import sourceCatalog from "./generated/enemyDamageTypeSources.generated.json";

export type EnemyDamageOrigin = "wow335" | "runewaker";
export type EnemyAttackKind = "melee" | "ranged" | "spell";
export type EnemyDamageSchool =
  | "physical"
  | "arcane"
  | "fire"
  | "frost"
  | "nature"
  | "shadow"
  | "holy";

export interface WowEnemyHitSource {
  readonly attributes0: number;
  readonly attributes3: number;
  readonly attributes7: number;
}

export interface WowEnemyDamageTypeSource {
  readonly spellId: number;
  readonly name: string;
  readonly damageClass: number;
  readonly schoolMask: number;
  /** Raw hit-gate attribute words copied from a matched WoW Spell.dbc row. */
  readonly hitSource?: WowEnemyHitSource;
  readonly schools: readonly EnemyDamageSchool[];
  readonly school?: EnemyDamageSchool;
  readonly attackKind?: EnemyAttackKind;
  readonly damageEffects: readonly number[];
  readonly source: string;
}

export interface RunewakerEnemyDamageTypeComponent {
  readonly componentId: number;
  /** MagicObject.Attack.CalType; direct packet class, independent of EffectType. */
  readonly calculationType: number;
  /** Raw MagicObject.EffectType, retained as source metadata. */
  readonly effectType: number;
  readonly magicType: number;
  /** Formula-specific handling; not a packet class and not the MagicCollect hit gate. */
  readonly directFormula?: "throw" | "fixed" | "target-hp-percent";
  /** Absorption branch selected by the direct formula and raw component flags. */
  readonly formulaMitigation?: "weapon-absorb" | "magic-absorb" | "bypassed";
  readonly sourceDamageClass?: "physical" | "magical";
  readonly attackKind?: EnemyAttackKind;
  readonly sourceChannel?: "physical" | "earth" | "water" | "fire" | "wind" | "light" | "darkness";
  /** Approximate mapping into HealerMan's seven-school resistance model. */
  readonly school?: EnemyDamageSchool;
}

export interface RunewakerEnemyDamageTypeSource {
  readonly spellId: number;
  readonly name: string;
  readonly components: readonly RunewakerEnemyDamageTypeComponent[];
  readonly source: string;
}

export type EnemyDamageTypeSource = WowEnemyDamageTypeSource | RunewakerEnemyDamageTypeSource;

export interface ResolveEnemyDamageTypeInput {
  readonly origin?: EnemyDamageOrigin;
  readonly spellId?: number;
  readonly componentId?: number;
  /** Raw WoW Spell.dbc DmgClass when present. */
  readonly damageClass?: number;
  /** Runtime delivery classification, authored or normalized by the importer. */
  readonly attackKind?: EnemyAttackKind;
  /** Raw WoW Spell.dbc SchoolMask; bit values are preserved. */
  readonly schoolMask?: number;
  /** Authored runtime school used when source school data is absent or ambiguous. */
  readonly school?: EnemyDamageSchool;
}

export interface ResolvedEnemyDamageType {
  readonly attackKind?: EnemyAttackKind;
  readonly damageClass?: number;
  readonly sourceDamageClass?: "none" | "magic" | "melee" | "ranged" | "physical" | "magical";
  readonly schoolMask?: number;
  /** Copied only from a matched WoW damage row; absent means unknown/not WoW. */
  readonly hitSource?: WowEnemyHitSource;
  readonly schools: readonly EnemyDamageSchool[];
  /** Present only when source evidence identifies exactly one runtime school. */
  readonly school?: EnemyDamageSchool;
  readonly unknownSchoolMaskBits?: number;
  readonly sourceVerified: boolean;
}

type GeneratedCatalog = {
  readonly wow335: Readonly<Record<string, WowEnemyDamageTypeSource>>;
  readonly runewaker: Readonly<Record<string, RunewakerEnemyDamageTypeSource>>;
};

const catalog = sourceCatalog as GeneratedCatalog;
const WOW_SCHOOL_BITS: readonly (readonly [number, EnemyDamageSchool])[] = [
  [1, "physical"],
  [2, "holy"],
  [4, "fire"],
  [8, "nature"],
  [16, "frost"],
  [32, "shadow"],
  [64, "arcane"],
];
const KNOWN_WOW_SCHOOL_BITS = WOW_SCHOOL_BITS.reduce((mask, [bit]) => mask | bit, 0);

export function enemyDamageTypeSourceForSpell(
  origin: EnemyDamageOrigin,
  spellId: number,
): EnemyDamageTypeSource | undefined {
  if (!Number.isSafeInteger(spellId) || spellId <= 0) return undefined;
  const key = String(spellId);
  return origin === "wow335" ? catalog.wow335[key] : catalog.runewaker[key];
}

export function enemyDamageTypeComponentForSpell(
  spellId: number,
  componentId: number,
): RunewakerEnemyDamageTypeComponent | undefined {
  const source = enemyDamageTypeSourceForSpell("runewaker", spellId);
  if (!source || !("components" in source)) return undefined;
  return source.components.find((component) => component.componentId === componentId);
}

/**
 * Converts WotLK SchoolMask bits without imposing a strongest-school rule.
 * Composite masks remain a list; callers should keep the authored single-school
 * fallback until the damage resolver supports combined-school mitigation.
 */
export function wowSchoolsFromSchoolMask(mask: number): {
  readonly schools: readonly EnemyDamageSchool[];
  readonly unknownBits: number;
} {
  if (!Number.isSafeInteger(mask) || mask < 0) return { schools: [], unknownBits: 0 };
  return {
    schools: WOW_SCHOOL_BITS.filter(([bit]) => (mask & bit) !== 0).map(([, school]) => school),
    unknownBits: (mask & ~KNOWN_WOW_SCHOOL_BITS) >>> 0,
  };
}

function sourceComponentForResolution(
  source: RunewakerEnemyDamageTypeSource | undefined,
  componentId: number | undefined,
): RunewakerEnemyDamageTypeComponent | undefined {
  if (!source) return undefined;
  if (componentId !== undefined) {
    return source.components.find((component) => component.componentId === componentId);
  }
  if (source.components.length === 1) return source.components[0];
  const first = source.components[0];
  if (first && source.components.every((component) => (
    component.sourceDamageClass === first.sourceDamageClass
    && component.attackKind === first.attackKind
    && component.school === first.school
    && component.sourceChannel === first.sourceChannel
  ))) return first;
  return undefined;
}

function attackKindForDamageClass(value: number | undefined): EnemyAttackKind | undefined {
  if (value === 1) return "spell";
  if (value === 2) return "melee";
  if (value === 3) return "ranged";
  return undefined;
}

export function resolveEnemyDamageType(input: ResolveEnemyDamageTypeInput): ResolvedEnemyDamageType {
  const source = input.origin && input.spellId !== undefined
    ? enemyDamageTypeSourceForSpell(input.origin, input.spellId)
    : undefined;
  const wowSource = source && "schoolMask" in source ? source : undefined;
  const runewakerSource = source && "components" in source ? source : undefined;
  const runewakerComponent = sourceComponentForResolution(runewakerSource, input.componentId);
  const damageClass = input.damageClass ?? wowSource?.damageClass;
  const schoolMask = input.schoolMask ?? wowSource?.schoolMask;
  const maskResult = schoolMask === undefined
    ? { schools: [] as readonly EnemyDamageSchool[], unknownBits: 0 }
    : wowSchoolsFromSchoolMask(schoolMask);
  const exactWoWSchool = schoolMask !== undefined
    && maskResult.schools.length === 1
    && maskResult.unknownBits === 0
    ? maskResult.schools[0]
    : undefined;
  const sourceDamageClass = input.origin === "runewaker"
    ? runewakerComponent?.sourceDamageClass
    : damageClass === 0 ? "none"
      : damageClass === 1 ? "magic"
        : damageClass === 2 ? "melee"
          : damageClass === 3 ? "ranged" : undefined;
  const attackKind = input.origin === "runewaker"
    ? runewakerComponent?.attackKind ?? input.attackKind
    : input.attackKind ?? attackKindForDamageClass(damageClass);
  const school = exactWoWSchool
    ?? runewakerComponent?.school
    ?? input.school;

  return {
    ...(attackKind ? { attackKind } : {}),
    ...(damageClass !== undefined ? { damageClass } : {}),
    ...(sourceDamageClass ? { sourceDamageClass } : {}),
    ...(schoolMask !== undefined ? { schoolMask } : {}),
    ...(wowSource?.hitSource ? { hitSource: wowSource.hitSource } : {}),
    schools: maskResult.schools.length ? maskResult.schools : runewakerComponent?.school ? [runewakerComponent.school] : [],
    ...(school ? { school } : {}),
    ...(maskResult.unknownBits ? { unknownSchoolMaskBits: maskResult.unknownBits } : {}),
    sourceVerified: Boolean(wowSource || runewakerComponent),
  };
}