effect: AbilityEffect,
): number {
  const coefficient = "coefficient" in effect
    ? effect.coefficient
    : effect.kind === "finisher-damage"
      ? effect.baseCoefficient + effect.perComboCoefficient * member.comboPoints
      : 0;
  return equipmentAdjustedCombatAmount(
    "coefficient" in effect ? effect : coefficient,
    member.level,
    member.gearStats,
    member.classId,
    ability,
  );
}