import type { GenderId } from "../app/characterCatalog";
import type { CharacterWeaponStance } from "../game/combatAnimation";
import type { InventoryItem } from "../game/lootTypes";
import type { TextureRegion } from "./characterManifest";

const ASSET_ROOT = "/assets/equipment/wow335a-v1";
const TEXTURE_ROOT = `${ASSET_ROOT}/textures`;

const ATLAS_REGIONS = Object.freeze({
  armUpper: [0, 0, 256, 128] as const,
  armLower: [0, 128, 256, 64] as const,
  hand: [0, 192, 256, 64] as const,
  torsoUpper: [256, 0, 256, 128] as const,
  torsoLower: [256, 128, 256, 64] as const,
  legUpper: [256, 192, 256, 128] as const,
  legLower: [256, 320, 256, 64] as const,
  foot: [256, 384, 256, 128] as const,
} satisfies Readonly<Record<string, TextureRegion>>);

export type EquipmentAttachmentName =
  | "shield"
  | "handRight"
  | "handLeft"
  | "shoulderRight"
  | "shoulderLeft";

export interface EquipmentTextureLayer {
  readonly url: string;
  readonly region: TextureRegion;
}

export interface EquipmentModelVisual {
  readonly itemId: number;
  readonly name: string;
  readonly url: string;
  readonly attachment: EquipmentAttachmentName;
  readonly fallbackKind?: "bow" | "dagger" | "mace" | "shield" | "staff" | "sword";
  readonly weaponStance?: CharacterWeaponStance;
}

interface GenderedTextureLayer {
  readonly region: TextureRegion;
  readonly url?: string;
  readonly male?: string;
  readonly female?: string;
}

interface EquipmentVisualDefinition {
  readonly layers?: readonly GenderedTextureLayer[];
  readonly layerOrder?: number;
  readonly geosets?: Readonly<Record<string, number>>;
  readonly cloakUrl?: string;
  readonly models?: readonly Omit<EquipmentModelVisual, "itemId">[];
}

export interface ResolvedEquipmentAppearance {
  readonly cacheKey: string;
  readonly bodyLayers: readonly EquipmentTextureLayer[];
  readonly cloakUrl: string;
  readonly geosets: Readonly<Record<string, number>>;
  readonly models: readonly EquipmentModelVisual[];
}

const texture = (path: string): string => `${TEXTURE_ROOT}/${path}`;
const model = (path: string): string => `${ASSET_ROOT}/${path}/${path}.glb`;

const EQUIPMENT_VISUALS: Readonly<Record<number, EquipmentVisualDefinition>> = Object.freeze({
  5243: {
    models: [{
      name: "Firebelcher",
      url: model("firebelcher-5243"),
      attachment: "handRight",
      fallbackKind: "mace",
      weaponStance: "one-handed",
    }],
  },
  5404: {
    models: [
      {
        name: "Serpent's Shoulders (left)",
        url: model("serpents-shoulders-5404-left"),
        attachment: "shoulderLeft",
      },
      {
        name: "Serpent's Shoulders (right)",
        url: model("serpents-shoulders-5404-right"),
        attachment: "shoulderRight",
      },
    ],
  },
  5970: {
    layers: [
      {
        url: texture("5970-serpent-gloves/arm-lower.png"),
        region: ATLAS_REGIONS.armLower,
      },
      {
        url: texture("5970-serpent-gloves/hand.png"),
        region: ATLAS_REGIONS.hand,
      },
    ],
    layerOrder: 20,
    geosets: { Gloves: 2 },
  },
  6447: {
    models: [{
      name: "Worn Turtle Shell Shield",
      url: model("worn-turtle-shell-shield-6447"),
      attachment: "shield",
      fallbackKind: "shield",
      weaponStance: "one-handed",
    }],
  },
  6448: {
    models: [{
      name: "Tail Spike",
      url: model("tail-spike-6448"),
      attachment: "handRight",
      fallbackKind: "dagger",
      weaponStance: "one-handed",
    }],
  },
  6449: {
    cloakUrl: texture("6449-glowing-lizardscale-cloak/cape.png"),
    geosets: { Cloak: 6 },
  },
  6459: {
    layers: [
      {
        url: texture("6459-savage-trodders/leg-lower.png"),
        region: ATLAS_REGIONS.legLower,
      },
      {
        url: texture("6459-savage-trodders/foot.png"),
        region: ATLAS_REGIONS.foot,
      },
    ],
    layerOrder: 11,
    geosets: { Boots: 1 },
  },
  6460: {
    layers: [{
      url: texture("6460-cobrahns-grasp/leg-upper.png"),
      region: ATLAS_REGIONS.legUpper,
    }],
    layerOrder: 18,
    geosets: { Belt: 1 },
  },
  6461: {
    models: [
      {
        name: "Slime-Encrusted Pads (left)",
        url: model("slime-encrusted-pads-6461-left"),
        attachment: "shoulderLeft",
      },
      {
        name: "Slime-Encrusted Pads (right)",
        url: model("slime-encrusted-pads-6461-right"),
        attachment: "shoulderRight",
      },
    ],
  },
  6465: {
    layers: [
      {
        url: texture("6465-robe-of-the-moccasin/arm-upper.png"),
        region: ATLAS_REGIONS.armUpper,
      },
      {
        url: texture("6465-robe-of-the-moccasin/arm-lower.png"),
        region: ATLAS_REGIONS.armLower,
      },
      {
        male: texture("6465-robe-of-the-moccasin/torso-upper-male.png"),
        female: texture("6465-robe-of-the-moccasin/torso-upper-female.png"),
        region: ATLAS_REGIONS.torsoUpper,
      },
      {
        male: texture("6465-robe-of-the-moccasin/torso-lower-male.png"),
        female: texture("6465-robe-of-the-moccasin/torso-lower-female.png"),
        region: ATLAS_REGIONS.torsoLower,
      },
      {
        url: texture("6465-robe-of-the-moccasin/leg-upper.png"),
        region: ATLAS_REGIONS.legUpper,
      },
      {
        url: texture("6465-robe-of-the-moccasin/leg-lower.png"),
        region: ATLAS_REGIONS.legLower,
      },
    ],
    layerOrder: 13,
    geosets: { Sleeves: 3, Chest: 1, Trousers: 2 },
  },
  6469: {
    models: [{
      name: "Venomstrike",
      url: model("venomstrike-6469"),
      attachment: "handLeft",
      fallbackKind: "bow",
      weaponStance: "bow",
    }],
  },
  6472: {
    models: [{
      name: "Stinging Viper",
      url: model("stinging-viper-6472"),
      attachment: "handRight",
      fallbackKind: "mace",
      weaponStance: "one-handed",
    }],
  },
  6473: {
    layers: [
      {
        url: texture("6473-armor-of-the-fang/torso-upper.png"),
        region: ATLAS_REGIONS.torsoUpper,
      },
      {
        url: texture("6473-armor-of-the-fang/torso-lower.png"),
        region: ATLAS_REGIONS.torsoLower,
      },
    ],
    layerOrder: 13,
    geosets: { Sleeves: 1, Chest: 1, Trousers: 1 },
  },
  6627: {
    layers: [
      {
        url: texture("6627-mutant-scale-breastplate/arm-upper.png"),
        region: ATLAS_REGIONS.armUpper,
      },
      {
        url: texture("6627-mutant-scale-breastplate/torso-upper.png"),
        region: ATLAS_REGIONS.torsoUpper,
      },
      {
        url: texture("6627-mutant-scale-breastplate/torso-lower.png"),
        region: ATLAS_REGIONS.torsoLower,
      },
    ],
    layerOrder: 13,
    geosets: { Sleeves: 1, Chest: 1, Trousers: 1 },
  },
  6629: {
    cloakUrl: texture("6629-sporid-cape/cape.png"),
    geosets: { Cloak: 3 },
  },
  6630: {
    models: [{
      name: "Seedcloud Buckler",
      url: model("seedcloud-buckler-6630"),
      attachment: "shield",
      fallbackKind: "shield",
      weaponStance: "one-handed",
    }],
  },
  6631: {
    models: [{
      name: "Living Root",
      url: model("living-root-6631"),
      attachment: "handRight",
      fallbackKind: "staff",
      weaponStance: "two-handed-left",
    }],
  },
  6632: {
    cloakUrl: texture("6632-feyscale-cloak/cape.png"),
    geosets: { Cloak: 6 },
  },
  10410: {
    layers: [
      {
        url: texture("10410-leggings-of-the-fang/leg-upper.png"),
        region: ATLAS_REGIONS.legUpper,
      },
      {
        url: texture("10410-leggings-of-the-fang/leg-lower.png"),
        region: ATLAS_REGIONS.legLower,
      },
    ],
    layerOrder: 10,
    geosets: { Pants: 1, Kneepads: 1, Trousers: 1 },
  },
  10411: {
    layers: [
      {
        url: texture("10411-footpads-of-the-fang/leg-lower.png"),
        region: ATLAS_REGIONS.legLower,
      },
      {
        url: texture("10411-footpads-of-the-fang/foot.png"),
        region: ATLAS_REGIONS.foot,
      },
    ],
    layerOrder: 11,
    geosets: { Boots: 1 },
  },
  10412: {
    layers: [{
      url: texture("10412-belt-of-the-fang/leg-upper.png"),
      region: ATLAS_REGIONS.legUpper,
    }],
    layerOrder: 18,
    geosets: { Belt: 1 },
  },
  13245: {
    models: [{
      name: "Kresh's Back",
      url: model("kreshs-back-13245"),
      attachment: "shield",
      fallbackKind: "shield",
      weaponStance: "one-handed",
    }],
  },
});

export function resolveEquipmentAppearance(
  items: readonly InventoryItem[],
  gender: GenderId,
): ResolvedEquipmentAppearance {
  const layers: EquipmentTextureLayer[] = [];
  const models: EquipmentModelVisual[] = [];
  const occupiedAttachments = new Set<EquipmentAttachmentName>();
  const geosets: Record<string, number> = { Cloak: 0 };
  let cloakUrl = "";

  const equippedVisuals = items.flatMap((item) => {
    const visual = EQUIPMENT_VISUALS[item.itemId];
    return visual ? [{ item, visual }] : [];
  });

  for (const { item, visual } of equippedVisuals
    .slice()
    .sort((left, right) => (left.visual.layerOrder ?? 0) - (right.visual.layerOrder ?? 0))) {
    for (const layer of visual.layers ?? []) {
      const url = layer.url ?? layer[gender];
      if (url) layers.push({ url, region: layer.region });
    }
    Object.assign(geosets, visual.geosets);
    if (visual.cloakUrl) cloakUrl = visual.cloakUrl;
    for (const itemModel of visual.models ?? []) {
      if (occupiedAttachments.has(itemModel.attachment)) continue;
      occupiedAttachments.add(itemModel.attachment);
      models.push({ ...itemModel, itemId: item.itemId });
    }
  }

  return {
    cacheKey: items.map((item) => item.itemId).join(","),
    bodyLayers: layers,
    cloakUrl,
    geosets,
    models,
  };
}

export function equipmentModelUrls(): readonly string[] {
  return Object.values(EQUIPMENT_VISUALS)
    .flatMap((visual) => visual.models?.map((itemModel) => itemModel.url) ?? []);
}

export function equipmentAssetUrls(): readonly string[] {
  const urls = new Set<string>();
  for (const visual of Object.values(EQUIPMENT_VISUALS)) {
    for (const itemModel of visual.models ?? []) urls.add(itemModel.url);
    for (const layer of visual.layers ?? []) {
      if (layer.url) urls.add(layer.url);
      if (layer.male) urls.add(layer.male);
      if (layer.female) urls.add(layer.female);
    }
    if (visual.cloakUrl) urls.add(visual.cloakUrl);
  }
  return [...urls];
}