import {
  baseClassFor,
  classById,
  classIconUrl,
  type ClassId,
} from "../app/characterCatalog";
import type { ItemStats, NumericItemStatKey } from "./itemStats";
import type { PartyRole } from "./partyRoles";

export type GearArchetype =
  | "strength-dps"
  | "agility-dps"
  | "ranged-dps"
  | "spell-dps"
  | "healer"
  | "block-tank"
  | "non-block-tank";

export type WeaponLayout =
  | "two-hand"
  | "dual-wield"
  | "weapon-shield"
  | "one-hand"
  | "ranged"
  | "caster";

export interface SpecializationDefinition {
  readonly id: string;
  readonly classId: ClassId;
  readonly displayName: string;
  readonly role: PartyRole;
  readonly talentTree: string;
  readonly gearArchetype: GearArchetype;
  readonly weaponLayout: WeaponLayout;
  readonly statWeights: Readonly<Partial<Record<NumericItemStatKey, number>>>;
}

const WEIGHTS: Readonly<Record<GearArchetype, Readonly<Partial<Record<NumericItemStatKey, number>>>>> = Object.freeze({
  "strength-dps": Object.freeze({ strength: 1, stamina: 0.18, attackPower: 0.5, hitRating: 0.82, criticalStrikeRating: 0.72, hasteRating: 0.62, expertiseRating: 0.76, armorPenetrationRating: 0.66 }),
  "agility-dps": Object.freeze({ agility: 1, stamina: 0.18, attackPower: 0.45, hitRating: 0.82, criticalStrikeRating: 0.78, hasteRating: 0.64, expertiseRating: 0.72, armorPenetrationRating: 0.66 }),
  "ranged-dps": Object.freeze({ agility: 1, stamina: 0.16, rangedAttackPower: 0.5, hitRating: 0.86, criticalStrikeRating: 0.78, hasteRating: 0.66, armorPenetrationRating: 0.6 }),
  "spell-dps": Object.freeze({ intellect: 0.8, spirit: 0.28, stamina: 0.14, spellPower: 1, hitRating: 0.86, criticalStrikeRating: 0.68, hasteRating: 0.74 }),
  healer: Object.freeze({ intellect: 0.82, spirit: 0.62, stamina: 0.16, spellPower: 1, criticalStrikeRating: 0.46, hasteRating: 0.68, mp5: 0.82 }),
  "block-tank": Object.freeze({ strength: 0.64, stamina: 1, armor: 0.12, defenseRating: 0.86, dodgeRating: 0.7, parryRating: 0.68, blockRating: 0.72, blockValue: 0.66, expertiseRating: 0.38 }),
  "non-block-tank": Object.freeze({ agility: 0.66, strength: 0.28, stamina: 1, armor: 0.14, defenseRating: 0.78, dodgeRating: 0.86, parryRating: 0.46, expertiseRating: 0.4 }),
});

const ROM_FIVE_HYBRID_PROFILES: Readonly<Partial<Record<ClassId, Readonly<{
  role: PartyRole;
  gearArchetype: GearArchetype;
  weaponLayout: WeaponLayout;
  statWeights: Readonly<Partial<Record<NumericItemStatKey, number>>>;
}>>>> = Object.freeze({
  "rom-knight": Object.freeze({ role: "tank", gearArchetype: "block-tank", weaponLayout: "weapon-shield", statWeights: Object.freeze({ ...WEIGHTS["block-tank"], armor: 0.16, blockValue: 0.76 }) }),
  "rom-priest": Object.freeze({ role: "healer", gearArchetype: "healer", weaponLayout: "weapon-shield", statWeights: Object.freeze({ ...WEIGHTS.healer, spirit: 0.7, mp5: 0.95 }) }),
  "rom-scout": Object.freeze({ role: "damage", gearArchetype: "ranged-dps", weaponLayout: "ranged", statWeights: Object.freeze({ ...WEIGHTS["ranged-dps"], rangedAttackPower: 0.6 }) }),
  "rom-rogue": Object.freeze({ role: "damage", gearArchetype: "agility-dps", weaponLayout: "dual-wield", statWeights: Object.freeze({ ...WEIGHTS["agility-dps"], expertiseRating: 0.78 }) }),
  "rom-mage": Object.freeze({ role: "damage", gearArchetype: "spell-dps", weaponLayout: "two-hand", statWeights: Object.freeze({ ...WEIGHTS["spell-dps"], spellPower: 1.1 }) }),
});

export function isRomHybridGearClass(classId: ClassId): boolean {
  return ROM_FIVE_HYBRID_PROFILES[classId] !== undefined;
}

type SpecTuple = readonly [
  classId: ClassId,
  displayName: string,
  role: PartyRole,
  gearArchetype: GearArchetype,
  weaponLayout: WeaponLayout,
  talentTree?: string,
];

function specId(classId: ClassId, name: string): string {
  return `${classId}:${name.toLowerCase().replace(/[^a-z0-9]+/g, "-").replace(/^-|-$/g, "")}`;
}

function define(tuple: SpecTuple): SpecializationDefinition {
  const [classId, displayName, role, gearArchetype, weaponLayout, talentTree = displayName] = tuple;
  return Object.freeze({
    id: specId(classId, displayName),
    classId,
    displayName,
    role,
    talentTree,
    gearArchetype,
    weaponLayout,
    statWeights: WEIGHTS[gearArchetype],
  });
}

const CLASSIC_SPECIALIZATIONS: readonly SpecTuple[] = [
  ["warrior", "Arms", "damage", "strength-dps", "two-hand"],
  ["warrior", "Fury", "damage", "strength-dps", "dual-wield"],
  ["warrior", "Protection", "tank", "block-tank", "weapon-shield"],
  ["paladin", "Holy", "healer", "healer", "weapon-shield"],
  ["paladin", "Protection", "tank", "block-tank", "weapon-shield"],
  ["paladin", "Retribution", "damage", "strength-dps", "two-hand"],
  ["hunter", "Beast Mastery", "damage", "ranged-dps", "ranged"],
  ["hunter", "Marksmanship", "damage", "ranged-dps", "ranged"],
  ["hunter", "Survival", "damage", "ranged-dps", "ranged"],
  ["rogue", "Assassination", "damage", "agility-dps", "dual-wield"],
  ["rogue", "Combat", "damage", "agility-dps", "dual-wield"],
  ["rogue", "Subtlety", "damage", "agility-dps", "dual-wield"],
  ["priest", "Discipline", "healer", "healer", "caster"],
  ["priest", "Holy", "healer", "healer", "caster"],
  ["priest", "Shadow", "damage", "spell-dps", "caster"],
  ["death-knight", "Blood", "tank", "non-block-tank", "two-hand"],
  ["death-knight", "Frost", "damage", "strength-dps", "dual-wield"],
  ["death-knight", "Unholy", "damage", "strength-dps", "two-hand"],
  ["shaman", "Elemental", "damage", "spell-dps", "weapon-shield"],
  ["shaman", "Enhancement", "damage", "agility-dps", "dual-wield"],
  ["shaman", "Restoration", "healer", "healer", "weapon-shield"],
  ["mage", "Arcane", "damage", "spell-dps", "caster"],
  ["mage", "Fire", "damage", "spell-dps", "caster"],
  ["mage", "Frost", "damage", "spell-dps", "caster"],
  ["warlock", "Affliction", "damage", "spell-dps", "caster"],
  ["warlock", "Demonology", "damage", "spell-dps", "caster"],
  ["warlock", "Destruction", "damage", "spell-dps", "caster"],
  ["druid", "Balance", "damage", "spell-dps", "caster"],
  ["druid", "Feral (Bear)", "tank", "non-block-tank", "two-hand", "Feral Combat"],
  ["druid", "Feral (Cat)", "damage", "agility-dps", "two-hand", "Feral Combat"],
  ["druid", "Restoration", "healer", "healer", "caster"],
] as const;

/** CoA roles are authored explicitly. Support trees map to damage, the closest runtime role. */
const COA_SPECIALIZATIONS: readonly SpecTuple[] = [
  ["barbarian", "Brutality", "damage", "agility-dps", "two-hand"], ["barbarian", "Headhunting", "damage", "agility-dps", "ranged"], ["barbarian", "Ancestry", "damage", "agility-dps", "two-hand"],
  ["witch-doctor", "Shadowhunting", "damage", "ranged-dps", "ranged"], ["witch-doctor", "Voodoo", "damage", "spell-dps", "caster"], ["witch-doctor", "Brewing", "healer", "healer", "caster"],
  ["felsworn", "Slayer", "damage", "agility-dps", "dual-wield"], ["felsworn", "Infernal", "tank", "non-block-tank", "two-hand"], ["felsworn", "Tyrant", "damage", "spell-dps", "caster"],
  ["witch-hunter", "Boltslinger", "damage", "ranged-dps", "ranged"], ["witch-hunter", "Houndmaster", "damage", "ranged-dps", "ranged"], ["witch-hunter", "Inquisition", "damage", "agility-dps", "dual-wield"], ["witch-hunter", "Black Knight", "tank", "non-block-tank", "two-hand"],
  ["stormbringer", "Maelstrom", "damage", "spell-dps", "caster"], ["stormbringer", "Lightning", "damage", "spell-dps", "caster"], ["stormbringer", "Wind", "damage", "spell-dps", "caster"],
  ["knight-of-xoroth", "Hellfire", "damage", "strength-dps", "two-hand"], ["knight-of-xoroth", "Defiance", "tank", "block-tank", "weapon-shield"], ["knight-of-xoroth", "War", "damage", "strength-dps", "two-hand"],
  ["guardian", "Gladiator", "damage", "strength-dps", "one-hand"], ["guardian", "Inspiration", "damage", "strength-dps", "weapon-shield"], ["guardian", "Vanguard", "tank", "block-tank", "weapon-shield"],
  ["templar", "Zealot", "damage", "agility-dps", "dual-wield"], ["templar", "Oathkeeper", "tank", "non-block-tank", "two-hand"], ["templar", "Crusader", "damage", "agility-dps", "two-hand"],
  ["bloodmage", "Sanguine", "damage", "agility-dps", "dual-wield"], ["bloodmage", "Accursed", "damage", "spell-dps", "caster"], ["bloodmage", "Eternal", "tank", "non-block-tank", "two-hand"], ["bloodmage", "Fleshweaver", "healer", "healer", "caster"],
  ["ranger", "Archery", "damage", "ranged-dps", "ranged"], ["ranger", "Brigand", "damage", "agility-dps", "dual-wield"], ["ranger", "Farstrider", "damage", "ranged-dps", "ranged"],
  ["chronomancer", "Infinite", "damage", "spell-dps", "caster"], ["chronomancer", "Time", "healer", "healer", "caster"], ["chronomancer", "Artificer", "damage", "spell-dps", "caster"],
  ["necromancer", "Death", "damage", "spell-dps", "caster"], ["necromancer", "Rime", "damage", "spell-dps", "caster"], ["necromancer", "Animation", "damage", "spell-dps", "caster"],
  ["pyromancer", "Incineration", "damage", "spell-dps", "caster"], ["pyromancer", "Flameweaving", "damage", "spell-dps", "caster"], ["pyromancer", "Draconic", "damage", "spell-dps", "caster"],
  ["cultist", "Godblade", "damage", "strength-dps", "two-hand"], ["cultist", "Corruption", "damage", "spell-dps", "caster"], ["cultist", "Heretic", "healer", "healer", "caster"], ["cultist", "Dreadnought", "tank", "block-tank", "weapon-shield"],
  ["starcaller", "Moon Guard", "tank", "block-tank", "weapon-shield"], ["starcaller", "Sentinel", "damage", "ranged-dps", "ranged"], ["starcaller", "Moon Priest", "healer", "healer", "caster"], ["starcaller", "Warden", "damage", "strength-dps", "two-hand"],
  ["sun-cleric", "Piety", "damage", "spell-dps", "caster"], ["sun-cleric", "Blessings", "healer", "healer", "caster"], ["sun-cleric", "Valkyrie", "tank", "block-tank", "weapon-shield"], ["sun-cleric", "Seraphim", "damage", "spell-dps", "caster"],
  ["tinker", "Demolition", "damage", "ranged-dps", "ranged"], ["tinker", "Invention", "healer", "healer", "ranged"], ["tinker", "Mechanics", "damage", "ranged-dps", "ranged"],
  ["venomancer", "Venom", "damage", "spell-dps", "caster"], ["venomancer", "Stalking", "damage", "agility-dps", "dual-wield"], ["venomancer", "Fortitude", "tank", "non-block-tank", "two-hand"], ["venomancer", "Vizier", "healer", "healer", "caster"],
  ["reaper", "Harvest", "damage", "agility-dps", "two-hand"], ["reaper", "Soul", "damage", "spell-dps", "caster"], ["reaper", "Domination", "tank", "non-block-tank", "two-hand"],
  ["primalist", "Primal", "damage", "agility-dps", "two-hand"], ["primalist", "Geomancy", "damage", "spell-dps", "caster"], ["primalist", "Life", "healer", "healer", "caster"], ["primalist", "Mountain King", "tank", "non-block-tank", "two-hand"],
  ["runemaster", "Runic", "damage", "spell-dps", "caster"], ["runemaster", "Arcane", "damage", "spell-dps", "caster"], ["runemaster", "Riftblade", "tank", "non-block-tank", "two-hand"],
] as const;

export const SPECIALIZATION_DEFINITIONS: readonly SpecializationDefinition[] = Object.freeze(
  [...CLASSIC_SPECIALIZATIONS, ...COA_SPECIALIZATIONS].map(define),
);

const BY_ID = new Map(SPECIALIZATION_DEFINITIONS.map((definition) => [definition.id, definition]));

const CLASSIC_SPECIALIZATION_ICON_BASENAME: Readonly<Record<string, string>> = Object.freeze({
  "warrior:arms": "ability_rogue_eviscerate",
  "warrior:fury": "ability_warrior_innerrage",
  "warrior:protection": "inv_shield_06",
  "paladin:holy": "spell_holy_holybolt",
  "paladin:protection": "spell_holy_devotionaura",
  "paladin:retribution": "spell_holy_auraoflight",
  "hunter:beast-mastery": "ability_hunter_beasttaming",
  "hunter:marksmanship": "ability_marksmanship",
  "hunter:survival": "ability_hunter_swiftstrike",
  "rogue:assassination": "ability_rogue_eviscerate",
  "rogue:combat": "ability_backstab",
  "rogue:subtlety": "ability_stealth",
  "priest:discipline": "spell_holy_wordfortitude",
  "priest:holy": "spell_holy_guardianspirit",
  "priest:shadow": "spell_shadow_shadowwordpain",
  "death-knight:blood": "spell_deathknight_bloodpresence",
  "death-knight:frost": "spell_deathknight_frostpresence",
  "death-knight:unholy": "spell_deathknight_unholypresence",
  "shaman:elemental": "spell_nature_lightning",
  "shaman:enhancement": "spell_nature_lightningshield",
  "shaman:restoration": "spell_nature_magicimmunity",
  "mage:arcane": "spell_holy_magicalsentry",
  "mage:fire": "spell_fire_firebolt02",
  "mage:frost": "spell_frost_frostbolt02",
  "warlock:affliction": "spell_shadow_deathcoil",
  "warlock:demonology": "spell_shadow_metamorphosis",
  "warlock:destruction": "spell_shadow_rainoffire",
  "druid:balance": "spell_nature_starfall",
  "druid:feral-bear": "ability_racial_bearform",
  "druid:feral-cat": "ability_racial_bearform",
  "druid:restoration": "spell_nature_healingtouch",
});

export function specializationsForClass(classId: ClassId): readonly SpecializationDefinition[] {
  return SPECIALIZATION_DEFINITIONS.filter((definition) => definition.classId === classId);
}

export function specializationById(id: string | null | undefined): SpecializationDefinition | null {
  return id ? BY_ID.get(id) ?? null : null;
}

/** Returns the dedicated WoW talent-tree icon when available, otherwise the class icon. */
export function specializationIconUrl(classId: ClassId, specializationId: string | null | undefined): string {
  const specialization = specializationById(specializationId);
  const iconBasename = specialization?.classId === classId
    ? CLASSIC_SPECIALIZATION_ICON_BASENAME[specialization.id]
    : undefined;
  return iconBasename
    ? `/assets/ui/talents/icons/${iconBasename}.png`
    : classIconUrl(classId);
}

export function normalizeSpecializationId(classId: ClassId, value: unknown): string | null {
  if (typeof value !== "string") return null;
  const definition = specializationById(value);
  return definition?.classId === classId ? definition.id : null;
}

export function specializationScore(stats: ItemStats, definition: SpecializationDefinition): number {
  let score = 0;
  for (const [key, weight] of Object.entries(definition.statWeights)) {
    const value = stats[key as NumericItemStatKey];
    if (typeof value === "number" && Number.isFinite(value)) score += value * (weight ?? 0);
  }
  const melee = stats.meleeWeapon;
  const ranged = stats.rangedWeapon;
  const weapon = definition.weaponLayout === "ranged" ? ranged : melee;
  if (weapon?.damageMax && weapon.speedMs) score += ((weapon.damageMin ?? 0) + weapon.damageMax) * 0.42;
  return Math.round(score * 100) / 100;
}

/** RoM has no saved specialization; derive a complete gear profile from primary class and activity role. */
export function romGearProfile(classId: ClassId, role: PartyRole): SpecializationDefinition {
  const definition = classById(classId);
  const hybrid = ROM_FIVE_HYBRID_PROFILES[classId];
  if (hybrid?.role === role) return Object.freeze({
    id: `${classId}:role-${role}`,
    classId,
    displayName: `${definition.name} ${role}`,
    role,
    talentTree: "Primary class",
    gearArchetype: hybrid.gearArchetype,
    weaponLayout: hybrid.weaponLayout,
    statWeights: hybrid.statWeights,
  });
  const base = baseClassFor(classId);
  const caster = ["priest", "mage", "warlock"].includes(base) || definition.primaryStat === "intellect" || definition.primaryStat === "spirit" || definition.primaryStat === "wisdom";
  const gearArchetype: GearArchetype = role === "healer"
    ? "healer"
    : role === "tank"
      ? (["warrior", "paladin"].includes(base) ? "block-tank" : "non-block-tank")
      : caster ? "spell-dps" : base === "hunter" ? "ranged-dps" : definition.primaryStat === "strength" ? "strength-dps" : "agility-dps";
  const weaponLayout: WeaponLayout = role === "tank" && gearArchetype === "block-tank"
    ? "weapon-shield"
    : gearArchetype === "ranged-dps" ? "ranged" : caster ? "caster" : base === "rogue" ? "dual-wield" : "two-hand";
  return Object.freeze({
    id: `${classId}:role-${role}`,
    classId,
    displayName: `${definition.name} ${role}`,
    role,
    talentTree: "Primary class",
    gearArchetype,
    weaponLayout,
    statWeights: WEIGHTS[gearArchetype],
  });
}

export function gearProfileFor(
  classId: ClassId,
  specializationId: string | null | undefined,
  fallbackRole: PartyRole,
): SpecializationDefinition {
  return specializationById(normalizeSpecializationId(classId, specializationId))
    ?? romGearProfile(classId, fallbackRole);
}