Modrinth/apps/app-frontend/src/helpers/skins.ts

import { invoke } from '@tauri-apps/api/core'
import { handleError } from '@/store/notifications'
import { arrayBufferToBase64 } from '@modrinth/utils'

export interface Cape {
  id: string
  name: string
  texture: string
  is_default: boolean
  is_equipped: boolean
}

export type SkinModel = 'CLASSIC' | 'SLIM' | 'UNKNOWN'
export type SkinSource = 'default' | 'custom_external' | 'custom'

export interface Skin {
  texture_key: string
  name?: string
  variant: SkinModel
  cape_id?: string
  texture: string
  source: SkinSource
  is_equipped: boolean
}

export const DEFAULT_MODEL_SORTING = ['Steve', 'Alex'] as string[]

export const DEFAULT_MODELS: Record<string, SkinModel> = {
  Steve: 'CLASSIC',
  Alex: 'SLIM',
  Zuri: 'CLASSIC',
  Sunny: 'CLASSIC',
  Noor: 'SLIM',
  Makena: 'SLIM',
  Kai: 'CLASSIC',
  Efe: 'SLIM',
  Ari: 'CLASSIC',
}

export function filterSavedSkins(list: Skin[]) {
  const customSkins = list.filter((s) => s.source !== 'default')
  fixUnknownSkins(customSkins).catch(handleError)
  return customSkins
}

export async function determineModelType(texture: string): Promise<'SLIM' | 'CLASSIC'> {
  return new Promise((resolve, reject) => {
    const canvas = document.createElement('canvas')
    const context = canvas.getContext('2d')

    if (!context) {
      return reject(new Error('Failed to create canvas rendering context.'))
    }

    const image = new Image()
    image.crossOrigin = 'anonymous'
    image.src = texture

    image.onload = () => {
      canvas.width = image.width
      canvas.height = image.height

      context.drawImage(image, 0, 0)

      const armX = 54
      const armY = 20
      const armWidth = 2
      const armHeight = 12
      const imageData = context.getImageData(armX, armY, armWidth, armHeight).data
      for (let alphaIndex = 3; alphaIndex < imageData.length; alphaIndex += 4) {
        if (imageData[alphaIndex] !== 0) {
          resolve('CLASSIC')
          return
        }
      }

      canvas.remove()
      resolve('SLIM')
    }

    image.onerror = () => {
      canvas.remove()
      reject(new Error('Failed to load the image.'))
    }
  })
}

export async function fixUnknownSkins(list: Skin[]) {
  const unknownSkins = list.filter((s) => s.variant === 'UNKNOWN')
  for (const unknownSkin of unknownSkins) {
    unknownSkin.variant = await determineModelType(unknownSkin.texture)
  }
}

export function filterDefaultSkins(list: Skin[]) {
  return list
    .filter(
      (s) =>
        s.source === 'default' &&
        (!s.name || !(s.name in DEFAULT_MODELS) || s.variant === DEFAULT_MODELS[s.name]),
    )
    .sort((a, b) => {
      const aIndex = a.name ? DEFAULT_MODEL_SORTING.indexOf(a.name) : -1
      const bIndex = b.name ? DEFAULT_MODEL_SORTING.indexOf(b.name) : -1
      return (aIndex === -1 ? Infinity : aIndex) - (bIndex === -1 ? Infinity : bIndex)
    })
}

export async function get_available_capes(): Promise<Cape[]> {
  return invoke('plugin:minecraft-skins|get_available_capes', {})
}

export async function get_available_skins(): Promise<Skin[]> {
  return invoke('plugin:minecraft-skins|get_available_skins', {})
}

export async function add_and_equip_custom_skin(
  textureBlob: Uint8Array,
  variant: SkinModel,
  capeOverride?: Cape,
): Promise<void> {
  await invoke('plugin:minecraft-skins|add_and_equip_custom_skin', {
    textureBlob,
    variant,
    capeOverride,
  })
}

export async function set_default_cape(cape?: Cape): Promise<void> {
  await invoke('plugin:minecraft-skins|set_default_cape', {
    cape,
  })
}

export async function equip_skin(skin: Skin): Promise<void> {
  await invoke('plugin:minecraft-skins|equip_skin', {
    skin,
  })
}

export async function remove_custom_skin(skin: Skin): Promise<void> {
  await invoke('plugin:minecraft-skins|remove_custom_skin', {
    skin,
  })
}

export async function get_normalized_skin_texture(skin: Skin): Promise<string> {
  const data = await normalize_skin_texture(skin.texture)
  const base64 = arrayBufferToBase64(data)
  return `data:image/png;base64,${base64}`
}

export async function normalize_skin_texture(texture: Uint8Array | string): Promise<Uint8Array> {
  return await invoke('plugin:minecraft-skins|normalize_skin_texture', { texture })
}

export async function unequip_skin(): Promise<void> {
  await invoke('plugin:minecraft-skins|unequip_skin')
}

export async function get_dragged_skin_data(path: string): Promise<Uint8Array> {
  const data = await invoke('plugin:minecraft-skins|get_dragged_skin_data', { path })
  return new Uint8Array(data)
}